diff options
| author | Xiaoyao Li <xiaoyao.li@intel.com> | 2025-05-08 10:59:58 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2025-05-28 19:35:55 +0200 |
| commit | deb9db6fb789cfe80527b75983e86137589227a4 (patch) | |
| tree | badf585c1c7bdbd65e56233c8a04204ca93d6983 | |
| parent | e3d1a4a6d1d61cf5fbd0e4b389cfb3976093739f (diff) | |
| download | qemu-deb9db6fb789cfe80527b75983e86137589227a4.zip qemu-deb9db6fb789cfe80527b75983e86137589227a4.tar.gz qemu-deb9db6fb789cfe80527b75983e86137589227a4.tar.bz2 | |
i386/tdx: Don't treat SYSCALL as unavailable
On Intel CPU, the value of CPUID_EXT2_SYSCALL depends on the mode of
the vcpu. It's 0 outside 64-bit mode and 1 in 64-bit mode.
The initial state of TDX vcpu is 32-bit protected mode. At the time of
calling KVM_TDX_GET_CPUID, vcpu hasn't started running so the value read
is 0.
In reality, 64-bit mode should always be supported. So mark
CPUID_EXT2_SYSCALL always supported to avoid false warning.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250508150002.689633-53-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | target/i386/kvm/tdx.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c index e474abf..7629302 100644 --- a/target/i386/kvm/tdx.c +++ b/target/i386/kvm/tdx.c @@ -845,6 +845,19 @@ static int tdx_check_features(X86ConfidentialGuest *cg, CPUState *cs) continue; } + /* Fixup for special cases */ + switch (w) { + case FEAT_8000_0001_EDX: + /* + * Intel enumerates SYSCALL bit as 1 only when processor in 64-bit + * mode and before vcpu running it's not in 64-bit mode. + */ + actual |= CPUID_EXT2_SYSCALL; + break; + default: + break; + } + requested = env->features[w]; unavailable = requested & ~actual; mark_unavailable_features(cpu, w, unavailable, unav_prefix); |