This is a note to let you know that I've just added the patch titled KVM: x86: Reset MMU context if guest toggles CR4.SMAP or CR4.PKE to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-x86-reset-mmu-context-if-guest-toggles-cr4.smap-.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 91ff03c94a74ba41c3ae1580c0f5262636ce1f53 Author: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Date: Wed Sep 23 14:53:52 2020 -0700 KVM: x86: Reset MMU context if guest toggles CR4.SMAP or CR4.PKE [ Upstream commit 8d214c481611b29458a57913bd786f0ac06f0605 ] Reset the MMU context during kvm_set_cr4() if SMAP or PKE is toggled. Recent commits to (correctly) not reload PDPTRs when SMAP/PKE are toggled inadvertantly skipped the MMU context reset due to the mask of bits that triggers PDPTR loads also being used to trigger MMU context resets. Fixes: 427890aff855 ("kvm: x86: Toggling CR4.SMAP does not load PDPTEs in PAE mode") Fixes: cb957adb4ea4 ("kvm: x86: Toggling CR4.PKE does not load PDPTEs in PAE mode") Cc: Jim Mattson <jmattson@xxxxxxxxxx> Cc: Peter Shier <pshier@xxxxxxxxxx> Cc: Oliver Upton <oupton@xxxxxxxxxx> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Message-Id: <20200923215352.17756-1-sean.j.christopherson@xxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 67ad417a29ca4..12e83297ea020 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -973,6 +973,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) unsigned long old_cr4 = kvm_read_cr4(vcpu); unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_SMEP; + unsigned long mmu_role_bits = pdptr_bits | X86_CR4_SMAP | X86_CR4_PKE; if (kvm_valid_cr4(vcpu, cr4)) return 1; @@ -1000,7 +1001,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) if (kvm_x86_ops->set_cr4(vcpu, cr4)) return 1; - if (((cr4 ^ old_cr4) & pdptr_bits) || + if (((cr4 ^ old_cr4) & mmu_role_bits) || (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE))) kvm_mmu_reset_context(vcpu);