diff options
| author | Vishal Annapurve <vannapurve@google.com> | 2026-03-05 22:26:26 +0000 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-05-27 17:15:56 -0700 |
| commit | 3e2dec1ede0a772c4d7cebd4130a7c4a12de2789 (patch) | |
| tree | 570cb06f6809276abbed181630fbee7bdc1cc961 /Documentation | |
| parent | b16c2aca369d180dc94275343b34966194317528 (diff) | |
KVM: TDX: Allow userspace to return errors to guest for MAPGPA
MAPGPA request from TDX VMs gets split into chunks by KVM using a loop
of userspace exits until the complete range is handled.
In some cases userspace VMM might decide to break the MAPGPA operation
and continue it later. For example: in the case of intrahost migration
userspace might decide to continue the MAPGPA operation after the
migration is completed.
Allow userspace to signal to TDX guests that the MAPGPA operation should
be retried the next time the guest is scheduled.
This is potentially a breaking change since if userspace sets
hypercall.ret to a value other than EBUSY or EINVAL an EINVAL error code
will be returned to userspace. As of now QEMU never sets hypercall.ret
to a non-zero value after handling KVM_EXIT_HYPERCALL so this change
should be safe.
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Vishal Annapurve <vannapurve@google.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
Link: https://patch.msgid.link/20260305222627.4193305-2-sagis@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 52bbbb553ce1..1a5a82ab0d66 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8818,6 +8818,9 @@ block sizes is exposed in KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES as a This capability, if enabled, will cause KVM to exit to userspace with KVM_EXIT_HYPERCALL exit reason to process some hypercalls. +Userspace may fail the hypercall by setting hypercall.ret to EINVAL +or may request the hypercall to be retried the next time the guest run +by setting hypercall.ret to EAGAIN. Calling KVM_CHECK_EXTENSION for this capability will return a bitmask of hypercalls that can be configured to exit to userspace. |