From: Xin Li <[email protected]> Introduce a new save/restore flag for FRED metadata (specifically, the event nested flag and data) being saved and restored during VM save/ restore and live migration.
Signed-off-by: Xin Li <[email protected]> Signed-off-by: Sohil Mehta <[email protected]> --- v10: - Advertise KVM_CAP_X86_FRED_EVENT only when KVM can virtualize FRED, and return -EINVAL from KVM_ENABLE_CAP otherwise. - Document the new return value in api.rst. --- Documentation/virt/kvm/api.rst | 22 ++++++++++++++++++++++ arch/x86/include/asm/kvm_host.h | 1 + arch/x86/include/uapi/asm/kvm.h | 1 + arch/x86/kvm/x86.c | 18 ++++++++++++++++++ include/uapi/linux/kvm.h | 1 + 5 files changed, 43 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 4eb7e75a7473..22ef94f3eb3a 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -1199,6 +1199,10 @@ The following bits are defined in the flags field: triple_fault_pending field contains a valid state. This bit will be set whenever KVM_CAP_X86_TRIPLE_FAULT_EVENT is enabled. +- KVM_VCPUEVENT_VALID_FRED_STATE may be set to inform that the exception + state includes FRED state (specifically, the event nested flag and data). + This bit will be set whenever KVM_CAP_X86_FRED_EVENT is enabled. + ARM64: ^^^^^^ @@ -1301,6 +1305,11 @@ If KVM_CAP_X86_TRIPLE_FAULT_EVENT is enabled, KVM_VCPUEVENT_VALID_TRIPLE_FAULT can be set in flags field to signal that the triple_fault field contains a valid state and shall be written into the VCPU. +If KVM_CAP_X86_FRED_EVENT is enabled, KVM_VCPUEVENT_VALID_FRED_STATE can be set +in the flags field to inform that the exception state contains FRED state +(specifically, the event nested flag and data), which shall be written into the +VCPU. + ARM64: ^^^^^^ @@ -8979,6 +8988,19 @@ enabled, cmma can't be enabled anymore and pfmfi and the storage key interpretation are disabled. If cmma has already been enabled or the hpage_2g module parameter is not set to 1, -EINVAL is returned. +7.48 KVM_CAP_X86_FRED_EVENT +--------------------------- + +:Architectures: x86 +:Parameters: args[0] whether feature should be enabled or not +:Returns: 0 on success; -EINVAL if KVM cannot virtualize FRED. + +With this capability enabled, KVM allows exception save and restore operations +to include FRED event context (specifically, the event nested flag and data). +When injecting a FRED exception during VM entry, FRED event delivery relies +on this information to select the correct event stack level and apply proper +event data. + 8. Other capabilities. ====================== diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 0fd5d4edeebb..dd68db17fdae 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1286,6 +1286,7 @@ struct kvm_arch { bool has_mapped_host_mmio; bool guest_can_read_msr_platform_info; bool exception_payload_enabled; + bool exception_fred_state_enabled; bool triple_fault_event; diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index 1585ec804066..6a67832c59bb 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -331,6 +331,7 @@ struct kvm_reinject_control { #define KVM_VCPUEVENT_VALID_SMM 0x00000008 #define KVM_VCPUEVENT_VALID_PAYLOAD 0x00000010 #define KVM_VCPUEVENT_VALID_TRIPLE_FAULT 0x00000020 +#define KVM_VCPUEVENT_VALID_FRED_STATE 0x00000040 /* Interrupt shadow states */ #define KVM_X86_SHADOW_INT_MOV_SS 0x01 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4b3681796c75..01198aba27cf 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2288,6 +2288,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_PRE_FAULT_MEMORY: r = tdp_enabled; break; + case KVM_CAP_X86_FRED_EVENT: + r = kvm_cpu_cap_has(X86_FEATURE_FRED); + break; case KVM_CAP_X86_APIC_BUS_CYCLES_NS: r = kvm ? kvm->arch.apic_bus_cycle_ns : APIC_BUS_CYCLE_NS_DEFAULT; break; @@ -3022,6 +3025,8 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu, | KVM_VCPUEVENT_VALID_SMM); if (vcpu->kvm->arch.exception_payload_enabled) events->flags |= KVM_VCPUEVENT_VALID_PAYLOAD; + if (vcpu->kvm->arch.exception_fred_state_enabled) + events->flags |= KVM_VCPUEVENT_VALID_FRED_STATE; if (vcpu->kvm->arch.triple_fault_event) { events->triple_fault.pending = kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu); events->flags |= KVM_VCPUEVENT_VALID_TRIPLE_FAULT; @@ -3036,6 +3041,7 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, | KVM_VCPUEVENT_VALID_SHADOW | KVM_VCPUEVENT_VALID_SMM | KVM_VCPUEVENT_VALID_PAYLOAD + | KVM_VCPUEVENT_VALID_FRED_STATE | KVM_VCPUEVENT_VALID_TRIPLE_FAULT)) return -EINVAL; @@ -3051,6 +3057,11 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, events->exception_has_payload = 0; } + if (events->flags & KVM_VCPUEVENT_VALID_FRED_STATE) { + if (!vcpu->kvm->arch.exception_fred_state_enabled) + return -EINVAL; + } + if ((events->exception.injected || events->exception.pending) && (events->exception.nr > 31 || events->exception.nr == NMI_VECTOR)) return -EINVAL; @@ -4038,6 +4049,13 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, kvm->arch.exception_payload_enabled = cap->args[0]; r = 0; break; + case KVM_CAP_X86_FRED_EVENT: + r = -EINVAL; + if (!kvm_cpu_cap_has(X86_FEATURE_FRED)) + break; + kvm->arch.exception_fred_state_enabled = cap->args[0]; + r = 0; + break; case KVM_CAP_X86_TRIPLE_FAULT_EVENT: kvm->arch.triple_fault_event = cap->args[0]; r = 0; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 9fc8dfdfd65f..c5ffc4e7ddb1 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -998,6 +998,7 @@ struct kvm_enable_cap { #define KVM_CAP_S390_VSIE_ESAMODE 248 #define KVM_CAP_S390_HPAGE_2G 249 #define KVM_CAP_ARM_PMU_V3_STRICT 250 +#define KVM_CAP_X86_FRED_EVENT 251 struct kvm_irq_routing_irqchip { __u32 irqchip; -- 2.43.0
