[PATCH V3 12/13] KVM/VMX: Change hv flush logic when ept tables are mismatched.

[Tianyu Lan]

If ept table pointers are mismatched, flushing tlb for each vcpus via
hv flush interface still helps to reduce vmexits which are triggered
by IPI and INEPT emulation.

Signed-off-by: Lan Tianyu <tianyu....@microsoft.com>
---
 arch/x86/kvm/vmx.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 533a327372c8..2869c3e78168 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1557,7 +1557,8 @@ static void check_ept_pointer_match(struct kvm *kvm)
 
 static int vmx_hv_remote_flush_tlb(struct kvm *kvm)
 {
-       int ret;
+       struct kvm_vcpu *vcpu;
+       int ret = -ENOTSUPP, i;
 
        spin_lock(&to_kvm_vmx(kvm)->ept_pointer_lock);
 
@@ -1565,14 +1566,14 @@ static int vmx_hv_remote_flush_tlb(struct kvm *kvm)
                check_ept_pointer_match(kvm);
 
        if (to_kvm_vmx(kvm)->ept_pointers_match != EPT_POINTERS_MATCH) {
-               ret = -ENOTSUPP;
-               goto out;
+               kvm_for_each_vcpu(i, vcpu, kvm)
+                       ret |= hyperv_flush_guest_mapping(
+                               to_vmx(kvm_get_vcpu(kvm, i))->ept_pointer);
+       } else {
+               ret = hyperv_flush_guest_mapping(
+                               to_vmx(kvm_get_vcpu(kvm, 0))->ept_pointer);
        }
 
-       ret = hyperv_flush_guest_mapping(
-                       to_vmx(kvm_get_vcpu(kvm, 0))->ept_pointer);
-
-out:
        spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock);
        return ret;
 }
-- 
2.14.4