Merge tag 'kvm-x86-gmem-6.20' of https://github.com/kvm-x86/linux into HEAD

KVM guest_memfd changes for 6.20

 - Remove kvm_gmem_populate()'s preparation tracking and half-baked hugepage
   handling, and instead rely on SNP (the only user of the tracking) to do its
   own tracking via the RMP.

 - Retroactively document and enforce (for SNP) that KVM_SEV_SNP_LAUNCH_UPDATE
   and KVM_TDX_INIT_MEM_REGION require the source page to be 4KiB aligned, to
   avoid non-trivial complexity for a non-existent usecase (and because
   in-place conversion simply can't support unaligned sources).

 - When populating guest_memfd memory, GUP the source page in common code and
   pass the refcounted page to the vendor callback, instead of letting vendor
   code do the heavy lifting.  Doing so avoids a looming deadlock bug with
   in-place due an AB-BA conflict betwee mmap_lock and guest_memfd's filemap
   invalidate lock.

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d93f75b05ae2..49c0cfe24fd8 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2566,7 +2566,7 @@ int kvm_arch_gmem_prepare(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int max_ord
  * @gfn: starting GFN to be populated
  * @src: userspace-provided buffer containing data to copy into GFN range
  *       (passed to @post_populate, and incremented on each iteration
- *       if not NULL)
+ *       if not NULL). Must be page-aligned.
  * @npages: number of pages to copy from userspace-buffer
  * @post_populate: callback to issue for each gmem page that backs the GPA
  *                 range
@@ -2581,7 +2581,7 @@ int kvm_arch_gmem_prepare(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int max_ord
  * Returns the number of pages that were populated.
  */
 typedef int (*kvm_gmem_populate_cb)(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
-				    void __user *src, int order, void *opaque);
+				    struct page *page, void *opaque);
 
 long kvm_gmem_populate(struct kvm *kvm, gfn_t gfn, void __user *src, long npages,
 		       kvm_gmem_populate_cb post_populate, void *opaque);