aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kvm
AgeCommit message (Collapse)Author
2020-08-03powerpc/kvm/book3s64: Fix kernel crash with nested kvm & DEBUG_VIRTUALAneesh Kumar K.V
commit c1ed1754f271f6b7acb1bfdc8cfb62220fbed423 upstream. With CONFIG_DEBUG_VIRTUAL=y, __pa() checks for addr value and if it's less than PAGE_OFFSET it leads to a BUG(). #define __pa(x) ({ VIRTUAL_BUG_ON((unsigned long)(x) < PAGE_OFFSET); (unsigned long)(x) & 0x0fffffffffffffffUL; }) kernel BUG at arch/powerpc/kvm/book3s_64_mmu_radix.c:43! cpu 0x70: Vector: 700 (Program Check) at [c0000018a2187360] pc: c000000000161b30: __kvmhv_copy_tofrom_guest_radix+0x130/0x1f0 lr: c000000000161d5c: kvmhv_copy_from_guest_radix+0x3c/0x80 ... kvmhv_copy_from_guest_radix+0x3c/0x80 kvmhv_load_from_eaddr+0x48/0xc0 kvmppc_ld+0x98/0x1e0 kvmppc_load_last_inst+0x50/0x90 kvmppc_hv_emulate_mmio+0x288/0x2b0 kvmppc_book3s_radix_page_fault+0xd8/0x2b0 kvmppc_book3s_hv_page_fault+0x37c/0x1050 kvmppc_vcpu_run_hv+0xbb8/0x1080 kvmppc_vcpu_run+0x34/0x50 kvm_arch_vcpu_ioctl_run+0x2fc/0x410 kvm_vcpu_ioctl+0x2b4/0x8f0 ksys_ioctl+0xf4/0x150 sys_ioctl+0x28/0x80 system_call_exception+0x104/0x1d0 system_call_common+0xe8/0x214 kvmhv_copy_tofrom_guest_radix() uses a NULL value for to/from to indicate direction of copy. Avoid calling __pa() if the value is NULL to avoid the BUG(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Massage change log a bit to mention CONFIG_DEBUG_VIRTUAL] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200611120159.680284-1-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-07-13KVM: PPC: Book3S: Fix some RCU-list locksQian Cai
commit ab8b65be183180c3eef405d449163964ecc4b571 upstream. It is unsafe to traverse kvm->arch.spapr_tce_tables and stt->iommu_tables without the RCU read lock held. Also, add cond_resched_rcu() in places with the RCU read lock held that could take a while to finish. arch/powerpc/kvm/book3s_64_vio.c:76 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by qemu-kvm/4265. stack backtrace: CPU: 96 PID: 4265 Comm: qemu-kvm Not tainted 5.7.0-rc4-next-20200508+ #2 Call Trace: [c000201a8690f720] [c000000000715948] dump_stack+0xfc/0x174 (unreliable) [c000201a8690f770] [c0000000001d9470] lockdep_rcu_suspicious+0x140/0x164 [c000201a8690f7f0] [c008000010b9fb48] kvm_spapr_tce_release_iommu_group+0x1f0/0x220 [kvm] [c000201a8690f870] [c008000010b8462c] kvm_spapr_tce_release_vfio_group+0x54/0xb0 [kvm] [c000201a8690f8a0] [c008000010b84710] kvm_vfio_destroy+0x88/0x140 [kvm] [c000201a8690f8f0] [c008000010b7d488] kvm_put_kvm+0x370/0x600 [kvm] [c000201a8690f990] [c008000010b7e3c0] kvm_vm_release+0x38/0x60 [kvm] [c000201a8690f9c0] [c0000000005223f4] __fput+0x124/0x330 [c000201a8690fa20] [c000000000151cd8] task_work_run+0xb8/0x130 [c000201a8690fa70] [c0000000001197e8] do_exit+0x4e8/0xfa0 [c000201a8690fb70] [c00000000011a374] do_group_exit+0x64/0xd0 [c000201a8690fbb0] [c000000000132c90] get_signal+0x1f0/0x1200 [c000201a8690fcc0] [c000000000020690] do_notify_resume+0x130/0x3c0 [c000201a8690fda0] [c000000000038d64] syscall_exit_prepare+0x1a4/0x280 [c000201a8690fe20] [c00000000000c8f8] system_call_common+0xf8/0x278 ==== arch/powerpc/kvm/book3s_64_vio.c:368 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by qemu-kvm/4264: #0: c000201ae2d000d8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0xdc/0x950 [kvm] #1: c000200c9ed0c468 (&kvm->srcu){....}-{0:0}, at: kvmppc_h_put_tce+0x88/0x340 [kvm] ==== arch/powerpc/kvm/book3s_64_vio.c:108 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by qemu-kvm/4257: #0: c000200b1b363a40 (&kv->lock){+.+.}-{3:3}, at: kvm_vfio_set_attr+0x598/0x6c0 [kvm] ==== arch/powerpc/kvm/book3s_64_vio.c:146 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by qemu-kvm/4257: #0: c000200b1b363a40 (&kv->lock){+.+.}-{3:3}, at: kvm_vfio_set_attr+0x598/0x6c0 [kvm] Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-07-13KVM: PPC: Book3S HV: Ignore kmemleak false positivesQian Cai
commit 0aca8a5575544bd21b3363058afb8f1e81505150 upstream. kvmppc_pmd_alloc() and kvmppc_pte_alloc() allocate some memory but then pud_populate() and pmd_populate() will use __pa() to reference the newly allocated memory. Since kmemleak is unable to track the physical memory resulting in false positives, silence those by using kmemleak_ignore(). unreferenced object 0xc000201c382a1000 (size 4096): comm "qemu-kvm", pid 124828, jiffies 4295733767 (age 341.250s) hex dump (first 32 bytes): c0 00 20 09 f4 60 03 87 c0 00 20 10 72 a0 03 87 .. ..`.... .r... c0 00 20 0e 13 a0 03 87 c0 00 20 1b dc c0 03 87 .. ....... ..... backtrace: [<000000004cc2790f>] kvmppc_create_pte+0x838/0xd20 [kvm_hv] kvmppc_pmd_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:366 (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:590 [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 [<000000004afc4310>] system_call_exception+0x114/0x1e0 [<00000000fb70a873>] system_call_common+0xf0/0x278 unreferenced object 0xc0002001f0c03900 (size 256): comm "qemu-kvm", pid 124830, jiffies 4295735235 (age 326.570s) hex dump (first 32 bytes): c0 00 20 10 fa a0 03 87 c0 00 20 10 fa a1 03 87 .. ....... ..... c0 00 20 10 fa a2 03 87 c0 00 20 10 fa a3 03 87 .. ....... ..... backtrace: [<0000000023f675b8>] kvmppc_create_pte+0x854/0xd20 [kvm_hv] kvmppc_pte_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:356 (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:593 [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 [<000000004afc4310>] system_call_exception+0x114/0x1e0 [<00000000fb70a873>] system_call_common+0xf0/0x278 Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-06-24powerpc: Fix compile issue with force DAWRMichael Neuling
commit a278e7ea608bea5fe6df9b6ae91fa134655c5d2c upstream. If you compile with KVM but without CONFIG_HAVE_HW_BREAKPOINT you fail at linking with: arch/powerpc/kvm/book3s_hv_rmhandlers.o:(.text+0x708): undefined reference to `dawr_force_enable' This was caused by commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option"). This moves a bunch of code around to fix this. It moves a lot of the DAWR code in a new file and creates a new CONFIG_PPC_DAWR to enable compiling it. Fixes: c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option") Signed-off-by: Michael Neuling <mikey@neuling.org> [mpe: Minor formatting in set_dawr()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-06-01KVM: PPC: Book3S HV: Fix H_CEDE return code for nested guestsMichael Roth
commit 1f50cc1705350a4697923203fedd7d8fb1087fe2 upstream. The h_cede_tm kvm-unit-test currently fails when run inside an L1 guest via the guest/nested hypervisor. ./run-tests.sh -v ... TESTNAME=h_cede_tm TIMEOUT=90s ACCEL= ./powerpc/run powerpc/tm.elf -smp 2,threads=2 -machine cap-htm=on -append "h_cede_tm" FAIL h_cede_tm (2 tests, 1 unexpected failures) While the test relates to transactional memory instructions, the actual failure is due to the return code of the H_CEDE hypercall, which is reported as 224 instead of 0. This happens even when no TM instructions are issued. 224 is the value placed in r3 to execute a hypercall for H_CEDE, and r3 is where the caller expects the return code to be placed upon return. In the case of guest running under a nested hypervisor, issuing H_CEDE causes a return from H_ENTER_NESTED. In this case H_CEDE is specially-handled immediately rather than later in kvmppc_pseries_do_hcall() as with most other hcalls, but we forget to set the return code for the caller, hence why kvm-unit-test sees the 224 return code and reports an error. Guest kernels generally don't check the return value of H_CEDE, so that likely explains why this hasn't caused issues outside of kvm-unit-tests so far. Fix this by setting r3 to 0 after we finish processing the H_CEDE. RHBZ: 1778556 Fixes: 4bad77799fed ("KVM: PPC: Book3S HV: Handle hypercalls correctly when nested") Cc: linuxppc-dev@ozlabs.org Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-15KVM: PPC: Remove set but not used variable 'ra', 'rs', 'rt'zhengbin
commit 4de0a8355463e068e443b48eb5ae32370155368b upstream. Fixes gcc '-Wunused-but-set-variable' warning: arch/powerpc/kvm/emulate_loadstore.c: In function kvmppc_emulate_loadstore: arch/powerpc/kvm/emulate_loadstore.c:87:6: warning: variable ra set but not used [-Wunused-but-set-variable] arch/powerpc/kvm/emulate_loadstore.c: In function kvmppc_emulate_loadstore: arch/powerpc/kvm/emulate_loadstore.c:87:10: warning: variable rs set but not used [-Wunused-but-set-variable] arch/powerpc/kvm/emulate_loadstore.c: In function kvmppc_emulate_loadstore: arch/powerpc/kvm/emulate_loadstore.c:87:14: warning: variable rt set but not used [-Wunused-but-set-variable] They are not used since commit 2b33cb585f94 ("KVM: PPC: Reimplement LOAD_FP/STORE_FP instruction mmio emulation with analyse_instr() input") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-04KVM: Use vcpu-specific gva->hva translation when querying host page sizeSean Christopherson
commit f9b84e19221efc5f493156ee0329df3142085f28 upstream. Use kvm_vcpu_gfn_to_hva() when retrieving the host page size so that the correct set of memslots is used when handling x86 page faults in SMM. Fixes: 54bf36aac520 ("KVM: x86: use vcpu-specific functions to read/write/translate GFNs") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-04KVM: PPC: Book3S PR: Free shared page if mmu initialization failsSean Christopherson
commit cb10bf9194f4d2c5d830eddca861f7ca0fecdbb4 upstream. Explicitly free the shared page if kvmppc_mmu_init() fails during kvmppc_core_vcpu_create(), as the page is freed only in kvmppc_core_vcpu_free(), which is not reached via kvm_vcpu_uninit(). Fixes: 96bc451a15329 ("KVM: PPC: Introduce shared page") Cc: stable@vger.kernel.org Reviewed-by: Greg Kurz <groug@kaod.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-04KVM: PPC: Book3S HV: Uninit vCPU if vcore creation failsSean Christopherson
commit 1a978d9d3e72ddfa40ac60d26301b154247ee0bc upstream. Call kvm_vcpu_uninit() if vcore creation fails to avoid leaking any resources allocated by kvm_vcpu_init(), i.e. the vcpu->run page. Fixes: 371fefd6f2dc4 ("KVM: PPC: Allow book3s_hv guests to use SMT processor modes") Cc: stable@vger.kernel.org Reviewed-by: Greg Kurz <groug@kaod.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-01-19KVM: PPC: Book3S HV: XIVE: Set kvm->arch.xive when VPs are allocatedGreg Kurz
commit e7d71c943040c23f2fd042033d319f56e84f845b upstream. If we cannot allocate the XIVE VPs in OPAL, the creation of a XIVE or XICS-on-XIVE device is aborted as expected, but we leave kvm->arch.xive set forever since the release method isn't called in this case. Any subsequent tentative to create a XIVE or XICS-on-XIVE for this VM will thus always fail (DoS). This is a problem for QEMU since it destroys and re-creates these devices when the VM is reset: the VM would be restricted to using the much slower emulated XIVE or XICS forever. As an alternative to adding rollback, do not assign kvm->arch.xive before making sure the XIVE VPs are allocated in OPAL. Cc: stable@vger.kernel.org # v5.2 Fixes: 5422e95103cf ("KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method by a 'release' method") Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-01-19KVM: PPC: Book3S HV: XIVE: Fix potential page leak on error pathGreg Kurz
commit 30486e72093ea2e594f44876b7a445c219449bce upstream. We need to check the host page size is big enough to accomodate the EQ. Let's do this before taking a reference on the EQ page to avoid a potential leak if the check fails. Cc: stable@vger.kernel.org # v5.2 Fixes: 13ce3297c576 ("KVM: PPC: Book3S HV: XIVE: Add controls for the EQ configuration") Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-01-19KVM: PPC: Book3S HV: XIVE: Free previous EQ page when setting up a new oneGreg Kurz
commit 31a88c82b466d2f31a44e21c479f45b4732ccfd0 upstream. The EQ page is allocated by the guest and then passed to the hypervisor with the H_INT_SET_QUEUE_CONFIG hcall. A reference is taken on the page before handing it over to the HW. This reference is dropped either when the guest issues the H_INT_RESET hcall or when the KVM device is released. But, the guest can legitimately call H_INT_SET_QUEUE_CONFIG several times, either to reset the EQ (vCPU hot unplug) or to set a new EQ (guest reboot). In both cases the existing EQ page reference is leaked because we simply overwrite it in the XIVE queue structure without calling put_page(). This is especially visible when the guest memory is backed with huge pages: start a VM up to the guest userspace, either reboot it or unplug a vCPU, quit QEMU. The leak is observed by comparing the value of HugePages_Free in /proc/meminfo before and after the VM is run. Ideally we'd want the XIVE code to handle the EQ page de-allocation at the platform level. This isn't the case right now because the various XIVE drivers have different allocation needs. It could maybe worth introducing hooks for this purpose instead of exposing XIVE internals to the drivers, but this is certainly a huge work to be done later. In the meantime, for easier backport, fix both vCPU unplug and guest reboot leaks by introducing a wrapper around xive_native_configure_queue() that does the necessary cleanup. Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v5.2 Fixes: 13ce3297c576 ("KVM: PPC: Book3S HV: XIVE: Add controls for the EQ configuration") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Greg Kurz <groug@kaod.org> Tested-by: Lijun Pan <ljp@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-12-02KVM: PPC: Book3S HV: Flush link stack on guest exit to host kernelMichael Ellerman
commit af2e8c68b9c5403f77096969c516f742f5bb29e0 upstream. On some systems that are vulnerable to Spectre v2, it is up to software to flush the link stack (return address stack), in order to protect against Spectre-RSB. When exiting from a guest we do some house keeping and then potentially exit to C code which is several stack frames deep in the host kernel. We will then execute a series of returns without preceeding calls, opening up the possiblity that the guest could have poisoned the link stack, and direct speculative execution of the host to a gadget of some sort. To prevent this we add a flush of the link stack on exit from a guest. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-25KVM: PPC: Book3S HV: XIVE: Ensure VP isn't already in useGreg Kurz
commit 12ade69c1eb9958b13374edf5ef742ea20ccffde upstream. Connecting a vCPU to a XIVE KVM device means establishing a 1:1 association between a vCPU id and the offset (VP id) of a VP structure within a fixed size block of VPs. We currently try to enforce the 1:1 relationship by checking that a vCPU with the same id isn't already connected. This is good but unfortunately not enough because we don't map VP ids to raw vCPU ids but to packed vCPU ids, and the packing function kvmppc_pack_vcpu_id() isn't bijective by design. We got away with it because QEMU passes vCPU ids that fit well in the packing pattern. But nothing prevents userspace to come up with a forged vCPU id resulting in a packed id collision which causes the KVM device to associate two vCPUs to the same VP. This greatly confuses the irq layer and ultimately crashes the kernel, as shown below. Example: a guest with 1 guest thread per core, a core stride of 8 and 300 vCPUs has vCPU ids 0,8,16...2392. If QEMU is patched to inject at some point an invalid vCPU id 348, which is the packed version of itself and 2392, we get: genirq: Flags mismatch irq 199. 00010000 (kvm-2-2392) vs. 00010000 (kvm-2-348) CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ #38 Call Trace: [c000003f7f9937e0] [c000000000c0110c] dump_stack+0xb0/0xf4 (unreliable) [c000003f7f993820] [c0000000001cb480] __setup_irq+0xa70/0xad0 [c000003f7f9938d0] [c0000000001cb75c] request_threaded_irq+0x13c/0x260 [c000003f7f993940] [c00800000d44e7ac] kvmppc_xive_attach_escalation+0x104/0x270 [kvm] [c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm] [c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm] [c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm] [c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30 [c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120 [c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80 [c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68 xive-kvm: Failed to request escalation interrupt for queue 0 of VCPU 2392 ------------[ cut here ]------------ remove_proc_entry: removing non-empty directory 'irq/199', leaking at least 'kvm-2-348' WARNING: CPU: 24 PID: 88176 at /home/greg/Work/linux/kernel-kvm-ppc/fs/proc/generic.c:684 remove_proc_entry+0x1ec/0x200 Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm] CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ #38 NIP: c00000000053b0cc LR: c00000000053b0c8 CTR: c0000000000ba3b0 REGS: c000003f7f9934b0 TRAP: 0700 Not tainted (5.3.0-xive-nr-servers-5.3-gku+) MSR: 9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 48228222 XER: 20040000 CFAR: c000000000131a50 IRQMASK: 0 GPR00: c00000000053b0c8 c000003f7f993740 c0000000015ec500 0000000000000057 GPR04: 0000000000000001 0000000000000000 000049fb98484262 0000000000001bcf GPR08: 0000000000000007 0000000000000007 0000000000000001 9000000000001033 GPR12: 0000000000008000 c000003ffffeb800 0000000000000000 000000012f4ce5a1 GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000 GPR20: 000000012f45d918 c000003f863758b0 c000003f86375870 0000000000000006 GPR24: c000003f86375a30 0000000000000007 c0002039373d9020 c0000000014c4a48 GPR28: 0000000000000001 c000003fe62a4f6b c00020394b2e9fab c000003fe62a4ec0 NIP [c00000000053b0cc] remove_proc_entry+0x1ec/0x200 LR [c00000000053b0c8] remove_proc_entry+0x1e8/0x200 Call Trace: [c000003f7f993740] [c00000000053b0c8] remove_proc_entry+0x1e8/0x200 (unreliable) [c000003f7f9937e0] [c0000000001d3654] unregister_irq_proc+0x114/0x150 [c000003f7f993880] [c0000000001c6284] free_desc+0x54/0xb0 [c000003f7f9938c0] [c0000000001c65ec] irq_free_descs+0xac/0x100 [c000003f7f993910] [c0000000001d1ff8] irq_dispose_mapping+0x68/0x80 [c000003f7f993940] [c00800000d44e8a4] kvmppc_xive_attach_escalation+0x1fc/0x270 [kvm] [c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm] [c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm] [c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm] [c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30 [c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120 [c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80 [c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68 Instruction dump: 2c230000 41820008 3923ff78 e8e900a0 3c82ff69 3c62ff8d 7fa6eb78 7fc5f378 3884f080 3863b948 4bbf6925 60000000 <0fe00000> 4bffff7c fba10088 4bbf6e41 ---[ end trace b925b67a74a1d8d1 ]--- BUG: Kernel NULL pointer dereference at 0x00000010 Faulting instruction address: 0xc00800000d44fc04 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm] CPU: 24 PID: 88176 Comm: qemu-system-ppc Tainted: G W 5.3.0-xive-nr-servers-5.3-gku+ #38 NIP: c00800000d44fc04 LR: c00800000d44fc00 CTR: c0000000001cd970 REGS: c000003f7f9938e0 TRAP: 0300 Tainted: G W (5.3.0-xive-nr-servers-5.3-gku+) MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 24228882 XER: 20040000 CFAR: c0000000001cd9ac DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0 GPR00: c00800000d44fc00 c000003f7f993b70 c00800000d468300 0000000000000000 GPR04: 00000000000000c7 0000000000000000 0000000000000000 c000003ffacd06d8 GPR08: 0000000000000000 c000003ffacd0738 0000000000000000 fffffffffffffffd GPR12: 0000000000000040 c000003ffffeb800 0000000000000000 000000012f4ce5a1 GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000 GPR20: 000000012f45d918 00007ffffe0d9a80 000000012f4f5df0 000000012ef8c9f8 GPR24: 0000000000000001 0000000000000000 c000003fe4501ed0 c000003f8b1d0000 GPR28: c0000033314689c0 c000003fe4501c00 c000003fe4501e70 c000003fe4501e90 NIP [c00800000d44fc04] kvmppc_xive_cleanup_vcpu+0xfc/0x210 [kvm] LR [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm] Call Trace: [c000003f7f993b70] [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm] (unreliable) [c000003f7f993bd0] [c00800000d450bd4] kvmppc_xive_release+0xdc/0x1b0 [kvm] [c000003f7f993c30] [c00800000d436a98] kvm_device_release+0xb0/0x110 [kvm] [c000003f7f993c70] [c00000000046730c] __fput+0xec/0x320 [c000003f7f993cd0] [c000000000164ae0] task_work_run+0x150/0x1c0 [c000003f7f993d30] [c000000000025034] do_notify_resume+0x304/0x440 [c000003f7f993e20] [c00000000000dcc4] ret_from_except_lite+0x70/0x74 Instruction dump: 3bff0008 7fbfd040 419e0054 847e0004 2fa30000 419effec e93d0000 8929203c 2f890000 419effb8 4800821d e8410018 <e9230010> e9490008 9b2a0039 7c0004ac ---[ end trace b925b67a74a1d8d2 ]--- Kernel panic - not syncing: Fatal exception This affects both XIVE and XICS-on-XIVE devices since the beginning. Check the VP id instead of the vCPU id when a new vCPU is connected. The allocation of the XIVE CPU structure in kvmppc_xive_connect_vcpu() is moved after the check to avoid the need for rollback. Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-14kvm: x86, powerpc: do not allow clearing largepages debugfs entryPaolo Bonzini
commit 833b45de69a6016c4b0cebe6765d526a31a81580 upstream. The largepages debugfs entry is incremented/decremented as shadow pages are created or destroyed. Clearing it will result in an underflow, which is harmless to KVM but ugly (and could be misinterpreted by tools that use debugfs information), so make this particular statistic read-only. Cc: kvm-ppc@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9Aneesh Kumar K.V
commit 047e6575aec71d75b765c22111820c4776cd1c43 upstream. On POWER9, under some circumstances, a broadcast TLB invalidation will fail to invalidate the ERAT cache on some threads when there are parallel mtpidr/mtlpidr happening on other threads of the same core. This can cause stores to continue to go to a page after it's unmapped. The workaround is to force an ERAT flush using PID=0 or LPID=0 tlbie flush. This additional TLB flush will cause the ERAT cache invalidation. Since we are using PID=0 or LPID=0, we don't get filtered out by the TLB snoop filtering logic. We need to still follow this up with another tlbie to take care of store vs tlbie ordering issue explained in commit: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9"). The presence of ERAT cache implies we can still get new stores and they may miss store queue marking flush. Cc: stable@vger.kernel.org Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190924035254.24612-3-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/book3s64/radix: Rename CPU_FTR_P9_TLBIE_BUG feature flagAneesh Kumar K.V
commit 09ce98cacd51fcd0fa0af2f79d1e1d3192f4cbb0 upstream. Rename the #define to indicate this is related to store vs tlbie ordering issue. In the next patch, we will be adding another feature flag that is used to handles ERAT flush vs tlbie ordering issue. Fixes: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190924035254.24612-2-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown racePaul Mackerras
commit da15c03b047dca891d37b9f4ef9ca14d84a6484f upstream. Testing has revealed the existence of a race condition where a XIVE interrupt being shut down can be in one of the XIVE interrupt queues (of which there are up to 8 per CPU, one for each priority) at the point where free_irq() is called. If this happens, can return an interrupt number which has been shut down. This can lead to various symptoms: - irq_to_desc(irq) can be NULL. In this case, no end-of-interrupt function gets called, resulting in the CPU's elevated interrupt priority (numerically lowered CPPR) never gets reset. That then means that the CPU stops processing interrupts, causing device timeouts and other errors in various device drivers. - The irq descriptor or related data structures can be in the process of being freed as the interrupt code is using them. This typically leads to crashes due to bad pointer dereferences. This race is basically what commit 62e0468650c3 ("genirq: Add optional hardware synchronization for shutdown", 2019-06-28) is intended to fix, given a get_irqchip_state() method for the interrupt controller being used. It works by polling the interrupt controller when an interrupt is being freed until the controller says it is not pending. With XIVE, the PQ bits of the interrupt source indicate the state of the interrupt source, and in particular the P bit goes from 0 to 1 at the point where the hardware writes an entry into the interrupt queue that this interrupt is directed towards. Normally, the code will then process the interrupt and do an end-of-interrupt (EOI) operation which will reset PQ to 00 (assuming another interrupt hasn't been generated in the meantime). However, there are situations where the code resets P even though a queue entry exists (for example, by setting PQ to 01, which disables the interrupt source), and also situations where the code leaves P at 1 after removing the queue entry (for example, this is done for escalation interrupts so they cannot fire again until they are explicitly re-enabled). The code already has a 'saved_p' flag for the interrupt source which indicates that a queue entry exists, although it isn't maintained consistently. This patch adds a 'stale_p' flag to indicate that P has been left at 1 after processing a queue entry, and adds code to set and clear saved_p and stale_p as necessary to maintain a consistent indication of whether a queue entry may or may not exist. With this, we can implement xive_get_irqchip_state() by looking at stale_p, saved_p and the ESB PQ bits for the interrupt. There is some additional code to handle escalation interrupts properly; because they are enabled and disabled in KVM assembly code, which does not have access to the xive_irq_data struct for the escalation interrupt. Hence, stale_p may be incorrect when the escalation interrupt is freed in kvmppc_xive_{,native_}cleanup_vcpu(). Fortunately, we can fix it up by looking at vcpu->arch.xive_esc_on, with some careful attention to barriers in order to ensure the correct result if xive_esc_irq() races with kvmppc_xive_cleanup_vcpu(). Finally, this adds code to make noise on the console (pr_crit and WARN_ON(1)) if we find an interrupt queue entry for an interrupt which does not have a descriptor. While this won't catch the race reliably, if it does get triggered it will be an indication that the race is occurring and needs to be debugged. Fixes: 243e25112d06 ("powerpc/xive: Native exploitation of the XIVE interrupt controller") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190813100648.GE9567@blackberry Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09KVM: PPC: Book3S HV: Don't lose pending doorbell request on migration on P9Paul Mackerras
commit ff42df49e75f053a8a6b4c2533100cdcc23afe69 upstream. On POWER9, when userspace reads the value of the DPDES register on a vCPU, it is possible for 0 to be returned although there is a doorbell interrupt pending for the vCPU. This can lead to a doorbell interrupt being lost across migration. If the guest kernel uses doorbell interrupts for IPIs, then it could malfunction because of the lost interrupt. This happens because a newly-generated doorbell interrupt is signalled by setting vcpu->arch.doorbell_request to 1; the DPDES value in vcpu->arch.vcore->dpdes is not updated, because it can only be updated when holding the vcpu mutex, in order to avoid races. To fix this, we OR in vcpu->arch.doorbell_request when reading the DPDES value. Cc: stable@vger.kernel.org # v4.13+ Fixes: 579006944e0d ("KVM: PPC: Book3S HV: Virtualize doorbell facility on POWER9") Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09KVM: PPC: Book3S HV: Check for MMU ready on piggybacked virtual coresPaul Mackerras
commit d28eafc5a64045c78136162af9d4ba42f8230080 upstream. When we are running multiple vcores on the same physical core, they could be from different VMs and so it is possible that one of the VMs could have its arch.mmu_ready flag cleared (for example by a concurrent HPT resize) when we go to run it on a physical core. We currently check the arch.mmu_ready flag for the primary vcore but not the flags for the other vcores that will be run alongside it. This adds that check, and also a check when we select the secondary vcores from the preempted vcores list. Cc: stable@vger.kernel.org # v4.14+ Fixes: 38c53af85306 ("KVM: PPC: Book3S HV: Fix exclusion between HPT resizing and other HPT updates") Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09KVM: PPC: Book3S HV: Fix race in re-enabling XIVE escalation interruptsPaul Mackerras
commit 959c5d5134786b4988b6fdd08e444aa67d1667ed upstream. Escalation interrupts are interrupts sent to the host by the XIVE hardware when it has an interrupt to deliver to a guest VCPU but that VCPU is not running anywhere in the system. Hence we disable the escalation interrupt for the VCPU being run when we enter the guest and re-enable it when the guest does an H_CEDE hypercall indicating it is idle. It is possible that an escalation interrupt gets generated just as we are entering the guest. In that case the escalation interrupt may be using a queue entry in one of the interrupt queues, and that queue entry may not have been processed when the guest exits with an H_CEDE. The existing entry code detects this situation and does not clear the vcpu->arch.xive_esc_on flag as an indication that there is a pending queue entry (if the queue entry gets processed, xive_esc_irq() will clear the flag). There is a comment in the code saying that if the flag is still set on H_CEDE, we have to abort the cede rather than re-enabling the escalation interrupt, lest we end up with two occurrences of the escalation interrupt in the interrupt queue. However, the exit code doesn't do that; it aborts the cede in the sense that vcpu->arch.ceded gets cleared, but it still enables the escalation interrupt by setting the source's PQ bits to 00. Instead we need to set the PQ bits to 10, indicating that an interrupt has been triggered. We also need to avoid setting vcpu->arch.xive_esc_on in this case (i.e. vcpu->arch.xive_esc_on seen to be set on H_CEDE) because xive_esc_irq() will run at some point and clear it, and if we race with that we may end up with an incorrect result (i.e. xive_esc_on set when the escalation interrupt has just been handled). It is extremely unlikely that having two queue entries would cause observable problems; theoretically it could cause queue overflow, but the CPU would have to have thousands of interrupts targetted to it for that to be possible. However, this fix will also make it possible to determine accurately whether there is an unhandled escalation interrupt in the queue, which will be needed by the following patch. Fixes: 9b9b13a6d153 ("KVM: PPC: Book3S HV: Keep XIVE escalation interrupt masked unless ceded") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190813100349.GD9567@blackberry Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09KVM: PPC: Book3S HV: Don't push XIVE context when not using XIVE devicePaul Mackerras
commit 8d4ba9c931bc384bcc6889a43915aaaf19d3e499 upstream. At present, when running a guest on POWER9 using HV KVM but not using an in-kernel interrupt controller (XICS or XIVE), for example if QEMU is run with the kernel_irqchip=off option, the guest entry code goes ahead and tries to load the guest context into the XIVE hardware, even though no context has been set up. To fix this, we check that the "CAM word" is non-zero before pushing it to the hardware. The CAM word is initialized to a non-zero value in kvmppc_xive_connect_vcpu() and kvmppc_xive_native_connect_vcpu(), and is now cleared in kvmppc_xive_{,native_}cleanup_vcpu. Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") Cc: stable@vger.kernel.org # v4.12+ Reported-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190813100100.GC9567@blackberry Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09KVM: PPC: Book3S HV: XIVE: Free escalation interrupts before disabling the VPCédric Le Goater
commit 237aed48c642328ff0ab19b63423634340224a06 upstream. When a vCPU is brought done, the XIVE VP (Virtual Processor) is first disabled and then the event notification queues are freed. When freeing the queues, we check for possible escalation interrupts and free them also. But when a XIVE VP is disabled, the underlying XIVE ENDs also are disabled in OPAL. When an END (Event Notification Descriptor) is disabled, its ESB pages (ESn and ESe) are disabled and loads return all 1s. Which means that any access on the ESB page of the escalation interrupt will return invalid values. When an interrupt is freed, the shutdown handler computes a 'saved_p' field from the value returned by a load in xive_do_source_set_mask(). This value is incorrect for escalation interrupts for the reason described above. This has no impact on Linux/KVM today because we don't make use of it but we will introduce in future changes a xive_get_irqchip_state() handler. This handler will use the 'saved_p' field to return the state of an interrupt and 'saved_p' being incorrect, softlockup will occur. Fix the vCPU cleanup sequence by first freeing the escalation interrupts if any, then disable the XIVE VP and last free the queues. Fixes: 90c73795afa2 ("KVM: PPC: Book3S HV: Add a new KVM device for the XIVE native exploitation mode") Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190806172538.5087-1-clg@kaod.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09KVM: PPC: Book3S: Enable XIVE native capability only if OPAL has required ↵Paul Mackerras
functions commit 2ad7a27deaf6d78545d97ab80874584f6990360e upstream. There are some POWER9 machines where the OPAL firmware does not support the OPAL_XIVE_GET_QUEUE_STATE and OPAL_XIVE_SET_QUEUE_STATE calls. The impact of this is that a guest using XIVE natively will not be able to be migrated successfully. On the source side, the get_attr operation on the KVM native device for the KVM_DEV_XIVE_GRP_EQ_CONFIG attribute will fail; on the destination side, the set_attr operation for the same attribute will fail. This adds tests for the existence of the OPAL get/set queue state functions, and if they are not supported, the XIVE-native KVM device is not created and the KVM_CAP_PPC_IRQ_XIVE capability returns false. Userspace can then either provide a software emulation of XIVE, or else tell the guest that it does not have a XIVE controller available to it. Cc: stable@vger.kernel.org # v5.2+ Fixes: 3fab2d10588e ("KVM: PPC: Book3S HV: XIVE: Activate XIVE exploitation mode") Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-06KVM: PPC: Book3S: Fix incorrect guest-to-user-translation error handlingAlexey Kardashevskiy
commit ddfd151f3def9258397fcde7a372205a2d661903 upstream. H_PUT_TCE_INDIRECT handlers receive a page with up to 512 TCEs from a guest. Although we verify correctness of TCEs before we do anything with the existing tables, there is a small window when a check in kvmppc_tce_validate might pass and right after that the guest alters the page of TCEs, causing an early exit from the handler and leaving srcu_read_lock(&vcpu->kvm->srcu) (virtual mode) or lock_rmap(rmap) (real mode) locked. This fixes the bug by jumping to the common exit code with an appropriate unlock. Cc: stable@vger.kernel.org # v4.11+ Fixes: 121f80ba68f1 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-16KVM: Fix leak vCPU's VMCS value into other pCPUWanpeng Li
commit 17e433b54393a6269acbcb792da97791fe1592d8 upstream. After commit d73eb57b80b (KVM: Boost vCPUs that are delivering interrupts), a five years old bug is exposed. Running ebizzy benchmark in three 80 vCPUs VMs on one 80 pCPUs Skylake server, a lot of rcu_sched stall warning splatting in the VMs after stress testing: INFO: rcu_sched detected stalls on CPUs/tasks: { 4 41 57 62 77} (detected by 15, t=60004 jiffies, g=899, c=898, q=15073) Call Trace: flush_tlb_mm_range+0x68/0x140 tlb_flush_mmu.part.75+0x37/0xe0 tlb_finish_mmu+0x55/0x60 zap_page_range+0x142/0x190 SyS_madvise+0x3cd/0x9c0 system_call_fastpath+0x1c/0x21 swait_active() sustains to be true before finish_swait() is called in kvm_vcpu_block(), voluntarily preempted vCPUs are taken into account by kvm_vcpu_on_spin() loop greatly increases the probability condition kvm_arch_vcpu_runnable(vcpu) is checked and can be true, when APICv is enabled the yield-candidate vCPU's VMCS RVI field leaks(by vmx_sync_pir_to_irr()) into spinning-on-a-taken-lock vCPU's current VMCS. This patch fixes it by checking conservatively a subset of events. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Marc Zyngier <Marc.Zyngier@arm.com> Cc: stable@vger.kernel.org Fixes: 98f4a1467 (KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop) Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-31KVM: PPC: Book3S HV: XIVE: fix rollback when kvmppc_xive_create failsCédric Le Goater
commit 9798f4ea71eaf8eaad7e688c5b298528089c7bf8 upstream. The XIVE device structure is now allocated in kvmppc_xive_get_device() and kfree'd in kvmppc_core_destroy_vm(). In case of an OPAL error when allocating the XIVE VPs, the kfree() call in kvmppc_xive_*create() will result in a double free and corrupt the host memory. Fixes: 5422e95103cf ("KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method by a 'release' method") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Cédric Le Goater <clg@kaod.org> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6ea6998b-a890-2511-01d1-747d7621eb19@kaod.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-31KVM: PPC: Book3S HV: Save and restore guest visible PSSCR bits on pseriesSuraj Jitindar Singh
commit c8b4083db915dfe5a3b4a755ad2317e0509b43f1 upstream. The Performance Stop Status and Control Register (PSSCR) is used to control the power saving facilities of the processor. This register has various fields, some of which can be modified only in hypervisor state, and others which can be modified in both hypervisor and privileged non-hypervisor state. The bits which can be modified in privileged non-hypervisor state are referred to as guest visible. Currently the L0 hypervisor saves and restores both it's own host value as well as the guest value of the PSSCR when context switching between the hypervisor and guest. However a nested hypervisor running it's own nested guests (as indicated by kvmhv_on_pseries()) doesn't context switch the PSSCR register. That means if a nested (L2) guest modifies the PSSCR then the L1 guest hypervisor will run with that modified value, and if the L1 guest hypervisor modifies the PSSCR and then goes to run the nested (L2) guest again then the L2 PSSCR value will be lost. Fix this by having the (L1) nested hypervisor save and restore both its host and the guest PSSCR value when entering and exiting a nested (L2) guest. Note that only the guest visible parts of the PSSCR are context switched since this is all the L1 nested hypervisor can access, this is fine however as these are the only fields the L0 hypervisor provides guest control of anyway and so all other fields are ignored. This could also have been implemented by adding the PSSCR register to the hv_regs passed to the L0 hypervisor as input to the H_ENTER_NESTED hcall, however this would have meant updating the structure layout and thus required modifications to both the L0 and L1 kernels. Whereas the approach used doesn't require L0 kernel modifications while achieving the same result. Fixes: 95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190703012022.15644-3-sjitindarsingh@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-31KVM: PPC: Book3S HV: Always save guest pmu for guest capable of nestingSuraj Jitindar Singh
commit 63279eeb7f93abb1692573c26f1e038e1a87358b upstream. The performance monitoring unit (PMU) registers are saved on guest exit when the guest has set the pmcregs_in_use flag in its lppaca, if it exists, or unconditionally if it doesn't. If a nested guest is being run then the hypervisor doesn't, and in most cases can't, know if the PMU registers are in use since it doesn't know the location of the lppaca for the nested guest, although it may have one for its immediate guest. This results in the values of these registers being lost across nested guest entry and exit in the case where the nested guest was making use of the performance monitoring facility while it's nested guest hypervisor wasn't. Further more the hypervisor could interrupt a guest hypervisor between when it has loaded up the PMU registers and it calling H_ENTER_NESTED or between returning from the nested guest to the guest hypervisor and the guest hypervisor reading the PMU registers, in kvmhv_p9_guest_entry(). This means that it isn't sufficient to just save the PMU registers when entering or exiting a nested guest, but that it is necessary to always save the PMU registers whenever a guest is capable of running nested guests to ensure the register values aren't lost in the context switch. Ensure the PMU register values are preserved by always saving their value into the vcpu struct when a guest is capable of running nested guests. This should have minimal performance impact however any impact can be avoided by booting a guest with "-machine pseries,cap-nested-hv=false" on the qemu commandline. Fixes: 95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190703012022.15644-1-sjitindarsingh@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26KVM: PPC: Book3S HV: Fix CR0 setting in TM emulationMichael Neuling
commit 3fefd1cd95df04da67c83c1cb93b663f04b3324f upstream. When emulating tsr, treclaim and trechkpt, we incorrectly set CR0. The code currently sets: CR0 <- 00 || MSR[TS] but according to the ISA it should be: CR0 <- 0 || MSR[TS] || 0 This fixes the bit shift to put the bits in the correct location. This is a data integrity issue as CR0 is corrupted. Fixes: 4bb3c7a0208f ("KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9") Cc: stable@vger.kernel.org # v4.17+ Tested-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26KVM: PPC: Book3S HV: Clear pending decrementer exceptions on nested guest entrySuraj Jitindar Singh
commit 3c25ab35fbc8526ac0c9b298e8a78e7ad7a55479 upstream. If we enter an L1 guest with a pending decrementer exception then this is cleared on guest exit if the guest has writtien a positive value into the decrementer (indicating that it handled the decrementer exception) since there is no other way to detect that the guest has handled the pending exception and that it should be dequeued. In the event that the L1 guest tries to run a nested (L2) guest immediately after this and the L2 guest decrementer is negative (which is loaded by L1 before making the H_ENTER_NESTED hcall), then the pending decrementer exception isn't cleared and the L2 entry is blocked since L1 has a pending exception, even though L1 may have already handled the exception and written a positive value for it's decrementer. This results in a loop of L1 trying to enter the L2 guest and L0 blocking the entry since L1 has an interrupt pending with the outcome being that L2 never gets to run and hangs. Fix this by clearing any pending decrementer exceptions when L1 makes the H_ENTER_NESTED hcall since it won't do this if it's decrementer has gone negative, and anyway it's decrementer has been communicated to L0 in the hdec_expires field and L0 will return control to L1 when this goes negative by delivering an H_DECREMENTER exception. Fixes: 95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26KVM: PPC: Book3S HV: Signed extend decrementer value if not using large ↵Suraj Jitindar Singh
decrementer commit 869537709ebf1dc865e75c3fc97b23f8acf37c16 upstream. On POWER9 the decrementer can operate in large decrementer mode where the decrementer is 56 bits and signed extended to 64 bits. When not operating in this mode the decrementer behaves as a 32 bit decrementer which is NOT signed extended (as on POWER8). Currently when reading a guest decrementer value we don't take into account whether the large decrementer is enabled or not, and this means the value will be incorrect when the guest is not using the large decrementer. Fix this by sign extending the value read when the guest isn't using the large decrementer. Fixes: 95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22Merge tag 'powerpc-5.2-5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "This is a frustratingly large batch at rc5. Some of these were sent earlier but were missed by me due to being distracted by other things, and some took a while to track down due to needing manual bisection on old hardware. But still we clearly need to improve our testing of KVM, and of 32-bit, so that we catch these earlier. Summary: seven fixes, all for bugs introduced this cycle. - The commit to add KASAN support broke booting on 32-bit SMP machines, due to a refactoring that moved some setup out of the secondary CPU path. - A fix for another 32-bit SMP bug introduced by the fast syscall entry implementation for 32-bit BOOKE. And a build fix for the same commit. - Our change to allow the DAWR to be force enabled on Power9 introduced a bug in KVM, where we clobber r3 leading to a host crash. - The same commit also exposed a previously unreachable bug in the nested KVM handling of DAWR, which could lead to an oops in a nested host. - One of the DMA reworks broke the b43legacy WiFi driver on some people's powermacs, fix it by enabling a 30-bit ZONE_DMA on 32-bit. - A fix for TLB flushing in KVM introduced a new bug, as it neglected to also flush the ERAT, this could lead to memory corruption in the guest. Thanks to: Aaro Koskinen, Christoph Hellwig, Christophe Leroy, Larry Finger, Michael Neuling, Suraj Jitindar Singh" * tag 'powerpc-5.2-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac KVM: PPC: Book3S HV: Only write DAWR[X] when handling h_set_dawr in real mode KVM: PPC: Book3S HV: Fix r3 corruption in h_set_dabr() powerpc/32: fix build failure on book3e with KVM powerpc/booke: fix fast syscall entry on SMP powerpc/32s: fix initial setup of segment registers on secondary CPU
2019-06-20KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entriesSuraj Jitindar Singh
When a guest vcpu moves from one physical thread to another it is necessary for the host to perform a tlb flush on the previous core if another vcpu from the same guest is going to run there. This is because the guest may use the local form of the tlb invalidation instruction meaning stale tlb entries would persist where it previously ran. This is handled on guest entry in kvmppc_check_need_tlb_flush() which calls flush_guest_tlb() to perform the tlb flush. Previously the generic radix__local_flush_tlb_lpid_guest() function was used, however the functionality was reimplemented in flush_guest_tlb() to avoid the trace_tlbie() call as the flushing may be done in real mode. The reimplementation in flush_guest_tlb() was missing an erat invalidation after flushing the tlb. This lead to observable memory corruption in the guest due to the caching of stale translations. Fix this by adding the erat invalidation. Fixes: 70ea13f6e609 ("KVM: PPC: Book3S HV: Flush TLB on secondary radix threads") Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18KVM: PPC: Book3S HV: Only write DAWR[X] when handling h_set_dawr in real modeSuraj Jitindar Singh
The hcall H_SET_DAWR is used by a guest to set the data address watchpoint register (DAWR). This hcall is handled in the host in kvmppc_h_set_dawr() which can be called in either real mode on the guest exit path from hcall_try_real_mode() in book3s_hv_rmhandlers.S, or in virtual mode when called from kvmppc_pseries_do_hcall() in book3s_hv.c. The function kvmppc_h_set_dawr() updates the dawr and dawrx fields in the vcpu struct accordingly and then also writes the respective values into the DAWR and DAWRX registers directly. It is necessary to write the registers directly here when calling the function in real mode since the path to re-enter the guest won't do this. However when in virtual mode the host DAWR and DAWRX values have already been restored, and so writing the registers would overwrite these. Additionally there is no reason to write the guest values here as these will be read from the vcpu struct and written to the registers appropriately the next time the vcpu is run. This also avoids the case when handling h_set_dawr for a nested guest where the guest hypervisor isn't able to write the DAWR and DAWRX registers directly and must rely on the real hypervisor to do this for it when it calls H_ENTER_NESTED. Fixes: c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option") Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-18KVM: PPC: Book3S HV: Fix r3 corruption in h_set_dabr()Michael Neuling
Commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option") screwed up some assembler and corrupted a pointer in r3. This resulted in crashes like the below: BUG: Kernel NULL pointer dereference at 0x000013bf Faulting instruction address: 0xc00000000010b044 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA pSeries CPU: 8 PID: 1771 Comm: qemu-system-ppc Kdump: loaded Not tainted 5.2.0-rc4+ #3 NIP: c00000000010b044 LR: c0080000089dacf4 CTR: c00000000010aff4 REGS: c00000179b397710 TRAP: 0300 Not tainted (5.2.0-rc4+) MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 42244842 XER: 00000000 CFAR: c00000000010aff8 DAR: 00000000000013bf DSISR: 42000000 IRQMASK: 0 GPR00: c0080000089dd6bc c00000179b3979a0 c008000008a04300 ffffffffffffffff GPR04: 0000000000000000 0000000000000003 000000002444b05d c0000017f11c45d0 ... NIP kvmppc_h_set_dabr+0x50/0x68 LR kvmppc_pseries_do_hcall+0xa3c/0xeb0 [kvm_hv] Call Trace: 0xc0000017f11c0000 (unreliable) kvmppc_vcpu_run_hv+0x694/0xec0 [kvm_hv] kvmppc_vcpu_run+0x34/0x48 [kvm] kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm] kvm_vcpu_ioctl+0x460/0x850 [kvm] do_vfs_ioctl+0xe4/0xb40 ksys_ioctl+0xc4/0x110 sys_ioctl+0x28/0x80 system_call+0x5c/0x70 Instruction dump: 4082fff4 4c00012c 38600000 4e800020 e96280c0 896b0000 2c2b0000 3860ffff 4d820020 50852e74 508516f6 78840724 <f88313c0> f8a313c8 7c942ba6 7cbc2ba6 Fix the bug by only changing r3 when we are returning immediately. Fixes: c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option") Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reported-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 67 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141333.953658117@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "Fixes for PPC and s390" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: PPC: Book3S HV: Restore SPRG3 in kvmhv_p9_guest_entry() KVM: PPC: Book3S HV: Fix lockdep warning when entering guest on POWER9 KVM: PPC: Book3S HV: XIVE: Fix page offset when clearing ESB pages KVM: PPC: Book3S HV: XIVE: Take the srcu read lock when accessing memslots KVM: PPC: Book3S HV: XIVE: Do not clear IRQ data of passthrough interrupts KVM: PPC: Book3S HV: XIVE: Introduce a new mutex for the XIVE device KVM: PPC: Book3S HV: XIVE: Fix the enforced limit on the vCPU identifier KVM: PPC: Book3S HV: XIVE: Do not test the EQ flag validity when resetting KVM: PPC: Book3S HV: XIVE: Clear file mapping when device is released KVM: PPC: Book3S HV: Don't take kvm->lock around kvm_for_each_vcpu KVM: PPC: Book3S: Use new mutex to synchronize access to rtas token list KVM: PPC: Book3S HV: Use new mutex to synchronize MMU setup KVM: PPC: Book3S HV: Avoid touching arch.mmu_ready in XIVE release functions KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID kvm: fix compile on s390 part 2
2019-06-01Merge tag 'kvm-s390-master-5.2-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master KVM: s390: Fixes - fix compilation for !CONFIG_PCI - fix the output of KVM_CAP_MAX_VCPU_ID
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 655 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30KVM: PPC: Book3S HV: Restore SPRG3 in kvmhv_p9_guest_entry()Suraj Jitindar Singh
The sprgs are a set of 4 general purpose sprs provided for software use. SPRG3 is special in that it can also be read from userspace. Thus it is used on linux to store the cpu and numa id of the process to speed up syscall access to this information. This register is overwritten with the guest value on kvm guest entry, and so needs to be restored on exit again. Thus restore the value on the guest exit path in kvmhv_p9_guest_entry(). Cc: stable@vger.kernel.org # v4.20+ Fixes: 95a6432ce9038 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-30KVM: PPC: Book3S HV: Fix lockdep warning when entering guest on POWER9Paul Mackerras
Commit 3309bec85e60 ("KVM: PPC: Book3S HV: Fix lockdep warning when entering the guest") moved calls to trace_hardirqs_{on,off} in the entry path used for HPT guests. Similar code exists in the new streamlined entry path used for radix guests on POWER9. This makes the same change there, so as to avoid lockdep warnings such as this: [ 228.686461] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) [ 228.686480] WARNING: CPU: 116 PID: 3803 at ../kernel/locking/lockdep.c:4219 check_flags.part.23+0x21c/0x270 [ 228.686544] Modules linked in: vhost_net vhost xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat +xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter +ebtables ip6table_filter ip6_tables iptable_filter fuse kvm_hv kvm at24 ipmi_powernv regmap_i2c ipmi_devintf +uio_pdrv_genirq ofpart ipmi_msghandler uio powernv_flash mtd ibmpowernv opal_prd ip_tables ext4 mbcache jbd2 btrfs +zstd_decompress zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx libcrc32c xor +raid6_pq raid1 raid0 ses sd_mod enclosure scsi_transport_sas ast i2c_opal i2c_algo_bit drm_kms_helper syscopyarea +sysfillrect sysimgblt fb_sys_fops ttm drm i40e e1000e cxl aacraid tg3 drm_panel_orientation_quirks i2c_core [ 228.686859] CPU: 116 PID: 3803 Comm: qemu-system-ppc Kdump: loaded Not tainted 5.2.0-rc1-xive+ #42 [ 228.686911] NIP: c0000000001b394c LR: c0000000001b3948 CTR: c000000000bfad20 [ 228.686963] REGS: c000200cdb50f570 TRAP: 0700 Not tainted (5.2.0-rc1-xive+) [ 228.687001] MSR: 9000000002823033 <SF,HV,VEC,VSX,FP,ME,IR,DR,RI,LE> CR: 48222222 XER: 20040000 [ 228.687060] CFAR: c000000000116db0 IRQMASK: 1 [ 228.687060] GPR00: c0000000001b3948 c000200cdb50f800 c0000000015e7600 000000000000002e [ 228.687060] GPR04: 0000000000000001 c0000000001c71a0 000000006e655f73 72727563284e4f5f [ 228.687060] GPR08: 0000200e60680000 0000000000000000 c000200cdb486180 0000000000000000 [ 228.687060] GPR12: 0000000000002000 c000200fff61a680 0000000000000000 00007fffb75c0000 [ 228.687060] GPR16: 0000000000000000 0000000000000000 c0000000017d6900 c000000001124900 [ 228.687060] GPR20: 0000000000000074 c008000006916f68 0000000000000074 0000000000000074 [ 228.687060] GPR24: ffffffffffffffff ffffffffffffffff 0000000000000003 c000200d4b600000 [ 228.687060] GPR28: c000000001627e58 c000000001489908 c000000001627e58 c000000002304de0 [ 228.687377] NIP [c0000000001b394c] check_flags.part.23+0x21c/0x270 [ 228.687415] LR [c0000000001b3948] check_flags.part.23+0x218/0x270 [ 228.687466] Call Trace: [ 228.687488] [c000200cdb50f800] [c0000000001b3948] check_flags.part.23+0x218/0x270 (unreliable) [ 228.687542] [c000200cdb50f870] [c0000000001b6548] lock_is_held_type+0x188/0x1c0 [ 228.687595] [c000200cdb50f8d0] [c0000000001d939c] rcu_read_lock_sched_held+0xdc/0x100 [ 228.687646] [c000200cdb50f900] [c0000000001dd704] rcu_note_context_switch+0x304/0x340 [ 228.687701] [c000200cdb50f940] [c0080000068fcc58] kvmhv_run_single_vcpu+0xdb0/0x1120 [kvm_hv] [ 228.687756] [c000200cdb50fa20] [c0080000068fd5b0] kvmppc_vcpu_run_hv+0x5e8/0xe40 [kvm_hv] [ 228.687816] [c000200cdb50faf0] [c0080000071797dc] kvmppc_vcpu_run+0x34/0x48 [kvm] [ 228.687863] [c000200cdb50fb10] [c0080000071755dc] kvm_arch_vcpu_ioctl_run+0x244/0x420 [kvm] [ 228.687916] [c000200cdb50fba0] [c008000007165ccc] kvm_vcpu_ioctl+0x424/0x838 [kvm] [ 228.687957] [c000200cdb50fd10] [c000000000433a24] do_vfs_ioctl+0xd4/0xcd0 [ 228.687995] [c000200cdb50fdb0] [c000000000434724] ksys_ioctl+0x104/0x120 [ 228.688033] [c000200cdb50fe00] [c000000000434768] sys_ioctl+0x28/0x80 [ 228.688072] [c000200cdb50fe20] [c00000000000b888] system_call+0x5c/0x70 [ 228.688109] Instruction dump: [ 228.688142] 4bf6342d 60000000 0fe00000 e8010080 7c0803a6 4bfffe60 3c82ff87 3c62ff87 [ 228.688196] 388472d0 3863d738 4bf63405 60000000 <0fe00000> 4bffff4c 3c82ff87 3c62ff87 [ 228.688251] irq event stamp: 205 [ 228.688287] hardirqs last enabled at (205): [<c0080000068fc1b4>] kvmhv_run_single_vcpu+0x30c/0x1120 [kvm_hv] [ 228.688344] hardirqs last disabled at (204): [<c0080000068fbff0>] kvmhv_run_single_vcpu+0x148/0x1120 [kvm_hv] [ 228.688412] softirqs last enabled at (180): [<c000000000c0b2ac>] __do_softirq+0x4ac/0x5d4 [ 228.688464] softirqs last disabled at (169): [<c000000000122aa8>] irq_exit+0x1f8/0x210 [ 228.688513] ---[ end trace eb16f6260022a812 ]--- [ 228.688548] possible reason: unannotated irqs-off. [ 228.688571] irq event stamp: 205 [ 228.688607] hardirqs last enabled at (205): [<c0080000068fc1b4>] kvmhv_run_single_vcpu+0x30c/0x1120 [kvm_hv] [ 228.688664] hardirqs last disabled at (204): [<c0080000068fbff0>] kvmhv_run_single_vcpu+0x148/0x1120 [kvm_hv] [ 228.688719] softirqs last enabled at (180): [<c000000000c0b2ac>] __do_softirq+0x4ac/0x5d4 [ 228.688758] softirqs last disabled at (169): [<c000000000122aa8>] irq_exit+0x1f8/0x210 Cc: stable@vger.kernel.org # v4.20+ Fixes: 95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> Tested-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-30KVM: PPC: Book3S HV: XIVE: Fix page offset when clearing ESB pagesCédric Le Goater
Under XIVE, the ESB pages of an interrupt are used for interrupt management (EOI) and triggering. They are made available to guests through a mapping of the XIVE KVM device. When a device is passed-through, the passthru_irq helpers, kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), clear the ESB pages of the guest IRQ number being mapped and let the VM fault handler repopulate with the correct page. The ESB pages are mapped at offset 4 (KVM_XIVE_ESB_PAGE_OFFSET) in the KVM device mapping. Unfortunately, this offset was not taken into account when clearing the pages. This lead to issues with the passthrough devices for which the interrupts were not functional under some guest configuration (tg3 and single CPU) or in any configuration (e1000e adapter). Reviewed-by: Greg Kurz <groug@kaod.org> Tested-by: Greg Kurz <groug@kaod.org> Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-30KVM: PPC: Book3S HV: XIVE: Take the srcu read lock when accessing memslotsCédric Le Goater
According to Documentation/virtual/kvm/locking.txt, the srcu read lock should be taken when accessing the memslots of the VM. The XIVE KVM device needs to do so when configuring the page of the OS event queue of vCPU for a given priority and when marking the same page dirty before migration. This avoids warnings such as : [ 208.224882] ============================= [ 208.224884] WARNING: suspicious RCU usage [ 208.224889] 5.2.0-rc2-xive+ #47 Not tainted [ 208.224890] ----------------------------- [ 208.224894] ../include/linux/kvm_host.h:633 suspicious rcu_dereference_check() usage! [ 208.224896] other info that might help us debug this: [ 208.224898] rcu_scheduler_active = 2, debug_locks = 1 [ 208.224901] no locks held by qemu-system-ppc/3923. [ 208.224902] stack backtrace: [ 208.224907] CPU: 64 PID: 3923 Comm: qemu-system-ppc Kdump: loaded Not tainted 5.2.0-rc2-xive+ #47 [ 208.224909] Call Trace: [ 208.224918] [c000200cdd98fa30] [c000000000be1934] dump_stack+0xe8/0x164 (unreliable) [ 208.224924] [c000200cdd98fa80] [c0000000001aec80] lockdep_rcu_suspicious+0x110/0x180 [ 208.224935] [c000200cdd98fb00] [c0080000075933a0] gfn_to_memslot+0x1c8/0x200 [kvm] [ 208.224943] [c000200cdd98fb40] [c008000007599600] gfn_to_pfn+0x28/0x60 [kvm] [ 208.224951] [c000200cdd98fb70] [c008000007599658] gfn_to_page+0x20/0x40 [kvm] [ 208.224959] [c000200cdd98fb90] [c0080000075b495c] kvmppc_xive_native_set_attr+0x8b4/0x1480 [kvm] [ 208.224967] [c000200cdd98fca0] [c00800000759261c] kvm_device_ioctl_attr+0x64/0xb0 [kvm] [ 208.224974] [c000200cdd98fcf0] [c008000007592730] kvm_device_ioctl+0xc8/0x110 [kvm] [ 208.224979] [c000200cdd98fd10] [c000000000433a24] do_vfs_ioctl+0xd4/0xcd0 [ 208.224981] [c000200cdd98fdb0] [c000000000434724] ksys_ioctl+0x104/0x120 [ 208.224984] [c000200cdd98fe00] [c000000000434768] sys_ioctl+0x28/0x80 [ 208.224988] [c000200cdd98fe20] [c00000000000b888] system_call+0x5c/0x70 legoater@boss01:~$ Fixes: 13ce3297c576 ("KVM: PPC: Book3S HV: XIVE: Add controls for the EQ configuration") Fixes: e6714bd1671d ("KVM: PPC: Book3S HV: XIVE: Add a control to dirty the XIVE EQ pages") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-30KVM: PPC: Book3S HV: XIVE: Do not clear IRQ data of passthrough interruptsCédric Le Goater
The passthrough interrupts are defined at the host level and their IRQ data should not be cleared unless specifically deconfigured (shutdown) by the host. They differ from the IPI interrupts which are allocated by the XIVE KVM device and reserved to the guest usage only. This fixes a host crash when destroying a VM in which a PCI adapter was passed-through. In this case, the interrupt is cleared and freed by the KVM device and then shutdown by vfio at the host level. [ 1007.360265] BUG: Kernel NULL pointer dereference at 0x00000d00 [ 1007.360285] Faulting instruction address: 0xc00000000009da34 [ 1007.360296] Oops: Kernel access of bad area, sig: 7 [#1] [ 1007.360303] LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV [ 1007.360314] Modules linked in: vhost_net vhost iptable_mangle ipt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc kvm_hv kvm xt_tcpudp iptable_filter squashfs fuse binfmt_misc vmx_crypto ib_iser rdma_cm iw_cm ib_cm libiscsi scsi_transport_iscsi nfsd ip_tables x_tables autofs4 btrfs zstd_decompress zstd_compress lzo_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq multipath mlx5_ib ib_uverbs ib_core crc32c_vpmsum mlx5_core [ 1007.360425] CPU: 9 PID: 15576 Comm: CPU 18/KVM Kdump: loaded Not tainted 5.1.0-gad7e7d0ef #4 [ 1007.360454] NIP: c00000000009da34 LR: c00000000009e50c CTR: c00000000009e5d0 [ 1007.360482] REGS: c000007f24ccf330 TRAP: 0300 Not tainted (5.1.0-gad7e7d0ef) [ 1007.360500] MSR: 900000000280b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24002484 XER: 00000000 [ 1007.360532] CFAR: c00000000009da10 DAR: 0000000000000d00 DSISR: 00080000 IRQMASK: 1 [ 1007.360532] GPR00: c00000000009e62c c000007f24ccf5c0 c000000001510600 c000007fe7f947c0 [ 1007.360532] GPR04: 0000000000000d00 0000000000000000 0000000000000000 c000005eff02d200 [ 1007.360532] GPR08: 0000000000400000 0000000000000000 0000000000000000 fffffffffffffffd [ 1007.360532] GPR12: c00000000009e5d0 c000007fffff7b00 0000000000000031 000000012c345718 [ 1007.360532] GPR16: 0000000000000000 0000000000000008 0000000000418004 0000000000040100 [ 1007.360532] GPR20: 0000000000000000 0000000008430000 00000000003c0000 0000000000000027 [ 1007.360532] GPR24: 00000000000000ff 0000000000000000 00000000000000ff c000007faa90d98c [ 1007.360532] GPR28: c000007faa90da40 00000000000fe040 ffffffffffffffff c000007fe7f947c0 [ 1007.360689] NIP [c00000000009da34] xive_esb_read+0x34/0x120 [ 1007.360706] LR [c00000000009e50c] xive_do_source_set_mask.part.0+0x2c/0x50 [ 1007.360732] Call Trace: [ 1007.360738] [c000007f24ccf5c0] [c000000000a6383c] snooze_loop+0x15c/0x270 (unreliable) [ 1007.360775] [c000007f24ccf5f0] [c00000000009e62c] xive_irq_shutdown+0x5c/0xe0 [ 1007.360795] [c000007f24ccf630] [c00000000019e4a0] irq_shutdown+0x60/0xe0 [ 1007.360813] [c000007f24ccf660] [c000000000198c44] __free_irq+0x3a4/0x420 [ 1007.360831] [c000007f24ccf700] [c000000000198dc8] free_irq+0x78/0xe0 [ 1007.360849] [c000007f24ccf730] [c00000000096c5a8] vfio_msi_set_vector_signal+0xa8/0x350 [ 1007.360878] [c000007f24ccf7f0] [c00000000096c938] vfio_msi_set_block+0xe8/0x1e0 [ 1007.360899] [c000007f24ccf850] [c00000000096cae0] vfio_msi_disable+0xb0/0x110 [ 1007.360912] [c000007f24ccf8a0] [c00000000096cd04] vfio_pci_set_msi_trigger+0x1c4/0x3d0 [ 1007.360922] [c000007f24ccf910] [c00000000096d910] vfio_pci_set_irqs_ioctl+0xa0/0x170 [ 1007.360941] [c000007f24ccf930] [c00000000096b400] vfio_pci_disable+0x80/0x5e0 [ 1007.360963] [c000007f24ccfa10] [c00000000096b9bc] vfio_pci_release+0x5c/0x90 [ 1007.360991] [c000007f24ccfa40] [c000000000963a9c] vfio_device_fops_release+0x3c/0x70 [ 1007.361012] [c000007f24ccfa70] [c0000000003b5668] __fput+0xc8/0x2b0 [ 1007.361040] [c000007f24ccfac0] [c0000000001409b0] task_work_run+0x140/0x1b0 [ 1007.361059] [c000007f24ccfb20] [c000000000118f8c] do_exit+0x3ac/0xd00 [ 1007.361076] [c000007f24ccfc00] [c0000000001199b0] do_group_exit+0x60/0x100 [ 1007.361094] [c000007f24ccfc40] [c00000000012b514] get_signal+0x1a4/0x8f0 [ 1007.361112] [c000007f24ccfd30] [c000000000021cc8] do_notify_resume+0x1a8/0x430 [ 1007.361141] [c000007f24ccfe20] [c00000000000e444] ret_from_except_lite+0x70/0x74 [ 1007.361159] Instruction dump: [ 1007.361175] 38422c00 e9230000 712a0004 41820010 548a2036 7d442378 78840020 71290020 [ 1007.361194] 4082004c e9230010 7c892214 7c0004ac <e9240000> 0c090000 4c00012c 792a0022 Cc: stable@vger.kernel.org # v4.12+ Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Greg Kurz <groug@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-30KVM: PPC: Book3S HV: XIVE: Introduce a new mutex for the XIVE deviceCédric Le Goater
The XICS-on-XIVE KVM device needs to allocate XIVE event queues when a priority is used by the OS. This is referred as EQ provisioning and it is done under the hood when : 1. a CPU is hot-plugged in the VM 2. the "set-xive" is called at VM startup 3. sources are restored at VM restore The kvm->lock mutex is used to protect the different XIVE structures being modified but in some contexts, kvm->lock is taken under the vcpu->mutex which is not permitted by the KVM locking rules. Introduce a new mutex 'lock' for the KVM devices for them to synchronize accesses to the XIVE device structures. Reviewed-by: Greg Kurz <groug@kaod.org> Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-29KVM: PPC: Book3S HV: XIVE: Fix the enforced limit on the vCPU identifierCédric Le Goater
When a vCPU is connected to the KVM device, it is done using its vCPU identifier in the guest. Fix the enforced limit on the vCPU identifier by taking into account the SMT mode. Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Greg Kurz <groug@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-29KVM: PPC: Book3S HV: XIVE: Do not test the EQ flag validity when resettingCédric Le Goater
When a CPU is hot-unplugged, the EQ is deconfigured using a zero size and a zero address. In this case, there is no need to check the flag and queue size validity. Move the checks after the queue reset code section to fix CPU hot-unplug. Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Greg Kurz <groug@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-28 04:07:38 +0000