[v2,2/3] KVM: x86/mmu: Remove superfluous is_error_pfn() check from THP adjust
diff mbox series

Message ID 20191111221229.24732-3-sean.j.christopherson@intel.com
State New
Headers show
Series
  • KVM: MMU: Fix a refcount bug with ZONE_DEVICE pages
Related show

Commit Message

Sean Christopherson Nov. 11, 2019, 10:12 p.m. UTC
Replace the is_error_noslot_pfn() check in transparent_hugepage_adjust()
with an is_noslot_pfn() check.  thp_adjust() cannot be reached with an
error pfn as it is always called after handle_abnormal_pfn(), which
aborts the page fault handler if an error pfn is encountered.  Don't
bother future proofing thp_adjust() with a WARN on is_error_pfn(), as
calling thp_adjust() before handle_abnormal_pfn() is impossible for all
intents and purposes, e.g. thp_adjust() relies on being called after
mmu_notifier_retry() and while holding mmu_lock, thus moving it would
essentially require a complete rewrite of KVM's page fault handlers.

No functional change intended.

Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch
diff mbox series

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index bf82b1f2e834..c35c6fb2635a 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3305,7 +3305,7 @@  static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
 	 * PT_PAGE_TABLE_LEVEL and there would be no adjustment done
 	 * here.
 	 */
-	if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) &&
+	if (!is_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) &&
 	    !kvm_is_zone_device_pfn(pfn) && level == PT_PAGE_TABLE_LEVEL &&
 	    PageTransCompoundMap(pfn_to_page(pfn)) &&
 	    !mmu_gfn_lpage_is_disallowed(vcpu, gfn, PT_DIRECTORY_LEVEL)) {