The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f156abec725f945f9884bc6a5bd0dccb5aac16a8 Mon Sep 17 00:00:00 2001

From: Sean Christopherson seanjc@google.com Date: Wed, 3 Feb 2021 16:01:06 -0800 Subject: [PATCH] KVM: x86: Set so called 'reserved CR3 bits in LM mask' at vCPU reset

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@vger.kernel.org Fixes: 0107973a80ad ("KVM: x86: Introduce cr3_lm_rsvd_bits in kvm_vcpu_arch") Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20210204000117.3303214-2-seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 838ce5e9814b..10414a78b951 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10080,6 +10080,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *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;