From: Eduardo Habkost <ehabkost@redhat.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
kvm@vger.kernel.org
Cc: Jim Mattson <jmattson@google.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
KarimAllah Ahmed <karahmed@amazon.de>,
David Woodhouse <dwmw2@infradead.org>
Subject: [PATCH] kvm: x86: Report STIBP on GET_SUPPORTED_CPUID
Date: Wed, 5 Dec 2018 17:19:56 -0200 [thread overview]
Message-ID: <20181205191956.31480-1-ehabkost@redhat.com> (raw)
Months ago, we have added code to allow direct access to MSR_IA32_SPEC_CTRL
to the guest, which makes STIBP available to guests. This was implemented
by commits d28b387fb74d ("KVM/VMX: Allow direct access to
MSR_IA32_SPEC_CTRL") and b2ac58f90540 ("KVM/SVM: Allow direct access to
MSR_IA32_SPEC_CTRL").
However, we never updated GET_SUPPORTED_CPUID to let userspace know that
STIBP can be enabled in CPUID. Fix that by updating
kvm_cpuid_8000_0008_ebx_x86_features and kvm_cpuid_7_0_edx_x86_features.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
arch/x86/kvm/cpuid.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 7bcfa61375c0..cc6dd65828a4 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -381,7 +381,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
/* cpuid 0x80000008.ebx */
const u32 kvm_cpuid_8000_0008_ebx_x86_features =
F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
- F(AMD_SSB_NO);
+ F(AMD_SSB_NO) | F(AMD_STIBP);
/* cpuid 0xC0000001.edx */
const u32 kvm_cpuid_C000_0001_edx_x86_features =
@@ -411,7 +411,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
/* cpuid 7.0.edx*/
const u32 kvm_cpuid_7_0_edx_x86_features =
F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
- F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES);
+ F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP);
/* all calls to cpuid_count() should be made on the same cpu */
get_cpu();
--
2.18.0.rc1.1.g3f1ff2140
next reply other threads:[~2018-12-05 19:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-05 19:19 Eduardo Habkost [this message]
2018-12-05 19:36 ` [PATCH] kvm: x86: Report STIBP on GET_SUPPORTED_CPUID Jim Mattson
2018-12-05 22:02 ` Konrad Rzeszutek Wilk
2018-12-05 22:47 ` Jim Mattson
2018-12-07 16:48 ` Eduardo Habkost
2018-12-14 10:55 ` Paolo Bonzini
2022-05-17 0:35 ` Jim Mattson
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