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* KVM: arm/arm64: Fix occasional warning from the timer work functionChristoffer Dall2017-12-091-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 63e41226afc3f7a044b70325566fa86ac3142538 ] When a VCPU blocks (WFI) and has programmed the vtimer, we program a soft timer to expire in the future to wake up the vcpu thread when appropriate. Because such as wake up involves a vcpu kick, and the timer expire function can get called from interrupt context, and the kick may sleep, we have to schedule the kick in the work function. The work function currently has a warning that gets raised if it turns out that the timer shouldn't fire when it's run, which was added because the idea was that in that case the work should never have been cancelled. However, it turns out that this whole thing is racy and we can get spurious warnings. The problem is that we clear the armed flag in the work function, which may run in parallel with the kvm_timer_unschedule->timer_disarm() call. This results in a possible situation where the timer_disarm() call does not call cancel_work_sync(), which effectively synchronizes the completion of the work function with running the VCPU. As a result, the VCPU thread proceeds before the work function completees, causing changes to the timer state such that kvm_timer_should_fire(vcpu) returns false in the work function. All we do in the work function is to kick the VCPU, and an occasional rare extra kick never harmed anyone. Since the race above is extremely rare, we don't bother checking if the race happens but simply remove the check and the clearing of the armed flag from the work function. Reported-by: Matthias Brugger <mbrugger@suse.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio: New external user group/file matchAlex Williamson2017-07-271-8/+19
| | | | | | | | | | | | | | | | | | | | commit 5d6dee80a1e94cc284d03e06d930e60e8d3ecf7d upstream. At the point where the kvm-vfio pseudo device wants to release its vfio group reference, we can't always acquire a new reference to make that happen. The group can be in a state where we wouldn't allow a new reference to be added. This new helper function allows a caller to match a file to a group to facilitate this. Given a file and group, report if they match. Thus the caller needs to already have a group reference to match to the file. This allows the deletion of a group without acquiring a new reference. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: kvm_io_bus_unregister_dev() should never failDavid Hildenbrand2017-04-082-18/+25
| | | | | | | | | | | | | | | | | | | | | | | | | commit 90db10434b163e46da413d34db8d0e77404cc645 upstream. No caller currently checks the return value of kvm_io_bus_unregister_dev(). This is evil, as all callers silently go on freeing their device. A stale reference will remain in the io_bus, getting at least used again, when the iobus gets teared down on kvm_destroy_vm() - leading to use after free errors. There is nothing the callers could do, except retrying over and over again. So let's simply remove the bus altogether, print an error and make sure no one can access this broken bus again (returning -ENOMEM on any attempt to access it). Fixes: e93f8a0f821e ("KVM: convert io_bus to SRCU") Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: clear bus pointer when destroyedPeter Xu2017-04-081-1/+11
| | | | | | | | | | | | | commit df630b8c1e851b5e265dc2ca9c87222e342c093b upstream. When releasing the bus, let's clear the bus pointers to mark it out. If any further device unregister happens on this bus, we know that we're done if we found the bus being released already. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: eventfd: fix NULL deref irqbypass consumerWanpeng Li2017-01-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4f3dbdf47e150016aacd734e663347fcaa768303 upstream. Reported syzkaller: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] PGD 0 Oops: 0002 [#1] SMP CPU: 1 PID: 125 Comm: kworker/1:1 Not tainted 4.9.0+ #1 Workqueue: kvm-irqfd-cleanup irqfd_shutdown [kvm] task: ffff9bbe0dfbb900 task.stack: ffffb61802014000 RIP: 0010:irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] Call Trace: irqfd_shutdown+0x66/0xa0 [kvm] process_one_work+0x16b/0x480 worker_thread+0x4b/0x500 kthread+0x101/0x140 ? process_one_work+0x480/0x480 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x25/0x30 RIP: irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] RSP: ffffb61802017e20 CR2: 0000000000000008 The syzkaller folks reported a NULL pointer dereference that due to unregister an consumer which fails registration before. The syzkaller creates two VMs w/ an equal eventfd occasionally. So the second VM fails to register an irqbypass consumer. It will make irqfd as inactive and queue an workqueue work to shutdown irqfd and unregister the irqbypass consumer when eventfd is closed. However, the second consumer has been initialized though it fails registration. So the token(same as the first VM's) is taken to unregister the consumer through the workqueue, the consumer of the first VM is found and unregistered, then NULL deref incurred in the path of deleting consumer from the consumers list. This patch fixes it by making irq_bypass_register/unregister_consumer() looks for the consumer entry based on consumer pointer itself instead of token matching. Reported-by: Dmitry Vyukov <dvyukov@google.com> Suggested-by: Alex Williamson <alex.williamson@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: nVMX: Fix memory corruption when using VMCS shadowingJim Mattson2016-08-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | | commit 2f1fe81123f59271bddda673b60116bde9660385 upstream. When freeing the nested resources of a vcpu, there is an assumption that the vcpu's vmcs01 is the current VMCS on the CPU that executes nested_release_vmcs12(). If this assumption is violated, the vcpu's vmcs01 may be made active on multiple CPUs at the same time, in violation of Intel's specification. Moreover, since the vcpu's vmcs01 is not VMCLEARed on every CPU on which it is active, it can linger in a CPU's VMCS cache after it has been freed and potentially repurposed. Subsequent eviction from the CPU's VMCS cache on a capacity miss can result in memory corruption. It is not sufficient for vmx_free_vcpu() to call vmx_load_vmcs01(). If the vcpu in question was last loaded on a different CPU, it must be migrated to the current CPU before calling vmx_load_vmcs01(). Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: Fix irq route entries exceeding KVM_MAX_IRQ_ROUTESXiubo Li2016-07-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit caf1ff26e1aa178133df68ac3d40815fed2187d9 upstream. These days, we experienced one guest crash with 8 cores and 3 disks, with qemu error logs as bellow: qemu-system-x86_64: /build/qemu-2.0.0/kvm-all.c:984: kvm_irqchip_commit_routes: Assertion `ret == 0' failed. And then we found one patch(bdf026317d) in qemu tree, which said could fix this bug. Execute the following script will reproduce the BUG quickly: irq_affinity.sh ======================================================================== vda_irq_num=25 vdb_irq_num=27 while [ 1 ] do for irq in {1,2,4,8,10,20,40,80} do echo $irq > /proc/irq/$vda_irq_num/smp_affinity echo $irq > /proc/irq/$vdb_irq_num/smp_affinity dd if=/dev/vda of=/dev/zero bs=4K count=100 iflag=direct dd if=/dev/vdb of=/dev/zero bs=4K count=100 iflag=direct done done ======================================================================== The following qemu log is added in the qemu code and is displayed when this bug reproduced: kvm_irqchip_commit_routes: max gsi: 1008, nr_allocated_irq_routes: 1024, irq_routes->nr: 1024, gsi_count: 1024. That's to say when irq_routes->nr == 1024, there are 1024 routing entries, but in the kernel code when routes->nr >= 1024, will just return -EINVAL; The nr is the number of the routing entries which is in of [1 ~ KVM_MAX_IRQ_ROUTES], not the index in [0 ~ KVM_MAX_IRQ_ROUTES - 1]. This patch fix the BUG above. Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com> Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com> Signed-off-by: Zhang Zhuoyu <zhangzhuoyu@cmss.chinamobile.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: irqfd: fix NULL pointer dereference in kvm_irq_map_gsiPaolo Bonzini2016-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c622a3c21ede892e370b56e1ceb9eb28f8bbda6b upstream. Found by syzkaller: BUG: unable to handle kernel NULL pointer dereference at 0000000000000120 IP: [<ffffffffa0797202>] kvm_irq_map_gsi+0x12/0x90 [kvm] PGD 6f80b067 PUD b6535067 PMD 0 Oops: 0000 [#1] SMP CPU: 3 PID: 4988 Comm: a.out Not tainted 4.4.9-300.fc23.x86_64 #1 [...] Call Trace: [<ffffffffa0795f62>] irqfd_update+0x32/0xc0 [kvm] [<ffffffffa0796c7c>] kvm_irqfd+0x3dc/0x5b0 [kvm] [<ffffffffa07943f4>] kvm_vm_ioctl+0x164/0x6f0 [kvm] [<ffffffff81241648>] do_vfs_ioctl+0x298/0x480 [<ffffffff812418a9>] SyS_ioctl+0x79/0x90 [<ffffffff817a1062>] tracesys_phase2+0x84/0x89 Code: b5 71 a7 e0 5b 41 5c 41 5d 5d f3 c3 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 8b 8f 10 2e 00 00 31 c0 48 89 e5 <39> 91 20 01 00 00 76 6a 48 63 d2 48 8b 94 d1 28 01 00 00 48 85 RIP [<ffffffffa0797202>] kvm_irq_map_gsi+0x12/0x90 [kvm] RSP <ffff8800926cbca8> CR2: 0000000000000120 Testcase: #include <unistd.h> #include <sys/syscall.h> #include <string.h> #include <stdint.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> long r[26]; int main() { memset(r, -1, sizeof(r)); r[2] = open("/dev/kvm", 0); r[3] = ioctl(r[2], KVM_CREATE_VM, 0); struct kvm_irqfd ifd; ifd.fd = syscall(SYS_eventfd2, 5, 0); ifd.gsi = 3; ifd.flags = 2; ifd.resamplefd = ifd.fd; r[25] = ioctl(r[3], KVM_IRQFD, &ifd); return 0; } Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: arm/arm64: Handle forward time correction gracefullyMarc Zyngier2016-05-041-10/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1c5631c73fc2261a5df64a72c155cb53dcdc0c45 upstream. On a host that runs NTP, corrections can have a direct impact on the background timer that we program on the behalf of a vcpu. In particular, NTP performing a forward correction will result in a timer expiring sooner than expected from a guest point of view. Not a big deal, we kick the vcpu anyway. But on wake-up, the vcpu thread is going to perform a check to find out whether or not it should block. And at that point, the timer check is going to say "timer has not expired yet, go back to sleep". This results in the timer event being lost forever. There are multiple ways to handle this. One would be record that the timer has expired and let kvm_cpu_has_pending_timer return true in that case, but that would be fairly invasive. Another is to check for the "short sleep" condition in the hrtimer callback, and restart the timer for the remaining time when the condition is detected. This patch implements the latter, with a bit of refactoring in order to avoid too much code duplication. Reported-by: Alexander Graf <agraf@suse.de> Reviewed-by: Alexander Graf <agraf@suse.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: fix spin_lock_init order on x86Paolo Bonzini2016-04-121-10/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e9ad4ec8379ad1ba6f68b8ca1c26b50b5ae0a327 upstream. Moving the initialization earlier is needed in 4.6 because kvm_arch_init_vm is now using mmu_lock, causing lockdep to complain: [ 284.440294] INFO: trying to register non-static key. [ 284.445259] the code is fine but needs lockdep annotation. [ 284.450736] turning off the locking correctness validator. ... [ 284.528318] [<ffffffff810aecc3>] lock_acquire+0xd3/0x240 [ 284.533733] [<ffffffffa0305aa0>] ? kvm_page_track_register_notifier+0x20/0x60 [kvm] [ 284.541467] [<ffffffff81715581>] _raw_spin_lock+0x41/0x80 [ 284.546960] [<ffffffffa0305aa0>] ? kvm_page_track_register_notifier+0x20/0x60 [kvm] [ 284.554707] [<ffffffffa0305aa0>] kvm_page_track_register_notifier+0x20/0x60 [kvm] [ 284.562281] [<ffffffffa02ece70>] kvm_mmu_init_vm+0x20/0x30 [kvm] [ 284.568381] [<ffffffffa02dbf7a>] kvm_arch_init_vm+0x1ea/0x200 [kvm] [ 284.574740] [<ffffffffa02bff3f>] kvm_dev_ioctl+0xbf/0x4d0 [kvm] However, it also helps fixing a preexisting problem, which is why this patch is also good for stable kernels: kvm_create_vm was incrementing current->mm->mm_count but not decrementing it at the out_err label (in case kvm_init_mmu_notifier failed). The new initialization order makes it possible to add the required mmdrop without adding a new error label. Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: cap halt polling at exactly halt_poll_nsDavid Matlack2016-03-161-0/+3
| | | | | | | | | | | | | | | | | | | | commit 313f636d5c490c9741d3f750dc8da33029edbc6b upstream. When growing halt-polling, there is no check that the poll time exceeds the limit. It's possible for vcpu->halt_poll_ns grow once past halt_poll_ns, and stay there until a halt which takes longer than vcpu->halt_poll_ns. For example, booting a Linux guest with halt_poll_ns=11000: ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 0 (shrink 10000) ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 10000 (grow 0) ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 20000 (grow 10000) Signed-off-by: David Matlack <dmatlack@google.com> Fixes: aca6ff29c4063a8d467cdee241e6b3bf7dc4a171 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: arm/arm64: vgic: Ensure bitmaps are long enoughMark Rutland2016-03-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 236cf17c2502007a9d2dda3c39fb0d9a6bd03cc2 upstream. When we allocate bitmaps in vgic_vcpu_init_maps, we divide the number of bits we need by 8 to figure out how many bytes to allocate. However, bitmap elements are always accessed as unsigned longs, and if we didn't happen to allocate a size such that size % sizeof(unsigned long) == 0, bitmap accesses may go past the end of the allocation. When using KASAN (which does byte-granular access checks), this results in a continuous stream of BUGs whenever these bitmaps are accessed: ============================================================================= BUG kmalloc-128 (Tainted: G B ): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in vgic_init.part.25+0x55c/0x990 age=7493 cpu=3 pid=1730 INFO: Slab 0xffffffbde6d5da40 objects=16 used=15 fp=0xffffffc935769700 flags=0x4000000000000080 INFO: Object 0xffffffc935769500 @offset=1280 fp=0x (null) Bytes b4 ffffffc9357694f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769510: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769520: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769530: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769540: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769550: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769560: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769570: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ CPU: 3 PID: 1740 Comm: kvm-vcpu-0 Tainted: G B 4.4.0+ #17 Hardware name: ARM Juno development board (r1) (DT) Call trace: [<ffffffc00008e770>] dump_backtrace+0x0/0x280 [<ffffffc00008ea04>] show_stack+0x14/0x20 [<ffffffc000726360>] dump_stack+0x100/0x188 [<ffffffc00030d324>] print_trailer+0xfc/0x168 [<ffffffc000312294>] object_err+0x3c/0x50 [<ffffffc0003140fc>] kasan_report_error+0x244/0x558 [<ffffffc000314548>] __asan_report_load8_noabort+0x48/0x50 [<ffffffc000745688>] __bitmap_or+0xc0/0xc8 [<ffffffc0000d9e44>] kvm_vgic_flush_hwstate+0x1bc/0x650 [<ffffffc0000c514c>] kvm_arch_vcpu_ioctl_run+0x2ec/0xa60 [<ffffffc0000b9a6c>] kvm_vcpu_ioctl+0x474/0xa68 [<ffffffc00036b7b0>] do_vfs_ioctl+0x5b8/0xcb0 [<ffffffc00036bf34>] SyS_ioctl+0x8c/0xa0 [<ffffffc000086cb0>] el0_svc_naked+0x24/0x28 Memory state around the buggy address: ffffffc935769400: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffffffc935769480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffffffc935769500: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffffffc935769580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffffffc935769600: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Fix the issue by always allocating a multiple of sizeof(unsigned long), as we do elsewhere in the vgic code. Fixes: c1bfb577a ("arm/arm64: KVM: vgic: switch to dynamic allocation") Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: async_pf: do not warn on page allocation failuresChristian Borntraeger2016-03-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d7444794a02ff655eda87e3cc54e86b940e7736f upstream. In async_pf we try to allocate with NOWAIT to get an element quickly or fail. This code also handle failures gracefully. Lets silence potential page allocation failures under load. qemu-system-s39: page allocation failure: order:0,mode:0x2200000 [...] Call Trace: ([<00000000001146b8>] show_trace+0xf8/0x148) [<000000000011476a>] show_stack+0x62/0xe8 [<00000000004a36b8>] dump_stack+0x70/0x98 [<0000000000272c3a>] warn_alloc_failed+0xd2/0x148 [<000000000027709e>] __alloc_pages_nodemask+0x94e/0xb38 [<00000000002cd36a>] new_slab+0x382/0x400 [<00000000002cf7ac>] ___slab_alloc.constprop.30+0x2dc/0x378 [<00000000002d03d0>] kmem_cache_alloc+0x160/0x1d0 [<0000000000133db4>] kvm_setup_async_pf+0x6c/0x198 [<000000000013dee8>] kvm_arch_vcpu_ioctl_run+0xd48/0xd58 [<000000000012fcaa>] kvm_vcpu_ioctl+0x372/0x690 [<00000000002f66f6>] do_vfs_ioctl+0x3be/0x510 [<00000000002f68ec>] SyS_ioctl+0xa4/0xb8 [<0000000000781c5e>] system_call+0xd6/0x264 [<000003ffa24fa06a>] 0x3ffa24fa06a Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: arm/arm64: Fix reference to uninitialised VGICAndre Przywara2016-02-251-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b3aff6ccbb1d25e506b60ccd9c559013903f3464 upstream. Commit 4b4b4512da2a ("arm/arm64: KVM: Rework the arch timer to use level-triggered semantics") brought the virtual architected timer closer to the VGIC. There is one occasion were we don't properly check for the VGIC actually having been initialized before, but instead go on to check the active state of some IRQ number. If userland hasn't instantiated a virtual GIC, we end up with a kernel NULL pointer dereference: ========= Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = ffffffc9745c5000 [00000000] *pgd=00000009f631e003, *pud=00000009f631e003, *pmd=0000000000000000 Internal error: Oops: 96000006 [#2] PREEMPT SMP Modules linked in: CPU: 0 PID: 2144 Comm: kvm_simplest-ar Tainted: G D 4.5.0-rc2+ #1300 Hardware name: ARM Juno development board (r1) (DT) task: ffffffc976da8000 ti: ffffffc976e28000 task.ti: ffffffc976e28000 PC is at vgic_bitmap_get_irq_val+0x78/0x90 LR is at kvm_vgic_map_is_active+0xac/0xc8 pc : [<ffffffc0000b7e28>] lr : [<ffffffc0000b972c>] pstate: 20000145 .... ========= Fix this by bailing out early of kvm_timer_flush_hwstate() if we don't have a VGIC at all. Reported-by: Cosmin Gorgovan <cosmin@linux-geek.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: arm/arm64: vgic: Fix kvm_vgic_map_is_active's dist checkChristoffer Dall2015-12-111-1/+1
| | | | | | | | | | | | | | | | | | External inputs to the vgic from time to time need to poke into the state of a virtual interrupt, the prime example is the architected timer code. Since the IRQ's active state can be represented in two places; the LR or the distributor, we first loop over the LRs but if not active in the LRs we just return if *any* IRQ is active on the VCPU in question. This is of course bogus, as we should check if the specific IRQ in quesiton is active on the distributor instead. Reported-by: Eric Auger <eric.auger@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm/arm64: vgic: Trust the LR state for HW IRQsChristoffer Dall2015-11-241-14/+2
| | | | | | | | | | | | | | | | We were probing the physial distributor state for the active state of a HW virtual IRQ, because we had seen evidence that the LR state was not cleared when the guest deactivated a virtual interrupted. However, this issue turned out to be a software bug in the GIC, which was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29 (KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active, 2015-11-24) Therefore, get rid of the complexities and just look at the LR. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.activeChristoffer Dall2015-11-242-23/+39
| | | | | | | | | | | | | | | | | We were incorrectly removing the active state from the physical distributor on the timer interrupt when the timer output level was deasserted. We shouldn't be doing this without considering the virtual interrupt's active state, because the architecture requires that when an LR has the HW bit set and the pending or active bits set, then the physical interrupt must also have the corresponding bits set. This addresses an issue where we have been observing an inconsistency between the LR state and the physical distributor state where the LR state was active and the physical distributor was not active, which shouldn't happen. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
* Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2015-11-0514-364/+681
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM updates from Paolo Bonzini: "First batch of KVM changes for 4.4. s390: A bunch of fixes and optimizations for interrupt and time handling. PPC: Mostly bug fixes. ARM: No big features, but many small fixes and prerequisites including: - a number of fixes for the arch-timer - introducing proper level-triggered semantics for the arch-timers - a series of patches to synchronously halt a guest (prerequisite for IRQ forwarding) - some tracepoint improvements - a tweak for the EL2 panic handlers - some more VGIC cleanups getting rid of redundant state x86: Quite a few changes: - support for VT-d posted interrupts (i.e. PCI devices can inject interrupts directly into vCPUs). This introduces a new component (in virt/lib/) that connects VFIO and KVM together. The same infrastructure will be used for ARM interrupt forwarding as well. - more Hyper-V features, though the main one Hyper-V synthetic interrupt controller will have to wait for 4.5. These will let KVM expose Hyper-V devices. - nested virtualization now supports VPID (same as PCID but for vCPUs) which makes it quite a bit faster - for future hardware that supports NVDIMM, there is support for clflushopt, clwb, pcommit - support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in userspace, which reduces the attack surface of the hypervisor - obligatory smattering of SMM fixes - on the guest side, stable scheduler clock support was rewritten to not require help from the hypervisor" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits) KVM: VMX: Fix commit which broke PML KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0() KVM: x86: allow RSM from 64-bit mode KVM: VMX: fix SMEP and SMAP without EPT KVM: x86: move kvm_set_irq_inatomic to legacy device assignment KVM: device assignment: remove pointless #ifdefs KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic KVM: x86: zero apic_arb_prio on reset drivers/hv: share Hyper-V SynIC constants with userspace KVM: x86: handle SMBASE as physical address in RSM KVM: x86: add read_phys to x86_emulate_ops KVM: x86: removing unused variable KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr() KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings KVM: arm/arm64: Optimize away redundant LR tracking KVM: s390: use simple switch statement as multiplexer KVM: s390: drop useless newline in debugging data KVM: s390: SCA must not cross page boundaries KVM: arm: Do not indent the arguments of DECLARE_BITMAP ...
| * KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomicPaolo Bonzini2015-11-041-7/+4
| | | | | | | | | | | | | | | | | | | | | | We do not want to do too much work in atomic context, in particular not walking all the VCPUs of the virtual machine. So we want to distinguish the architecture-specific injection function for irqfd from kvm_set_msi. Since it's still empty, reuse the newly added kvm_arch_set_irq and rename it to kvm_arch_set_irq_inatomic. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configsJan Beulich2015-11-041-1/+1
| | | | | | | | | | | | | | The symbol was missing a KVM dependency. Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * Merge tag 'kvm-arm-for-4.4' of ↵Paolo Bonzini2015-11-046-248/+331
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/ARM Changes for v4.4-rc1 Includes a number of fixes for the arch-timer, introducing proper level-triggered semantics for the arch-timers, a series of patches to synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups getting rid of redundant state, and finally a stylistic change that gets rid of some ctags warnings. Conflicts: arch/x86/include/asm/kvm_host.h
| | * KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()Pavel Fedin2015-11-043-22/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Now we see that vgic_set_lr() and vgic_sync_lr_elrsr() are always used together. Merge them into one function, saving from second vgic_ops dereferencing every time. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * KVM: arm/arm64: Clean up vgic_retire_lr() and surroundingsPavel Fedin2015-11-041-27/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. Remove unnecessary 'irq' argument, because irq number can be retrieved from the LR. 2. Since cff9211eb1a1f58ce7f5a2d596b617928fd4be0e ("arm/arm64: KVM: Fix arch timer behavior for disabled interrupts ") LR_STATE_PENDING is queued back by vgic_retire_lr() itself. Also, it clears vlr.state itself. Therefore, we remove the same, now duplicated, check with all accompanying bit manipulations from vgic_unqueue_irqs(). 3. vgic_retire_lr() is always accompanied by vgic_irq_clear_queued(). Since it already does more than just clearing the LR, move vgic_irq_clear_queued() inside of it. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * KVM: arm/arm64: Optimize away redundant LR trackingPavel Fedin2015-11-043-38/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we use vgic_irq_lr_map in order to track which LRs hold which IRQs, and lr_used bitmap in order to track which LRs are used or free. vgic_irq_lr_map is actually used only for piggy-back optimization, and can be easily replaced by iteration over lr_used. This is good because in future, when LPI support is introduced, number of IRQs will grow up to at least 16384, while numbers from 1024 to 8192 are never going to be used. This would be a huge memory waste. In its turn, lr_used is also completely redundant since ae705930fca6322600690df9dc1c7d0516145a93 ("arm/arm64: KVM: Keep elrsr/aisr in sync with software model"), because together with lr_used we also update elrsr. This allows to easily replace lr_used with elrsr, inverting all conditions (because in elrsr '1' means 'free'). Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * arm/arm64: KVM: Add tracepoints for vgic and timerChristoffer Dall2015-10-223-0/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The VGIC and timer code for KVM arm/arm64 doesn't have any tracepoints or tracepoint infrastructure defined. Rewriting some of the timer code handling showed me how much we need this, so let's add these simple trace points once and for all and we can easily expand with additional trace points in these files as we go along. Cc: Wei Huang <wei@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * arm/arm64: KVM: Support edge-triggered forwarded interruptsChristoffer Dall2015-10-221-18/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We mark edge-triggered interrupts with the HW bit set as queued to prevent the VGIC code from injecting LRs with both the Active and Pending bits set at the same time while also setting the HW bit, because the hardware does not support this. However, this means that we must also clear the queued flag when we sync back a LR where the state on the physical distributor went from active to inactive because the guest deactivated the interrupt. At this point we must also check if the interrupt is pending on the distributor, and tell the VGIC to queue it again if it is. Since these actions on the sync path are extremely close to those for level-triggered interrupts, rename process_level_irq to process_queued_irq, allowing it to cater for both cases. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * arm/arm64: KVM: Rework the arch timer to use level-triggered semanticsChristoffer Dall2015-10-222-101/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The arch timer currently uses edge-triggered semantics in the sense that the line is never sampled by the vgic and lowering the line from the timer to the vgic doesn't have any effect on the pending state of virtual interrupts in the vgic. This means that we do not support a guest with the otherwise valid behavior of (1) disable interrupts (2) enable the timer (3) disable the timer (4) enable interrupts. Such a guest would validly not expect to see any interrupts on real hardware, but will see interrupts on KVM. This patch fixes this shortcoming through the following series of changes. First, we change the flow of the timer/vgic sync/flush operations. Now the timer is always flushed/synced before the vgic, because the vgic samples the state of the timer output. This has the implication that we move the timer operations in to non-preempible sections, but that is fine after the previous commit getting rid of hrtimer schedules on every entry/exit. Second, we change the internal behavior of the timer, letting the timer keep track of its previous output state, and only lower/raise the line to the vgic when the state changes. Note that in theory this could have been accomplished more simply by signalling the vgic every time the state *potentially* changed, but we don't want to be hitting the vgic more often than necessary. Third, we get rid of the use of the map->active field in the vgic and instead simply set the interrupt as active on the physical distributor whenever the input to the GIC is asserted and conversely clear the physical active state when the input to the GIC is deasserted. Fourth, and finally, we now initialize the timer PPIs (and all the other unused PPIs for now), to be level-triggered, and modify the sync code to sample the line state on HW sync and re-inject a new interrupt if it is still pending at that time. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * arm/arm64: KVM: Use appropriate define in VGIC reset codeChristoffer Dall2015-10-221-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently initialize the SGIs to be enabled in the VGIC code, but we use the VGIC_NR_PPIS define for this purpose, instead of the the more natural VGIC_NR_SGIS. Change this slightly confusing use of the defines. Note: This should have no functional change, as both names are defined to the number 16. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * arm/arm64: KVM: Implement GICD_ICFGR as RO for PPIsChristoffer Dall2015-10-221-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The GICD_ICFGR allows the bits for the SGIs and PPIs to be read only. We currently simulate this behavior by writing a hardcoded value to the register for the SGIs and PPIs on every write of these bits to the register (ignoring what the guest actually wrote), and by writing the same value as the reset value to the register. This is a bit counter-intuitive, as the register is RO for these bits, and we can just implement it that way, allowing us to control the value of the bits purely in the reset code. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * arm/arm64: KVM: vgic: Factor out level irq processing on guest exitChristoffer Dall2015-10-221-38/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently vgic_process_maintenance() processes dealing with a completed level-triggered interrupt directly, but we are soon going to reuse this logic for level-triggered mapped interrupts with the HW bit set, so move this logic into a separate static function. Probably the most scary part of this commit is convincing yourself that the current flow is safe compared to the old one. In the following I try to list the changes and why they are harmless: Move vgic_irq_clear_queued after kvm_notify_acked_irq: Harmless because the only potential effect of clearing the queued flag wrt. kvm_set_irq is that vgic_update_irq_pending does not set the pending bit on the emulated CPU interface or in the pending_on_cpu bitmask if the function is called with level=1. However, the point of kvm_notify_acked_irq is to call kvm_set_irq with level=0, and we set the queued flag again in __kvm_vgic_sync_hwstate later on if the level is stil high. Move vgic_set_lr before kvm_notify_acked_irq: Also, harmless because the LR are cpu-local operations and kvm_notify_acked only affects the dist Move vgic_dist_irq_clear_soft_pend after kvm_notify_acked_irq: Also harmless, because now we check the level state in the clear_soft_pend function and lower the pending bits if the level is low. Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_blockChristoffer Dall2015-10-221-34/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently schedule a soft timer every time we exit the guest if the timer did not expire while running the guest. This is really not necessary, because the only work we do in the timer work function is to kick the vcpu. Kicking the vcpu does two things: (1) If the vpcu thread is on a waitqueue, make it runnable and remove it from the waitqueue. (2) If the vcpu is running on a different physical CPU from the one doing the kick, it sends a reschedule IPI. The second case cannot happen, because the soft timer is only ever scheduled when the vcpu is not running. The first case is only relevant when the vcpu thread is on a waitqueue, which is only the case when the vcpu thread has called kvm_vcpu_block(). Therefore, we only need to make sure a timer is scheduled for kvm_vcpu_block(), which we do by encapsulating all calls to kvm_vcpu_block() with kvm_timer_{un}schedule calls. Additionally, we only schedule a soft timer if the timer is enabled and unmasked, since it is useless otherwise. Note that theoretically userspace can use the SET_ONE_REG interface to change registers that should cause the timer to fire, even if the vcpu is blocked without a scheduled timer, but this case was not supported before this patch and we leave it for future work for now. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| | * KVM: Add kvm_arch_vcpu_{un}blocking callbacksChristoffer Dall2015-10-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some times it is useful for architecture implementations of KVM to know when the VCPU thread is about to block or when it comes back from blocking (arm/arm64 needs to know this to properly implement timers, for example). Therefore provide a generic architecture callback function in line with what we do elsewhere for KVM generic-arch interactions. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| * | kvm/irqchip: allow only multiple irqchip routes per GSIAndrey Smetanin2015-10-161-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Any other irq routing types (MSI, S390_ADAPTER, upcoming Hyper-V SynIC) map one-to-one to GSI. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm/eventfd: add arch-specific set_irqAndrey Smetanin2015-10-161-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow for arch-specific interrupt types to be set. For that, add kvm_arch_set_irq() which takes interrupt type-specific action if it recognizes the interrupt type given, and -EWOULDBLOCK otherwise. The default implementation always returns -EWOULDBLOCK. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm/eventfd: factor out kvm_notify_acked_gsi()Andrey Smetanin2015-10-161-5/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Factor out kvm_notify_acked_gsi() helper to iterate over EOI listeners and notify those matching the given gsi. It will be reused in the upcoming Hyper-V SynIC implementation. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm/eventfd: avoid loop inside irqfd_update()Andrey Smetanin2015-10-161-8/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The loop(for) inside irqfd_update() is unnecessary because any other value for irq_entry.type will just trigger schedule_work(&irqfd->inject) in irqfd_wakeup. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm: fix waitqueue_active without memory barrier in virt/kvm/async_pf.cKosuke Tatsukawa2015-10-141-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | async_pf_execute() seems to be missing a memory barrier which might cause the waker to not notice the waiter and miss sending a wake_up as in the following figure. async_pf_execute kvm_vcpu_block ------------------------------------------------------------------------ spin_lock(&vcpu->async_pf.lock); if (waitqueue_active(&vcpu->wq)) /* The CPU might reorder the test for the waitqueue up here, before prior writes complete */ prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE); /*if (kvm_vcpu_check_block(vcpu) < 0) */ /*if (kvm_arch_vcpu_runnable(vcpu)) { */ ... return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE && !vcpu->arch.apf.halted) || !list_empty_careful(&vcpu->async_pf.done) ... return 0; list_add_tail(&apf->link, &vcpu->async_pf.done); spin_unlock(&vcpu->async_pf.lock); waited = true; schedule(); ------------------------------------------------------------------------ The attached patch adds the missing memory barrier. I found this issue when I was looking through the linux source code for places calling waitqueue_active() before wake_up*(), but without preceding memory barriers, after sending a patch to fix a similar issue in drivers/tty/n_tty.c (Details about the original issue can be found here: https://lkml.org/lkml/2015/9/28/849). Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | KVM: Update Posted-Interrupts Descriptor when vCPU is blockedFeng Wu2015-10-011-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch updates the Posted-Interrupts Descriptor when vCPU is blocked. pre-block: - Add the vCPU to the blocked per-CPU list - Set 'NV' to POSTED_INTR_WAKEUP_VECTOR post-block: - Remove the vCPU from the per-CPU list Signed-off-by: Feng Wu <feng.wu@intel.com> [Concentrate invocation of pre/post-block hooks to vcpu_block. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | KVM: Add an arch specific hooks in 'struct kvm_kernel_irqfd'Feng Wu2015-10-011-1/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds an arch specific hooks 'arch_update' in 'struct kvm_kernel_irqfd'. On Intel side, it is used to update the IRTE when VT-d posted-interrupts is used. Signed-off-by: Feng Wu <feng.wu@intel.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | KVM: eventfd: add irq bypass consumer managementEric Auger2015-10-011-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the registration/unregistration of an irq_bypass_consumer on irqfd assignment/deassignment. Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Feng Wu <feng.wu@intel.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | KVM: introduce kvm_arch functions for IRQ bypassEric Auger2015-10-012-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces - kvm_arch_irq_bypass_add_producer - kvm_arch_irq_bypass_del_producer - kvm_arch_irq_bypass_stop - kvm_arch_irq_bypass_start They make possible to specialize the KVM IRQ bypass consumer in case CONFIG_KVM_HAVE_IRQ_BYPASS is set. Signed-off-by: Eric Auger <eric.auger@linaro.org> [Add weak implementations of the callbacks. - Feng] Signed-off-by: Feng Wu <feng.wu@intel.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | KVM: create kvm_irqfd.hEric Auger2015-10-011-72/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move _irqfd_resampler and _irqfd struct declarations in a new public header: kvm_irqfd.h. They are respectively renamed into kvm_kernel_irqfd_resampler and kvm_kernel_irqfd. Those datatypes will be used by architecture specific code, in the context of IRQ bypass manager integration. Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Feng Wu <feng.wu@intel.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | virt: Add virt directory to the top MakefileFeng Wu2015-10-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | We need to build files in virt/lib/, which are now used by KVM and VFIO, so add virt directory to the top Makefile. Signed-off-by: Feng Wu <feng.wu@intel.com> Acked-by: Michal Marek <mmarek@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | virt: IRQ bypass managerAlex Williamson2015-10-013-0/+260
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a physical I/O device is assigned to a virtual machine through facilities like VFIO and KVM, the interrupt for the device generally bounces through the host system before being injected into the VM. However, hardware technologies exist that often allow the host to be bypassed for some of these scenarios. Intel Posted Interrupts allow the specified physical edge interrupts to be directly injected into a guest when delivered to a physical processor while the vCPU is running. ARM IRQ Forwarding allows forwarded physical interrupts to be directly deactivated by the guest. The IRQ bypass manager here is meant to provide the shim to connect interrupt producers, generally the host physical device driver, with interrupt consumers, generally the hypervisor, in order to configure these bypass mechanism. To do this, we base the connection on a shared, opaque token. For KVM-VFIO this is expected to be an eventfd_ctx since this is the connection we already use to connect an eventfd to an irqfd on the in-kernel path. When a producer and consumer with matching tokens is found, callbacks via both registered participants allow the bypass facilities to be automatically enabled. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Tested-by: Eric Auger <eric.auger@linaro.org> Tested-by: Feng Wu <feng.wu@intel.com> Signed-off-by: Feng Wu <feng.wu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm: add capability for any-length ioeventfdsJason Wang2015-10-012-3/+2
| | | | | | | | | | | | | | | | | | | | | Cc: Gleb Natapov <gleb@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm: use kmalloc() instead of kzalloc() during iodev register/unregisterJason Wang2015-10-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All fields of kvm_io_range were initialized or copied explicitly afterwards. So switch to use kmalloc(). Cc: Gleb Natapov <gleb@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | KVM: x86: Add EOI exit bitmap inferenceSteve Rutherford2015-10-011-10/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to support a userspace IOAPIC interacting with an in kernel APIC, the EOI exit bitmaps need to be configurable. If the IOAPIC is in userspace (i.e. the irqchip has been split), the EOI exit bitmaps will be set whenever the GSI Routes are configured. In particular, for the low MSI routes are reservable for userspace IOAPICs. For these MSI routes, the EOI Exit bit corresponding to the destination vector of the route will be set for the destination VCPU. The intention is for the userspace IOAPICs to use the reservable MSI routes to inject interrupts into the guest. This is a slight abuse of the notion of an MSI Route, given that MSIs classically bypass the IOAPIC. It might be worthwhile to add an additional route type to improve clarity. Compile tested for Intel x86. Signed-off-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2015-11-031-2/+2
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The irq departement delivers: - Rework the irqdomain core infrastructure to accomodate ACPI based systems. This is required to support ARM64 without creating artificial device tree nodes. - Sanitize the ACPI based ARM GIC initialization by making use of the new firmware independent irqdomain core - Further improvements to the generic MSI management - Generalize the irq migration on CPU hotplug - Improvements to the threaded interrupt infrastructure - Allow the migration of "chained" low level interrupt handlers - Allow optional force masking of interrupts in disable_irq[_nosysnc] - Support for two new interrupt chips - Sigh! - A larger set of errata fixes for ARM gicv3 - The usual pile of fixes, updates, improvements and cleanups all over the place" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) Document that IRQ_NONE should be returned when IRQ not actually handled PCI/MSI: Allow the MSI domain to be device-specific PCI: Add per-device MSI domain hook of/irq: Use the msi-map property to provide device-specific MSI domain of/irq: Split of_msi_map_rid to reuse msi-map lookup irqchip/gic-v3-its: Parse new version of msi-parent property PCI/MSI: Use of_msi_get_domain instead of open-coded "msi-parent" parsing of/irq: Use of_msi_get_domain instead of open-coded "msi-parent" parsing of/irq: Add support code for multi-parent version of "msi-parent" irqchip/gic-v3-its: Add handling of PCI requester id. PCI/MSI: Add helper function pci_msi_domain_get_msi_rid(). of/irq: Add new function of_msi_map_rid() Docs: dt: Add PCI MSI map bindings irqchip/gic-v2m: Add support for multiple MSI frames irqchip/gic-v3: Fix translation of LPIs after conversion to irq_fwspec irqchip/mxs: Add Alphascale ASM9260 support irqchip/mxs: Prepare driver for hardware with different offsets irqchip/mxs: Panic if ioremap or domain creation fails irqdomain: Documentation updates irqdomain/msi: Use fwnode instead of of_node ...
| * | arm/arm64: KVM: Only allow 64bit hosts to build VGICv3Jean-Philippe Brucker2015-10-091-2/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hardware virtualisation of GICv3 is only supported by 64bit hosts for the moment. Some VGICv3 bits are missing from the 32bit side, and this patch allows to still be able to build 32bit hosts when CONFIG_ARM_GIC_V3 is selected. To this end, we introduce a new option, CONFIG_KVM_ARM_VGIC_V3, that is only enabled on the 64bit side. The selection is done unconditionally because CONFIG_ARM_GIC_V3 is always enabled on arm64. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* | arm/arm64: KVM: Fix disabled distributor operationChristoffer Dall2015-10-201-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently do a single update of the vgic state when the distributor enable/disable control register is accessed and then bypass updating the state for as long as the distributor remains disabled. This is incorrect, because updating the state does not consider the distributor enable bit, and this you can end up in a situation where an interrupt is marked as pending on the CPU interface, but not pending on the distributor, which is an impossible state to be in, and triggers a warning. Consider for example the following sequence of events: 1. An interrupt is marked as pending on the distributor - the interrupt is also forwarded to the CPU interface 2. The guest turns off the distributor (it's about to do a reboot) - we stop updating the CPU interface state from now on 3. The guest disables the pending interrupt - we remove the pending state from the distributor, but don't touch the CPU interface, see point 2. Since the distributor disable bit really means that no interrupts should be forwarded to the CPU interface, we modify the code to keep updating the internal VGIC state, but always set the CPU interface pending bits to zero when the distributor is disabled. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 11:23:54 +0000