From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Tom Lendacky <thomas.lendacky@amd.com>,
Borislav Petkov <bp@suse.de>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH 05/13] KVM: x86: Override reported SME/SEV feature flags with host mask
Date: Fri, 8 Jan 2021 16:47:06 -0800 [thread overview]
Message-ID: <20210109004714.1341275-6-seanjc@google.com> (raw)
In-Reply-To: <20210109004714.1341275-1-seanjc@google.com>
Add a reverse-CPUID entry for the memory encryption word, 0x8000001F.EAX,
and use it to override the supported CPUID flags reported to userspace.
Masking the reported CPUID flags avoids over-reporting KVM support, e.g.
without the mask a SEV-SNP capable CPU may incorrectly advertise SNP
support to userspace.
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/cpuid.c | 2 ++
arch/x86/kvm/cpuid.h | 1 +
2 files changed, 3 insertions(+)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 13036cf0b912..b7618cdd06b5 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -855,6 +855,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
case 0x8000001F:
if (!boot_cpu_has(X86_FEATURE_SEV))
entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ else
+ cpuid_entry_override(entry, CPUID_8000_001F_EAX);
break;
/*Add support for Centaur's CPUID instruction*/
case 0xC0000000:
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index dc921d76e42e..8b6fc9bde248 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -63,6 +63,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
[CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
[CPUID_7_EDX] = { 7, 0, CPUID_EDX},
[CPUID_7_1_EAX] = { 7, 1, CPUID_EAX},
+ [CPUID_8000_001F_EAX] = {0x8000001f, 1, CPUID_EAX},
};
/*
--
2.30.0.284.gd98b1dd5eaa7-goog
next prev parent reply other threads:[~2021-01-09 0:49 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-09 0:47 [PATCH 00/13] KVM: SVM: Misc SEV cleanups Sean Christopherson
2021-01-09 0:47 ` [PATCH 01/13] KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails Sean Christopherson
2021-01-11 14:42 ` Tom Lendacky
2021-01-11 18:07 ` Sean Christopherson
2021-01-09 0:47 ` [PATCH 02/13] KVM: SVM: Zero out the VMCB array used to track SEV ASID association Sean Christopherson
2021-01-09 0:47 ` [PATCH 03/13] KVM: SVM: Move SEV module params/variables to sev.c Sean Christopherson
2021-01-11 10:42 ` Vitaly Kuznetsov
2021-01-11 15:36 ` Tom Lendacky
2021-01-11 16:58 ` Vitaly Kuznetsov
2021-01-12 22:18 ` Sean Christopherson
2021-01-11 15:30 ` Tom Lendacky
2021-01-09 0:47 ` [PATCH 04/13] x86/cpufeatures: Assign dedicated feature word for AMD mem encryption Sean Christopherson
2021-01-09 0:47 ` Sean Christopherson [this message]
2021-01-09 0:47 ` [PATCH 06/13] x86/sev: Rename global "sev_enabled" flag to "sev_guest" Sean Christopherson
2021-01-11 16:02 ` Tom Lendacky
2021-01-11 16:47 ` Tom Lendacky
2021-01-11 17:58 ` Sean Christopherson
2021-01-11 20:28 ` Sean Christopherson
2021-01-09 0:47 ` [PATCH 07/13] KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables Sean Christopherson
2021-01-11 16:03 ` Tom Lendacky
2021-01-09 0:47 ` [PATCH 08/13] KVM: SVM: Unconditionally invoke sev_hardware_teardown() Sean Christopherson
2021-01-09 0:47 ` [PATCH 09/13] KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() Sean Christopherson
2021-01-09 0:47 ` [PATCH 10/13] KVM: SVM: Move SEV VMCB tracking allocation to sev.c Sean Christopherson
2021-01-09 0:47 ` [PATCH 11/13] KVM: SVM: Drop redundant svm_sev_enabled() helper Sean Christopherson
2021-01-11 17:57 ` Tom Lendacky
2021-01-11 20:59 ` Sean Christopherson
2021-01-09 0:47 ` [PATCH 12/13] KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() Sean Christopherson
2021-01-09 0:47 ` [PATCH 13/13] KVM: SVM: Skip SEV cache flush if no ASIDs have been used Sean Christopherson
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