[v13,03/85] KVM: Add kvm_release_page_unused() API to put pages that KVM never consumes

Commit Message

Sean Christopherson Oct. 10, 2024, 6:23 p.m. UTC

Add an API to release an unused page, i.e. to put a page without marking
it accessed or dirty.  The API will be used when KVM faults-in a page but
bails before installing the guest mapping (and other similar flows).

Reviewed-by: Alex Bennée <[e-mail]>
Tested-by: Alex Bennée <[e-mail]>
Signed-off-by: Sean Christopherson <[e-mail]>
---
 include/linux/kvm_host.h | 9 +++++++++
 1 file changed, 9 insertions(+)

Patch

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ee186a1fbaad..ab4485b2bddc 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1216,6 +1216,15 @@  unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable);
 unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn);
 unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot, gfn_t gfn,
 				      bool *writable);
+
+static inline void kvm_release_page_unused(struct page *page)
+{
+	if (!page)
+		return;
+
+	put_page(page);
+}
+
 void kvm_release_page_clean(struct page *page);
 void kvm_release_page_dirty(struct page *page);