[PATCH v2 03/10] KVM: x86/mmu: Grab mmu_invalidate_seq in kvm_faultin_pfn()

[David Matlack <dmatlack@google.com>]

Grab mmu_invalidate_seq in kvm_faultin_pfn() and stash it in struct
kvm_page_fault. The eliminates duplicate code and reduces the amount of
parameters needed for is_page_fault_stale().

Preemptively split out __kvm_faultin_pfn() to a separate function for
use in subsequent commits.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
---
 arch/x86/kvm/mmu/mmu.c          | 21 ++++++++++++---------
 arch/x86/kvm/mmu/mmu_internal.h |  1 +
 arch/x86/kvm/mmu/paging_tmpl.h  |  6 +-----
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index ff428152abce..49dbe274c709 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4132,7 +4132,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
 	kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true);
 }
 
-static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
+static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 {
 	struct kvm_memory_slot *slot = fault->slot;
 	bool async;
@@ -4188,12 +4188,20 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 	return RET_PF_CONTINUE;
 }
 
+static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
+{
+	fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq;
+	smp_rmb();
+
+	return __kvm_faultin_pfn(vcpu, fault);
+}
+
 /*
  * Returns true if the page fault is stale and needs to be retried, i.e. if the
  * root was invalidated by a memslot update or a relevant mmu_notifier fired.
  */
 static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
-				struct kvm_page_fault *fault, int mmu_seq)
+				struct kvm_page_fault *fault)
 {
 	struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa);
 
@@ -4213,14 +4221,12 @@ static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
 		return true;
 
 	return fault->slot &&
-	       mmu_invalidate_retry_hva(vcpu->kvm, mmu_seq, fault->hva);
+	       mmu_invalidate_retry_hva(vcpu->kvm, fault->mmu_seq, fault->hva);
 }
 
 static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 {
 	bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
-
-	unsigned long mmu_seq;
 	int r;
 
 	fault->gfn = fault->addr >> PAGE_SHIFT;
@@ -4237,9 +4243,6 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	if (r)
 		return r;
 
-	mmu_seq = vcpu->kvm->mmu_invalidate_seq;
-	smp_rmb();
-
 	r = kvm_faultin_pfn(vcpu, fault);
 	if (r != RET_PF_CONTINUE)
 		return r;
@@ -4255,7 +4258,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	else
 		write_lock(&vcpu->kvm->mmu_lock);
 
-	if (is_page_fault_stale(vcpu, fault, mmu_seq))
+	if (is_page_fault_stale(vcpu, fault))
 		goto out_unlock;
 
 	r = make_mmu_pages_available(vcpu);
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 582def531d4d..1c0a1e7c796d 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -221,6 +221,7 @@ struct kvm_page_fault {
 	struct kvm_memory_slot *slot;
 
 	/* Outputs of kvm_faultin_pfn.  */
+	unsigned long mmu_seq;
 	kvm_pfn_t pfn;
 	hva_t hva;
 	bool map_writable;
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 39e0205e7300..98f4abce4eaf 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -791,7 +791,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 {
 	struct guest_walker walker;
 	int r;
-	unsigned long mmu_seq;
 	bool is_self_change_mapping;
 
 	pgprintk("%s: addr %lx err %x\n", __func__, fault->addr, fault->error_code);
@@ -838,9 +837,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	else
 		fault->max_level = walker.level;
 
-	mmu_seq = vcpu->kvm->mmu_invalidate_seq;
-	smp_rmb();
-
 	r = kvm_faultin_pfn(vcpu, fault);
 	if (r != RET_PF_CONTINUE)
 		return r;
@@ -871,7 +867,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	r = RET_PF_RETRY;
 	write_lock(&vcpu->kvm->mmu_lock);
 
-	if (is_page_fault_stale(vcpu, fault, mmu_seq))
+	if (is_page_fault_stale(vcpu, fault))
 		goto out_unlock;
 
 	r = make_mmu_pages_available(vcpu);
-- 
2.37.2.672.g94769d06f0-goog