[PATCH 06/21] KVM: x86/mmu: Move fast_page_fault() call above mmu_topup_memory_caches()

Sean Christopherson
2020-06-05T21:39:18Z

Avoid refilling the memory caches and potentially slow reclaim/swap when
handling a fast page fault, which does not need to allocate any new
objects.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/mmu/mmu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 5e773564ab20..4b4c3234d623 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4095,6 +4095,9 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
if (page_fault_handle_page_track(vcpu, error_code, gfn))
return RET_PF_EMULATE;

+ if (fast_page_fault(vcpu, gpa, error_code))
+ return RET_PF_RETRY;
+
r = mmu_topup_memory_caches(vcpu);
if (r)
return r;
@@ -4102,9 +4105,6 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
if (lpage_disallowed)
max_level = PG_LEVEL_4K;

- if (fast_page_fault(vcpu, gpa, error_code))
- return RET_PF_RETRY;
-
mmu_seq = vcpu->kvm->mmu_notifier_seq;
smp_rmb();

--
2.26.0