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authorSean Christopherson <seanjc@google.com>2024-10-10 20:23:31 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2024-10-25 18:57:59 +0200
commit3154ddcb6a9016f314a2f5f1293808ad07c5fab9 (patch)
tree365546c6cf7c18507bf46e7d574e4bfd4b9d4f00
parentKVM: Move kvm_{set,release}_page_{clean,dirty}() helpers up in kvm_main.c (diff)
downloadlinux-3154ddcb6a9016f314a2f5f1293808ad07c5fab9.tar.xz
linux-3154ddcb6a9016f314a2f5f1293808ad07c5fab9.zip
KVM: pfncache: Precisely track refcounted pages
Track refcounted struct page memory using kvm_follow_pfn.refcounted_page instead of relying on kvm_release_pfn_clean() to correctly detect that the pfn is associated with a struct page. Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20241010182427.1434605-30-seanjc@google.com>
-rw-r--r--virt/kvm/pfncache.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 067daf9ad6ef..728d2c1b488a 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -159,11 +159,14 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
kvm_pfn_t new_pfn = KVM_PFN_ERR_FAULT;
void *new_khva = NULL;
unsigned long mmu_seq;
+ struct page *page;
+
struct kvm_follow_pfn kfp = {
.slot = gpc->memslot,
.gfn = gpa_to_gfn(gpc->gpa),
.flags = FOLL_WRITE,
.hva = gpc->uhva,
+ .refcounted_page = &page,
};
lockdep_assert_held(&gpc->refresh_lock);
@@ -198,7 +201,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
if (new_khva != old_khva)
gpc_unmap(new_pfn, new_khva);
- kvm_release_pfn_clean(new_pfn);
+ kvm_release_page_unused(page);
cond_resched();
}
@@ -218,7 +221,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
new_khva = gpc_map(new_pfn);
if (!new_khva) {
- kvm_release_pfn_clean(new_pfn);
+ kvm_release_page_unused(page);
goto out_error;
}
@@ -236,11 +239,11 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
gpc->khva = new_khva + offset_in_page(gpc->uhva);
/*
- * Put the reference to the _new_ pfn. The pfn is now tracked by the
+ * Put the reference to the _new_ page. The page is now tracked by the
* cache and can be safely migrated, swapped, etc... as the cache will
* invalidate any mappings in response to relevant mmu_notifier events.
*/
- kvm_release_pfn_clean(new_pfn);
+ kvm_release_page_clean(page);
return 0;