diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2024-07-11 18:27:45 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-07-26 14:46:14 -0400 |
| commit | d04c77d231223563405e8874fa7edfdc65e545fe (patch) | |
| tree | 74976dd8c68e1a920dc5e66a6c71852d118bcf78 /virt | |
| parent | d0d87226f535965b4dafc6ef79246456503a4503 (diff) | |
KVM: guest_memfd: delay folio_mark_uptodate() until after successful preparation
The up-to-date flag as is now is not too useful; it tells guest_memfd not
to overwrite the contents of a folio, but it doesn't say that the page
is ready to be mapped into the guest. For encrypted guests, mapping
a private page requires that the "preparation" phase has succeeded,
and at the same time the same page cannot be prepared twice.
So, ensure that folio_mark_uptodate() is only called on a prepared page. If
kvm_gmem_prepare_folio() or the post_populate callback fail, the folio
will not be marked up-to-date; it's not a problem to call clear_highpage()
again on such a page prior to the next preparation attempt.
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/guest_memfd.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index 522e1b28e7ae..1ea632dbae57 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -73,8 +73,6 @@ static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index, bool for (i = 0; i < nr_pages; i++) clear_highpage(folio_page(folio, i)); - - folio_mark_uptodate(folio); } if (prepare) { @@ -84,6 +82,8 @@ static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index, bool folio_put(folio); return ERR_PTR(r); } + + folio_mark_uptodate(folio); } /* @@ -646,6 +646,8 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long p = src ? src + i * PAGE_SIZE : NULL; ret = post_populate(kvm, gfn, pfn, p, max_order, opaque); + if (!ret) + folio_mark_uptodate(folio); folio_put(folio); if (ret) |