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2023-05-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "s390: - More phys_to_virt conversions - Improvement of AP management for VSIE (nested virtualization) ARM64: - Numerous fixes for the pathological lock inversion issue that plagued KVM/arm64 since... forever. - New framework allowing SMCCC-compliant hypercalls to be forwarded to userspace, hopefully paving the way for some more features being moved to VMMs rather than be implemented in the kernel. - Large rework of the timer code to allow a VM-wide offset to be applied to both virtual and physical counters as well as a per-timer, per-vcpu offset that complements the global one. This last part allows the NV timer code to be implemented on top. - A small set of fixes to make sure that we don't change anything affecting the EL1&0 translation regime just after having having taken an exception to EL2 until we have executed a DSB. This ensures that speculative walks started in EL1&0 have completed. - The usual selftest fixes and improvements. x86: - Optimize CR0.WP toggling by avoiding an MMU reload when TDP is enabled, and by giving the guest control of CR0.WP when EPT is enabled on VMX (VMX-only because SVM doesn't support per-bit controls) - Add CR0/CR4 helpers to query single bits, and clean up related code where KVM was interpreting kvm_read_cr4_bits()'s "unsigned long" return as a bool - Move AMD_PSFD to cpufeatures.h and purge KVM's definition - Avoid unnecessary writes+flushes when the guest is only adding new PTEs - Overhaul .sync_page() and .invlpg() to utilize .sync_page()'s optimizations when emulating invalidations - Clean up the range-based flushing APIs - Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a single A/D bit using a LOCK AND instead of XCHG, and skip all of the "handle changed SPTE" overhead associated with writing the entire entry - Track the number of "tail" entries in a pte_list_desc to avoid having to walk (potentially) all descriptors during insertion and deletion, which gets quite expensive if the guest is spamming fork() - Disallow virtualizing legacy LBRs if architectural LBRs are available, the two are mutually exclusive in hardware - Disallow writes to immutable feature MSRs (notably PERF_CAPABILITIES) after KVM_RUN, similar to CPUID features - Overhaul the vmx_pmu_caps selftest to better validate PERF_CAPABILITIES - Apply PMU filters to emulated events and add test coverage to the pmu_event_filter selftest - AMD SVM: - Add support for virtual NMIs - Fixes for edge cases related to virtual interrupts - Intel AMX: - Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if XTILE_DATA is not being reported due to userspace not opting in via prctl() - Fix a bug in emulation of ENCLS in compatibility mode - Allow emulation of NOP and PAUSE for L2 - AMX selftests improvements - Misc cleanups MIPS: - Constify MIPS's internal callbacks (a leftover from the hardware enabling rework that landed in 6.3) Generic: - Drop unnecessary casts from "void *" throughout kvm_main.c - Tweak the layout of "struct kvm_mmu_memory_cache" to shrink the struct size by 8 bytes on 64-bit kernels by utilizing a padding hole Documentation: - Fix goof introduced by the conversion to rST" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (211 commits) KVM: s390: pci: fix virtual-physical confusion on module unload/load KVM: s390: vsie: clarifications on setting the APCB KVM: s390: interrupt: fix virtual-physical confusion for next alert GISA KVM: arm64: Have kvm_psci_vcpu_on() use WRITE_ONCE() to update mp_state KVM: arm64: Acquire mp_state_lock in kvm_arch_vcpu_ioctl_vcpu_init() KVM: selftests: Test the PMU event "Instructions retired" KVM: selftests: Copy full counter values from guest in PMU event filter test KVM: selftests: Use error codes to signal errors in PMU event filter test KVM: selftests: Print detailed info in PMU event filter asserts KVM: selftests: Add helpers for PMC asserts in PMU event filter test KVM: selftests: Add a common helper for the PMU event filter guest code KVM: selftests: Fix spelling mistake "perrmited" -> "permitted" KVM: arm64: vhe: Drop extra isb() on guest exit KVM: arm64: vhe: Synchronise with page table walker on MMU update KVM: arm64: pkvm: Document the side effects of kvm_flush_dcache_to_poc() KVM: arm64: nvhe: Synchronise with page table walker on TLBI KVM: arm64: Handle 32bit CNTPCTSS traps KVM: arm64: nvhe: Synchronise with page table walker on vcpu run KVM: arm64: vgic: Don't acquire its_lock before config_lock KVM: selftests: Add test to verify KVM's supported XCR0 ...
2023-04-28Merge tag 'smp-core-2023-04-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP cross-CPU function-call updates from Ingo Molnar: - Remove diagnostics and adjust config for CSD lock diagnostics - Add a generic IPI-sending tracepoint, as currently there's no easy way to instrument IPI origins: it's arch dependent and for some major architectures it's not even consistently available. * tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: trace,smp: Trace all smp_function_call*() invocations trace: Add trace_ipi_send_cpu() sched, smp: Trace smp callback causing an IPI smp: reword smp call IPI comment treewide: Trace IPIs sent via smp_send_reschedule() irq_work: Trace self-IPIs sent via arch_irq_work_raise() smp: Trace IPIs sent via arch_send_call_function_ipi_mask() sched, smp: Trace IPIs sent via send_call_function_single_ipi() trace: Add trace_ipi_send_cpumask() kernel/smp: Make csdlock_debug= resettable locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging locking/csd_lock: Remove added data from CSD lock debugging locking/csd_lock: Add Kconfig option for csd_debug default
2023-03-31KVM: PPC: Make KVM_CAP_IRQFD_RESAMPLE platform dependentAlexey Kardashevskiy
When introduced, IRQFD resampling worked on POWER8 with XICS. However KVM on POWER9 has never implemented it - the compatibility mode code ("XICS-on-XIVE") misses the kvm_notify_acked_irq() call and the native XIVE mode does not handle INTx in KVM at all. This moved the capability support advertising to platforms and stops advertising it on XIVE, i.e. POWER9 and later. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Anup Patel <anup@brainfault.org> Acked-by: Nicholas Piggin <npiggin@gmail.com> Message-Id: <20220504074807.3616813-1-aik@ozlabs.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-03-24KVM: Fix comments that refer to the non-existent install_new_memslots()Jun Miao
Fix stale comments that were left behind when install_new_memslots() was replaced by kvm_swap_active_memslots() as part of the scalable memslots rework. Fixes: a54d806688fe ("KVM: Keep memslots in tree-based structures instead of array-based ones") Signed-off-by: Jun Miao <jun.miao@intel.com> Link: https://lore.kernel.org/r/20230223052851.1054799-1-jun.miao@intel.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-03-24treewide: Trace IPIs sent via smp_send_reschedule()Valentin Schneider
To be able to trace invocations of smp_send_reschedule(), rename the arch-specific definitions of it to arch_smp_send_reschedule() and wrap it into an smp_send_reschedule() that contains a tracepoint. Changes to include the declaration of the tracepoint were driven by the following coccinelle script: @func_use@ @@ smp_send_reschedule(...); @include@ @@ #include <trace/events/ipi.h> @no_include depends on func_use && !include@ @@ #include <...> + + #include <trace/events/ipi.h> [csky bits] [riscv bits] Signed-off-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230307143558.294354-6-vschneid@redhat.com
2023-03-23kvm: kvm_main: Remove unnecessary (void*) conversionsLi kunyu
void * pointer assignment does not require a forced replacement. Signed-off-by: Li kunyu <kunyu@nfschina.com> Link: https://lore.kernel.org/r/20221213080236.3969-1-kunyu@nfschina.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-03-16KVM: Standardize on "int" return types instead of "long" in kvm_main.cThomas Huth
KVM functions use "long" return values for functions that are wired up to "struct file_operations", but otherwise use "int" return values for functions that can return 0/-errno in order to avoid unintentional divergences between 32-bit and 64-bit kernels. Some code still uses "long" in unnecessary spots, though, which can cause a little bit of confusion and unnecessary size casts. Let's change these spots to use "int" types, too. Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20230208140105.655814-6-thuth@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-24Merge branch 'kvm-v6.2-rc4-fixes' into HEADPaolo Bonzini
ARM: * Fix the PMCR_EL0 reset value after the PMU rework * Correctly handle S2 fault triggered by a S1 page table walk by not always classifying it as a write, as this breaks on R/O memslots * Document why we cannot exit with KVM_EXIT_MMIO when taking a write fault from a S1 PTW on a R/O memslot * Put the Apple M2 on the naughty list for not being able to correctly implement the vgic SEIS feature, just like the M1 before it * Reviewer updates: Alex is stepping down, replaced by Zenghui x86: * Fix various rare locking issues in Xen emulation and teach lockdep to detect them * Documentation improvements * Do not return host topology information from KVM_GET_SUPPORTED_CPUID
2023-01-11KVM: Ensure lockdep knows about kvm->lock vs. vcpu->mutex ordering ruleDavid Woodhouse
Documentation/virt/kvm/locking.rst tells us that kvm->lock is taken outside vcpu->mutex. But that doesn't actually happen very often; it's only in some esoteric cases like migration with AMD SEV. This means that lockdep usually doesn't notice, and doesn't do its job of keeping us honest. Ensure that lockdep *always* knows about the ordering of these two locks, by briefly taking vcpu->mutex in kvm_vm_ioctl_create_vcpu() while kvm->lock is held. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20230111180651.14394-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Clean up error labels in kvm_init()Sean Christopherson
Convert the last two "out" lables to "err" labels now that the dust has settled, i.e. now that there are no more planned changes to the order of things in kvm_init(). Use "err" instead of "out" as it's easier to describe what failed than it is to describe what needs to be unwound, e.g. if allocating a per-CPU kick mask fails, KVM needs to free any masks that were allocated, and of course needs to unwind previous operations. Reported-by: Chao Gao <chao.gao@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-51-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Opt out of generic hardware enabling on s390 and PPCSean Christopherson
Allow architectures to opt out of the generic hardware enabling logic, and opt out on both s390 and PPC, which don't need to manually enable virtualization as it's always on (when available). In addition to letting s390 and PPC drop a bit of dead code, this will hopefully also allow ARM to clean up its related code, e.g. ARM has its own per-CPU flag to track which CPUs have enable hardware due to the need to keep hardware enabled indefinitely when pKVM is enabled. Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Anup Patel <anup@brainfault.org> Message-Id: <20221130230934.1014142-50-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Register syscore (suspend/resume) ops early in kvm_init()Sean Christopherson
Register the suspend/resume notifier hooks at the same time KVM registers its reboot notifier so that all the code in kvm_init() that deals with enabling/disabling hardware is bundled together. Opportunstically move KVM's implementations to reside near the reboot notifier code for the same reason. Bunching the code together will allow architectures to opt out of KVM's generic hardware enable/disable logic with minimal #ifdeffery. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-49-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Make hardware_enable_failed a local variable in the "enable all" pathIsaku Yamahata
Rework detecting hardware enabling errors to use a local variable in the "enable all" path to track whether or not enabling was successful across all CPUs. Using a global variable complicates paths that enable hardware only on the current CPU, e.g. kvm_resume() and kvm_online_cpu(). Opportunistically add a WARN if hardware enabling fails during kvm_resume(), KVM is all kinds of hosed if CPU0 fails to enable hardware. The WARN is largely futile in the current code, as KVM BUG()s on spurious faults on VMX instructions, e.g. attempting to run a vCPU on CPU if hardware enabling fails will explode. ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/x86.c:508! invalid opcode: 0000 [#1] SMP CPU: 3 PID: 1009 Comm: CPU 4/KVM Not tainted 6.1.0-rc1+ #11 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_spurious_fault+0xa/0x10 Call Trace: vmx_vcpu_load_vmcs+0x192/0x230 [kvm_intel] vmx_vcpu_load+0x16/0x60 [kvm_intel] kvm_arch_vcpu_load+0x32/0x1f0 vcpu_load+0x2f/0x40 kvm_arch_vcpu_ioctl_run+0x19/0x9d0 kvm_vcpu_ioctl+0x271/0x660 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x2b/0x50 entry_SYSCALL_64_after_hwframe+0x46/0xb0 But, the WARN may provide a breadcrumb to understand what went awry, and someday KVM may fix one or both of those bugs, e.g. by finding a way to eat spurious faults no matter the context (easier said than done due to side effects of certain operations, e.g. Intel's VMCLEAR). Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> [sean: rebase, WARN on failure in kvm_resume()] Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-48-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Use a per-CPU variable to track which CPUs have enabled virtualizationSean Christopherson
Use a per-CPU variable instead of a shared bitmap to track which CPUs have successfully enabled virtualization hardware. Using a per-CPU bool avoids the need for an additional allocation, and arguably yields easier to read code. Using a bitmap would be advantageous if KVM used it to avoid generating IPIs to CPUs that failed to enable hardware, but that's an extreme edge case and not worth optimizing, and the low level helpers would still want to keep their individual checks as attempting to enable virtualization hardware when it's already enabled can be problematic, e.g. Intel's VMXON will fault. Opportunistically change the order in hardware_enable_nolock() to set the flag if and only if hardware enabling is successful, instead of speculatively setting the flag and then clearing it on failure. Add a comment explaining that the check in hardware_disable_nolock() isn't simply paranoia. Waaay back when, commit 1b6c016818a5 ("KVM: Keep track of which cpus have virtualization enabled"), added the logic as a guards against CPU hotplug racing with hardware enable/disable. Now that KVM has eliminated the race by taking cpu_hotplug_lock for read (via cpus_read_lock()) when enabling or disabling hardware, at first glance it appears that the check is now superfluous, i.e. it's tempting to remove the per-CPU flag entirely... Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-47-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Remove on_each_cpu(hardware_disable_nolock) in kvm_exit()Isaku Yamahata
Drop the superfluous invocation of hardware_disable_nolock() during kvm_exit(), as it's nothing more than a glorified nop. KVM automatically disables hardware on all CPUs when the last VM is destroyed, and kvm_exit() cannot be called until the last VM goes away as the calling module is pinned by an elevated refcount of the fops associated with /dev/kvm. This holds true even on x86, where the caller of kvm_exit() is not kvm.ko, but is instead a dependent module, kvm_amd.ko or kvm_intel.ko, as kvm_chardev_ops.owner is set to the module that calls kvm_init(), not hardcoded to the base kvm.ko module. Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> [sean: rework changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-46-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lockIsaku Yamahata
Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock now that KVM hooks CPU hotplug during the ONLINE phase, which can sleep. Previously, KVM hooked the STARTING phase, which is not allowed to sleep and thus could not take kvm_lock (a mutex). This effectively allows the task that's initiating hardware enabling/disabling to preempted and/or migrated. Note, the Documentation/virt/kvm/locking.rst statement that kvm_count_lock is "raw" because hardware enabling/disabling needs to be atomic with respect to migration is wrong on multiple fronts. First, while regular spinlocks can be preempted, the task holding the lock cannot be migrated. Second, preventing migration is not required. on_each_cpu() disables preemption, which ensures that cpus_hardware_enabled correctly reflects hardware state. The task may be preempted/migrated between bumping kvm_usage_count and invoking on_each_cpu(), but that's perfectly ok as kvm_usage_count is still protected, e.g. other tasks that call hardware_enable_all() will be blocked until the preempted/migrated owner exits its critical section. KVM does have lockless accesses to kvm_usage_count in the suspend/resume flows, but those are safe because all tasks must be frozen prior to suspending CPUs, and a task cannot be frozen while it holds one or more locks (userspace tasks are frozen via a fake signal). Preemption doesn't need to be explicitly disabled in the hotplug path. The hotplug thread is pinned to the CPU that's being hotplugged, and KVM only cares about having a stable CPU, i.e. to ensure hardware is enabled on the correct CPU. Lockep, i.e. check_preemption_disabled(), plays nice with this state too, as is_percpu_thread() is true for the hotplug thread. Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-45-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Ensure CPU is stable during low level hardware enable/disableSean Christopherson
Use the non-raw smp_processor_id() in the low hardware enable/disable helpers as KVM absolutely relies on the CPU being stable, e.g. KVM would end up with incorrect state if the task were migrated between accessing cpus_hardware_enabled and actually enabling/disabling hardware. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-44-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Disable CPU hotplug during hardware enabling/disablingChao Gao
Disable CPU hotplug when enabling/disabling hardware to prevent the corner case where if the following sequence occurs: 1. A hotplugged CPU marks itself online in cpu_online_mask 2. The hotplugged CPU enables interrupt before invoking KVM's ONLINE callback 3 hardware_{en,dis}able_all() is invoked on another CPU the hotplugged CPU will be included in on_each_cpu() and thus get sent through hardware_{en,dis}able_nolock() before kvm_online_cpu() is called. start_secondary { ... set_cpu_online(smp_processor_id(), true); <- 1 ... local_irq_enable(); <- 2 ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); <- 3 } KVM currently fudges around this race by keeping track of which CPUs have done hardware enabling (see commit 1b6c016818a5 "KVM: Keep track of which cpus have virtualization enabled"), but that's an inefficient, convoluted, and hacky solution. Signed-off-by: Chao Gao <chao.gao@intel.com> [sean: split to separate patch, write changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-43-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Rename and move CPUHP_AP_KVM_STARTING to ONLINE sectionChao Gao
The CPU STARTING section doesn't allow callbacks to fail. Move KVM's hotplug callback to ONLINE section so that it can abort onlining a CPU in certain cases to avoid potentially breaking VMs running on existing CPUs. For example, when KVM fails to enable hardware virtualization on the hotplugged CPU. Place KVM's hotplug state before CPUHP_AP_SCHED_WAIT_EMPTY as it ensures when offlining a CPU, all user tasks and non-pinned kernel tasks have left the CPU, i.e. there cannot be a vCPU task around. So, it is safe for KVM's CPU offline callback to disable hardware virtualization at that point. Likewise, KVM's online callback can enable hardware virtualization before any vCPU task gets a chance to run on hotplugged CPUs. Drop kvm_x86_check_processor_compatibility()'s WARN that IRQs are disabled, as the ONLINE section runs with IRQs disabled. The WARN wasn't intended to be a requirement, e.g. disabling preemption is sufficient, the IRQ thing was purely an aggressive sanity check since the helper was only ever invoked via SMP function call. Rename KVM's CPU hotplug callbacks accordingly. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chao Gao <chao.gao@intel.com> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Reviewed-by: Yuan Yao <yuan.yao@intel.com> [sean: drop WARN that IRQs are disabled] Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-42-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Drop kvm_arch_check_processor_compat() hookSean Christopherson
Drop kvm_arch_check_processor_compat() and its support code now that all architecture implementations are nops. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Eric Farman <farman@linux.ibm.com> # s390 Acked-by: Anup Patel <anup@brainfault.org> Reviewed-by: Kai Huang <kai.huang@intel.com> Message-Id: <20221130230934.1014142-33-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Drop kvm_arch_{init,exit}() hooksSean Christopherson
Drop kvm_arch_init() and kvm_arch_exit() now that all implementations are nops. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> # s390 Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Acked-by: Anup Patel <anup@brainfault.org> Message-Id: <20221130230934.1014142-30-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Drop arch hardware (un)setup hooksSean Christopherson
Drop kvm_arch_hardware_setup() and kvm_arch_hardware_unsetup() now that all implementations are nops. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> # s390 Acked-by: Anup Patel <anup@brainfault.org> Message-Id: <20221130230934.1014142-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Teardown VFIO ops earlier in kvm_exit()Sean Christopherson
Move the call to kvm_vfio_ops_exit() further up kvm_exit() to try and bring some amount of symmetry to the setup order in kvm_init(), and more importantly so that the arch hooks are invoked dead last by kvm_exit(). This will allow arch code to move away from the arch hooks without any change in ordering between arch code and common code in kvm_exit(). That kvm_vfio_ops_exit() is called last appears to be 100% arbitrary. It was bolted on after the fact by commit 571ee1b68598 ("kvm: vfio: fix unregister kvm_device_ops of vfio"). The nullified kvm_device_ops_table is also local to kvm_main.c and is used only when there are active VMs, so unless arch code is doing something truly bizarre, nullifying the table earlier in kvm_exit() is little more than a nop. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20221130230934.1014142-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Allocate cpus_hardware_enabled after arch hardware setupSean Christopherson
Allocate cpus_hardware_enabled after arch hardware setup so that arch "init" and "hardware setup" are called back-to-back and thus can be combined in a future patch. cpus_hardware_enabled is never used before kvm_create_vm(), i.e. doesn't have a dependency with hardware setup and only needs to be allocated before /dev/kvm is exposed to userspace. Free the object before the arch hooks are invoked to maintain symmetry, and so that arch code can move away from the hooks without having to worry about ordering changes. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Yuan Yao <yuan.yao@intel.com> Message-Id: <20221130230934.1014142-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Initialize IRQ FD after arch hardware setupSean Christopherson
Move initialization of KVM's IRQ FD workqueue below arch hardware setup as a step towards consolidating arch "init" and "hardware setup", and eventually towards dropping the hooks entirely. There is no dependency on the workqueue being created before hardware setup, the workqueue is used only when destroying VMs, i.e. only needs to be created before /dev/kvm is exposed to userspace. Move the destruction of the workqueue before the arch hooks to maintain symmetry, and so that arch code can move away from the hooks without having to worry about ordering changes. Reword the comment about kvm_irqfd_init() needing to come after kvm_arch_init() to call out that kvm_arch_init() must come before common KVM does _anything_, as x86 very subtly relies on that behavior to deal with multiple calls to kvm_init(), e.g. if userspace attempts to load kvm_amd.ko and kvm_intel.ko. Tag the code with a FIXME, as x86's subtle requirement is gross, and invoking an arch callback as the very first action in a helper that is called only from arch code is silly. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: Register /dev/kvm as the _very_ last thing during initializationSean Christopherson
Register /dev/kvm, i.e. expose KVM to userspace, only after all other setup has completed. Once /dev/kvm is exposed, userspace can start invoking KVM ioctls, creating VMs, etc... If userspace creates a VM before KVM is done with its configuration, bad things may happen, e.g. KVM will fail to properly migrate vCPU state if a VM is created before KVM has registered preemption notifiers. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM64: - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on (see merge commit 382b5b87a97d: "Fix a number of issues with MTE, such as races on the tags being initialised vs the PG_mte_tagged flag as well as the lack of support for VM_SHARED when KVM is involved. Patches from Catalin Marinas and Peter Collingbourne"). - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. s390: - Second batch of the lazy destroy patches - First batch of KVM changes for kernel virtual != physical address support - Removal of a unused function x86: - Allow compiling out SMM support - Cleanup and documentation of SMM state save area format - Preserve interrupt shadow in SMM state save area - Respond to generic signals during slow page faults - Fixes and optimizations for the non-executable huge page errata fix. - Reprogram all performance counters on PMU filter change - Cleanups to Hyper-V emulation and tests - Process Hyper-V TLB flushes from a nested guest (i.e. from a L2 guest running on top of a L1 Hyper-V hypervisor) - Advertise several new Intel features - x86 Xen-for-KVM: - Allow the Xen runstate information to cross a page boundary - Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured - Add support for 32-bit guests in SCHEDOP_poll - Notable x86 fixes and cleanups: - One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). - Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. - Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. - Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. - Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. - Advertise (on AMD) that the SMM_CTL MSR is not supported - Remove unnecessary exports Generic: - Support for responding to signals during page faults; introduces new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks Selftests: - Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. - Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. - Introduce actual atomics for clear/set_bit() in selftests - Add support for pinning vCPUs in dirty_log_perf_test. - Rename the so called "perf_util" framework to "memstress". - Add a lightweight psuedo RNG for guest use, and use it to randomize the access pattern and write vs. read percentage in the memstress tests. - Add a common ucall implementation; code dedup and pre-work for running SEV (and beyond) guests in selftests. - Provide a common constructor and arch hook, which will eventually be used by x86 to automatically select the right hypercall (AMD vs. Intel). - A bunch of added/enabled/fixed selftests for ARM64, covering memslots, breakpoints, stage-2 faults and access tracking. - x86-specific selftest changes: - Clean up x86's page table management. - Clean up and enhance the "smaller maxphyaddr" test, and add a related test to cover generic emulation failure. - Clean up the nEPT support checks. - Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values. - Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). Documentation: - Remove deleted ioctls from documentation - Clean up the docs for the x86 MSR filter. - Various fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits) KVM: x86: Add proper ReST tables for userspace MSR exits/flags KVM: selftests: Allocate ucall pool from MEM_REGION_DATA KVM: arm64: selftests: Align VA space allocator with TTBR0 KVM: arm64: Fix benign bug with incorrect use of VA_BITS KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow KVM: x86: Advertise that the SMM_CTL MSR is not supported KVM: x86: remove unnecessary exports KVM: selftests: Fix spelling mistake "probabalistic" -> "probabilistic" tools: KVM: selftests: Convert clear/set_bit() to actual atomics tools: Drop "atomic_" prefix from atomic test_and_set_bit() tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests perf tools: Use dedicated non-atomic clear/set bit helpers tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers KVM: arm64: selftests: Enable single-step without a "full" ucall() KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself KVM: Remove stale comment about KVM_REQ_UNHALT KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR KVM: Reference to kvm_userspace_memory_region in doc and comments KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl ...
2022-12-12Merge remote-tracking branch 'kvm/queue' into HEADPaolo Bonzini
x86 Xen-for-KVM: * Allow the Xen runstate information to cross a page boundary * Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured * add support for 32-bit guests in SCHEDOP_poll x86 fixes: * One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). * Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. * Clean up the MSR filter docs. * Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. * Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. * Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. * Advertise (on AMD) that the SMM_CTL MSR is not supported * Remove unnecessary exports Selftests: * Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. * Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). * Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. * Introduce actual atomics for clear/set_bit() in selftests Documentation: * Remove deleted ioctls from documentation * Various fixes
2022-12-09Merge tag 'kvmarm-6.2' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.2 - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on. - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Add/Enable/Fix a bunch of selftests covering memslots, breakpoints, stage-2 faults and access tracking. You name it, we got it, we probably broke it. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. As a side effect, this tag also drags: - The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring series - A shared branch with the arm64 tree that repaints all the system registers to match the ARM ARM's naming, and resulting in interesting conflicts
2022-12-05Merge branch kvm-arm64/dirty-ring into kvmarm-master/nextMarc Zyngier
* kvm-arm64/dirty-ring: : . : Add support for the "per-vcpu dirty-ring tracking with a bitmap : and sprinkles on top", courtesy of Gavin Shan. : : This branch drags the kvmarm-fixes-6.1-3 tag which was already : merged in 6.1-rc4 so that the branch is in a working state. : . KVM: Push dirty information unconditionally to backup bitmap KVM: selftests: Automate choosing dirty ring size in dirty_log_test KVM: selftests: Clear dirty ring states between two modes in dirty_log_test KVM: selftests: Use host page size to map ring buffer in dirty_log_test KVM: arm64: Enable ring-based dirty memory tracking KVM: Support dirty ring in conjunction with bitmap KVM: Move declaration of kvm_cpu_dirty_log_size() to kvm_dirty_ring.h KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-12-02KVM: Remove stale comment about KVM_REQ_UNHALTSean Christopherson
Remove a comment about KVM_REQ_UNHALT being set by kvm_vcpu_check_block() that was missed when KVM_REQ_UNHALT was dropped. Fixes: c59fb1275838 ("KVM: remove KVM_REQ_UNHALT") Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221201220433.31366-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: x86: avoid memslot check in NX hugepage recovery if it cannot succeedPaolo Bonzini
Since gfn_to_memslot() is relatively expensive, it helps to skip it if it the memslot cannot possibly have dirty logging enabled. In order to do this, add to struct kvm a counter of the number of log-page memslots. While the correct value can only be read with slots_lock taken, the NX recovery thread is content with using an approximate value. Therefore, the counter is an atomic_t. Based on https://lore.kernel.org/kvm/20221027200316.2221027-2-dmatlack@google.com/ by David Matlack. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: Obey kvm.halt_poll_ns in VMs not using KVM_CAP_HALT_POLLDavid Matlack
Obey kvm.halt_poll_ns in VMs not using KVM_CAP_HALT_POLL on every halt, rather than just sampling the module parameter when the VM is first created. This restore the original behavior of kvm.halt_poll_ns for VMs that have not opted into KVM_CAP_HALT_POLL. Notably, this change restores the ability for admins to disable or change the maximum halt-polling time system wide for VMs not using KVM_CAP_HALT_POLL. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Fixes: acd05785e48c ("kvm: add capability for halt polling") Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20221117001657.1067231-4-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: Avoid re-reading kvm->max_halt_poll_ns during halt-pollingDavid Matlack
Avoid re-reading kvm->max_halt_poll_ns multiple times during halt-polling except when it is explicitly useful, e.g. to check if the max time changed across a halt. kvm->max_halt_poll_ns can be changed at any time by userspace via KVM_CAP_HALT_POLL. This bug is unlikely to cause any serious side-effects. In the worst case one halt polls for shorter or longer than it should, and then is fixed up on the next halt. Furthmore, this is still possible since kvm->max_halt_poll_ns are not synchronized with halts. Fixes: acd05785e48c ("kvm: add capability for halt polling") Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20221117001657.1067231-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: Cap vcpu->halt_poll_ns before halting rather than afterDavid Matlack
Cap vcpu->halt_poll_ns based on the max halt polling time just before halting, rather than after the last halt. This arguably provides better accuracy if an admin disables halt polling in between halts, although the improvement is nominal. A side-effect of this change is that grow_halt_poll_ns() no longer needs to access vcpu->kvm->max_halt_poll_ns, which will be useful in a future commit where the max halt polling time can come from the module parameter halt_poll_ns instead. Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20221117001657.1067231-2-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-12KVM: Push dirty information unconditionally to backup bitmapGavin Shan
In mark_page_dirty_in_slot(), we bail out when no running vcpu exists and a running vcpu context is strictly required by architecture. It may cause backwards compatible issue. Currently, saving vgic/its tables is the only known case where no running vcpu context is expected. We may have other unknown cases where no running vcpu context exists and it's reported by the warning message and we bail out without pushing the dirty information to the backup bitmap. For this, the application is going to enable the backup bitmap for the unknown cases. However, the dirty information can't be pushed to the backup bitmap even though the backup bitmap is enabled for those unknown cases in the application, until the unknown cases are added to the allowed list of non-running vcpu context with extra code changes to the host kernel. In order to make the new application, where the backup bitmap has been enabled, to work with the unchanged host, we continue to push the dirty information to the backup bitmap instead of bailing out early. With the added check on 'memslot->dirty_bitmap' to mark_page_dirty_in_slot(), the kernel crash is avoided silently by the combined conditions: no running vcpu context, kvm_arch_allow_write_without_running_vcpu() returns 'true', and the backup bitmap (KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP) isn't enabled yet. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221112094322.21911-1-gshan@redhat.com
2022-11-10KVM: Support dirty ring in conjunction with bitmapGavin Shan
ARM64 needs to dirty memory outside of a VCPU context when VGIC/ITS is enabled. It's conflicting with that ring-based dirty page tracking always requires a running VCPU context. Introduce a new flavor of dirty ring that requires the use of both VCPU dirty rings and a dirty bitmap. The expectation is that for non-VCPU sources of dirty memory (such as the VGIC/ITS on arm64), KVM writes to the dirty bitmap. Userspace should scan the dirty bitmap before migrating the VM to the target. Use an additional capability to advertise this behavior. The newly added capability (KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP) can't be enabled before KVM_CAP_DIRTY_LOG_RING_ACQ_REL on ARM64. In this way, the newly added capability is treated as an extension of KVM_CAP_DIRTY_LOG_RING_ACQ_REL. Suggested-by: Marc Zyngier <maz@kernel.org> Suggested-by: Peter Xu <peterx@redhat.com> Co-developed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Gavin Shan <gshan@redhat.com> Acked-by: Peter Xu <peterx@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110104914.31280-4-gshan@redhat.com
2022-11-10KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULLGavin Shan
The VCPU isn't expected to be runnable when the dirty ring becomes soft full, until the dirty pages are harvested and the dirty ring is reset from userspace. So there is a check in each guest's entrace to see if the dirty ring is soft full or not. The VCPU is stopped from running if its dirty ring has been soft full. The similar check will be needed when the feature is going to be supported on ARM64. As Marc Zyngier suggested, a new event will avoid pointless overhead to check the size of the dirty ring ('vcpu->kvm->dirty_ring_size') in each guest's entrance. Add KVM_REQ_DIRTY_RING_SOFT_FULL. The event is raised when the dirty ring becomes soft full in kvm_dirty_ring_push(). The event is only cleared in the check, done in the newly added helper kvm_dirty_ring_check_request(). Since the VCPU is not runnable when the dirty ring becomes soft full, the KVM_REQ_DIRTY_RING_SOFT_FULL event is always set to prevent the VCPU from running until the dirty pages are harvested and the dirty ring is reset by userspace. kvm_dirty_ring_soft_full() becomes a private function with the newly added helper kvm_dirty_ring_check_request(). The alignment for the various event definitions in kvm_host.h is changed to tab character by the way. In order to avoid using 'container_of()', the argument @ring is replaced by @vcpu in kvm_dirty_ring_push(). Link: https://lore.kernel.org/kvmarm/87lerkwtm5.wl-maz@kernel.org Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110104914.31280-2-gshan@redhat.com
2022-11-09kvm: Add interruptible flag to __gfn_to_pfn_memslot()Peter Xu
Add a new "interruptible" flag showing that the caller is willing to be interrupted by signals during the __gfn_to_pfn_memslot() request. Wire it up with a FOLL_INTERRUPTIBLE flag that we've just introduced. This prepares KVM to be able to respond to SIGUSR1 (for QEMU that's the SIGIPI) even during e.g. handling an userfaultfd page fault. No functional change intended. Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221011195809.557016-4-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09kvm: Add KVM_PFN_ERR_SIGPENDINGPeter Xu
Add a new pfn error to show that we've got a pending signal to handle during hva_to_pfn_slow() procedure (of -EINTR retval). Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221011195809.557016-3-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-06Merge tag 'kvmarm-fixes-6.1-3' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD * Fix the pKVM stage-1 walker erronously using the stage-2 accessor * Correctly convert vcpu->kvm to a hyp pointer when generating an exception in a nVHE+MTE configuration * Check that KVM_CAP_DIRTY_LOG_* are valid before enabling them * Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE * Document the boot requirements for FGT when entering the kernel at EL1
2022-10-31KVM: Check KVM_CAP_DIRTY_LOG_{RING, RING_ACQ_REL} prior to enabling themGavin Shan
There are two capabilities related to ring-based dirty page tracking: KVM_CAP_DIRTY_LOG_RING and KVM_CAP_DIRTY_LOG_RING_ACQ_REL. Both are supported by x86. However, arm64 supports KVM_CAP_DIRTY_LOG_RING_ACQ_REL only when the feature is supported on arm64. The userspace doesn't have to enable the advertised capability, meaning KVM_CAP_DIRTY_LOG_RING can be enabled on arm64 by userspace and it's wrong. Fix it by double checking if the capability has been advertised prior to enabling it. It's rejected to enable the capability if it hasn't been advertised. Fixes: 17601bfed909 ("KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option") Reported-by: Sean Christopherson <seanjc@google.com> Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221031003621.164306-4-gshan@redhat.com
2022-10-27KVM: debugfs: Return retval of simple_attr_open() if it failsHou Wenlong
Although simple_attr_open() fails only with -ENOMEM with current code base, it would be nicer to return retval of simple_attr_open() directly in kvm_debugfs_open(). No functional change intended. Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com> Message-Id: <69d64d93accd1f33691b8a383ae555baee80f943.1665975828.git.houwenlong.hwl@antgroup.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-22kvm: Add support for arch compat vm ioctlsAlexander Graf
We will introduce the first architecture specific compat vm ioctl in the next patch. Add all necessary boilerplate to allow architectures to override compat vm ioctls when necessary. Signed-off-by: Alexander Graf <graf@amazon.com> Message-Id: <20221017184541.2658-2-graf@amazon.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-03Merge tag 'kvmarm-6.1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for v6.1 - Fixes for single-stepping in the presence of an async exception as well as the preservation of PSTATE.SS - Better handling of AArch32 ID registers on AArch64-only systems - Fixes for the dirty-ring API, allowing it to work on architectures with relaxed memory ordering - Advertise the new kvmarm mailing list - Various minor cleanups and spelling fixes
2022-09-29KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config optionMarc Zyngier
In order to differenciate between architectures that require no extra synchronisation when accessing the dirty ring and those who do, add a new capability (KVM_CAP_DIRTY_LOG_RING_ACQ_REL) that identify the latter sort. TSO architectures can obviously advertise both, while relaxed architectures must only advertise the ACQ_REL version. This requires some configuration symbol rejigging, with HAVE_KVM_DIRTY_RING being only indirectly selected by two top-level config symbols: - HAVE_KVM_DIRTY_RING_TSO for strongly ordered architectures (x86) - HAVE_KVM_DIRTY_RING_ACQ_REL for weakly ordered architectures (arm64) Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/r/20220926145120.27974-3-maz@kernel.org
2022-09-26KVM: remove KVM_REQ_UNHALTPaolo Bonzini
KVM_REQ_UNHALT is now unnecessary because it is replaced by the return value of kvm_vcpu_block/kvm_vcpu_halt. Remove it. No functional change intended. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Marc Zyngier <maz@kernel.org> Message-Id: <20220921003201.1441511-13-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-26KVM: fix memoryleak in kvm_init()Miaohe Lin
When alloc_cpumask_var_node() fails for a certain cpu, there might be some allocated cpumasks for percpu cpu_kick_mask. We should free these cpumasks or memoryleak will occur. Fixes: baff59ccdc65 ("KVM: Pre-allocate cpumasks for kvm_make_all_cpus_request_except()") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Link: https://lore.kernel.org/r/20220823063414.59778-1-linmiaohe@huawei.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-19KVM: Drop unnecessary initialization of "ops" in kvm_ioctl_create_device()Li kunyu
The variable is initialized but it is only used after its assignment. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Li kunyu <kunyu@nfschina.com> Message-Id: <20220819021535.483702-1-kunyu@nfschina.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-19KVM: Drop unnecessary initialization of "npages" in hva_to_pfn_slow()Li kunyu
The variable is initialized but it is only used after its assignment. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Li kunyu <kunyu@nfschina.com> Message-Id: <20220819022804.483914-1-kunyu@nfschina.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>