KVM: x86: Supplement __cr4_reserved_bits() with X86_FEATURE_PCID check

[ Upstream commit 4683d758f48e6ae87d3d3493ffa00aceb955ee16 ] Commit 7a873e455567 ("KVM: selftests: Verify supported CR4 bits can be set before KVM_SET_CPUID2") reveals that KVM allows to set X86_CR4_PCIDE even when PCID support is missing: ==== Test Assertion Failure ==== x86_64/set_sregs_test.c:41: rc pid=6956 tid=6956 - Invalid argument 1 0x000000000040177d: test_cr4_feature_bit at set_sregs_test.c:41 2 0x00000000004014fc: main at set_sregs_test.c:119 3 0x00007f2d9346d041: ?? ??:0 4 0x000000000040164d: _start at ??:? KVM allowed unsupported CR4 bit (0x20000) Add X86_FEATURE_PCID feature check to __cr4_reserved_bits() to make kvm_is_valid_cr4() fail. Signed-off-by: Vitaly Kuznetsov <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
sourajitk · Mar 11, 2021 · c7ebe45 · c7ebe45
1 parent 422da31
commit c7ebe45
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
@@ -404,6 +404,8 @@ bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type);
 		__reserved_bits |= X86_CR4_UMIP;        \
 	if (!__cpu_has(__c, X86_FEATURE_VMX))           \
 		__reserved_bits |= X86_CR4_VMXE;        \
+	if (!__cpu_has(__c, X86_FEATURE_PCID))          \
+		__reserved_bits |= X86_CR4_PCIDE;       \
 	__reserved_bits;                                \
 })