From: Dexuan Cui <decui@microsoft.com>
To: "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
Stephen Hemminger <sthemmin@microsoft.com>,
Sasha Levin <Alexander.Levin@microsoft.com>,
"sashal@kernel.org" <sashal@kernel.org>,
Haiyang Zhang <haiyangz@microsoft.com>,
KY Srinivasan <kys@microsoft.com>,
Michael Kelley <mikelley@microsoft.com>,
"tglx@linutronix.de" <tglx@linutronix.de>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Dexuan Cui <decui@microsoft.com>
Subject: [PATCH v5 5/9] Drivers: hv: vmbus: Ignore the offers when resuming from hibernation
Date: Thu, 5 Sep 2019 23:01:18 +0000 [thread overview]
Message-ID: <1567724446-30990-6-git-send-email-decui@microsoft.com> (raw)
In-Reply-To: <1567724446-30990-1-git-send-email-decui@microsoft.com>
When the VM resumes, the host re-sends the offers. We should not add the
offers to the global vmbus_connection.chn_list again.
This patch assumes the RELIDs of the channels don't change across
hibernation. Actually this is not always true, especially in the case of
NIC SR-IOV the VF vmbus device's RELID sometimes can change. A later patch
will address this issue by mapping the new offers to the old channels and
fixing up the old channels, if necessary.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
---
drivers/hv/channel_mgmt.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 57 insertions(+), 1 deletion(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index addcef5..44b92fa 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -848,18 +848,74 @@ void vmbus_initiate_unload(bool crash)
}
/*
+ * find_primary_channel_by_offer - Get the channel object given the new offer.
+ * This is only used in the resume path of hibernation.
+ */
+static struct vmbus_channel *
+find_primary_channel_by_offer(const struct vmbus_channel_offer_channel *offer)
+{
+ struct vmbus_channel *channel = NULL, *iter;
+ const guid_t *inst1, *inst2;
+
+ /* Ignore sub-channel offers. */
+ if (offer->offer.sub_channel_index != 0)
+ return NULL;
+
+ mutex_lock(&vmbus_connection.channel_mutex);
+
+ list_for_each_entry(iter, &vmbus_connection.chn_list, listentry) {
+ inst1 = &iter->offermsg.offer.if_instance;
+ inst2 = &offer->offer.if_instance;
+
+ if (guid_equal(inst1, inst2)) {
+ channel = iter;
+ break;
+ }
+ }
+
+ mutex_unlock(&vmbus_connection.channel_mutex);
+
+ return channel;
+}
+
+/*
* vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
*
*/
static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
{
struct vmbus_channel_offer_channel *offer;
- struct vmbus_channel *newchannel;
+ struct vmbus_channel *oldchannel, *newchannel;
+ size_t offer_sz;
offer = (struct vmbus_channel_offer_channel *)hdr;
trace_vmbus_onoffer(offer);
+ oldchannel = find_primary_channel_by_offer(offer);
+
+ if (oldchannel != NULL) {
+ atomic_dec(&vmbus_connection.offer_in_progress);
+
+ /*
+ * We're resuming from hibernation: we expect the host to send
+ * exactly the same offers that we had before the hibernation.
+ */
+ offer_sz = sizeof(*offer);
+ if (memcmp(offer, &oldchannel->offermsg, offer_sz) == 0)
+ return;
+
+ pr_debug("Mismatched offer from the host (relid=%d)\n",
+ offer->child_relid);
+
+ print_hex_dump_debug("Old vmbus offer: ", DUMP_PREFIX_OFFSET,
+ 16, 4, &oldchannel->offermsg, offer_sz,
+ false);
+ print_hex_dump_debug("New vmbus offer: ", DUMP_PREFIX_OFFSET,
+ 16, 4, offer, offer_sz, false);
+ return;
+ }
+
/* Allocate the channel object and save this offer. */
newchannel = alloc_channel();
if (!newchannel) {
--
1.8.3.1
next prev parent reply other threads:[~2019-09-05 23:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 23:01 [PATCH v5 0/9] Enhance the hv_vmbus driver to support hibernation Dexuan Cui
2019-09-05 23:01 ` [PATCH v5 1/9] Drivers: hv: vmbus: Break out synic enable and disable operations Dexuan Cui
2019-09-05 23:01 ` [PATCH v5 3/9] Drivers: hv: vmbus: Add a helper function is_sub_channel() Dexuan Cui
2019-09-05 23:01 ` [PATCH v5 2/9] Drivers: hv: vmbus: Suspend/resume the synic for hibernation Dexuan Cui
2019-09-05 23:01 ` [PATCH v5 4/9] Drivers: hv: vmbus: Implement suspend/resume for VSC drivers " Dexuan Cui
2019-09-05 23:01 ` Dexuan Cui [this message]
2019-09-05 23:01 ` [PATCH v5 6/9] Drivers: hv: vmbus: Suspend/resume the vmbus itself " Dexuan Cui
2019-09-05 23:01 ` [PATCH v5 7/9] Drivers: hv: vmbus: Clean up hv_sock channels by force upon suspend Dexuan Cui
2019-09-05 23:01 ` [PATCH v5 8/9] Drivers: hv: vmbus: Suspend after cleaning up hv_sock and sub channels Dexuan Cui
2019-09-05 23:01 ` [PATCH v5 9/9] Drivers: hv: vmbus: Resume after fixing up old primary channels Dexuan Cui
2019-09-06 20:03 ` [PATCH v5 0/9] Enhance the hv_vmbus driver to support hibernation Sasha Levin
2019-09-06 22:45 ` Dexuan Cui
2019-09-08 12:13 ` Sasha Levin
2019-09-08 16:32 ` Dexuan Cui
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