This is a note to let you know that I've just added the patch titled arm/arm64: KVM: Keep elrsr/aisr in sync with software model to the 3.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm-arm64-kvm-keep-elrsr-aisr-in-sync-with-software-model.patch and it can be found in the queue-3.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ae705930fca6322600690df9dc1c7d0516145a93 Mon Sep 17 00:00:00 2001 From: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Date: Fri, 13 Mar 2015 17:02:56 +0000 Subject: arm/arm64: KVM: Keep elrsr/aisr in sync with software model MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Christoffer Dall <christoffer.dall@xxxxxxxxxx> commit ae705930fca6322600690df9dc1c7d0516145a93 upstream. 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 <marc.zyngier@xxxxxxx> Reported-by: Alex Bennee <alex.bennee@xxxxxxxxxx> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx> Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/kvm/arm_vgic.h | 1 + virt/kvm/arm/vgic-v2.c | 8 ++++++++ virt/kvm/arm/vgic-v3.c | 8 ++++++++ virt/kvm/arm/vgic.c | 16 ++++++++++++++++ 4 files changed, 33 insertions(+) --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -113,6 +113,7 @@ struct vgic_ops { void (*sync_lr_elrsr)(struct kvm_vcpu *, int, struct vgic_lr); u64 (*get_elrsr)(const struct kvm_vcpu *vcpu); u64 (*get_eisr)(const struct kvm_vcpu *vcpu); + void (*clear_eisr)(struct kvm_vcpu *vcpu); u32 (*get_interrupt_status)(const struct kvm_vcpu *vcpu); void (*enable_underflow)(struct kvm_vcpu *vcpu); void (*disable_underflow)(struct kvm_vcpu *vcpu); --- a/virt/kvm/arm/vgic-v2.c +++ b/virt/kvm/arm/vgic-v2.c @@ -72,6 +72,8 @@ static void vgic_v2_sync_lr_elrsr(struct { if (!(lr_desc.state & LR_STATE_MASK)) vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr |= (1ULL << lr); + else + vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr &= ~(1ULL << lr); } static u64 vgic_v2_get_elrsr(const struct kvm_vcpu *vcpu) @@ -84,6 +86,11 @@ static u64 vgic_v2_get_eisr(const struct return vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr; } +static void vgic_v2_clear_eisr(struct kvm_vcpu *vcpu) +{ + vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr = 0; +} + static u32 vgic_v2_get_interrupt_status(const struct kvm_vcpu *vcpu) { u32 misr = vcpu->arch.vgic_cpu.vgic_v2.vgic_misr; @@ -148,6 +155,7 @@ static const struct vgic_ops vgic_v2_ops .sync_lr_elrsr = vgic_v2_sync_lr_elrsr, .get_elrsr = vgic_v2_get_elrsr, .get_eisr = vgic_v2_get_eisr, + .clear_eisr = vgic_v2_clear_eisr, .get_interrupt_status = vgic_v2_get_interrupt_status, .enable_underflow = vgic_v2_enable_underflow, .disable_underflow = vgic_v2_disable_underflow, --- a/virt/kvm/arm/vgic-v3.c +++ b/virt/kvm/arm/vgic-v3.c @@ -86,6 +86,8 @@ static void vgic_v3_sync_lr_elrsr(struct { if (!(lr_desc.state & LR_STATE_MASK)) vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr |= (1U << lr); + else + vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr &= ~(1U << lr); } static u64 vgic_v3_get_elrsr(const struct kvm_vcpu *vcpu) @@ -98,6 +100,11 @@ static u64 vgic_v3_get_eisr(const struct return vcpu->arch.vgic_cpu.vgic_v3.vgic_eisr; } +static void vgic_v3_clear_eisr(struct kvm_vcpu *vcpu) +{ + vcpu->arch.vgic_cpu.vgic_v3.vgic_eisr = 0; +} + static u32 vgic_v3_get_interrupt_status(const struct kvm_vcpu *vcpu) { u32 misr = vcpu->arch.vgic_cpu.vgic_v3.vgic_misr; @@ -162,6 +169,7 @@ static const struct vgic_ops vgic_v3_ops .sync_lr_elrsr = vgic_v3_sync_lr_elrsr, .get_elrsr = vgic_v3_get_elrsr, .get_eisr = vgic_v3_get_eisr, + .clear_eisr = vgic_v3_clear_eisr, .get_interrupt_status = vgic_v3_get_interrupt_status, .enable_underflow = vgic_v3_enable_underflow, .disable_underflow = vgic_v3_disable_underflow, --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1219,6 +1219,11 @@ static inline u64 vgic_get_eisr(struct k return vgic_ops->get_eisr(vcpu); } +static inline void vgic_clear_eisr(struct kvm_vcpu *vcpu) +{ + vgic_ops->clear_eisr(vcpu); +} + static inline u32 vgic_get_interrupt_status(struct kvm_vcpu *vcpu) { return vgic_ops->get_interrupt_status(vcpu); @@ -1258,6 +1263,7 @@ static void vgic_retire_lr(int lr_nr, in vgic_set_lr(vcpu, lr_nr, vlr); clear_bit(lr_nr, vgic_cpu->lr_used); vgic_cpu->vgic_irq_lr_map[irq] = LR_EMPTY; + vgic_sync_lr_elrsr(vcpu, lr_nr, vlr); } /* @@ -1313,6 +1319,7 @@ static bool vgic_queue_irq(struct kvm_vc BUG_ON(!test_bit(lr, vgic_cpu->lr_used)); vlr.state |= LR_STATE_PENDING; vgic_set_lr(vcpu, lr, vlr); + vgic_sync_lr_elrsr(vcpu, lr, vlr); return true; } } @@ -1334,6 +1341,7 @@ static bool vgic_queue_irq(struct kvm_vc vlr.state |= LR_EOI_INT; vgic_set_lr(vcpu, lr, vlr); + vgic_sync_lr_elrsr(vcpu, lr, vlr); return true; } @@ -1502,6 +1510,14 @@ static bool vgic_process_maintenance(str if (status & INT_STATUS_UNDERFLOW) vgic_disable_underflow(vcpu); + /* + * In the next iterations of the vcpu loop, if we sync the vgic state + * after flushing it, but before entering the guest (this happens for + * pending signals and vmid rollovers), then make sure we don't pick + * up any old maintenance interrupts here. + */ + vgic_clear_eisr(vcpu); + return level_pending; } Patches currently in stable-queue which might be from christoffer.dall@xxxxxxxxxx are queue-3.19/arm64-kvm-do-not-use-pgd_index-to-index-stage-2-pgd.patch queue-3.19/kvm-arm-arm64-vgic-vgic_init-returns-enodev-when-no-online-vcpu.patch queue-3.19/arm-arm64-kvm-keep-elrsr-aisr-in-sync-with-software-model.patch queue-3.19/kvm-arm-arm64-check-irq-number-on-userland-injection.patch queue-3.19/arm64-kvm-fix-stage-2-pgd-allocation-to-have-per-page-refcounting.patch queue-3.19/arm-kvm-fix-size-check-in-__coherent_cache_guest_page.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html