From 662d9715840aef44dcb573b0f9fab9e8319c868a Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Wed, 11 Mar 2015 14:21:31 +0100 Subject: arm/arm64: KVM: Kill CONFIG_KVM_ARM_{VGIC,TIMER} We can definitely decide at run-time whether to use the GIC and timers or not, and the extra code and data structures that we allocate space for is really negligable with this config option, so I don't think it's worth the extra complexity of always having to define stub static inlines. The !CONFIG_KVM_ARM_VGIC/TIMER case is pretty much an untested code path anyway, so we're better off just getting rid of it. Signed-off-by: Christoffer Dall Acked-by: Marc Zyngier --- include/kvm/arm_arch_timer.h | 31 ------------------------------- 1 file changed, 31 deletions(-) (limited to 'include/kvm/arm_arch_timer.h') diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index b3f45a578344..a74e4c2bf188 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -24,17 +24,14 @@ #include struct arch_timer_kvm { -#ifdef CONFIG_KVM_ARM_TIMER /* Is the timer enabled */ bool enabled; /* Virtual offset */ cycle_t cntvoff; -#endif }; struct arch_timer_cpu { -#ifdef CONFIG_KVM_ARM_TIMER /* Registers: control register, timer value */ u32 cntv_ctl; /* Saved/restored */ cycle_t cntv_cval; /* Saved/restored */ @@ -55,10 +52,8 @@ struct arch_timer_cpu { /* Timer IRQ */ const struct kvm_irq_level *irq; -#endif }; -#ifdef CONFIG_KVM_ARM_TIMER int kvm_timer_hyp_init(void); void kvm_timer_enable(struct kvm *kvm); void kvm_timer_init(struct kvm *kvm); @@ -72,30 +67,4 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu); u64 kvm_arm_timer_get_reg(struct kvm_vcpu *, u64 regid); int kvm_arm_timer_set_reg(struct kvm_vcpu *, u64 regid, u64 value); -#else -static inline int kvm_timer_hyp_init(void) -{ - return 0; -}; - -static inline void kvm_timer_enable(struct kvm *kvm) {} -static inline void kvm_timer_init(struct kvm *kvm) {} -static inline void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu, - const struct kvm_irq_level *irq) {} -static inline void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) {} -static inline void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu) {} -static inline void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) {} -static inline void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) {} - -static inline int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) -{ - return 0; -} - -static inline u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid) -{ - return 0; -} -#endif - #endif -- cgit From 1a74847885cc87857d631f91cca4d83924f75674 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Fri, 13 Mar 2015 17:02:55 +0000 Subject: arm/arm64: KVM: Fix migration race in the arch timer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When a VCPU is no longer running, we currently check to see if it has a timer scheduled in the future, and if it does, we schedule a host hrtimer to notify is in case the timer expires while the VCPU is still not running. When the hrtimer fires, we mask the guest's timer and inject the timer IRQ (still relying on the guest unmasking the time when it receives the IRQ). This is all good and fine, but when migration a VM (checkpoint/restore) this introduces a race. It is unlikely, but possible, for the following sequence of events to happen: 1. Userspace stops the VM 2. Hrtimer for VCPU is scheduled 3. Userspace checkpoints the VGIC state (no pending timer interrupts) 4. The hrtimer fires, schedules work in a workqueue 5. Workqueue function runs, masks the timer and injects timer interrupt 6. Userspace checkpoints the timer state (timer masked) At restore time, you end up with a masked timer without any timer interrupts and your guest halts never receiving timer interrupts. Fix this by only kicking the VCPU in the workqueue function, and sample the expired state of the timer when entering the guest again and inject the interrupt and mask the timer only then. Signed-off-by: Christoffer Dall Signed-off-by: Alex Bennée Signed-off-by: Christoffer Dall --- include/kvm/arm_arch_timer.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/kvm/arm_arch_timer.h') diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index a74e4c2bf188..e5966758c093 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -67,4 +67,6 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu); u64 kvm_arm_timer_get_reg(struct kvm_vcpu *, u64 regid); int kvm_arm_timer_set_reg(struct kvm_vcpu *, u64 regid, u64 value); +bool kvm_timer_should_fire(struct kvm_vcpu *vcpu); + #endif -- cgit