Commit bb9eadf0 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: MMU: micro-optimize gpte_access 



Avoid AND-NOT, most x86 processor lack an instruction for it.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6bb69c9b

arch/x86/kvm/paging_tmpl.h

+5 −2
Original line number Diff line number Diff line
@@ -189,8 +189,11 @@ static inline unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, u64 gpte) 
		((gpte & VMX_EPT_EXECUTABLE_MASK) ? ACC_EXEC_MASK : 0) |

		ACC_USER_MASK;

#else

	access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK;

	access &= ~(gpte >> PT64_NX_SHIFT);

	BUILD_BUG_ON(ACC_EXEC_MASK != PT_PRESENT_MASK);

	BUILD_BUG_ON(ACC_EXEC_MASK != 1);

	access = gpte & (PT_WRITABLE_MASK | PT_USER_MASK | PT_PRESENT_MASK);

	/* Combine NX with P (which is set here) to get ACC_EXEC_MASK.  */

	access ^= (gpte >> PT64_NX_SHIFT);

#endif



	return access;