mirror-linux/Documentation/virt
Binbin Wu 25e8b1dd48 KVM: TDX: Exit to userspace for GetTdVmCallInfo
Exit to userspace for TDG.VP.VMCALL<GetTdVmCallInfo> via KVM_EXIT_TDX,
to allow userspace to provide information about the support of
TDVMCALLs when r12 is 1 for the TDVMCALLs beyond the GHCI base API.

GHCI spec defines the GHCI base TDVMCALLs: <GetTdVmCallInfo>, <MapGPA>,
<ReportFatalError>, <Instruction.CPUID>, <#VE.RequestMMIO>,
<Instruction.HLT>, <Instruction.IO>, <Instruction.RDMSR> and
<Instruction.WRMSR>. They must be supported by VMM to support TDX guests.

For GetTdVmCallInfo
- When leaf (r12) to enumerate TDVMCALL functionality is set to 0,
  successful execution indicates all GHCI base TDVMCALLs listed above are
  supported.

  Update the KVM TDX document with the set of the GHCI base APIs.

- When leaf (r12) to enumerate TDVMCALL functionality is set to 1, it
  indicates the TDX guest is querying the supported TDVMCALLs beyond
  the GHCI base TDVMCALLs.
  Exit to userspace to let userspace set the TDVMCALL sub-function bit(s)
  accordingly to the leaf outputs.  KVM could set the TDVMCALL bit(s)
  supported by itself when the TDVMCALLs don't need support from userspace
  after returning from userspace and before entering guest. Currently, no
  such TDVMCALLs implemented, KVM just sets the values returned from
  userspace.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
[Adjust userspace API. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-06-20 13:55:47 -04:00
..
acrn
coco ARM: 2024-07-20 12:41:03 -07:00
hyperv Documentation: hyperv: Update VMBus doc with new features and info 2025-05-23 16:30:56 +00:00
kvm KVM: TDX: Exit to userspace for GetTdVmCallInfo 2025-06-20 13:55:47 -04:00
uml um: Remove legacy network transport infrastructure 2025-05-05 10:26:59 +02:00
guest-halt-polling.rst Documentation: virt: correct location of haltpoll module params 2023-06-16 08:17:21 -06:00
index.rst Docs/subsystem-apis: Remove '[The ]Linux' prefixes from titles of listed documents 2023-01-24 15:27:08 -07:00
ne_overview.rst nitro_enclaves: Update documentation for Arm64 support 2021-09-14 11:11:20 +02:00
paravirt_ops.rst Documentation: virt: Clean up paravirt_ops doc 2023-06-19 12:09:54 +02:00