- KVM_CAP_ARM_INJECT_EXT_IABT: userspace can inject external instruction abort to guest. - ext_abt_has_esr and ext_abt_esr: userspace can supplement ISS fields while injecting SEA, for both data and instruction aborts. Signed-off-by: Jiaqi Yan <jiaqiyan@xxxxxxxxxx> --- Documentation/virt/kvm/api.rst | 48 +++++++++++++++++++++++++--------- 1 file changed, 36 insertions(+), 12 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 53e0179d52949..8190ffb145c37 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -1236,9 +1236,11 @@ directly to the virtual CPU). __u8 serror_pending; __u8 serror_has_esr; __u8 ext_dabt_pending; + __u8 ext_iabt_pending; /* Align it to 8 bytes */ - __u8 pad[5]; + __u8 pad[4]; __u64 serror_esr; + __u64 ext_abt_esr; } exception; __u32 reserved[12]; }; @@ -1292,20 +1294,42 @@ ARM64: User space may need to inject several types of events to the guest. +Inject SError +~~~~~~~~~~~~~ + 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. +Inject SEA (synchronous external abort) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- 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. + +- If the guest consumed an uncorrectable memory error on guest owned memory, + and RAS in the Trusted Firmware chooses to notify PE with SEA, KVM has to + handle it when host APEI is unable to claim the SEA. If userspace has enabled + KVM_CAP_ARM_SEA_TO_USER, KVM returns to userspace with KVM_EXIT_ARM_SEA. + +For the cases above, userspace can ask the kernel to replay either an external +data abort (by setting ext_dabt_pending) or an external instruction abort +(by setting ext_iabt_pending) into the faulting VCPU. Userspace can provide +Instruction Specific Syndrome (ISS) in the ext_abt_esr field to supplement +the ESR register value being injected into the faulting VCPU. KVM will use the +address from the existing fault on the VCPU. Setting both ext_dabt_pending and +ext_iabt_pending at the same time will return -EINVAL. Setting anything not +being part of the ISS (bits [24:0] of ext_abt_esr) will return -EINVAL. + +It is a programming error to set ext_dabt_pending or ext_iabt_pending after an +exit which was not KVM_EXIT_MMIO, KVM_EXIT_ARM_NISV or KVM_EXIT_ARM_SEA. +Injecting SEA for data and instruction abort is only available if KVM supports +KVM_CAP_ARM_INJECT_EXT_DABT and KVM_CAP_ARM_INJECT_EXT_IABT respectively. + +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. -- 2.50.1.565.gc32cd1483b-goog
