[Qemu-devel] [PATCH] pvusb: set max grants only in initialise

[Qemu-devel] [PATCH] pvusb: set max grants only in initialise

[Juergen Gross]

Don't call xen_be_set_max_grant_refs() in usbback_alloc(), as the
gnttabdev pointer won't be initialised yet. The call can easily be
moved to usbback_connect().

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 hw/usb/xen-usb.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/hw/usb/xen-usb.c b/hw/usb/xen-usb.c
index 5b2e21ed18..f5d5c91094 100644
--- a/hw/usb/xen-usb.c
+++ b/hw/usb/xen-usb.c
@@ -860,10 +860,14 @@ static int usbback_connect(struct XenDevice *xendev)
     struct usbif_conn_sring *conn_sring;
     int urb_ring_ref;
     int conn_ring_ref;
-    unsigned int i;
+    unsigned int i, max_grants;
 
     TR_BUS(xendev, "start\n");
 
+    /* max_grants: for each request and for the rings (request and connect). */
+    max_grants = USBIF_MAX_SEGMENTS_PER_REQUEST * USB_URB_RING_SIZE + 2;
+    xen_be_set_max_grant_refs(xendev, max_grants);
+
     usbif = container_of(xendev, struct usbback_info, xendev);
 
     if (xenstore_read_fe_int(xendev, "urb-ring-ref", &urb_ring_ref)) {
@@ -1005,7 +1009,7 @@ static void usbback_alloc(struct XenDevice *xendev)
 {
     struct usbback_info *usbif;
     USBPort *p;
-    unsigned int i, max_grants;
+    unsigned int i;
 
     usbif = container_of(xendev, struct usbback_info, xendev);
 
@@ -1021,10 +1025,6 @@ static void usbback_alloc(struct XenDevice *xendev)
     QTAILQ_INIT(&usbif->req_free_q);
     QSIMPLEQ_INIT(&usbif->hotplug_q);
     usbif->bh = qemu_bh_new(usbback_bh, usbif);
-
-    /* max_grants: for each request and for the rings (request and connect). */
-    max_grants = USBIF_MAX_SEGMENTS_PER_REQUEST * USB_URB_RING_SIZE + 2;
-    xen_be_set_max_grant_refs(xendev, max_grants);
 }
 
 static int usbback_free(struct XenDevice *xendev)
-- 
2.16.4

Re: [Qemu-devel] [PATCH] pvusb: set max grants only in initialise

[Gerd Hoffmann]

On Thu, Dec 06, 2018 at 02:39:23PM +0100, Juergen Gross wrote:
> Don't call xen_be_set_max_grant_refs() in usbback_alloc(), as the
> gnttabdev pointer won't be initialised yet. The call can easily be
> moved to usbback_connect().

Added to usb queue.

thanks,
  Gerd