[PATCH RFC 34/39] xen/gntdev: xen_shim_domain() support

[Joao Martins]

From: Ankur Arora <ankur.a.arora@xxxxxxxxxx>

GNTTABOP_map_grant_ref treats host_addr as an OUT parameter for
xen_shim_domaim().

Accordingly it's updated in struct gnttab_unmap_grant_ref before it gets
used via GNTTABOP_unmap_grant_ref.

Co-developed-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
---
 drivers/xen/gntdev.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 5efc5eee9544..8540a51f7597 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -351,6 +351,8 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map)
 		}
 
 		map->unmap_ops[i].handle = map->map_ops[i].handle;
+		if (xen_shim_domain())
+			map->unmap_ops[i].host_addr = map->map_ops[i].host_addr;
 		if (use_ptemod)
 			map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
@@ -1122,7 +1124,9 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
 				(map->flags & GNTMAP_readonly))
 			goto out_unlock_put;
 	} else {
-		map->flags = GNTMAP_host_map;
+		map->flags = 0;
+		if (!xen_shim_domain())
+			map->flags = GNTMAP_host_map;
 		if (!(vma->vm_flags & VM_WRITE))
 			map->flags |= GNTMAP_readonly;
 	}
@@ -1207,7 +1211,7 @@ static int __init gntdev_init(void)
 {
 	int err;
 
-	if (!xen_domain())
+	if (!xen_domain() && !xen_shim_domain_get())
 		return -ENODEV;
 
 	use_ptemod = !xen_feature(XENFEAT_auto_translated_physmap);
@@ -1215,6 +1219,7 @@ static int __init gntdev_init(void)
 	err = misc_register(&gntdev_miscdev);
 	if (err != 0) {
 		pr_err("Could not register gntdev device\n");
+		xen_shim_domain_put();
 		return err;
 	}
 	return 0;
@@ -1223,6 +1228,7 @@ static int __init gntdev_init(void)
 static void __exit gntdev_exit(void)
 {
 	misc_deregister(&gntdev_miscdev);
+	xen_shim_domain_put();
 }
 
 module_init(gntdev_init);
-- 
2.11.0