kevin/linux
1
Fork 0
Code

KVM: guest_memfd: extract __kvm_gmem_get_pfn()

Browse Source 
In preparation for adding a function that walks a set of pages
provided by userspace and populates them in a guest_memfd,
add a version of kvm_gmem_get_pfn() that has a "bool prepare"
argument and passes it down to kvm_gmem_get_folio().

Populating guest memory has to call repeatedly __kvm_gmem_get_pfn()
on the same file, so make the new function take struct file*.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2024-04-04 13:27:46 -04:00
parent 3bb2531e20
commit 17573fd971
1 changed files with 24 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
virt/kvm/guest_memfd.c
View File

@ -528,33 +528,29 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot)
fput(file);
}
int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
gfn_t gfn, kvm_pfn_t *pfn, int *max_order)
static int __kvm_gmem_get_pfn(struct file *file, struct kvm_memory_slot *slot,
gfn_t gfn, kvm_pfn_t *pfn, int *max_order, bool prepare)
{
pgoff_t index = gfn - slot->base_gfn + slot->gmem.pgoff;
struct kvm_gmem *gmem;
struct kvm_gmem *gmem = file->private_data;
struct folio *folio;
struct page *page;
struct file *file;
int r;
file = kvm_gmem_get_file(slot);
if (!file)
if (file != slot->gmem.file) {
WARN_ON_ONCE(slot->gmem.file);
return -EFAULT;
}
gmem = file->private_data;
if (xa_load(&gmem->bindings, index) != slot) {
WARN_ON_ONCE(xa_load(&gmem->bindings, index));
r = -EIO;
goto out_fput;
return -EIO;
}
folio = kvm_gmem_get_folio(file_inode(file), index, true);
if (IS_ERR(folio)) {
r = PTR_ERR(folio);
goto out_fput;
}
folio = kvm_gmem_get_folio(file_inode(file), index, prepare);
if (IS_ERR(folio))
return PTR_ERR(folio);
if (folio_test_hwpoison(folio)) {
r = -EHWPOISON;
@ -571,9 +567,21 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
out_unlock:
folio_unlock(folio);
out_fput:
fput(file);
return r;
}
int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
gfn_t gfn, kvm_pfn_t *pfn, int *max_order)
{
struct file *file = kvm_gmem_get_file(slot);
int r;
if (!file)
return -EFAULT;
r = __kvm_gmem_get_pfn(file, slot, gfn, pfn, max_order, true);
fput(file);
return r;
}
EXPORT_SYMBOL_GPL(kvm_gmem_get_pfn);