Thread (154 messages) 154 messages, 12 authors, 2d ago
WARM2d

[PATCH v8 19/46] KVM: guest_memfd: Use actual size for invalidation in kvm_gmem_release()

From: Ackerley Tng via B4 Relay <devnull+ackerleytng.google.com@kernel.org>
Date: 2026-06-19 00:31:48
Also in: b4-sent, kvm, linux-doc, linux-kselftest, linux-mm, linux-trace-kernel, lkml
Subsystem: kernel virtual machine (kvm), the rest · Maintainers: Paolo Bonzini, Linus Torvalds

From: Ackerley Tng <redacted>

__kvm_gmem_invalidate_begin() and __kvm_gmem_invalidate_end() actually do
not specially handle -1ul. -1ul is used as a huge number, which legal
indices do not exceed, and hence the invalidation works as expected.

Since a later patch is going to make use of the exact range, calculate the
size of the guest_memfd inode and use it as the end range for invalidating
SPTEs.

Signed-off-by: Ackerley Tng <redacted>
---
 virt/kvm/guest_memfd.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index d163559da0235..d72ecbfcc3144 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -366,6 +366,7 @@ static long kvm_gmem_fallocate(struct file *file, int mode, loff_t offset,
 
 static int kvm_gmem_release(struct inode *inode, struct file *file)
 {
+	pgoff_t end = i_size_read(inode) >> PAGE_SHIFT;
 	struct gmem_file *f = file->private_data;
 	struct kvm_memory_slot *slot;
 	struct kvm *kvm = f->kvm;
@@ -396,9 +397,9 @@ static int kvm_gmem_release(struct inode *inode, struct file *file)
 	 * Zap all SPTEs pointed at by this file.  Do not free the backing
 	 * memory, as its lifetime is associated with the inode, not the file.
 	 */
-	__kvm_gmem_invalidate_start(f, 0, -1ul,
+	__kvm_gmem_invalidate_start(f, 0, end,
 				    kvm_gmem_get_invalidate_filter(inode));
-	__kvm_gmem_invalidate_end(f, 0, -1ul);
+	__kvm_gmem_invalidate_end(f, 0, end);
 
 	list_del(&f->entry);
 
-- 
2.55.0.rc0.738.g0c8ab3ebcc-goog

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help