From: Jim Mattson <jmattson@google.com>
To: Avi Kivity <avi@redhat.com>, Babu Moger <babu.moger@amd.com>,
Borislav Petkov <bp@alien8.de>,
"Chang S. Bae" <chang.seok.bae@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
Joerg Roedel <joerg.roedel@amd.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Paolo Bonzini <pbonzini@redhat.com>,
Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Sean Christopherson <seanjc@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Wyes Karny <wyes.karny@amd.com>,
x86@kernel.org
Cc: Jim Mattson <jmattson@google.com>
Subject: [PATCH 5/5] KVM: svm: Set X86_FEATURE_NO_LMSLE when !nested
Date: Thu, 15 Sep 2022 21:58:32 -0700 [thread overview]
Message-ID: <20220916045832.461395-6-jmattson@google.com> (raw)
In-Reply-To: <20220916045832.461395-1-jmattson@google.com>
KVM has never allowed a guest to set EFER.LMSLE when the "nested"
module parameter was false. In the past, there was no way for a guest
to know whether or not this was a legal EFER bit. Now, we can let the
guest know this bit is illegal by reporting X86_FEATURE_NO_LMSLE in
KVM_GET_SUPPORTED_CPUID.
Signed-off-by: Jim Mattson <jmattson@google.com>
---
arch/x86/kvm/svm/svm.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 7c4fd594166c..942602d503ad 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4945,6 +4945,8 @@ static __init void svm_set_cpu_caps(void)
if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) ||
boot_cpu_has(X86_FEATURE_AMD_SSBD))
kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD);
+ if (!nested)
+ kvm_cpu_cap_set(X86_FEATURE_NO_LMSLE);
/* AMD PMU PERFCTR_CORE CPUID */
if (enable_pmu && boot_cpu_has(X86_FEATURE_PERFCTR_CORE))
--
2.37.3.968.ga6b4b080e4-goog
prev parent reply other threads:[~2022-09-16 4:59 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-16 4:58 [PATCH 0/5] KVM: EFER.LMSLE cleanup Jim Mattson
2022-09-16 4:58 ` [PATCH 1/5] x86/cpufeatures: Introduce X86_FEATURE_NO_LMSLE Jim Mattson
2022-09-16 4:58 ` [PATCH 2/5] KVM: svm: Disallow EFER.LMSLE on hardware that doesn't support it Jim Mattson
2022-09-16 20:14 ` Sean Christopherson
2022-09-16 21:00 ` Jim Mattson
2022-09-16 22:09 ` Borislav Petkov
2022-09-16 22:33 ` Sean Christopherson
2022-09-18 19:04 ` Borislav Petkov
2022-09-19 18:09 ` Jim Mattson
2022-09-16 4:58 ` [PATCH 3/5] KVM: x86: Report host's X86_FEATURE_NO_LMSLE in KVM_GET_SUPPORTED_CPUID Jim Mattson
2022-09-16 4:58 ` [PATCH 4/5] KVM: x86: Enforce X86_FEATURE_NO_LMSLE in guest cpuid Jim Mattson
2022-09-16 4:58 ` Jim Mattson [this message]
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