Patch "KVM: nSVM: CR3 MBZ bits are only 63:52" has been added to the 5.9-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    KVM: nSVM: CR3 MBZ bits are only 63:52

to the 5.9-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-nsvm-cr3-mbz-bits-are-only-63-52.patch
and it can be found in the queue-5.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit ffd59ebd0c8aaa56ebe4ea1ec303cf20d9176842
Author: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Date:   Sat Aug 29 00:48:22 2020 +0000

    KVM: nSVM: CR3 MBZ bits are only 63:52
    
    [ Upstream commit fb0f33fdefe9f473dc5f7b71345096c8d60ab9dd ]
    
    Commit 761e4169346553c180bbd4a383aedd72f905bc9a created a wrong mask for the
    CR3 MBZ bits. According to APM vol 2, only the upper 12 bits are MBZ.
    
    Fixes: 761e41693465 ("KVM: nSVM: Check that MBZ bits in CR3 and CR4 are not set on vmrun of nested guests", 2020-07-08)
    Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
    Message-Id: <20200829004824.4577-2-krish.sadhukhan@xxxxxxxxxx>
    Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index e90bc436f5849..27042c9ea40d6 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -243,7 +243,7 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb)
 	} else {
 		if (!(vmcb->save.cr4 & X86_CR4_PAE) ||
 		    !(vmcb->save.cr0 & X86_CR0_PE) ||
-		    (vmcb->save.cr3 & MSR_CR3_LONG_RESERVED_MASK))
+		    (vmcb->save.cr3 & MSR_CR3_LONG_MBZ_MASK))
 			return false;
 	}
 	if (kvm_valid_cr4(&svm->vcpu, vmcb->save.cr4))
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index a798e17317094..c0d75b1e06645 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -345,7 +345,7 @@ static inline bool gif_set(struct vcpu_svm *svm)
 /* svm.c */
 #define MSR_CR3_LEGACY_RESERVED_MASK		0xfe7U
 #define MSR_CR3_LEGACY_PAE_RESERVED_MASK	0x7U
-#define MSR_CR3_LONG_RESERVED_MASK		0xfff0000000000fe7U
+#define MSR_CR3_LONG_MBZ_MASK			0xfff0000000000000U
 #define MSR_INVALID				0xffffffffU
 
 u32 svm_msrpm_offset(u32 msr);