diff options
Diffstat (limited to 'Documentation/virtual/kvm/api.txt')
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 80 |
1 files changed, 76 insertions, 4 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 7b83b176c662..0acdbac3a2d7 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -835,11 +835,13 @@ struct kvm_clock_data { Capability: KVM_CAP_VCPU_EVENTS Extended by: KVM_CAP_INTR_SHADOW -Architectures: x86 -Type: vm ioctl +Architectures: x86, arm, arm64 +Type: vcpu ioctl Parameters: struct kvm_vcpu_event (out) Returns: 0 on success, -1 on error +X86: + Gets currently pending exceptions, interrupts, and NMIs as well as related states of the vcpu. @@ -881,15 +883,64 @@ Only two fields are defined in the flags field: - KVM_VCPUEVENT_VALID_SMM may be set in the flags field to signal that smi contains a valid state. +ARM/ARM64: + +If the guest accesses a device that is being emulated by the host kernel in +such a way that a real device would generate a physical SError, KVM may make +a virtual SError pending for that VCPU. This system error interrupt remains +pending until the guest takes the exception by unmasking PSTATE.A. + +Running the VCPU may cause it to take a pending SError, or make an access that +causes an SError to become pending. The event's description is only valid while +the VPCU is not running. + +This API provides a way to read and write the pending 'event' state that is not +visible to the guest. To save, restore or migrate a VCPU the struct representing +the state can be read then written using this GET/SET API, along with the other +guest-visible registers. It is not possible to 'cancel' an SError that has been +made pending. + +A device being emulated in user-space may also wish to generate an SError. To do +this the events structure can be populated by user-space. The current state +should be read first, to ensure no existing SError is pending. If an existing +SError is pending, the architecture's 'Multiple SError interrupts' rules should +be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and +Serviceability (RAS) Specification"). + +SError exceptions always have an ESR value. Some CPUs have the ability to +specify what the virtual SError's ESR value should be. These systems will +advertise KVM_CAP_ARM_SET_SERROR_ESR. In this case exception.has_esr will +always have a non-zero value when read, and the agent making an SError pending +should specify the ISS field in the lower 24 bits of exception.serror_esr. If +the system supports KVM_CAP_ARM_SET_SERROR_ESR, but user-space sets the events +with exception.has_esr as zero, KVM will choose an ESR. + +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. + +struct kvm_vcpu_events { + struct { + __u8 serror_pending; + __u8 serror_has_esr; + /* Align it to 8 bytes */ + __u8 pad[6]; + __u64 serror_esr; + } exception; + __u32 reserved[12]; +}; + 4.32 KVM_SET_VCPU_EVENTS Capability: KVM_CAP_VCPU_EVENTS Extended by: KVM_CAP_INTR_SHADOW -Architectures: x86 -Type: vm ioctl +Architectures: x86, arm, arm64 +Type: vcpu ioctl Parameters: struct kvm_vcpu_event (in) Returns: 0 on success, -1 on error +X86: + Set pending exceptions, interrupts, and NMIs as well as related states of the vcpu. @@ -910,6 +961,13 @@ shall be written into the VCPU. KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. +ARM/ARM64: + +Set the pending SError exception state for this VCPU. It is not possible to +'cancel' an Serror that has been made pending. + +See KVM_GET_VCPU_EVENTS for the data structure. + 4.33 KVM_GET_DEBUGREGS @@ -4690,3 +4748,17 @@ This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush hypercalls: HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, HvFlushVirtualAddressList, HvFlushVirtualAddressListEx. + +8.19 KVM_CAP_ARM_SET_SERROR_ESR + +Architectures: arm, arm64 + +This capability indicates that userspace can specify (via the +KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it +takes a virtual SError interrupt exception. +If KVM advertises this capability, userspace can only specify the ISS field for +the ESR syndrome. Other parts of the ESR, such as the EC are generated by the +CPU when the exception is taken. If this virtual SError is taken to EL1 using +AArch64, this value will be reported in the ISS field of ESR_ELx. + +See KVM_CAP_VCPU_EVENTS for more details. |