[PATCH 2/3] xen/privcmd: report paged-out frames in PRIVCMD_MMAPBATCH ioctl

[David Vrabel <david.vrabel@citrix.com>]

From: David Vrabel <david.vrabel@citrix.com>

libxc handles paged-out frames in xc_map_foreign_bulk() and friends by
retrying the map operation.  libxc expects the PRIVCMD_MMAPBATCH ioctl
to report paged out frames by setting bit 31 in the mfn.

Do this for the PRIVCMD_MMAPBATCH ioctl if
xen_remap_domain_mfn_range() returned -ENOENT.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
 drivers/xen/privcmd.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index ccee0f1..f8c1b6d 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -255,10 +255,15 @@ static int mmap_batch_fn(void *data, void *state)
 {
 	xen_pfn_t *mfnp = data;
 	struct mmap_batch_state *st = state;
+	int ret;
 
-	if (xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
-				       st->vma->vm_page_prot, st->domain) < 0) {
-		*mfnp |= 0xf0000000U;
+	ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
+					 st->vma->vm_page_prot, st->domain);
+	if (ret < 0) {
+		if (ret == -ENOENT)
+			*mfnp |= 0x80000000U;
+		else
+			*mfnp |= 0xf0000000U;
 		st->err++;
 	}
 	st->va += PAGE_SIZE;
-- 
1.7.2.5