From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Subject: xen: use vma_lookup() in privcmd_ioctl_mmap()

vma_lookup() walks the VMA tree for a specific value, find_vma() will
search the tree after walking to a specific value.  It is more efficient
to only walk to the requested value since privcmd_ioctl_mmap() will exit
the loop if vm_start != msg->va.

Link: https://lkml.kernel.org/r/20220426150616.3937571-21-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/xen/privcmd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/xen/privcmd.c~xen-use-vma_lookup-in-privcmd_ioctl_mmap
+++ a/drivers/xen/privcmd.c
@@ -282,7 +282,7 @@ static long privcmd_ioctl_mmap(struct fi
 						     struct page, lru);
 		struct privcmd_mmap_entry *msg = page_address(page);
 
-		vma = find_vma(mm, msg->va);
+		vma = vma_lookup(mm, msg->va);
 		rc = -EINVAL;
 
 		if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data)
_