From: Hou Wenlong houwenlong.hwl@antgroup.com
[ Upstream commit a836839cbfe60dc434c5476a7429cf2bae36415d ]
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: fb6d4d340e05 ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kvm/emulate.c | 4 +++- arch/x86/kvm/kvm_emulate.h | 1 + arch/x86/kvm/x86.c | 6 ++++++ 3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 4cf0938a876b..3747a754a8e8 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3514,8 +3514,10 @@ 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; } diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h index 68b420289d7e..fb09cd22cb7f 100644 --- a/arch/x86/kvm/kvm_emulate.h +++ b/arch/x86/kvm/kvm_emulate.h @@ -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);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3e606a6940dc..5e2983959f23 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7393,6 +7393,11 @@ 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); @@ -7475,6 +7480,7 @@ 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,