Commit 79462faa authored by Binbin Wu's avatar Binbin Wu Committed by Paolo Bonzini
Browse files

KVM: TDX: Handle TDG.VP.VMCALL<ReportFatalError> 



Convert TDG.VP.VMCALL<ReportFatalError> to KVM_EXIT_SYSTEM_EVENT with
a new type KVM_SYSTEM_EVENT_TDX_FATAL and forward it to userspace for
handling.

TD guest can use TDG.VP.VMCALL<ReportFatalError> to report the fatal
error it has experienced.  This hypercall is special because TD guest
is requesting a termination with the error information, KVM needs to
forward the hypercall to userspace anyway, KVM doesn't do parsing or
conversion, it just dumps the 16 general-purpose registers to userspace
and let userspace decide what to do.

Signed-off-by: default avatarBinbin Wu <binbin.wu@linux.intel.com>
Message-ID: <20250222014225.897298-8-binbin.wu@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 2c304880

Documentation/virt/kvm/api.rst

+6 −0
Original line number Diff line number Diff line
@@ -6823,6 +6823,7 @@ should put the acknowledged interrupt vector into the 'epr' field. 
  #define KVM_SYSTEM_EVENT_WAKEUP         4

  #define KVM_SYSTEM_EVENT_SUSPEND        5

  #define KVM_SYSTEM_EVENT_SEV_TERM       6

  #define KVM_SYSTEM_EVENT_TDX_FATAL      7

			__u32 type;

                        __u32 ndata;

                        __u64 data[16];
@@ -6849,6 +6850,11 @@ Valid values for 'type' are: 
   reset/shutdown of the VM.

 - KVM_SYSTEM_EVENT_SEV_TERM -- an AMD SEV guest requested termination.

   The guest physical address of the guest's GHCB is stored in `data[0]`.

 - KVM_SYSTEM_EVENT_TDX_FATAL -- a TDX guest reported a fatal error state.

   KVM doesn't do any parsing or conversion, it just dumps 16 general-purpose

   registers to userspace, in ascending order of the 4-bit indices for x86-64

   general-purpose registers in instruction encoding, as defined in the Intel

   SDM.

 - KVM_SYSTEM_EVENT_WAKEUP -- the exiting vCPU is in a suspended state and

   KVM has recognized a wakeup event. Userspace may honor this event by

   marking the exiting vCPU as runnable, or deny it and call KVM_RUN again.

arch/x86/kvm/vmx/tdx.c

+28 −0
Original line number Diff line number Diff line
@@ -1104,11 +1104,39 @@ static int tdx_map_gpa(struct kvm_vcpu *vcpu) 
	return 1;

}



static int tdx_report_fatal_error(struct kvm_vcpu *vcpu)

{

	struct vcpu_tdx *tdx = to_tdx(vcpu);

	u64 *regs = vcpu->run->system_event.data;

	u64 *module_regs = &tdx->vp_enter_args.r8;

	int index = VCPU_REGS_RAX;



	vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;

	vcpu->run->system_event.type = KVM_SYSTEM_EVENT_TDX_FATAL;

	vcpu->run->system_event.ndata = 16;



	/* Dump 16 general-purpose registers to userspace in ascending order. */

	regs[index++] = tdx->vp_enter_ret;

	regs[index++] = tdx->vp_enter_args.rcx;

	regs[index++] = tdx->vp_enter_args.rdx;

	regs[index++] = tdx->vp_enter_args.rbx;

	regs[index++] = 0;

	regs[index++] = 0;

	regs[index++] = tdx->vp_enter_args.rsi;

	regs[index] = tdx->vp_enter_args.rdi;

	for (index = 0; index < 8; index++)

		regs[VCPU_REGS_R8 + index] = module_regs[index];



	return 0;

}



static int handle_tdvmcall(struct kvm_vcpu *vcpu)

{

	switch (tdvmcall_leaf(vcpu)) {

	case TDVMCALL_MAP_GPA:

		return tdx_map_gpa(vcpu);

	case TDVMCALL_REPORT_FATAL_ERROR:

		return tdx_report_fatal_error(vcpu);

	default:

		break;

	}

include/uapi/linux/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -375,6 +375,7 @@ struct kvm_run { 
#define KVM_SYSTEM_EVENT_WAKEUP         4

#define KVM_SYSTEM_EVENT_SUSPEND        5

#define KVM_SYSTEM_EVENT_SEV_TERM       6

#define KVM_SYSTEM_EVENT_TDX_FATAL      7

			__u32 type;

			__u32 ndata;

			union {