KVM: Use gfn instead of hva for mmu_notifier_retry

Currently in mmu_notifier invalidate path, hva range is recorded and then
checked against by mmu_invalidate_retry_hva() in the page fault handling
path. However, for the soon-to-be-introduced private memory, a page fault
may not have a hva associated, checking gfn(gpa) makes more sense.

For existing hva based shared memory, gfn is expected to also work. The
only downside is when aliasing multiple gfns to a single hva, the
current algorithm of checking multiple ranges could result in a much
larger range being rejected. Such aliasing should be uncommon, so the
impact is expected small.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
[sean: convert vmx_set_apic_access_page_addr() to gfn-based API]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Xu Yilun <yilun.xu@linux.intel.com>
Message-Id: <20231027182217.3615211-4-seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index b0f01d605617..b2d916f786ca 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3056,7 +3056,7 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
  *
  * There are several ways to safely use this helper:
  *
- * - Check mmu_invalidate_retry_hva() after grabbing the mapping level, before
+ * - Check mmu_invalidate_retry_gfn() after grabbing the mapping level, before
  *   consuming it.  In this case, mmu_lock doesn't need to be held during the
  *   lookup, but it does need to be held while checking the MMU notifier.
  *
@@ -4366,7 +4366,7 @@ static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
 		return true;
 
 	return fault->slot &&
-	       mmu_invalidate_retry_hva(vcpu->kvm, fault->mmu_seq, fault->hva);
+	       mmu_invalidate_retry_gfn(vcpu->kvm, fault->mmu_seq, fault->gfn);
 }
 
 static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
@@ -6260,7 +6260,9 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 
 	write_lock(&kvm->mmu_lock);
 
-	kvm_mmu_invalidate_begin(kvm, 0, -1ul);
+	kvm_mmu_invalidate_begin(kvm);
+
+	kvm_mmu_invalidate_range_add(kvm, gfn_start, gfn_end);
 
 	flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end);
 
@@ -6270,7 +6272,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 	if (flush)
 		kvm_flush_remote_tlbs_range(kvm, gfn_start, gfn_end - gfn_start);
 
-	kvm_mmu_invalidate_end(kvm, 0, -1ul);
+	kvm_mmu_invalidate_end(kvm);
 
 	write_unlock(&kvm->mmu_lock);
 }