[PATCH 01/23] KVM: x86/mmu: Optimize MMU page cache lookup for all direct SPs

[David Matlack <dmatlack@google.com>]

Commit fb58a9c345f6 ("KVM: x86/mmu: Optimize MMU page cache lookup for
fully direct MMUs") skipped the unsync checks and write flood clearing
for full direct MMUs. We can extend this further and skip the checks for
all direct shadow pages. Direct shadow pages are never marked unsynced
or have a non-zero write-flooding count.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
---
 arch/x86/kvm/mmu/mmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 296f8723f9ae..6ca38277f2ab 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2052,7 +2052,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 					     int direct,
 					     unsigned int access)
 {
-	bool direct_mmu = vcpu->arch.mmu->direct_map;
 	union kvm_mmu_page_role role;
 	struct hlist_head *sp_list;
 	unsigned quadrant;
@@ -2093,7 +2092,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 			continue;
 		}
 
-		if (direct_mmu)
+		/* unsync and write-flooding only apply to indirect SPs. */
+		if (sp->role.direct)
 			goto trace_get_page;
 
 		if (sp->unsync) {
-- 
2.35.0.rc2.247.g8bbb082509-goog