The patch below does not apply to the 5.12-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 17e368d94af77c1533bfd4136e080a33a6330282 Mon Sep 17 00:00:00 2001
From: Sean Christopherson seanjc@google.com Date: Thu, 4 Mar 2021 17:10:54 -0800 Subject: [PATCH] KVM: x86/mmu: Set the C-bit in the PDPTRs and LM pseudo-PDPTRs
Set the C-bit in SPTEs that are set outside of the normal MMU flows, specifically the PDPDTRs and the handful of special cased "LM root" entries, all of which are shadow paging only.
Note, the direct-mapped-root PDPTR handling is needed for the scenario where paging is disabled in the guest, in which case KVM uses a direct mapped MMU even though TDP is disabled.
Fixes: d0ec49d4de90 ("kvm/x86/svm: Support Secure Memory Encryption within KVM") Cc: stable@vger.kernel.org Cc: Brijesh Singh brijesh.singh@amd.com Cc: Tom Lendacky thomas.lendacky@amd.com Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20210305011101.3597423-11-seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index da94734272db..ff7e050ba1ac 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3261,7 +3261,8 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), i << 30, PT32_ROOT_LEVEL, true); - mmu->pae_root[i] = root | PT_PRESENT_MASK; + mmu->pae_root[i] = root | PT_PRESENT_MASK | + shadow_me_mask; } mmu->root_hpa = __pa(mmu->pae_root); } else @@ -3314,7 +3315,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) * or a PAE 3-level page table. In either case we need to be aware that * the shadow page table may be a PAE or a long mode page table. */ - pm_mask = PT_PRESENT_MASK; + pm_mask = PT_PRESENT_MASK | shadow_me_mask; if (mmu->shadow_root_level == PT64_ROOT_4LEVEL) { pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK;