[PATCH 5.9 570/757] KVM: nSVM: CR3 MBZ bits are only 63:52

Greg Kroah-Hartman
2020-10-27T16:39:49Z

From: Krish Sadhukhan <krish.sadhukhan@oracle.com>

[ 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@oracle.com>
Message-Id: <20200829004824.4577-2-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kvm/svm/nested.c | 2 +-
arch/x86/kvm/svm/svm.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

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);
--
2.25.1