[RFC PATCH v2 22/25] KVM: x86/mmu: Refactor kvm_mmu_invlpg() to allow skipping the gva flush

[Yosry Ahmed]

Refactor helpers out of kvm_mmu_invalidate_addr() and kvm_mmu_invlpg()
that take in an extra argument to skip the GVA flush.

This will be used when invalidating GVAs in a different context than the
correct one (i.e.  invalidating an L2 GVA from L1), so flushing the
current context would flush the wrong TLB entries.

No functional change intended.

Signed-off-by: Yosry Ahmed <yosry@xxxxxxxxxx>
---
 arch/x86/kvm/mmu/mmu.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 65c35ed8f4a01..3feb75732f7b4 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6615,15 +6615,15 @@ static void kvm_mmu_invalidate_addr_in_root(struct kvm_vcpu *vcpu,
 	write_unlock(&vcpu->kvm->mmu_lock);
 }
 
-void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
-			     u64 addr, unsigned long roots)
+static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
+				      u64 addr, unsigned long roots, bool flush_gva)
 {
 	int i;
 
 	WARN_ON_ONCE(roots & ~KVM_MMU_ROOTS_ALL);
 
 	/* It's actually a GPA for vcpu->arch.guest_mmu.  */
-	if (mmu != &vcpu->arch.guest_mmu) {
+	if (flush_gva && mmu != &vcpu->arch.guest_mmu) {
 		/* INVLPG on a non-canonical address is a NOP according to the SDM.  */
 		if (is_noncanonical_invlpg_address(addr, vcpu))
 			return;
@@ -6642,9 +6642,15 @@ void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 			kvm_mmu_invalidate_addr_in_root(vcpu, mmu, addr, mmu->prev_roots[i].hpa);
 	}
 }
+
+void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
+			       u64 addr, unsigned long roots)
+{
+	__kvm_mmu_invalidate_addr(vcpu, mmu, addr, roots, true);
+}
 EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_mmu_invalidate_addr);
 
-void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
+static void __kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva, bool flush_gva)
 {
 	/*
 	 * INVLPG is required to invalidate any global mappings for the VA,
@@ -6656,11 +6662,16 @@ void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
 	 * be synced when switching to that new cr3, so nothing needs to be
 	 * done here for them.
 	 */
-	kvm_mmu_invalidate_addr(vcpu, vcpu->arch.walk_mmu, gva, KVM_MMU_ROOTS_ALL);
+	__kvm_mmu_invalidate_addr(vcpu, vcpu->arch.walk_mmu, gva,
+				  KVM_MMU_ROOTS_ALL, flush_gva);
 	++vcpu->stat.invlpg;
 }
-EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_mmu_invlpg);
 
+void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
+{
+	__kvm_mmu_invlpg(vcpu, gva, true);
+}
+EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_mmu_invlpg);
 
 void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid)
 {
-- 
2.54.0.1136.gdb2ca164c4-goog