aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/xen
AgeCommit message (Collapse)Author
2020-09-09xen/xenbus: Fix granting of vmalloc'd memorySimon Leiner
[ Upstream commit d742db70033c745e410523e00522ee0cfe2aa416 ] On some architectures (like ARM), virt_to_gfn cannot be used for vmalloc'd memory because of its reliance on virt_to_phys. This patch introduces a check for vmalloc'd addresses and obtains the PFN using vmalloc_to_pfn in that case. Signed-off-by: Simon Leiner <simon@leiner.me> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20200825093153.35500-1-simon@leiner.me Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN ↵Thomas Gleixner
data pointer which contains XEN specific information. commit c330fb1ddc0a922f044989492b7fcca77ee1db46 upstream. handler data is meant for interrupt handlers and not for storing irq chip specific information as some devices require handler data to store internal per interrupt information, e.g. pinctrl/GPIO chained interrupt handlers. This obviously creates a conflict of interests and crashes the machine because the XEN pointer is overwritten by the driver pointer. As the XEN data is not handler specific it should be stored in irqdesc::irq_data::chip_data instead. A simple sed s/irq_[sg]et_handler_data/irq_[sg]et_chip_data/ cures that. Cc: stable@vger.kernel.org Reported-by: Roman Shaposhnik <roman@zededa.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Roman Shaposhnik <roman@zededa.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/87lfi2yckt.fsf@nanos.tec.linutronix.de Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26xen: don't reschedule in preemption off sectionsJuergen Gross
For support of long running hypercalls xen_maybe_preempt_hcall() is calling cond_resched() in case a hypercall marked as preemptible has been interrupted. Normally this is no problem, as only hypercalls done via some ioctl()s are marked to be preemptible. In rare cases when during such a preemptible hypercall an interrupt occurs and any softirq action is started from irq_exit(), a further hypercall issued by the softirq handler will be regarded to be preemptible, too. This might lead to rescheduling in spite of the softirq handler potentially having set preempt_disable(), leading to splats like: BUG: sleeping function called from invalid context at drivers/xen/preempt.c:37 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 20775, name: xl INFO: lockdep is turned off. CPU: 1 PID: 20775 Comm: xl Tainted: G D W 5.4.46-1_prgmr_debug.el7.x86_64 #1 Call Trace: <IRQ> dump_stack+0x8f/0xd0 ___might_sleep.cold.76+0xb2/0x103 xen_maybe_preempt_hcall+0x48/0x70 xen_do_hypervisor_callback+0x37/0x40 RIP: e030:xen_hypercall_xen_version+0xa/0x20 Code: ... RSP: e02b:ffffc900400dcc30 EFLAGS: 00000246 RAX: 000000000004000d RBX: 0000000000000200 RCX: ffffffff8100122a RDX: ffff88812e788000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff83ee3ad0 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: ffff8881824aa0b0 R13: 0000000865496000 R14: 0000000865496000 R15: ffff88815d040000 ? xen_hypercall_xen_version+0xa/0x20 ? xen_force_evtchn_callback+0x9/0x10 ? check_events+0x12/0x20 ? xen_restore_fl_direct+0x1f/0x20 ? _raw_spin_unlock_irqrestore+0x53/0x60 ? debug_dma_sync_single_for_cpu+0x91/0xc0 ? _raw_spin_unlock_irqrestore+0x53/0x60 ? xen_swiotlb_sync_single_for_cpu+0x3d/0x140 ? mlx4_en_process_rx_cq+0x6b6/0x1110 [mlx4_en] ? mlx4_en_poll_rx_cq+0x64/0x100 [mlx4_en] ? net_rx_action+0x151/0x4a0 ? __do_softirq+0xed/0x55b ? irq_exit+0xea/0x100 ? xen_evtchn_do_upcall+0x2c/0x40 ? xen_do_hypervisor_callback+0x29/0x40 </IRQ> ? xen_hypercall_domctl+0xa/0x20 ? xen_hypercall_domctl+0x8/0x20 ? privcmd_ioctl+0x221/0x990 [xen_privcmd] ? do_vfs_ioctl+0xa5/0x6f0 ? ksys_ioctl+0x60/0x90 ? trace_hardirqs_off_thunk+0x1a/0x20 ? __x64_sys_ioctl+0x16/0x20 ? do_syscall_64+0x62/0x250 ? entry_SYSCALL_64_after_hwframe+0x49/0xbe Fix that by testing preempt_count() before calling cond_resched(). In kernel 5.8 this can't happen any more due to the entry code rework (more than 100 patches, so not a candidate for backporting). The issue was introduced in kernel 4.3, so this patch should go into all stable kernels in [4.3 ... 5.7]. Reported-by: Sarah Newman <srn@prgmr.com> Fixes: 0fa2f5cb2b0ecd8 ("sched/preempt, xen: Use need_resched() instead of should_resched()") Cc: Sarah Newman <srn@prgmr.com> Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Chris Brannon <cmb@prgmr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-19xen/gntdev: Fix dmabuf import with non-zero sgt offsetOleksandr Andrushchenko
commit 5fa4e6f1c2d8c9a4e47e1931b42893172d388f2b upstream. It is possible that the scatter-gather table during dmabuf import has non-zero offset of the data, but user-space doesn't expect that. Fix this by failing the import, so user-space doesn't access wrong data. Fixes: bf8dc55b1358 ("xen/gntdev: Implement dma-buf import functionality") Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200813062113.11030-2-andr2000@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-19xen/balloon: make the balloon wait interruptibleRoger Pau Monne
commit 88a479ff6ef8af7f07e11593d58befc644244ff7 upstream. So it can be killed, or else processes can get hung indefinitely waiting for balloon pages. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200727091342.52325-3-roger.pau@citrix.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-19xen/balloon: fix accounting in alloc_xenballooned_pages error pathRoger Pau Monne
commit 1951fa33ec259abdf3497bfee7b63e7ddbb1a394 upstream. target_unpopulated is incremented with nr_pages at the start of the function, but the call to free_xenballooned_pages will only subtract pgno number of pages, and thus the rest need to be subtracted before returning or else accounting will be skewed. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200727091342.52325-2-roger.pau@citrix.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22xen/pvcalls-back: test for errors when calling backend_connect()Juergen Gross
commit c8d70a29d6bbc956013f3401f92a4431a9385a3c upstream. backend_connect() can fail, so switch the device to connected only if no error occurred. Fixes: 0a9c75c2c7258f2 ("xen/pvcalls: xenbus state handling") Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20200511074231.19794-1-jgross@suse.com Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02xen/xenbus: ensure xenbus_map_ring_valloc() returns proper grant statusJuergen Gross
[ Upstream commit 6b51fd3f65a22e3d1471b18a1d56247e246edd46 ] xenbus_map_ring_valloc() maps a ring page and returns the status of the used grant (0 meaning success). There are Xen hypervisors which might return the value 1 for the status of a failed grant mapping due to a bug. Some callers of xenbus_map_ring_valloc() test for errors by testing the returned status to be less than zero, resulting in no error detected and crashing later due to a not available ring page. Set the return value of xenbus_map_ring_valloc() to GNTST_general_error in case the grant status reported by Xen is greater than zero. This is part of XSA-316. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Wei Liu <wl@xen.org> Link: https://lore.kernel.org/r/20200326080358.1018-1-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25xenbus: req->err should be updated before req->stateDongli Zhang
[ Upstream commit 8130b9d5b5abf26f9927b487c15319a187775f34 ] This patch adds the barrier to guarantee that req->err is always updated before req->state. Otherwise, read_reply() would not return ERR_PTR(req->err) but req->body, when process_writes()->xb_write() is failed. Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Link: https://lore.kernel.org/r/20200303221423.21962-2-dongli.zhang@oracle.com Reviewed-by: Julien Grall <jgrall@amazon.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25xenbus: req->body should be updated before req->stateDongli Zhang
[ Upstream commit 1b6a51e86cce38cf4d48ce9c242120283ae2f603 ] The req->body should be updated before req->state is updated and the order should be guaranteed by a barrier. Otherwise, read_reply() might return req->body = NULL. Below is sample callstack when the issue is reproduced on purpose by reordering the updates of req->body and req->state and adding delay in code between updates of req->state and req->body. [ 22.356105] general protection fault: 0000 [#1] SMP PTI [ 22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6 [ 22.366727] Hardware name: Xen HVM domU, BIOS ... [ 22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60 ... ... [ 22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246 [ 22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000 [ 22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d [ 22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd [ 22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000 [ 22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000 [ 22.423726] FS: 0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000 [ 22.429898] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0 [ 22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 22.450342] Call Trace: [ 22.452509] simple_strtoull+0x27/0x70 [ 22.455572] xenbus_transaction_start+0x31/0x50 [ 22.459104] netback_changed+0x76c/0xcc1 [xen_netfront] [ 22.463279] ? find_watch+0x40/0x40 [ 22.466156] xenwatch_thread+0xb4/0x150 [ 22.469309] ? wait_woken+0x80/0x80 [ 22.472198] kthread+0x10e/0x130 [ 22.474925] ? kthread_park+0x80/0x80 [ 22.477946] ret_from_fork+0x35/0x40 [ 22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront [ 22.486783] ---[ end trace a9222030a747c3f7 ]--- [ 22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60 The virt_rmb() is added in the 'true' path of test_reply(). The "while" is changed to "do while" so that test_reply() is used as a read memory barrier. Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com Reviewed-by: Julien Grall <jgrall@amazon.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-28xen: Enable interrupts when calling _cond_resched()Thomas Gleixner
commit 8645e56a4ad6dcbf504872db7f14a2f67db88ef2 upstream. xen_maybe_preempt_hcall() is called from the exception entry point xen_do_hypervisor_callback with interrupts disabled. _cond_resched() evades the might_sleep() check in cond_resched() which would have caught that and schedule_debug() unfortunately lacks a check for irqs_disabled(). Enable interrupts around the call and use cond_resched() to catch future issues. Fixes: fdfd811ddde3 ("x86/xen: allow privcmd hypercalls to be preempted") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/878skypjrh.fsf@nanos.tec.linutronix.de Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11xen/balloon: Support xend-based toolstack take twoJuergen Gross
commit eda4eabf86fd6806eaabc23fb90dd056fdac037b upstream. Commit 3aa6c19d2f38be ("xen/balloon: Support xend-based toolstack") tried to fix a regression with running on rather ancient Xen versions. Unfortunately the fix was based on the assumption that xend would just use another Xenstore node, but in reality only some downstream versions of xend are doing that. The upstream xend does not write that Xenstore node at all, so the problem must be fixed in another way. The easiest way to achieve that is to fall back to the behavior before commit 96edd61dcf4436 ("xen/balloon: don't online new memory initially") in case the static memory maximum can't be read. This is achieved by setting static_max to the current number of memory pages known by the system resulting in target_diff becoming zero. Fixes: 3aa6c19d2f38be ("xen/balloon: Support xend-based toolstack") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: <stable@vger.kernel.org> # 4.13 Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-27net: add {READ|WRITE}_ONCE() annotations on ->rskq_accept_headEric Dumazet
[ Upstream commit 60b173ca3d1cd1782bd0096dc17298ec242f6fb1 ] reqsk_queue_empty() is called from inet_csk_listen_poll() while other cpus might write ->rskq_accept_head value. Use {READ|WRITE}_ONCE() to avoid compiler tricks and potential KCSAN splats. Fixes: fff1f3001cc5 ("tcp: add a spinlock to protect struct request_sock_queue") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27xen, cpu_hotplug: Prevent an out of bounds accessDan Carpenter
[ Upstream commit 201676095dda7e5b31a5e1d116d10fc22985075e ] The "cpu" variable comes from the sscanf() so Smatch marks it as untrusted data. We can't pass a higher value than "nr_cpu_ids" to cpu_possible() or it results in an out of bounds access. Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09xen/balloon: fix ballooned page accounting without hotplug enabledJuergen Gross
[ Upstream commit c673ec61ade89bf2f417960f986bc25671762efb ] When CONFIG_XEN_BALLOON_MEMORY_HOTPLUG is not defined reserve_additional_memory() will set balloon_stats.target_pages to a wrong value in case there are still some ballooned pages allocated via alloc_xenballooned_pages(). This will result in balloon_process() no longer be triggered when ballooned pages are freed in batches. Reported-by: Nicholas Tsirakis <niko.tsirakis@gmail.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31xen/gntdev: Use select for DMA_SHARED_BUFFERJason Gunthorpe
[ Upstream commit fa6614d8ef13c63aac52ad7c07c5e69ce4aba3dd ] DMA_SHARED_BUFFER can not be enabled by the user (it represents a library set in the kernel). The kconfig convention is to use select for such symbols so they are turned on implicitly when the user enables a kconfig that needs them. Otherwise the XEN_GNTDEV_DMABUF kconfig is overly difficult to enable. Fixes: 932d6562179e ("xen/gntdev: Add initial support for dma-buf UAPI") Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: xen-devel@lists.xenproject.org Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-17pvcalls-front: don't return error when the ring is fullStefano Stabellini
[ Upstream commit d90a1ca60a1eccb4383fe203c76223ab4c0799ed ] When the ring is full, size == array_size. It is not an error condition, so simply return 0 instead of an error. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05xen/pciback: Check dev_data before using itRoss Lagerwall
[ Upstream commit 1669907e3d1abfa3f7586e2d55dbbc117b5adba2 ] If pcistub_init_device fails, the release function will be called with dev_data set to NULL. Check it before using it to avoid a NULL pointer dereference. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01mm/memory_hotplug: make add_memory() take the device_hotplug_lockDavid Hildenbrand
[ Upstream commit 8df1d0e4a265f25dc1e7e7624ccdbcb4a6630c89 ] add_memory() currently does not take the device_hotplug_lock, however is aleady called under the lock from arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c to synchronize against CPU hot-remove and similar. In general, we should hold the device_hotplug_lock when adding memory to synchronize against online/offline request (e.g. from user space) - which already resulted in lock inversions due to device_lock() and mem_hotplug_lock - see 30467e0b3be ("mm, hotplug: fix concurrent memory hot-add deadlock"). add_memory()/add_memory_resource() will create memory block devices, so this really feels like the right thing to do. Holding the device_hotplug_lock makes sure that a memory block device can really only be accessed (e.g. via .online/.state) from user space, once the memory has been fully added to the system. The lock is not held yet in drivers/xen/balloon.c arch/powerpc/platforms/powernv/memtrace.c drivers/s390/char/sclp_cmd.c drivers/hv/hv_balloon.c So, let's either use the locked variants or take the lock. Don't export add_memory_resource(), as it once was exported to be used by XEN, which is never built as a module. If somebody requires it, we also have to export a locked variant (as device_hotplug_lock is never exported). Link: http://lkml.kernel.org/r/20180925091457.28651-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mathieu Malaterre <malat@debian.org> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11xen/pci: reserve MCFG areas earlierIgor Druzhinin
[ Upstream commit a4098bc6eed5e31e0391bcc068e61804c98138df ] If MCFG area is not reserved in E820, Xen by default will defer its usage until Dom0 registers it explicitly after ACPI parser recognizes it as a reserved resource in DSDT. Having it reserved in E820 is not mandatory according to "PCI Firmware Specification, rev 3.2" (par. 4.1.2) and firmware is free to keep a hole in E820 in that place. Xen doesn't know what exactly is inside this hole since it lacks full ACPI view of the platform therefore it's potentially harmful to access MCFG region without additional checks as some machines are known to provide inconsistent information on the size of the region. Now xen_mcfg_late() runs after acpi_init() which is too late as some basic PCI enumeration starts exactly there as well. Trying to register a device prior to MCFG reservation causes multiple problems with PCIe extended capability initializations in Xen (e.g. SR-IOV VF BAR sizing). There are no convenient hooks for us to subscribe to so register MCFG areas earlier upon the first invocation of xen_add_device(). It should be safe to do once since all the boot time buses must have their MCFG areas in MCFG table already and we don't support PCI bus hot-plug. Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11xen/xenbus: fix self-deadlock after killing user processJuergen Gross
commit a8fabb38525c51a094607768bac3ba46b3f4a9d5 upstream. In case a user process using xenbus has open transactions and is killed e.g. via ctrl-C the following cleanup of the allocated resources might result in a deadlock due to trying to end a transaction in the xenbus worker thread: [ 2551.474706] INFO: task xenbus:37 blocked for more than 120 seconds. [ 2551.492215] Tainted: P OE 5.0.0-29-generic #5 [ 2551.510263] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2551.528585] xenbus D 0 37 2 0x80000080 [ 2551.528590] Call Trace: [ 2551.528603] __schedule+0x2c0/0x870 [ 2551.528606] ? _cond_resched+0x19/0x40 [ 2551.528632] schedule+0x2c/0x70 [ 2551.528637] xs_talkv+0x1ec/0x2b0 [ 2551.528642] ? wait_woken+0x80/0x80 [ 2551.528645] xs_single+0x53/0x80 [ 2551.528648] xenbus_transaction_end+0x3b/0x70 [ 2551.528651] xenbus_file_free+0x5a/0x160 [ 2551.528654] xenbus_dev_queue_reply+0xc4/0x220 [ 2551.528657] xenbus_thread+0x7de/0x880 [ 2551.528660] ? wait_woken+0x80/0x80 [ 2551.528665] kthread+0x121/0x140 [ 2551.528667] ? xb_read+0x1d0/0x1d0 [ 2551.528670] ? kthread_park+0x90/0x90 [ 2551.528673] ret_from_fork+0x35/0x40 Fix this by doing the cleanup via a workqueue instead. Reported-by: James Dingwall <james@dingwall.me.uk> Fixes: fd8aa9095a95c ("xen: optimize xenbus driver for multiple concurrent xenstore accesses") Cc: <stable@vger.kernel.org> # 4.11 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25xen/pciback: remove set but not used variable 'old_state'YueHaibing
[ Upstream commit 09e088a4903bd0dd911b4f1732b250130cdaffed ] Fixes gcc '-Wunused-but-set-variable' warning: drivers/xen/xen-pciback/conf_space_capability.c: In function pm_ctrl_write: drivers/xen/xen-pciback/conf_space_capability.c:119:25: warning: variable old_state set but not used [-Wunused-but-set-variable] It is never used so can be removed. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06xen/swiotlb: fix condition for calling xen_destroy_contiguous_region()Juergen Gross
commit 50f6393f9654c561df4cdcf8e6cfba7260143601 upstream. The condition in xen_swiotlb_free_coherent() for deciding whether to call xen_destroy_contiguous_region() is wrong: in case the region to be freed is not contiguous calling xen_destroy_contiguous_region() is the wrong thing to do: it would result in inconsistent mappings of multiple PFNs to the same MFN. This will lead to various strange crashes or data corruption. Instead of calling xen_destroy_contiguous_region() in that case a warning should be issued as that situation should never occur. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26xen/events: fix binding user event channels to cpusJuergen Gross
commit bce5963bcb4f9934faa52be323994511d59fd13c upstream. When binding an interdomain event channel to a vcpu via IOCTL_EVTCHN_BIND_INTERDOMAIN not only the event channel needs to be bound, but the affinity of the associated IRQi must be changed, too. Otherwise the IRQ and the event channel won't be moved to another vcpu in case the original vcpu they were bound to is going offline. Cc: <stable@vger.kernel.org> # 4.13 Fixes: c48f64ab472389df ("xen-evtchn: Bind dyn evtchn:qemu-dm interrupt to next online VCPU") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26xen: let alloc_xenballooned_pages() fail if not enough memory freeJuergen Gross
commit a1078e821b605813b63bf6bca414a85f804d5c66 upstream. Instead of trying to allocate pages with GFP_USER in add_ballooned_pages() check the available free memory via si_mem_available(). GFP_USER is far less limiting memory exhaustion than the test via si_mem_available(). This will avoid dom0 running out of memory due to excessive foreign page mappings especially on ARM and on x86 in PVH mode, as those don't have a pre-ballooned area which can be used for foreign mappings. As the normal ballooning suffers from the same problem don't balloon down more than si_mem_available() pages in one iteration. At the same time limit the default maximum number of retries. This is part of XSA-300. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22xenbus: Avoid deadlock during suspend due to open transactionsRoss Lagerwall
[ Upstream commit d10e0cc113c9e1b64b5c6e3db37b5c839794f3df ] During a suspend/resume, the xenwatch thread waits for all outstanding xenstore requests and transactions to complete. This does not work correctly for transactions started by userspace because it waits for them to complete after freezing userspace threads which means the transactions have no way of completing, resulting in a deadlock. This is trivial to reproduce by running this script and then suspending the VM: import pyxs, time c = pyxs.client.Client(xen_bus_path="/dev/xen/xenbus") c.connect() c.transaction() time.sleep(3600) Even if this deadlock were resolved, misbehaving userspace should not prevent a VM from being migrated. So, instead of waiting for these transactions to complete before suspending, store the current generation id for each transaction when it is started. The global generation id is incremented during resume. If the caller commits the transaction and the generation id does not match the current generation id, return EAGAIN so that they try again. If the transaction was instead discarded, return OK since no changes were made anyway. This only affects users of the xenbus file interface. In-kernel users of xenbus are assumed to be well-behaved and complete all transactions before freezing. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-22xen/pvcalls: Remove set but not used variableYueHaibing
[ Upstream commit 41349672e3cbc2e8349831f21253509c3415aa2b ] Fixes gcc '-Wunused-but-set-variable' warning: drivers/xen/pvcalls-front.c: In function pvcalls_front_sendmsg: drivers/xen/pvcalls-front.c:543:25: warning: variable bedata set but not used [-Wunused-but-set-variable] drivers/xen/pvcalls-front.c: In function pvcalls_front_recvmsg: drivers/xen/pvcalls-front.c:638:25: warning: variable bedata set but not used [-Wunused-but-set-variable] They are never used since introduction. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-04xen/pciback: Don't disable PCI_COMMAND on PCI device reset.Konrad Rzeszutek Wilk
commit 7681f31ec9cdacab4fd10570be924f2cef6669ba upstream. There is no need for this at all. Worst it means that if the guest tries to write to BARs it could lead (on certain platforms) to PCI SERR errors. Please note that with af6fc858a35b90e89ea7a7ee58e66628c55c776b "xen-pciback: limit guest control of command register" a guest is still allowed to enable those control bits (safely), but is not allowed to disable them and that therefore a well behaved frontend which enables things before using them will still function correctly. This is done via an write to the configuration register 0x4 which triggers on the backend side: command_write \- pci_enable_device \- pci_enable_device_flags \- do_pci_enable_device \- pcibios_enable_device \-pci_enable_resourcess [which enables the PCI_COMMAND_MEMORY|PCI_COMMAND_IO] However guests (and drivers) which don't do this could cause problems, including the security issues which XSA-120 sought to address. Reported-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Juergen Gross <jgross@suse.com> Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-08fs: stream_open - opener for stream-like files so that read and write can ↵Kirill Smelkov
run simultaneously without deadlock [ Upstream commit 10dce8af34226d90fa56746a934f8da5dcdba3df ] Commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") added locking for file.f_pos access and in particular made concurrent read and write not possible - now both those functions take f_pos lock for the whole run, and so if e.g. a read is blocked waiting for data, write will deadlock waiting for that read to complete. This caused regression for stream-like files where previously read and write could run simultaneously, but after that patch could not do so anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes to /proc/xen/xenbus") which fixes such regression for particular case of /proc/xen/xenbus. The patch that added f_pos lock in 2014 did so to guarantee POSIX thread safety for read/write/lseek and added the locking to file descriptors of all regular files. In 2014 that thread-safety problem was not new as it was already discussed earlier in 2006. However even though 2006'th version of Linus's patch was adding f_pos locking "only for files that are marked seekable with FMODE_LSEEK (thus avoiding the stream-like objects like pipes and sockets)", the 2014 version - the one that actually made it into the tree as 9c225f2655e3 - is doing so irregardless of whether a file is seekable or not. See https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/ https://lwn.net/Articles/180387 https://lwn.net/Articles/180396 for historic context. The reason that it did so is, probably, that there are many files that are marked non-seekable, but e.g. their read implementation actually depends on knowing current position to correctly handle the read. Some examples: kernel/power/user.c snapshot_read fs/debugfs/file.c u32_array_read fs/fuse/control.c fuse_conn_waiting_read + ... drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read arch/s390/hypfs/inode.c hypfs_read_iter ... Despite that, many nonseekable_open users implement read and write with pure stream semantics - they don't depend on passed ppos at all. And for those cases where read could wait for something inside, it creates a situation similar to xenbus - the write could be never made to go until read is done, and read is waiting for some, potentially external, event, for potentially unbounded time -> deadlock. Besides xenbus, there are 14 such places in the kernel that I've found with semantic patch (see below): drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write() drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write() drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write() drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write() net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write() drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write() drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write() drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write() net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write() drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write() drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write() drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write() drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write() drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write() In addition to the cases above another regression caused by f_pos locking is that now FUSE filesystems that implement open with FOPEN_NONSEEKABLE flag, can no longer implement bidirectional stream-like files - for the same reason as above e.g. read can deadlock write locking on file.f_pos in the kernel. FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f715 ("fuse: implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and write routines not depending on current position at all, and with both read and write being potentially blocking operations: See https://github.com/libfuse/osspd https://lwn.net/Articles/308445 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510 Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as "somewhat pipe-like files ..." with read handler not using offset. However that test implements only read without write and cannot exercise the deadlock scenario: https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216 I've actually hit the read vs write deadlock for real while implementing my FUSE filesystem where there is /head/watch file, for which open creates separate bidirectional socket-like stream in between filesystem and its user with both read and write being later performed simultaneously. And there it is semantically not easy to split the stream into two separate read-only and write-only channels: https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169 Let's fix this regression. The plan is: 1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS - doing so would break many in-kernel nonseekable_open users which actually use ppos in read/write handlers. 2. Add stream_open() to kernel to open stream-like non-seekable file descriptors. Read and write on such file descriptors would never use nor change ppos. And with that property on stream-like files read and write will be running without taking f_pos lock - i.e. read and write could be running simultaneously. 3. With semantic patch search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. 4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via steam_open if that bit is present in filesystem open reply. It was tempting to change fs/fuse/ open handler to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. 5. Add stream_open and FOPEN_STREAM handling to stable kernels starting from v3.14+ (the kernel where 9c225f2655 first appeared). This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in their open handler and this way avoid the deadlock on all kernel versions. This should work because fs/fuse/ ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. This patch adds stream_open, converts /proc/xen/xenbus to it and adds semantic patch to automatically locate in-kernel places that are either required to be converted due to read vs write deadlock, or that are just safe to be converted because read and write do not use ppos and there are no other funky methods in file_operations. Regarding semantic patch I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05xen/gntdev: Do not destroy context while dma-bufs are in useOleksandr Andrushchenko
[ Upstream commit fa13e665e02874c0a5f4d06d6967ae34a6cb3d6a ] If there are exported DMA buffers which are still in use and grant device is closed by either normal user-space close or by a signal this leads to the grant device context to be destroyed, thus making it not possible to correctly destroy those exported buffers when they are returned back to gntdev and makes the module crash: [ 339.617540] [<ffff00000854c0d8>] dmabuf_exp_ops_release+0x40/0xa8 [ 339.617560] [<ffff00000867a6e8>] dma_buf_release+0x60/0x190 [ 339.617577] [<ffff0000082211f0>] __fput+0x88/0x1d0 [ 339.617589] [<ffff000008221394>] ____fput+0xc/0x18 [ 339.617607] [<ffff0000080ed4e4>] task_work_run+0x9c/0xc0 [ 339.617622] [<ffff000008089714>] do_notify_resume+0xfc/0x108 Fix this by referencing gntdev on each DMA buffer export and unreferencing on buffer release. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-27pvcalls-front: fix potential null dereferenceWen Yang
[ Upstream commit b4711098066f1cf808d4dc11a1a842860a3292fe ] static checker warning: drivers/xen/pvcalls-front.c:373 alloc_active_ring() error: we previously assumed 'map->active.ring' could be null (see line 357) drivers/xen/pvcalls-front.c 351 static int alloc_active_ring(struct sock_mapping *map) 352 { 353 void *bytes; 354 355 map->active.ring = (struct pvcalls_data_intf *) 356 get_zeroed_page(GFP_KERNEL); 357 if (!map->active.ring) ^^^^^^^^^^^^^^^^^ Check 358 goto out; 359 360 map->active.ring->ring_order = PVCALLS_RING_ORDER; 361 bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 362 PVCALLS_RING_ORDER); 363 if (!bytes) 364 goto out; 365 366 map->active.data.in = bytes; 367 map->active.data.out = bytes + 368 XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); 369 370 return 0; 371 372 out: --> 373 free_active_ring(map); ^^^ Add null check on map->active.ring before dereferencing it to avoid any NULL pointer dereferences. Fixes: 9f51c05dc41a ("pvcalls-front: Avoid get_free_pages(GFP_KERNEL) under spinlock") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: Juergen Gross <jgross@suse.com> CC: Stefano Stabellini <sstabellini@kernel.org> CC: Dan Carpenter <dan.carpenter@oracle.com> CC: xen-devel@lists.xenproject.org CC: linux-kernel@vger.kernel.org Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-27pvcalls-front: Avoid get_free_pages(GFP_KERNEL) under spinlockWen Yang
[ Upstream commit 9f51c05dc41a6d69423e3d03d18eb7ab22f9ec19 ] The problem is that we call this with a spin lock held. The call tree is: pvcalls_front_accept() holds bedata->socket_lock. -> create_active() -> __get_free_pages() uses GFP_KERNEL The create_active() function is only called from pvcalls_front_accept() with a spin_lock held, The allocation is not allowed to sleep and GFP_KERNEL is not sufficient. This issue was detected by using the Coccinelle software. v2: Add a function doing the allocations which is called outside the lock and passing the allocated data to create_active(). v3: Use the matching deallocators i.e., free_page() and free_pages(), respectively. v4: It would be better to pre-populate map (struct sock_mapping), rather than introducing one more new struct. v5: Since allocating the data outside of this call it should also be freed outside, when create_active() fails. Move kzalloc(sizeof(*map2), GFP_ATOMIC) outside spinlock and use GFP_KERNEL instead. v6: Drop the superfluous calls. Suggested-by: Juergen Gross <jgross@suse.com> Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Suggested-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Acked-by: Stefano Stabellini <sstabellini@kernel.org> CC: Julia Lawall <julia.lawall@lip6.fr> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: Juergen Gross <jgross@suse.com> CC: Stefano Stabellini <sstabellini@kernel.org> CC: xen-devel@lists.xenproject.org CC: linux-kernel@vger.kernel.org Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-27xen/pvcalls: remove set but not used variable 'intf'YueHaibing
[ Upstream commit 1f8ce09b36c41a026a37a24b20efa32000892a64 ] Fixes gcc '-Wunused-but-set-variable' warning: drivers/xen/pvcalls-back.c: In function 'pvcalls_sk_state_change': drivers/xen/pvcalls-back.c:286:28: warning: variable 'intf' set but not used [-Wunused-but-set-variable] It not used since e6587cdbd732 ("pvcalls-back: set -ENOTCONN in pvcalls_conn_back_read") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-27pvcalls-back: set -ENOTCONN in pvcalls_conn_back_readStefano Stabellini
[ Upstream commit e6587cdbd732eacb4c7ce592ed46f7bbcefb655f ] When a connection is closing we receive on pvcalls_sk_state_change notification. Instead of setting the connection as closed immediately (-ENOTCONN), let's read one more time from it: pvcalls_conn_back_read will set the connection as closed when necessary. That way, we avoid races between pvcalls_sk_state_change and pvcalls_back_ioworker. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-27pvcalls-front: properly allocate skStefano Stabellini
[ Upstream commit beee1fbe8f7d57d6ebaa5188f9f4db89c2077196 ] Don't use kzalloc: it ends up leaving sk->sk_prot not properly initialized. Use sk_alloc instead and define our own trivial struct proto. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-27pvcalls-front: don't try to free unallocated ringsStefano Stabellini
[ Upstream commit 96283f9a084e23d7cda2d3c5d1ffa6df6cf1ecec ] inflight_req_id is 0 when initialized. If inflight_req_id is 0, there is no accept_map to free. Fix the check in pvcalls_front_release. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-27pvcalls-front: read all data before closing the connectionStefano Stabellini
[ Upstream commit b79470b64fa9266948d1ce8d825ced94c4f63293 ] When a connection is closing in_error is set to ENOTCONN. There could still be outstanding data on the ring left by the backend. Before closing the connection on the frontend side, drain the ring. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-22xen: Fix x86 sched_clock() interface for xenJuergen Gross
commit 867cefb4cb1012f42cada1c7d1f35ac8dd276071 upstream. Commit f94c8d11699759 ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface") broke Xen guest time handling across migration: [ 187.249951] Freezing user space processes ... (elapsed 0.001 seconds) done. [ 187.251137] OOM killer disabled. [ 187.251137] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 187.252299] suspending xenstore... [ 187.266987] xen:grant_table: Grant tables using version 1 layout [18446743811.706476] OOM killer enabled. [18446743811.706478] Restarting tasks ... done. [18446743811.720505] Setting capacity to 16777216 Fix that by setting xen_sched_clock_offset at resume time to ensure a monotonic clock value. [boris: replaced pr_info() with pr_info_once() in xen_callback_vector() to avoid printing with incorrect timestamp during resume (as we haven't re-adjusted the clock yet)] Fixes: f94c8d11699759 ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface") Cc: <stable@vger.kernel.org> # 4.11 Reported-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17pvcalls-front: fixes incorrect error handlingPan Bian
[ Upstream commit 975ef94a0284648fb0137bd5e949b18cef604e33 ] kfree() is incorrectly used to release the pages allocated by __get_free_page() and __get_free_pages(). Use the matching deallocators i.e., free_page() and free_pages(), respectively. Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-17Revert "xen/balloon: Mark unallocated host memory as UNUSABLE"Igor Druzhinin
[ Upstream commit 123664101aa2156d05251704fc63f9bcbf77741a ] This reverts commit b3cf8528bb21febb650a7ecbf080d0647be40b9f. That commit unintentionally broke Xen balloon memory hotplug with "hotplug_unpopulated" set to 1. As long as "System RAM" resource got assigned under a new "Unusable memory" resource in IO/Mem tree any attempt to online this memory would fail due to general kernel restrictions on having "System RAM" resources as 1st level only. The original issue that commit has tried to workaround fa564ad96366 ("x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)") also got amended by the following 03a551734 ("x86/PCI: Move and shrink AMD 64-bit window to avoid conflict") which made the original fix to Xen ballooning unnecessary. Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-17xen: xlate_mmu: add missing header to fix 'W=1' warningSrikanth Boddepalli
[ Upstream commit 72791ac854fea36034fa7976b748fde585008e78 ] Add a missing header otherwise compiler warns about missed prototype: drivers/xen/xlate_mmu.c:183:5: warning: no previous prototype for 'xen_xlate_unmap_gfn_range?' [-Wmissing-prototypes] int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma, ^~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Srikanth Boddepalli <boddepalli.srikanth@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-27xen/grant-table: Fix incorrect gnttab_dma_free_pages() pr_debug messageLiam Merwick
[ Upstream commit d9cccfa7c4d1d9ef967ec9308df7304a18609b30 ] If a call to xenmem_reservation_increase() in gnttab_dma_free_pages() fails it triggers a message "Failed to decrease reservation..." which should be "Failed to increase reservation..." Fixes: 9bdc7304f536 ('xen/grant-table: Allow allocating buffers suitable for DMA') Reported-by: Ross Philipson <ross.philipson@oracle.com> Signed-off-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-13xen: remove size limit of privcmd-buf mapping interfaceJuergen Gross
commit 3941552aec1e04d63999988a057ae09a1c56ebeb upstream. Currently the size of hypercall buffers allocated via /dev/xen/hypercall is limited to a default of 64 memory pages. For live migration of guests this might be too small as the page dirty bitmask needs to be sized according to the size of the guest. This means migrating a 8GB sized guest is already exhausting the default buffer size for the dirty bitmap. There is no sensible way to set a sane limit, so just remove it completely. The device node's usage is limited to root anyway, so there is no additional DOS scenario added by allowing unlimited buffers. While at it make the error path for the -ENOMEM case a little bit cleaner by setting n_pages to the number of successfully allocated pages instead of the target size. Fixes: c51b3c639e01f2 ("xen: add new hypercall buffer mapping device") Cc: <stable@vger.kernel.org> #4.18 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13xen/balloon: Support xend-based toolstackBoris Ostrovsky
commit 3aa6c19d2f38be9c6e9a8ad5fa8e3c9d29ee3c35 upstream. Xend-based toolstacks don't have static-max entry in xenstore. The equivalent node for those toolstacks is memory_static_max. Fixes: 5266b8e4445c (xen: fix booting ballooned down hvm guest) Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: <stable@vger.kernel.org> # 4.13 Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13xen-swiotlb: use actually allocated size on check physical continuousJoe Jin
commit 7250f422da0480d8512b756640f131b9b893ccda upstream. xen_swiotlb_{alloc,free}_coherent() allocate/free memory based on the order of the pages and not size argument (bytes). This is inconsistent with range_straddles_page_boundary and memset which use the 'size' value, which may lead to not exchanging memory with Xen (range_straddles_page_boundary() returned true). And then the call to xen_swiotlb_free_coherent() would actually try to exchange the memory with Xen, leading to the kernel hitting an BUG (as the hypercall returned an error). This patch fixes it by making the 'size' variable be of the same size as the amount of memory allocated. CC: stable@vger.kernel.org Signed-off-by: Joe Jin <joe.jin@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christoph Helwig <hch@lst.de> Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: John Sobecki <john.sobecki@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-19xen: issue warning message when out of grant maptrack entriesJuergen Gross
When a driver domain (e.g. dom0) is running out of maptrack entries it can't map any more foreign domain pages. Instead of silently stalling the affected domUs issue a rate limited warning in this case in order to make it easier to detect that situation. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-09-14xen/gntdev: fix up blockable calls to mn_invl_range_startMichal Hocko
Patch series "mmu_notifiers follow ups". Tetsuo has noticed some fallouts from 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers"). One of them has been fixed and picked up by AMD/DRM maintainer [1]. XEN issue is fixed by patch 1. I have also clarified expectations about blockable semantic of invalidate_range_end. Finally the last patch removes MMU_INVALIDATE_DOES_NOT_BLOCK which is no longer used nor needed. [1] http://lkml.kernel.org/r/20180824135257.GU29735@dhcp22.suse.cz This patch (of 3): 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers") has introduced blockable parameter to all mmu_notifiers and the notifier has to back off when called in !blockable case and it could block down the road. The above commit implemented that for mn_invl_range_start but both in_range checks are done unconditionally regardless of the blockable mode and as such they would fail all the time for regular calls. Fix this by checking blockable parameter as well. Once we are there we can remove the stale TODO. The lock has to be sleepable because we wait for completion down in gnttab_unmap_refs_sync. Link: http://lkml.kernel.org/r/20180827112623.8992-2-mhocko@kernel.org Fixes: 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers") Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-09-14xen: fix GCC warning and remove duplicate EVTCHN_ROW/EVTCHN_COL usageJosh Abraham
This patch removes duplicate macro useage in events_base.c. It also fixes gcc warning: variable ‘col’ set but not used [-Wunused-but-set-variable] Signed-off-by: Joshua Abraham <j.abraham1776@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-09-14xen: avoid crash in disable_hotplug_cpuOlaf Hering
The command 'xl vcpu-set 0 0', issued in dom0, will crash dom0: BUG: unable to handle kernel NULL pointer dereference at 00000000000002d8 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 7 PID: 65 Comm: xenwatch Not tainted 4.19.0-rc2-1.ga9462db-default #1 openSUSE Tumbleweed (unreleased) Hardware name: Intel Corporation S5520UR/S5520UR, BIOS S5500.86B.01.00.0050.050620101605 05/06/2010 RIP: e030:device_offline+0x9/0xb0 Code: 77 24 00 e9 ce fe ff ff 48 8b 13 e9 68 ff ff ff 48 8b 13 e9 29 ff ff ff 48 8b 13 e9 ea fe ff ff 90 66 66 66 66 90 41 54 55 53 <f6> 87 d8 02 00 00 01 0f 85 88 00 00 00 48 c7 c2 20 09 60 81 31 f6 RSP: e02b:ffffc90040f27e80 EFLAGS: 00010203 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8801f3800000 RSI: ffffc90040f27e70 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff820e47b3 R09: 0000000000000000 R10: 0000000000007ff0 R11: 0000000000000000 R12: ffffffff822e6d30 R13: dead000000000200 R14: dead000000000100 R15: ffffffff8158b4e0 FS: 00007ffa595158c0(0000) GS:ffff8801f39c0000(0000) knlGS:0000000000000000 CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000002d8 CR3: 00000001d9602000 CR4: 0000000000002660 Call Trace: handle_vcpu_hotplug_event+0xb5/0xc0 xenwatch_thread+0x80/0x140 ? wait_woken+0x80/0x80 kthread+0x112/0x130 ? kthread_create_worker_on_cpu+0x40/0x40 ret_from_fork+0x3a/0x50 This happens because handle_vcpu_hotplug_event is called twice. In the first iteration cpu_present is still true, in the second iteration cpu_present is false which causes get_cpu_device to return NULL. In case of cpu#0, cpu_online is apparently always true. Fix this crash by checking if the cpu can be hotplugged, which is false for a cpu that was just removed. Also check if the cpu was actually offlined by device_remove, otherwise leave the cpu_present state as it is. Rearrange to code to do all work with device_hotplug_lock held. Signed-off-by: Olaf Hering <olaf@aepfle.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-09-14xen/balloon: add runtime control for scrubbing ballooned out pagesMarek Marczykowski-Górecki
Scrubbing pages on initial balloon down can take some time, especially in nested virtualization case (nested EPT is slow). When HVM/PVH guest is started with memory= significantly lower than maxmem=, all the extra pages will be scrubbed before returning to Xen. But since most of them weren't used at all at that point, Xen needs to populate them first (from populate-on-demand pool). In nested virt case (Xen inside KVM) this slows down the guest boot by 15-30s with just 1.5GB needed to be returned to Xen. Add runtime parameter to enable/disable it, to allow initially disabling scrubbing, then enable it back during boot (for example in initramfs). Such usage relies on assumption that a) most pages ballooned out during initial boot weren't used at all, and b) even if they were, very few secrets are in the guest at that time (before any serious userspace kicks in). Convert CONFIG_XEN_SCRUB_PAGES to CONFIG_XEN_SCRUB_PAGES_DEFAULT (also enabled by default), controlling default value for the new runtime switch. Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-29 01:20:10 +0000