@@ -1116,7 +1116,6 @@ unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot, gfn_t gfn,
bool *writable);
void kvm_release_page_clean(struct page *page);
void kvm_release_page_dirty(struct page *page);
-void kvm_set_page_accessed(struct page *page);
kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
@@ -2798,18 +2798,40 @@ struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn)
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_page);
+static bool kvm_is_ad_tracked_page(struct page *page)
+{
+ /*
+ * Per page-flags.h, pages tagged PG_reserved "should in general not be
+ * touched (e.g. set dirty) except by its owner".
+ */
+ return !PageReserved(page);
+}
+
+static void kvm_set_page_dirty(struct page *page)
+{
+ if (kvm_is_ad_tracked_page(page))
+ SetPageDirty(page);
+}
+
+static void kvm_set_page_accessed(struct page *page)
+{
+ if (kvm_is_ad_tracked_page(page))
+ mark_page_accessed(page);
+}
+
void kvm_release_page_clean(struct page *page)
{
WARN_ON(is_error_page(page));
- kvm_release_pfn_clean(page_to_pfn(page));
+ kvm_set_page_accessed(page);
+ put_page(page);
}
EXPORT_SYMBOL_GPL(kvm_release_page_clean);
void kvm_release_pfn_clean(kvm_pfn_t pfn)
{
if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
- put_page(pfn_to_page(pfn));
+ kvm_release_page_clean(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
@@ -2817,40 +2839,34 @@ void kvm_release_page_dirty(struct page *page)
{
WARN_ON(is_error_page(page));
- kvm_release_pfn_dirty(page_to_pfn(page));
+ kvm_set_page_dirty(page);
+ kvm_release_page_clean(page);
}
EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
void kvm_release_pfn_dirty(kvm_pfn_t pfn)
{
- kvm_set_pfn_dirty(pfn);
- kvm_release_pfn_clean(pfn);
+ if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
+ kvm_release_page_dirty(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
-static bool kvm_is_ad_tracked_pfn(kvm_pfn_t pfn)
-{
- if (!pfn_valid(pfn))
- return false;
-
- /*
- * Per page-flags.h, pages tagged PG_reserved "should in general not be
- * touched (e.g. set dirty) except by its owner".
- */
- return !PageReserved(pfn_to_page(pfn));
-}
-
+/*
+ * Note, checking for an error/noslot pfn is the caller's responsibility when
+ * directly marking a page dirty/accessed. Unlike the "release" helpers, the
+ * "set" helpers are not to be unused when the pfn might point at garbage.
+ */
void kvm_set_pfn_dirty(kvm_pfn_t pfn)
{
- if (kvm_is_ad_tracked_pfn(pfn))
- SetPageDirty(pfn_to_page(pfn));
+ if (pfn_valid(pfn))
+ kvm_set_page_dirty(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
void kvm_set_pfn_accessed(kvm_pfn_t pfn)
{
- if (kvm_is_ad_tracked_pfn(pfn))
- mark_page_accessed(pfn_to_page(pfn));
+ if (pfn_valid(pfn))
+ kvm_set_page_accessed(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
Invert the order of KVM's page/pfn release helpers so that the "inner" helper operates on a page instead of a pfn. As pointed out by Linus[*], converting between struct page and a pfn isn't necessarily cheap, and that's not even counting the overhead of is_error_noslot_pfn() and kvm_is_reserved_pfn(). Even if the checks were dirt cheap, there's no reason to convert from a page to a pfn and back to a page, just to mark the page dirty/accessed or to put a reference to the page. Opportunistically drop a stale declaration of kvm_set_page_accessed() from kvm_host.h (there was no implementation). No functional change intended. [*] https://lore.kernel.org/all/CAHk-=wifQimj2d6npq-wCi5onYPjzQg4vyO4tFcPJJZr268cRw@mail.gmail.com Signed-off-by: Sean Christopherson <seanjc@google.com> --- include/linux/kvm_host.h | 1 - virt/kvm/kvm_main.c | 58 +++++++++++++++++++++++++--------------- 2 files changed, 37 insertions(+), 22 deletions(-)