From 3217f7c25bca66eed9b07f0b8bfd1937169b0736 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Thu, 27 Aug 2015 16:41:15 +0200 Subject: KVM: Add kvm_arch_vcpu_{un}blocking callbacks Some times it is useful for architecture implementations of KVM to know when the VCPU thread is about to block or when it comes back from blocking (arm/arm64 needs to know this to properly implement timers, for example). Therefore provide a generic architecture callback function in line with what we do elsewhere for KVM generic-arch interactions. Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index c4072d9f32c7..84da97901f1f 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -234,4 +234,7 @@ static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} +static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} +static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} + #endif /* __ARM_KVM_HOST_H__ */ -- cgit v1.2.3 From d35268da66870d733ae763fd7f9b06a1f63f395e Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Tue, 25 Aug 2015 19:48:21 +0200 Subject: arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_block We currently schedule a soft timer every time we exit the guest if the timer did not expire while running the guest. This is really not necessary, because the only work we do in the timer work function is to kick the vcpu. Kicking the vcpu does two things: (1) If the vpcu thread is on a waitqueue, make it runnable and remove it from the waitqueue. (2) If the vcpu is running on a different physical CPU from the one doing the kick, it sends a reschedule IPI. The second case cannot happen, because the soft timer is only ever scheduled when the vcpu is not running. The first case is only relevant when the vcpu thread is on a waitqueue, which is only the case when the vcpu thread has called kvm_vcpu_block(). Therefore, we only need to make sure a timer is scheduled for kvm_vcpu_block(), which we do by encapsulating all calls to kvm_vcpu_block() with kvm_timer_{un}schedule calls. Additionally, we only schedule a soft timer if the timer is enabled and unmasked, since it is useless otherwise. Note that theoretically userspace can use the SET_ONE_REG interface to change registers that should cause the timer to fire, even if the vcpu is blocked without a scheduled timer, but this case was not supported before this patch and we leave it for future work for now. Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 84da97901f1f..c4072d9f32c7 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -234,7 +234,4 @@ static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} -static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} -static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} - #endif /* __ARM_KVM_HOST_H__ */ -- cgit v1.2.3 From 3781528e3045e7c9cc7c4846e0f675b1f353655f Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Fri, 25 Sep 2015 23:41:14 +0200 Subject: KVM: arm/arm64: rename pause into power_off The kvm_vcpu_arch pause field is renamed into power_off to prepare for the introduction of a new pause field. Also vcpu_pause is renamed into vcpu_sleep since we will sleep until both power_off and pause are false. Signed-off-by: Eric Auger Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index c4072d9f32c7..107374f986fd 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -126,8 +126,8 @@ struct kvm_vcpu_arch { * here. */ - /* Don't run the guest on this vcpu */ - bool pause; + /* vcpu power-off state */ + bool power_off; /* IO related fields */ struct kvm_decode mmio_decode; -- cgit v1.2.3 From 3b92830ad41b2fe377e0765322e8aefd0ab8388d Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Fri, 25 Sep 2015 23:41:17 +0200 Subject: KVM: arm/arm64: implement kvm_arm_[halt,resume]_guest We introduce kvm_arm_halt_guest and resume functions. They will be used for IRQ forward state change. Halt is synchronous and prevents the guest from being re-entered. We use the same mechanism put in place for PSCI former pause, now renamed power_off. A new flag is introduced in arch vcpu state, pause, only meant to be used by those functions. Signed-off-by: Eric Auger Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 107374f986fd..6692982c9b57 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -129,6 +129,9 @@ struct kvm_vcpu_arch { /* vcpu power-off state */ bool power_off; + /* Don't run the guest (internal implementation need) */ + bool pause; + /* IO related fields */ struct kvm_decode mmio_decode; -- cgit v1.2.3 From b5905dc12ed4254f7e0aac62bab48f002181f639 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Sun, 30 Aug 2015 15:55:22 +0200 Subject: arm/arm64: KVM: Improve kvm_exit tracepoint The ARM architecture only saves the exit class to the HSR (ESR_EL2 for arm64) on synchronous exceptions, not on asynchronous exceptions like an IRQ. However, we only report the exception class on kvm_exit, which is confusing because an IRQ looks like it exited at some PC with the same reason as the previous exit. Add a lookup table for the exception index and prepend the kvm_exit tracepoint text with the exception type to clarify this situation. Also resolve the exception class (EC) to a human-friendly text version so the trace output becomes immediately usable for debugging this code. Cc: Wei Huang Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_arm.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index d995821f1698..dc641ddf0784 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -218,4 +218,24 @@ #define HSR_DABT_CM (1U << 8) #define HSR_DABT_EA (1U << 9) +#define kvm_arm_exception_type \ + {0, "RESET" }, \ + {1, "UNDEFINED" }, \ + {2, "SOFTWARE" }, \ + {3, "PREF_ABORT" }, \ + {4, "DATA_ABORT" }, \ + {5, "IRQ" }, \ + {6, "FIQ" }, \ + {7, "HVC" } + +#define HSRECN(x) { HSR_EC_##x, #x } + +#define kvm_arm_exception_class \ + HSRECN(UNKNOWN), HSRECN(WFI), HSRECN(CP15_32), HSRECN(CP15_64), \ + HSRECN(CP14_MR), HSRECN(CP14_LS), HSRECN(CP_0_13), HSRECN(CP10_ID), \ + HSRECN(JAZELLE), HSRECN(BXJ), HSRECN(CP14_64), HSRECN(SVC_HYP), \ + HSRECN(HVC), HSRECN(SMC), HSRECN(IABT), HSRECN(IABT_HYP), \ + HSRECN(DABT), HSRECN(DABT_HYP) + + #endif /* __ARM_KVM_ARM_H__ */ -- cgit v1.2.3