linux-kernel - [PATCH 5.10 093/120] KVM: x86: Set so called reserved CR3 bits in LM mask at vCPU reset

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Date:   Mon,  8 Feb 2021 16:01:20 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH 5.10 093/120] KVM: x86: Set so called reserved CR3 bits in LM mask at vCPU reset

From: Sean Christopherson <seanjc@...gle.com>

commit 031b91a5fe6f1ce61b7617614ddde9ed61e252be upstream.

Set cr3_lm_rsvd_bits, which is effectively an invalid GPA mask, at vCPU
reset.  The reserved bits check needs to be done even if userspace never
configures the guest's CPUID model.

Cc: stable@...r.kernel.org
Fixes: 0107973a80ad ("KVM: x86: Introduce cr3_lm_rsvd_bits in kvm_vcpu_arch")
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
Message-Id: <20210204000117.3303214-2-seanjc@...gle.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/x86/kvm/x86.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9915,6 +9915,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu
 	fx_init(vcpu);
 
 	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
+	vcpu->arch.cr3_lm_rsvd_bits = rsvd_bits(cpuid_maxphyaddr(vcpu), 63);
 
 	vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;