kernel/linux.git/virt, branch v3.14.76

kvm: Fix irq route entries exceeding KVM_MAX_IRQ_ROUTES

2016-07-27T16:55:50+00:00

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 Signed-off-by: Wei Tang Signed-off-by: Zhang Zhuoyu Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

KVM: fix spin_lock_init order on x86

2016-04-12T16:12:38+00:00

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] [] lock_acquire+0xd3/0x240 [ 284.533733] [] ? kvm_page_track_register_notifier+0x20/0x60 [kvm] [ 284.541467] [] _raw_spin_lock+0x41/0x80 [ 284.546960] [] ? kvm_page_track_register_notifier+0x20/0x60 [kvm] [ 284.554707] [] kvm_page_track_register_notifier+0x20/0x60 [kvm] [ 284.562281] [] kvm_mmu_init_vm+0x20/0x30 [kvm] [ 284.568381] [] kvm_arch_init_vm+0x1ea/0x200 [kvm] [ 284.574740] [] 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 Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

KVM: async_pf: do not warn on page allocation failures

2016-03-03T23:06:53+00:00

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 Reviewed-by: Dominik Dingel Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

kvm: fix zero length mmio searching

2015-10-22T21:39:16+00:00

commit 8f4216c7d28976f7ec1b2bcbfa0a9f787133c45e upstream. Currently, if we had a zero length mmio eventfd assigned on KVM_MMIO_BUS. It will never be found by kvm_io_bus_cmp() since it always compares the kvm_io_range() with the length that guest wrote. This will cause e.g for vhost, kick will be trapped by qemu userspace instead of vhost. Fixing this by using zero length if an iodevice is zero length. Cc: Gleb Natapov Cc: Paolo Bonzini Signed-off-by: Jason Wang Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

arm/arm64: KVM: Keep elrsr/aisr in sync with software model

2015-07-10T17:38:01+00:00

commit ae705930fca6322600690df9dc1c7d0516145a93 upstream. [Note the upstream one of this patch requires applying full GICv3 support but it's out of the scope of stable kernel. So this patch has a huge modification for stable kernel comparing to the upstream one.] There is an interesting bug in the vgic code, which manifests itself when the KVM run loop has a signal pending or needs a vmid generation rollover after having disabled interrupts but before actually switching to the guest. In this case, we flush the vgic as usual, but we sync back the vgic state and exit to userspace before entering the guest. The consequence is that we will be syncing the list registers back to the software model using the GICH_ELRSR and GICH_EISR from the last execution of the guest, potentially overwriting a list register containing an interrupt. This showed up during migration testing where we would capture a state where the VM has masked the arch timer but there were no interrupts, resulting in a hung test. Cc: Marc Zyngier Reported-by: Alex Bennee Signed-off-by: Christoffer Dall Signed-off-by: Alex Bennée Acked-by: Marc Zyngier Signed-off-by: Shannon Zhao Signed-off-by: Greg Kroah-Hartman

arm/arm64: KVM: Require in-kernel vgic for the arch timers

2015-07-10T17:38:00+00:00

commit 05971120fca43e0357789a14b3386bb56eef2201 upstream. [Note this patch is a bit different from the original one as the names of vgic_initialized and kvm_vgic_init are different.] It is curently possible to run a VM with architected timers support without creating an in-kernel VGIC, which will result in interrupts from the virtual timer going nowhere. To address this issue, move the architected timers initialization to the time when we run a VCPU for the first time, and then only initialize (and enable) the architected timers if we have a properly created and initialized in-kernel VGIC. When injecting interrupts from the virtual timer to the vgic, the current setup should ensure that this never calls an on-demand init of the VGIC, which is the only call path that could return an error from kvm_vgic_inject_irq(), so capture the return value and raise a warning if there's an error there. We also change the kvm_timer_init() function from returning an int to be a void function, since the function always succeeds. Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Shannon Zhao Signed-off-by: Greg Kroah-Hartman

arm/arm64: KVM: vgic: Fix error code in kvm_vgic_create()

2015-07-04T02:49:06+00:00

commit 6b50f54064a02b77a7b990032b80234fee59bcd6 upstream. If we detect another vCPU is running we just exit and return 0 as if we succesfully created the VGIC, but the VGIC wouldn't actual be created. This shouldn't break in-kernel behavior because the kernel will not observe the failed the attempt to create the VGIC, but userspace could be rightfully confused. Cc: Andre Przywara Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Paolo Bonzini Signed-off-by: Shannon Zhao Signed-off-by: Greg Kroah-Hartman

arm/arm64: KVM: Fix set_clear_sgi_pend_reg offset

2015-07-04T02:49:06+00:00

commit 0fea6d7628ed6e25a9ee1b67edf7c859718d39e8 upstream. The sgi values calculated in read_set_clear_sgi_pend_reg() and write_set_clear_sgi_pend_reg() were horribly incorrectly multiplied by 4 with catastrophic results in that subfunctions ended up overwriting memory not allocated for the expected purpose. This showed up as bugs in kfree() and the kernel complaining a lot of you turn on memory debugging. This addresses: http://marc.info/?l=kvm&m=141164910007868&w=2 Reported-by: Shannon Zhao Signed-off-by: Christoffer Dall Signed-off-by: Shannon Zhao Signed-off-by: Greg Kroah-Hartman

KVM: ARM: vgic: plug irq injection race

2015-07-04T02:49:06+00:00

commit 71afaba4a2e98bb7bdeba5078370ab43d46e67a1 upstream. [Since we don't backport commit 227844f (arm/arm64: KVM: Rename irq_state to irq_pending) for linux-3.14.y, here we still use vgic_update_irq_state instead of vgic_update_irq_pending.] As it stands, nothing prevents userspace from injecting an interrupt before the guest's GIC is actually initialized. This goes unnoticed so far (as everything is pretty much statically allocated), but ends up exploding in a spectacular way once we switch to a more dynamic allocation (the GIC data structure isn't there yet). The fix is to test for the "ready" flag in the VGIC distributor before trying to inject the interrupt. Note that in order to avoid breaking userspace, we have to ignore what is essentially an error. Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall Signed-off-by: Shannon Zhao Signed-off-by: Greg Kroah-Hartman

KVM: vgic: return int instead of bool when checking I/O ranges

2015-06-29T19:25:38+00:00

commit 1fa451bcc67fa921a04c5fac8dbcde7844d54512 upstream. vgic_ioaddr_overlap claims to return a bool, but in reality it returns an int. Shut sparse up by fixing the type signature. Cc: Christoffer Dall Cc: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Christoffer Dall Signed-off-by: Shannon Zhao Signed-off-by: Greg Kroah-Hartman