kernel/virt, branch linux-4.7.y

KVM: arm/arm64: vgic: Don't flush/sync without a working vgic

2016-10-16T15:50:37Z

commit 0099b7701f5296a758d9e6b945ec96f96847cc2f upstream. If the vgic hasn't been created and initialized, we shouldn't attempt to look at its data structures or flush/sync anything to the GIC hardware. This fixes an issue reported by Alexander Graf when using a userspace irqchip. Fixes: 0919e84c0fc1 ("KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework") Reported-by: Alexander Graf Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Require in-kernel irqchip for PMU support

2016-10-16T15:50:37Z

commit 6fe407f2d18a4f94216263f91cb7d1f08fa5887c upstream. If userspace creates a PMU for the VCPU, but doesn't create an in-kernel irqchip, then we end up in a nasty path where we try to take an uninitialized spinlock, which can lead to all sorts of breakages. Luckily, QEMU always creates the VGIC before the PMU, so we can establish this as ABI and check for the VGIC in the PMU init stage. This can be relaxed at a later time if we want to support PMU with a userspace irqchip. Cc: Shannon Zhao Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Greg Kroah-Hartman

KVM: nVMX: Fix memory corruption when using VMCS shadowing

2016-08-20T16:10:50Z

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 Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

kvm: Fix irq route entries exceeding KVM_MAX_IRQ_ROUTES

2016-06-16T07:38:15Z

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. Cc: stable@vger.kernel.org Signed-off-by: Xiubo Li Signed-off-by: Wei Tang Signed-off-by: Zhang Zhuoyu Signed-off-by: Paolo Bonzini

KVM: x86: avoid vmalloc(0) in the KVM_SET_CPUID

2016-06-02T15:38:50Z

This causes an ugly dmesg splat. Beautified syzkaller testcase: #include #include #include #include #include long r[8]; int main() { struct kvm_irq_routing ir = { 0 }; r[2] = open("/dev/kvm", O_RDWR); r[3] = ioctl(r[2], KVM_CREATE_VM, 0); r[4] = ioctl(r[3], KVM_SET_GSI_ROUTING, &ir); return 0; } Reported-by: Dmitry Vyukov Signed-off-by: Paolo Bonzini Signed-off-by: Radim Krčmář

KVM: irqfd: fix NULL pointer dereference in kvm_irq_map_gsi

2016-06-02T15:38:50Z

Found by syzkaller: BUG: unable to handle kernel NULL pointer dereference at 0000000000000120 IP: [] 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: [] irqfd_update+0x32/0xc0 [kvm] [] kvm_irqfd+0x3dc/0x5b0 [kvm] [] kvm_vm_ioctl+0x164/0x6f0 [kvm] [] do_vfs_ioctl+0x298/0x480 [] SyS_ioctl+0x79/0x90 [] 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 [] kvm_irq_map_gsi+0x12/0x90 [kvm] RSP CR2: 0000000000000120 Testcase: #include #include #include #include #include #include #include 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 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Radim Krčmář

KVM: arm/arm64: vgic-new: Removel harmful BUG_ON

2016-06-02T09:52:21Z

When changing the active bit from an MMIO trap, we decide to explode if the intid is that of a private interrupt. This flawed logic comes from the fact that we were assuming that kvm_vcpu_kick() as called by kvm_arm_halt_vcpu() would not return before the called vcpu responded, but this is not the case, so we need to perform this wait even for private interrupts. Dropping the BUG_ON seems like the right thing to do. [ Commit message tweaked by Christoffer ] Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: vgic-v3: Always resample level interrupts

2016-05-31T14:12:16Z

When reading back from the list registers, we need to perform two actions for level interrupts: 1) clear the soft-pending bit if the interrupt is not pending anymore *in the list register* 2) resample the line level and propagate it to the pending state But these two actions shouldn't be linked, and we should *always* resample the line level, no matter what state is in the list register. Otherwise, we may end-up injecting spurious interrupts that have been already retired. Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: vgic-v2: Always resample level interrupts

2016-05-31T14:12:15Z

KVM: arm/arm64: vgic-v2: Clear all dirty LRs

2016-05-31T14:09:28Z

When saving the state of the list registers, it is critical to reset them zero, as we could otherwise leave unexpected EOI interrupts pending for virtual level interrupts. Cc: stable@vger.kernel.org # v4.6+ Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier