From: Xiaoyao Li <xiaoyao...@intel.com> Just mark XFD as always supported for TDX. This simple solution relies on the fact KVM will report XFD as 0 when it's not supported by the hardware.
Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com> Reviewed-by: Zhao Liu <zhao1....@intel.com> Link: https://lore.kernel.org/r/20250508150002.689633-49-xiaoyao...@intel.com Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- target/i386/cpu.h | 1 + target/i386/kvm/tdx.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/target/i386/cpu.h b/target/i386/cpu.h index b38e691f1af..8a4b4217d02 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1122,6 +1122,7 @@ uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord w); #define CPUID_XSAVE_XSAVEC (1U << 1) #define CPUID_XSAVE_XGETBV1 (1U << 2) #define CPUID_XSAVE_XSAVES (1U << 3) +#define CPUID_XSAVE_XFD (1U << 4) #define CPUID_6_EAX_ARAT (1U << 2) diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c index 188c2242d53..0f7f47c6da8 100644 --- a/target/i386/kvm/tdx.c +++ b/target/i386/kvm/tdx.c @@ -621,6 +621,12 @@ static void tdx_add_supported_cpuid_by_xfam(void) e->edx |= (tdx_caps->supported_xfam & CPUID_XSTATE_XCR0_MASK) >> 32; e = find_in_supported_entry(0xd, 1); + /* + * Mark XFD always support for TDX, it will be cleared finally in + * tdx_adjust_cpuid_features() if XFD is unavailable on the hardware + * because in this case the original data has it as 0. + */ + e->eax |= CPUID_XSAVE_XFD; e->ecx |= (tdx_caps->supported_xfam & CPUID_XSTATE_XSS_MASK); e->edx |= (tdx_caps->supported_xfam & CPUID_XSTATE_XSS_MASK) >> 32; } -- 2.49.0
