[PATCH v3 05/11] KVM: VMX: Do Hyper-V TLB flush iff vCPU's EPTP hasn't been flushed

From: Sean Christopherson
Date: Tue Oct 27 2020 - 17:34:37 EST


Combine the for-loops for Hyper-V TLB EPTP checking and flushing, and in
doing so skip flushes for vCPUs whose EPTP matches the target EPTP.

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 23 ++++++++---------------
1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f5e9e2f61e10..17b228c4ba19 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -505,33 +505,26 @@ static int hv_remote_flush_tlb_with_range(struct kvm *kvm,

spin_lock(&kvm_vmx->ept_pointer_lock);

- if (kvm_vmx->ept_pointers_match == EPT_POINTERS_CHECK) {
+ if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) {
kvm_vmx->ept_pointers_match = EPT_POINTERS_MATCH;
kvm_vmx->hv_tlb_eptp = INVALID_PAGE;

kvm_for_each_vcpu(i, vcpu, kvm) {
tmp_eptp = to_vmx(vcpu)->ept_pointer;
- if (!VALID_PAGE(tmp_eptp))
+ if (!VALID_PAGE(tmp_eptp) ||
+ tmp_eptp == kvm_vmx->hv_tlb_eptp)
continue;

- if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp)) {
+ if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp))
kvm_vmx->hv_tlb_eptp = tmp_eptp;
- } else if (kvm_vmx->hv_tlb_eptp != tmp_eptp) {
- kvm_vmx->hv_tlb_eptp = INVALID_PAGE;
+ else
kvm_vmx->ept_pointers_match
= EPT_POINTERS_MISMATCH;
- break;
- }
- }
- }

- if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) {
- kvm_for_each_vcpu(i, vcpu, kvm) {
- /* If ept_pointer is invalid pointer, bypass flush request. */
- if (VALID_PAGE(to_vmx(vcpu)->ept_pointer))
- ret |= hv_remote_flush_eptp(to_vmx(vcpu)->ept_pointer,
- range);
+ ret |= hv_remote_flush_eptp(tmp_eptp, range);
}
+ if (kvm_vmx->ept_pointers_match == EPT_POINTERS_MISMATCH)
+ kvm_vmx->hv_tlb_eptp = INVALID_PAGE;
} else if (VALID_PAGE(kvm_vmx->hv_tlb_eptp)) {
ret = hv_remote_flush_eptp(kvm_vmx->hv_tlb_eptp, range);
}
--
2.28.0