qemu-kvm/kvm-virtio-scsi-Forbid-devices-with-different-iothreads-.patch

From 5910975bcc4445e366399a438b811cdc8c3dd87e Mon Sep 17 00:00:00 2001
From: Markus Armbruster <armbru@redhat.com>
Date: Thu, 7 Feb 2019 12:18:19 +0000
Subject: [PATCH 8/8] virtio-scsi: Forbid devices with different iothreads
 sharing a blockdev

RH-Author: Markus Armbruster <armbru@redhat.com>
Message-id: <20190207121819.20092-4-armbru@redhat.com>
Patchwork-id: 84289
O-Subject: [RHEL-8.0/AV qemu-kvm PATCH 3/3] virtio-scsi: Forbid devices with different iothreads sharing a blockdev
Bugzilla: 1656276 1662508
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

From: Alberto Garcia <berto@igalia.com>

This patch forbids attaching a disk to a SCSI device if its using a
different AioContext. Test case included.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit eb97813ff5fd5bdffc8ed9f5be5a3a50eae70a2c)
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 hw/scsi/virtio-scsi.c      |  7 +++++++
 tests/qemu-iotests/240     | 22 ++++++++++++++++++++++
 tests/qemu-iotests/240.out | 20 ++++++++++++++++++++
 3 files changed, 49 insertions(+)

diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index f0d4f10..66df30d 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -800,9 +800,16 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
         return;
     }
     if (s->ctx && !s->dataplane_fenced) {
+        AioContext *ctx;
         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
             return;
         }
+        ctx = blk_get_aio_context(sd->conf.blk);
+        if (ctx != s->ctx && ctx != qemu_get_aio_context()) {
+            error_setg(errp, "Cannot attach a blockdev that is using "
+                       "a different iothread");
+            return;
+        }
         virtio_scsi_acquire(s);
         blk_set_aio_context(sd->conf.blk, s->ctx);
         virtio_scsi_release(s);
diff --git a/tests/qemu-iotests/240 b/tests/qemu-iotests/240
index 5d499c9..65cc3b3 100755
--- a/tests/qemu-iotests/240
+++ b/tests/qemu-iotests/240
@@ -101,6 +101,28 @@ run_qemu <<EOF
 { "execute": "quit"}
 EOF
 
+echo
+echo === Attach two SCSI disks using the same block device but different iothreads ===
+echo
+
+run_qemu <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "hd0", "read-only": true}}
+{ "execute": "object-add", "arguments": {"qom-type": "iothread", "id": "iothread0"}}
+{ "execute": "object-add", "arguments": {"qom-type": "iothread", "id": "iothread1"}}
+{ "execute": "device_add", "arguments": {"id": "scsi0", "driver": "${virtio_scsi}", "iothread": "iothread0"}}
+{ "execute": "device_add", "arguments": {"id": "scsi1", "driver": "${virtio_scsi}", "iothread": "iothread1"}}
+{ "execute": "device_add", "arguments": {"id": "scsi-hd0", "driver": "scsi-hd", "drive": "hd0", "bus": "scsi0.0"}}
+{ "execute": "device_add", "arguments": {"id": "scsi-hd1", "driver": "scsi-hd", "drive": "hd0", "bus": "scsi1.0"}}
+{ "execute": "device_del", "arguments": {"id": "scsi-hd0"}}
+{ "execute": "device_add", "arguments": {"id": "scsi-hd1", "driver": "scsi-hd", "drive": "hd0", "bus": "scsi1.0"}}
+{ "execute": "device_del", "arguments": {"id": "scsi-hd1"}}
+{ "execute": "device_del", "arguments": {"id": "scsi0"}}
+{ "execute": "device_del", "arguments": {"id": "scsi1"}}
+{ "execute": "blockdev-del", "arguments": {"node-name": "hd0"}}
+{ "execute": "quit"}
+EOF
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/240.out b/tests/qemu-iotests/240.out
index 701cb5c..d763929 100644
--- a/tests/qemu-iotests/240.out
+++ b/tests/qemu-iotests/240.out
@@ -31,4 +31,24 @@ QMP_VERSION
 {"return": {}}
 {"return": {}}
 {"return": {}}
+
+=== Attach two SCSI disks using the same block device but different iothreads ===
+
+Testing:
+QMP_VERSION
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"error": {"class": "GenericError", "desc": "Cannot attach a blockdev that is using a different iothread"}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
 *** done
-- 
1.8.3.1