KVM: x86/emulator: Emulate RDPID only if it is enabled in guest

When RDTSCP is supported but RDPID is not supported in host,
RDPID emulation is available. However, __kvm_get_msr() would
only fail when RDTSCP/RDPID both are disabled in guest, so
the emulator wouldn't inject a #UD when RDPID is disabled but
RDTSCP is enabled in guest.

Fixes: fb6d4d340e ("KVM: x86: emulate RDPID")
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Message-Id: <1dfd46ae5b76d3ed87bde3154d51c64ea64c99c1.1646226788.git.houwenlong.hwl@antgroup.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Hou Wenlong 2022-03-02 21:15:14 +08:00 committed by Paolo Bonzini
parent e644896f51
commit a836839cbf
3 changed files with 10 additions and 1 deletions

View File

@ -3521,8 +3521,10 @@ static int em_rdpid(struct x86_emulate_ctxt *ctxt)
{
u64 tsc_aux = 0;
if (ctxt->ops->get_msr(ctxt, MSR_TSC_AUX, &tsc_aux))
if (!ctxt->ops->guest_has_rdpid(ctxt))
return emulate_ud(ctxt);
ctxt->ops->get_msr(ctxt, MSR_TSC_AUX, &tsc_aux);
ctxt->dst.val = tsc_aux;
return X86EMUL_CONTINUE;
}

View File

@ -226,6 +226,7 @@ struct x86_emulate_ops {
bool (*guest_has_long_mode)(struct x86_emulate_ctxt *ctxt);
bool (*guest_has_movbe)(struct x86_emulate_ctxt *ctxt);
bool (*guest_has_fxsr)(struct x86_emulate_ctxt *ctxt);
bool (*guest_has_rdpid)(struct x86_emulate_ctxt *ctxt);
void (*set_nmi_mask)(struct x86_emulate_ctxt *ctxt, bool masked);

View File

@ -7728,6 +7728,11 @@ static bool emulator_guest_has_fxsr(struct x86_emulate_ctxt *ctxt)
return guest_cpuid_has(emul_to_vcpu(ctxt), X86_FEATURE_FXSR);
}
static bool emulator_guest_has_rdpid(struct x86_emulate_ctxt *ctxt)
{
return guest_cpuid_has(emul_to_vcpu(ctxt), X86_FEATURE_RDPID);
}
static ulong emulator_read_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg)
{
return kvm_register_read_raw(emul_to_vcpu(ctxt), reg);
@ -7810,6 +7815,7 @@ static const struct x86_emulate_ops emulate_ops = {
.guest_has_long_mode = emulator_guest_has_long_mode,
.guest_has_movbe = emulator_guest_has_movbe,
.guest_has_fxsr = emulator_guest_has_fxsr,
.guest_has_rdpid = emulator_guest_has_rdpid,
.set_nmi_mask = emulator_set_nmi_mask,
.get_hflags = emulator_get_hflags,
.exiting_smm = emulator_exiting_smm,