diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt index 7403f15657c2..bd29d44af32b 100644 --- a/Documentation/virt/kvm/api.txt +++ b/Documentation/virt/kvm/api.txt @@ -1002,12 +1002,18 @@ Specifying exception.has_esr on a system that does not support it will return -EINVAL. Setting anything other than the lower 24bits of exception.serror_esr will return -EINVAL. +It is not possible to read back a pending external abort (injected via +KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered +directly to the virtual CPU). + + struct kvm_vcpu_events { struct { __u8 serror_pending; __u8 serror_has_esr; + __u8 ext_dabt_pending; /* Align it to 8 bytes */ - __u8 pad[6]; + __u8 pad[5]; __u64 serror_esr; } exception; __u32 reserved[12]; @@ -1051,9 +1057,23 @@ contain a valid state and shall be written into the VCPU. ARM/ARM64: +User space may need to inject several types of events to the guest. + Set the pending SError exception state for this VCPU. It is not possible to 'cancel' an Serror that has been made pending. +If the guest performed an access to I/O memory which could not be handled by +userspace, for example because of missing instruction syndrome decode +information or because there is no device mapped at the accessed IPA, then +userspace can ask the kernel to inject an external abort using the address +from the exiting fault on the VCPU. It is a programming error to set +ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or +KVM_EXIT_ARM_NISV. This feature is only available if the system supports +KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in +how userspace reports accesses for the above cases to guests, across different +userspace implementations. Nevertheless, userspace can still emulate all Arm +exceptions by manipulating individual registers using the KVM_SET_ONE_REG API. + See KVM_GET_VCPU_EVENTS for the data structure. diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 2769360f195c..03cd7c19a683 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -131,8 +131,9 @@ struct kvm_vcpu_events { struct { __u8 serror_pending; __u8 serror_has_esr; + __u8 ext_dabt_pending; /* Align it to 8 bytes */ - __u8 pad[6]; + __u8 pad[5]; __u64 serror_esr; } exception; __u32 reserved[12]; diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c index 684cf64b4033..735f9b007e58 100644 --- a/arch/arm/kvm/guest.c +++ b/arch/arm/kvm/guest.c @@ -255,6 +255,12 @@ int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, { events->exception.serror_pending = !!(*vcpu_hcr(vcpu) & HCR_VA); + /* + * We never return a pending ext_dabt here because we deliver it to + * the virtual CPU directly when setting the event and it's no longer + * 'pending' at this point. + */ + return 0; } @@ -263,12 +269,16 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, { bool serror_pending = events->exception.serror_pending; bool has_esr = events->exception.serror_has_esr; + bool ext_dabt_pending = events->exception.ext_dabt_pending; if (serror_pending && has_esr) return -EINVAL; else if (serror_pending) kvm_inject_vabt(vcpu); + if (ext_dabt_pending) + kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); + return 0; } diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index 67c21f9bdbad..d49c17a80491 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -164,8 +164,9 @@ struct kvm_vcpu_events { struct { __u8 serror_pending; __u8 serror_has_esr; + __u8 ext_dabt_pending; /* Align it to 8 bytes */ - __u8 pad[6]; + __u8 pad[5]; __u64 serror_esr; } exception; __u32 reserved[12]; diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index dfd626447482..ca613a44c6ec 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -712,6 +712,12 @@ int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, if (events->exception.serror_pending && events->exception.serror_has_esr) events->exception.serror_esr = vcpu_get_vsesr(vcpu); + /* + * We never return a pending ext_dabt here because we deliver it to + * the virtual CPU directly when setting the event and it's no longer + * 'pending' at this point. + */ + return 0; } @@ -720,6 +726,7 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, { bool serror_pending = events->exception.serror_pending; bool has_esr = events->exception.serror_has_esr; + bool ext_dabt_pending = events->exception.ext_dabt_pending; if (serror_pending && has_esr) { if (!cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) @@ -733,6 +740,9 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, kvm_inject_vabt(vcpu); } + if (ext_dabt_pending) + kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); + return 0; } diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index a9d25a305af5..ccdb6a051ab2 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -109,7 +109,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu) /** * kvm_inject_dabt - inject a data abort into the guest - * @vcpu: The VCPU to receive the undefined exception + * @vcpu: The VCPU to receive the data abort * @addr: The address to report in the DFAR * * It is assumed that this code is called from the VCPU thread and that the @@ -125,7 +125,7 @@ void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr) /** * kvm_inject_pabt - inject a prefetch abort into the guest - * @vcpu: The VCPU to receive the undefined exception + * @vcpu: The VCPU to receive the prefetch abort * @addr: The address to report in the DFAR * * It is assumed that this code is called from the VCPU thread and that the diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 7336ee8d98d7..65db5a4257ec 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1007,6 +1007,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 174 #define KVM_CAP_HYPERV_DIRECT_TLBFLUSH 175 #define KVM_CAP_ARM_NISV_TO_USER 176 +#define KVM_CAP_ARM_INJECT_EXT_DABT 177 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index e6d56f60e4b6..12064780f1d8 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -218,6 +218,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_VCPU_EVENTS: case KVM_CAP_ARM_IRQ_LINE_LAYOUT_2: case KVM_CAP_ARM_NISV_TO_USER: + case KVM_CAP_ARM_INJECT_EXT_DABT: r = 1; break; case KVM_CAP_ARM_SET_DEVICE_ADDR: