user/sven/linux.git/virt, branch v4.7

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

KVM: Create debugfs dir and stat files for each VM

2016-05-25T14:12:05Z

This patch adds a kvm debugfs subdirectory for each VM, which is named after its pid and file descriptor. The directories contain the same kind of files that are already in the kvm debugfs directory, but the data exported through them is now VM specific. This makes the debugfs kvm data a convenient alternative to the tracepoints which already have per VM data. The debugfs data is easy to read and low overhead. CC: Dan Carpenter [includes fixes by Dan Carpenter] Signed-off-by: Janosch Frank Signed-off-by: Paolo Bonzini

Merge tag 'kvm-arm-for-4-7-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next

2016-05-24T10:10:51Z

KVM/ARM Changes for v4.7 take 2 "The GIC is dead; Long live the GIC" This set of changes include the new vgic, which is a reimplementation of our horribly broken legacy vgic implementation. The two implementations will live side-by-side (with the new being the configured default) for one kernel release and then we'll remove it. Also fixes a non-critical issue with virtual abort injection to guests.

KVM: arm/arm64: vgic-new: Synchronize changes to active state

2016-05-20T14:26:38Z

When modifying the active state of an interrupt via the MMIO interface, we should ensure that the write has the intended effect. If a guest sets an interrupt to active, but that interrupt is already flushed into a list register on a running VCPU, then that VCPU will write the active state back into the struct vgic_irq upon returning from the guest and syncing its state. This is a non-benign race, because the guest can observe that an interrupt is not active, and it can have a reasonable expectations that other VCPUs will not ack any IRQs, and then set the state to active, and expect it to stay that way. Currently we are not honoring this case. Thefore, change both the SACTIVE and CACTIVE mmio handlers to stop the world, change the irq state, potentially queue the irq if we're setting it to active, and then continue. We take this chance to slightly optimize these functions by not stopping the world when touching private interrupts where there is inherently no possible race. Signed-off-by: Christoffer Dall