svn commit: r366720 - head/sys/dev/hyperv/pcib

[Wei Hu]

Author: whu
Date: Thu Oct 15 05:57:20 2020
New Revision: 366720
URL: https://svnweb.freebsd.org/changeset/base/366720

Log:
  Hyper-V: pcib: Check revoke status during device attach
  
  It is possible that the vmbus pcib channel is revoked during attach path.
  The attach path could be waiting for response from host and this response will never
  arrive since the channel has already been revoked from host point of view. Check
  this situation during wait complete and return failed if this happens.
  
  Reported by:	Netapp
  MFC after:	2 weeks
  Sponsored by:	Microsoft
  Differential Revision:	https://reviews.freebsd.org/D26486

Modified:
  head/sys/dev/hyperv/pcib/vmbus_pcib.c

Modified: head/sys/dev/hyperv/pcib/vmbus_pcib.c
==============================================================================
--- head/sys/dev/hyperv/pcib/vmbus_pcib.c	Thu Oct 15 05:11:16 2020	(r366719)
+++ head/sys/dev/hyperv/pcib/vmbus_pcib.c	Thu Oct 15 05:57:20 2020	(r366720)
@@ -117,6 +117,31 @@ wait_for_completion(struct completion *c)
 	mtx_unlock(&c->lock);
 }
 
+/*
+ * Return: 0 if completed, a non-zero value if timed out.
+ */
+static int
+wait_for_completion_timeout(struct completion *c, int timeout)
+{
+	int ret;
+
+	mtx_lock(&c->lock);
+
+	if (c->done == 0)
+		mtx_sleep(c, &c->lock, 0, "hvwfc", timeout);
+
+	if (c->done > 0) {
+		c->done--;
+		ret = 0;
+	} else {
+		ret = 1;
+	}
+
+	mtx_unlock(&c->lock);
+
+	return (ret);
+}
+
 #define PCI_MAKE_VERSION(major, minor) ((uint32_t)(((major) << 16) | (major)))
 
 enum {
@@ -438,6 +463,25 @@ struct compose_comp_ctxt {
 	struct tran_int_desc int_desc;
 };
 
+/*
+ * It is possible the device is revoked during initialization.
+ * Check if this happens during wait.
+ * Return: 0 if response arrived, ENODEV if device revoked.
+ */
+static int
+wait_for_response(struct hv_pcibus *hbus, struct completion *c)
+{
+	do {
+		if (vmbus_chan_is_revoked(hbus->sc->chan)) {
+			device_printf(hbus->pcib,
+			    "The device is revoked.\n");
+			return (ENODEV);
+		}
+	} while (wait_for_completion_timeout(c, hz /10) != 0);
+
+	return 0;
+}
+
 static void
 hv_pci_generic_compl(void *context, struct pci_response *resp,
     int resp_packet_size)
@@ -568,7 +612,9 @@ new_pcichild_device(struct hv_pcibus *hbus, struct pci
 	if (ret)
 		goto err;
 
-	wait_for_completion(&comp_pkt.host_event);
+	if (wait_for_response(hbus, &comp_pkt.host_event))
+		goto err;
+
 	free_completion(&comp_pkt.host_event);
 
 	hpdev->desc = *desc;
@@ -1011,11 +1057,16 @@ hv_pci_protocol_negotiation(struct hv_pcibus *hbus)
 	ret = vmbus_chan_send(hbus->sc->chan, VMBUS_CHANPKT_TYPE_INBAND,
 	    VMBUS_CHANPKT_FLAG_RC, version_req, sizeof(*version_req),
 	    (uint64_t)(uintptr_t)&ctxt.pkt);
-	if (ret)
+	if (!ret)
+		ret = wait_for_response(hbus, &comp_pkt.host_event);
+
+	if (ret) {
+		device_printf(hbus->pcib,
+		    "vmbus_pcib failed to request version: %d\n",
+		    ret);
 		goto out;
+	}
 
-	wait_for_completion(&comp_pkt.host_event);
-
 	if (comp_pkt.completion_status < 0) {
 		device_printf(hbus->pcib,
 		    "vmbus_pcib version negotiation failed: %x\n",
@@ -1072,11 +1123,12 @@ hv_pci_enter_d0(struct hv_pcibus *hbus)
 	ret = vmbus_chan_send(hbus->sc->chan, VMBUS_CHANPKT_TYPE_INBAND,
 	    VMBUS_CHANPKT_FLAG_RC, d0_entry, sizeof(*d0_entry),
 	    (uint64_t)(uintptr_t)&ctxt.pkt);
+	if (!ret)
+		ret = wait_for_response(hbus, &comp_pkt.host_event);
+
 	if (ret)
 		goto out;
 
-	wait_for_completion(&comp_pkt.host_event);
-
 	if (comp_pkt.completion_status < 0) {
 		device_printf(hbus->pcib, "vmbus_pcib failed to enable D0\n");
 		ret = EPROTO;
@@ -1125,14 +1177,14 @@ hv_send_resources_allocated(struct hv_pcibus *hbus)
 		    VMBUS_CHANPKT_TYPE_INBAND, VMBUS_CHANPKT_FLAG_RC,
 		    &pkt->message, sizeof(*res_assigned),
 		    (uint64_t)(uintptr_t)pkt);
-		if (ret) {
-			free_completion(&comp_pkt.host_event);
-			break;
-		}
+		if (!ret)
+			ret = wait_for_response(hbus, &comp_pkt.host_event);
 
-		wait_for_completion(&comp_pkt.host_event);
 		free_completion(&comp_pkt.host_event);
 
+		if (ret)
+			break;
+
 		if (comp_pkt.completion_status < 0) {
 			ret = EPROTO;
 			device_printf(hbus->pcib,
@@ -1413,9 +1465,11 @@ vmbus_pcib_attach(device_t dev)
 		goto vmbus_close;
 
 	ret = hv_pci_query_relations(hbus);
+	if (!ret)
+		ret = wait_for_response(hbus, hbus->query_comp);
+
 	if (ret)
 		goto vmbus_close;
-	wait_for_completion(hbus->query_comp);
 
 	ret = hv_pci_enter_d0(hbus);
 	if (ret)