Legacy (non-pvops) gntdev drivers may require this to be done when the
number of grants intended to be used simultaneously exceeds a certain
driver specific default limit.
Change in v2: Double the number requested, as we need to account for
the allocations needing to happen in contiguous chunks. The worst case
number would be max_req * max_seg + (max_req - 1) * (max_seg - 1) + 1,
but in order to keep things simple just use 2 * max_req * max_seg.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
--- a/hw/xen_disk.c
+++ b/hw/xen_disk.c
@@ -548,6 +548,11 @@ static void blk_alloc(struct XenDevice *
if (xen_mode != XEN_EMULATE) {
batch_maps = 1;
}
+ if (xc_gnttab_set_max_grants(xendev->gnttabdev,
+ 2 * max_requests * BLKIF_MAX_SEGMENTS_PER_REQUEST) < 0) {
+ xen_be_printf(xendev, 0, "xc_gnttab_set_max_grants failed: %s\n",
+ strerror(errno));
+ }
}
static int blk_init(struct XenDevice *xendev)
qemu/xendisk: set maximum number of grants to be used
Legacy (non-pvops) gntdev drivers may require this to be done when the
number of grants intended to be used simultaneously exceeds a certain
driver specific default limit.
Change in v2: Double the number requested, as we need to account for
the allocations needing to happen in contiguous chunks. The worst case
number would be max_req * max_seg + (max_req - 1) * (max_seg - 1) + 1,
but in order to keep things simple just use 2 * max_req * max_seg.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
--- a/hw/xen_disk.c
+++ b/hw/xen_disk.c
@@ -548,6 +548,11 @@ static void blk_alloc(struct XenDevice *
if (xen_mode != XEN_EMULATE) {
batch_maps = 1;
}
+ if (xc_gnttab_set_max_grants(xendev->gnttabdev,
+ 2 * max_requests * BLKIF_MAX_SEGMENTS_PER_REQUEST) < 0) {
+ xen_be_printf(xendev, 0, "xc_gnttab_set_max_grants failed: %s\n",
+ strerror(errno));
+ }
}
static int blk_init(struct XenDevice *xendev)
