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authorSean Christopherson <seanjc@google.com>2022-04-29 21:00:21 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2022-05-25 05:23:41 -0400
commit3dddf65b4f4c451c345d34ae85bdf1791a746e49 (patch)
tree8b068db831c9b8db6a179763a710adec69a75469
parent345b0fd6fe5f66dfe841bad0b39dd11a5672df68 (diff)
downloadlinux-3dddf65b4f4c451c345d34ae85bdf1791a746e49.tar.gz
KVM: Put the extra pfn reference when reusing a pfn in the gpc cache
Put the struct page reference to pfn acquired by hva_to_pfn() when the
old and new pfns for a gfn=>pfn cache match.  The cache already has a
reference via the old/current pfn, and will only put one reference when
the cache is done with the pfn.

Fixes: 982ed0de4753 ("KVM: Reinstate gfn_to_pfn_cache with invalidation support")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220429210025.3293691-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--virt/kvm/pfncache.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index e05a6a1b8eff..40cbe90d52e0 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -206,6 +206,14 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
 
 		if (gpc->usage & KVM_HOST_USES_PFN) {
 			if (new_pfn == old_pfn) {
+				/*
+				 * Reuse the existing pfn and khva, but put the
+				 * reference acquired hva_to_pfn_retry(); the
+				 * cache still holds a reference to the pfn
+				 * from the previous refresh.
+				 */
+				gpc_release_pfn_and_khva(kvm, new_pfn, NULL);
+
 				new_khva = old_khva;
 				old_pfn = KVM_PFN_ERR_FAULT;
 				old_khva = NULL;