Merge tag 'for-linus-5.19-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:

 - decouple the PV interface from kernel internals in the Xen
   scsifront/scsiback pv drivers

 - harden the Xen scsifront PV driver against a malicious backend driver

 - simplify Xen PV frontend driver ring page setup

 - support Xen setups with multiple domains created at boot time to
   tolerate Xenstore coming up late

 - two small cleanup patches

* tag 'for-linus-5.19-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits)
  xen: add support for initializing xenstore later as HVM domain
  xen: sync xs_wire.h header with upstream xen
  x86: xen: remove STACK_FRAME_NON_STANDARD from xen_cpuid
  xen-blk{back,front}: Update contact points for buffer_squeeze_duration_ms and feature_persistent
  xen/xenbus: eliminate xenbus_grant_ring()
  xen/sndfront: use xenbus_setup_ring() and xenbus_teardown_ring()
  xen/usbfront: use xenbus_setup_ring() and xenbus_teardown_ring()
  xen/scsifront: use xenbus_setup_ring() and xenbus_teardown_ring()
  xen/pcifront: use xenbus_setup_ring() and xenbus_teardown_ring()
  xen/drmfront: use xenbus_setup_ring() and xenbus_teardown_ring()
  xen/tpmfront: use xenbus_setup_ring() and xenbus_teardown_ring()
  xen/netfront: use xenbus_setup_ring() and xenbus_teardown_ring()
  xen/blkfront: use xenbus_setup_ring() and xenbus_teardown_ring()
  xen/xenbus: add xenbus_setup_ring() service function
  xen: update ring.h
  xen/shbuf: switch xen-front-pgdir-shbuf to use INVALID_GRANT_REF
  xen/dmabuf: switch gntdev-dmabuf to use INVALID_GRANT_REF
  xen/sound: switch xen_snd_front to use INVALID_GRANT_REF
  xen/drm: switch xen_drm_front to use INVALID_GRANT_REF
  xen/usb: switch xen-hcd to use INVALID_GRANT_REF
  ...

2 files changed, 11 insertions, 41 deletions

diff --git a/drivers/gpu/drm/xen/xen_drm_front.h b/drivers/gpu/drm/xen/xen_drm_front.h
index cefafe859aba..a987c78abe41 100644
--- a/drivers/gpu/drm/xen/xen_drm_front.h
+++ b/drivers/gpu/drm/xen/xen_drm_front.h
@@ -80,15 +80,6 @@ struct drm_pending_vblank_event;
 /* timeout in ms to wait for backend to respond */
 #define XEN_DRM_FRONT_WAIT_BACK_MS	3000
 
-#ifndef GRANT_INVALID_REF
-/*
- * Note on usage of grant reference 0 as invalid grant reference:
- * grant reference 0 is valid, but never exposed to a PV driver,
- * because of the fact it is already in use/reserved by the PV console.
- */
-#define GRANT_INVALID_REF	0
-#endif
-
 struct xen_drm_front_info {
 	struct xenbus_device *xb_dev;
 	struct xen_drm_front_drm_info *drm_info;
diff --git a/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c
index 08b526eeec16..e52afd792346 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c
@@ -123,12 +123,12 @@ out:
 static void evtchnl_free(struct xen_drm_front_info *front_info,
 			 struct xen_drm_front_evtchnl *evtchnl)
 {
-	unsigned long page = 0;
+	void *page = NULL;
 
 	if (evtchnl->type == EVTCHNL_TYPE_REQ)
-		page = (unsigned long)evtchnl->u.req.ring.sring;
+		page = evtchnl->u.req.ring.sring;
 	else if (evtchnl->type == EVTCHNL_TYPE_EVT)
-		page = (unsigned long)evtchnl->u.evt.page;
+		page = evtchnl->u.evt.page;
 	if (!page)
 		return;
 
@@ -147,8 +147,7 @@ static void evtchnl_free(struct xen_drm_front_info *front_info,
 		xenbus_free_evtchn(front_info->xb_dev, evtchnl->port);
 
 	/* end access and free the page */
-	if (evtchnl->gref != GRANT_INVALID_REF)
-		gnttab_end_foreign_access(evtchnl->gref, page);
+	xenbus_teardown_ring(&page, 1, &evtchnl->gref);
 
 	memset(evtchnl, 0, sizeof(*evtchnl));
 }
@@ -158,8 +157,7 @@ static int evtchnl_alloc(struct xen_drm_front_info *front_info, int index,
 			 enum xen_drm_front_evtchnl_type type)
 {
 	struct xenbus_device *xb_dev = front_info->xb_dev;
-	unsigned long page;
-	grant_ref_t gref;
+	void *page;
 	irq_handler_t handler;
 	int ret;
 
@@ -168,44 +166,25 @@ static int evtchnl_alloc(struct xen_drm_front_info *front_info, int index,
 	evtchnl->index = index;
 	evtchnl->front_info = front_info;
 	evtchnl->state = EVTCHNL_STATE_DISCONNECTED;
-	evtchnl->gref = GRANT_INVALID_REF;
 
-	page = get_zeroed_page(GFP_NOIO | __GFP_HIGH);
-	if (!page) {
-		ret = -ENOMEM;
+	ret = xenbus_setup_ring(xb_dev, GFP_NOIO | __GFP_HIGH, &page,
+				1, &evtchnl->gref);
+	if (ret)
 		goto fail;
-	}
 
 	if (type == EVTCHNL_TYPE_REQ) {
 		struct xen_displif_sring *sring;
 
 		init_completion(&evtchnl->u.req.completion);
 		mutex_init(&evtchnl->u.req.req_io_lock);
-		sring = (struct xen_displif_sring *)page;
-		SHARED_RING_INIT(sring);
-		FRONT_RING_INIT(&evtchnl->u.req.ring, sring, XEN_PAGE_SIZE);
-
-		ret = xenbus_grant_ring(xb_dev, sring, 1, &gref);
-		if (ret < 0) {
-			evtchnl->u.req.ring.sring = NULL;
-			free_page(page);
-			goto fail;
-		}
+		sring = page;
+		XEN_FRONT_RING_INIT(&evtchnl->u.req.ring, sring, XEN_PAGE_SIZE);
 
 		handler = evtchnl_interrupt_ctrl;
 	} else {
-		ret = gnttab_grant_foreign_access(xb_dev->otherend_id,
-						  virt_to_gfn((void *)page), 0);
-		if (ret < 0) {
-			free_page(page);
-			goto fail;
-		}
-
-		evtchnl->u.evt.page = (struct xendispl_event_page *)page;
-		gref = ret;
+		evtchnl->u.evt.page = page;
 		handler = evtchnl_interrupt_evt;
 	}
-	evtchnl->gref = gref;
 
 	ret = xenbus_alloc_evtchn(xb_dev, &evtchnl->port);
 	if (ret < 0)