Commit 1441ca14 authored by Junaid Shahid's avatar Junaid Shahid Committed by Paolo Bonzini
Browse files

kvm: x86: mmu: Drop the need_remote_flush() function 



This is only used by kvm_mmu_pte_write(), which no longer actually
creates the new SPTE and instead just clears the old SPTE. So we
just need to check if the old SPTE was shadow-present instead of
calling need_remote_flush(). Hence we can drop this function. It was
incomplete anyway as it didn't take access-tracking into account.

This patch should not result in any functional change.

Signed-off-by: default avatarJunaid Shahid <junaids@google.com>
Reviewed-by: default avatarDavid Matlack <dmatlack@google.com>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20220723024316.2725328-1-junaids@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 959d6c4a

arch/x86/kvm/mmu/mmu.c

+1 −14
Original line number Diff line number Diff line
@@ -5361,19 +5361,6 @@ void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 
	__kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu);

}



static bool need_remote_flush(u64 old, u64 new)

{

	if (!is_shadow_present_pte(old))

		return false;

	if (!is_shadow_present_pte(new))

		return true;

	if ((old ^ new) & SPTE_BASE_ADDR_MASK)

		return true;

	old ^= shadow_nx_mask;

	new ^= shadow_nx_mask;

	return (old & ~new & SPTE_PERM_MASK) != 0;

}



static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa,

				    int *bytes)

{
@@ -5519,7 +5506,7 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 
			mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL);

			if (gentry && sp->role.level != PG_LEVEL_4K)

				++vcpu->kvm->stat.mmu_pde_zapped;

			if (need_remote_flush(entry, *spte))

			if (is_shadow_present_pte(entry))

				flush = true;

			++spte;

		}