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authorIsaku Yamahata <isaku.yamahata@intel.com>2025-02-27 09:20:06 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2025-03-14 14:20:57 -0400
commit3bf31b5786eaa362df31343f9cd7249eab0b6da3 (patch)
treeb07453060df89515d2755b5071077fb04ae9406d
parent4b2abc49712b2f50ee57d71a47f6a771b86f1bd8 (diff)
KVM: TDX: Handle TDX PV CPUID hypercall
Handle TDX PV CPUID hypercall for the CPUIDs virtualized by VMM according to TDX Guest Host Communication Interface (GHCI). For TDX, most CPUID leaf/sub-leaf combinations are virtualized by the TDX module while some trigger #VE. On #VE, TDX guest can issue TDG.VP.VMCALL<INSTRUCTION.CPUID> (same value as EXIT_REASON_CPUID) to request VMM to emulate CPUID operation. Morph PV CPUID hypercall to EXIT_REASON_CPUID and wire up to the KVM backend function. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> [binbin: rewrite changelog] Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com> Message-ID: <20250227012021.1778144-6-binbin.wu@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/vmx/tdx.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 9a03b189f64a..f0e11c24b4e6 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -844,6 +844,7 @@ int tdx_vcpu_pre_run(struct kvm_vcpu *vcpu)
static __always_inline u32 tdcall_to_vmx_exit_reason(struct kvm_vcpu *vcpu)
{
switch (tdvmcall_leaf(vcpu)) {
+ case EXIT_REASON_CPUID:
case EXIT_REASON_IO_INSTRUCTION:
return tdvmcall_leaf(vcpu);
case EXIT_REASON_EPT_VIOLATION:
@@ -1238,6 +1239,25 @@ static int tdx_report_fatal_error(struct kvm_vcpu *vcpu)
return 0;
}
+static int tdx_emulate_cpuid(struct kvm_vcpu *vcpu)
+{
+ u32 eax, ebx, ecx, edx;
+ struct vcpu_tdx *tdx = to_tdx(vcpu);
+
+ /* EAX and ECX for cpuid is stored in R12 and R13. */
+ eax = tdx->vp_enter_args.r12;
+ ecx = tdx->vp_enter_args.r13;
+
+ kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, false);
+
+ tdx->vp_enter_args.r12 = eax;
+ tdx->vp_enter_args.r13 = ebx;
+ tdx->vp_enter_args.r14 = ecx;
+ tdx->vp_enter_args.r15 = edx;
+
+ return 1;
+}
+
static int tdx_complete_pio_out(struct kvm_vcpu *vcpu)
{
vcpu->arch.pio.count = 0;
@@ -1912,6 +1932,8 @@ int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
case EXIT_REASON_EXTERNAL_INTERRUPT:
++vcpu->stat.irq_exits;
return 1;
+ case EXIT_REASON_CPUID:
+ return tdx_emulate_cpuid(vcpu);
case EXIT_REASON_TDCALL:
return handle_tdvmcall(vcpu);
case EXIT_REASON_VMCALL: