If __kvm_gmem_get_pfn() detects an hwpoisoned page, it returns -EHWPOISON
but it does not put back the reference that kvm_gmem_get_folio() had
grabbed. Move the whole check to kvm_gmem_get_folio(), via an __-prefixed
function. This removes a "goto" and simplifies the code.
Now even fallocate() is prevented from picking an hwpoisoned page successfully.
This is temporary until the page allocation flow is cleaned up.
Signed-off-by: Paolo Bonzini <[email protected]>
---
virt/kvm/guest_memfd.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 9714add38852..53742ec34a31 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -49,7 +49,7 @@ static int kvm_gmem_prepare_folio(struct inode *inode, pgoff_t index, struct fol
return 0;
}
-static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index, bool prepare)
+static struct folio *__kvm_gmem_get_folio(struct inode *inode, pgoff_t index)
{
struct folio *folio;
@@ -58,6 +58,19 @@ static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index, bool
if (IS_ERR(folio))
return folio;
+ if (folio_test_hwpoison(folio)) {
+ folio_unlock(folio);
+ folio_put(folio);
+ folio = ERR_PTR(-EHWPOISON);
+ }
+
+ return folio;
+}
+
+static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index, bool prepare)
+{
+ struct folio *folio = __kvm_gmem_get_folio(inode, index);
+
/*
* Use the up-to-date flag to track whether or not the memory has been
* zeroed before being handed off to the guest. There is no backing
@@ -549,7 +562,6 @@ static int __kvm_gmem_get_pfn(struct file *file, struct kvm_memory_slot *slot,
struct kvm_gmem *gmem = file->private_data;
struct folio *folio;
struct page *page;
- int r;
if (file != slot->gmem.file) {
WARN_ON_ONCE(slot->gmem.file);
@@ -566,23 +578,14 @@ static int __kvm_gmem_get_pfn(struct file *file, struct kvm_memory_slot *slot,
if (IS_ERR(folio))
return PTR_ERR(folio);
- if (folio_test_hwpoison(folio)) {
- r = -EHWPOISON;
- goto out_unlock;
- }
-
page = folio_file_page(folio, index);
*pfn = page_to_pfn(page);
if (max_order)
*max_order = 0;
- r = 0;
-
-out_unlock:
folio_unlock(folio);
-
- return r;
+ return 0;
}
int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
--
2.43.0