From e0999eaacc6e74f5e56f51fcf3b3d7aeca7d3b04 Mon Sep 17 00:00:00 2001

From: Markus Armbruster <armbru@redhat.com>

Date: Thu, 6 Jun 2019 19:15:23 +0100

Subject: [PATCH 6/7] scsi-disk: Acquire the AioContext in scsi_*_realize()

RH-Author: Markus Armbruster <armbru@redhat.com>

Message-id: <20190606191524.30797-3-armbru@redhat.com>

Patchwork-id: 88605

O-Subject: [RHEL-8.1.0 qemu-kvm PATCH 2/3] scsi-disk: Acquire the AioContext in scsi_*_realize()

Bugzilla: 1718992

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

From: Alberto Garcia <berto@igalia.com>

This fixes a crash when attaching two disks with the same blockdev to

a SCSI device that is using iothreads. Test case included.

Signed-off-by: Alberto Garcia <berto@igalia.com>

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

(cherry picked from commit 3ff35ba391134e4e43ab96152deb38a62e62f858)

[Trivial conflict in hw/scsi/scsi-disk.c due to lack of commit

51f43d5792e resolved]

Signed-off-by: Markus Armbruster <armbru@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 hw/scsi/scsi-disk.c        | 23 ++++++++++++++++++++---

 tests/qemu-iotests/240     | 18 ++++++++++++++++++

 tests/qemu-iotests/240.out | 16 ++++++++++++++++

 3 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c

index a20ef91..08da23d 100644

--- a/hw/scsi/scsi-disk.c

+++ b/hw/scsi/scsi-disk.c

@@ -2378,10 +2378,13 @@ static void scsi_realize(SCSIDevice *dev, Error **errp)

 static void scsi_hd_realize(SCSIDevice *dev, Error **errp)

 {

     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);

+    AioContext *ctx = NULL;

     /* can happen for devices without drive. The error message for missing

      * backend will be issued in scsi_realize

      */

     if (s->qdev.conf.blk) {

+        ctx = blk_get_aio_context(s->qdev.conf.blk);

+        aio_context_acquire(ctx);

         blkconf_blocksizes(&s->qdev.conf);

     }

     s->qdev.blocksize = s->qdev.conf.logical_block_size;

@@ -2390,11 +2393,15 @@ static void scsi_hd_realize(SCSIDevice *dev, Error **errp)

         s->product = g_strdup("QEMU HARDDISK");

     }

     scsi_realize(&s->qdev, errp);

+    if (ctx) {

+        aio_context_release(ctx);

+    }

 }

 static void scsi_cd_realize(SCSIDevice *dev, Error **errp)

 {

     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);

+    AioContext *ctx;

     int ret;

     if (!dev->conf.blk) {

@@ -2405,6 +2412,8 @@ static void scsi_cd_realize(SCSIDevice *dev, Error **errp)

         assert(ret == 0);

     }

+    ctx = blk_get_aio_context(dev->conf.blk);

+    aio_context_acquire(ctx);

     s->qdev.blocksize = 2048;

     s->qdev.type = TYPE_ROM;

     s->features |= 1 << SCSI_DISK_F_REMOVABLE;

@@ -2412,6 +2421,7 @@ static void scsi_cd_realize(SCSIDevice *dev, Error **errp)

         s->product = g_strdup("QEMU CD-ROM");

     }

     scsi_realize(&s->qdev, errp);

+    aio_context_release(ctx);

 }

 static void scsi_disk_realize(SCSIDevice *dev, Error **errp)

@@ -2550,6 +2560,7 @@ static int get_device_type(SCSIDiskState *s)

 static void scsi_block_realize(SCSIDevice *dev, Error **errp)

 {

     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);

+    AioContext *ctx;

     int sg_version;

     int rc;

@@ -2558,6 +2569,9 @@ static void scsi_block_realize(SCSIDevice *dev, Error **errp)

         return;

     }

+    ctx = blk_get_aio_context(s->qdev.conf.blk);

+    aio_context_acquire(ctx);

+

     /* check we are using a driver managing SG_IO (version 3 and after) */

     rc = blk_ioctl(s->qdev.conf.blk, SG_GET_VERSION_NUM, &sg_version);

     if (rc < 0) {

@@ -2565,18 +2579,18 @@ static void scsi_block_realize(SCSIDevice *dev, Error **errp)

         if (rc != -EPERM) {

             error_append_hint(errp, "Is this a SCSI device?\n");

         }

-        return;

+        goto out;

     }

     if (sg_version < 30000) {

         error_setg(errp, "scsi generic interface too old");

-        return;

+        goto out;

     }

     /* get device type from INQUIRY data */

     rc = get_device_type(s);

     if (rc < 0) {

         error_setg(errp, "INQUIRY failed");

-        return;

+        goto out;

     }

     /* Make a guess for the block size, we'll fix it when the guest sends.

@@ -2596,6 +2610,9 @@ static void scsi_block_realize(SCSIDevice *dev, Error **errp)

     scsi_realize(&s->qdev, errp);

     scsi_generic_read_device_inquiry(&s->qdev);

+

+out:

+    aio_context_release(ctx);

 }

 typedef struct SCSIBlockReq {

diff --git a/tests/qemu-iotests/240 b/tests/qemu-iotests/240

index ead7ee0..5d499c9 100755

--- a/tests/qemu-iotests/240

+++ b/tests/qemu-iotests/240

@@ -83,6 +83,24 @@ run_qemu <

 { "execute": "quit"}

 EOF

+echo

+echo === Attach two SCSI disks using the same block device and the same iothread ===

+echo

+

+run_qemu <

+{ "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": "device_add", "arguments": {"id": "scsi0", "driver": "${virtio_scsi}", "iothread": "iothread0"}}

+{ "execute": "device_add", "arguments": {"id": "scsi-hd0", "driver": "scsi-hd", "drive": "hd0"}}

+{ "execute": "device_add", "arguments": {"id": "scsi-hd1", "driver": "scsi-hd", "drive": "hd0"}}

+{ "execute": "device_del", "arguments": {"id": "scsi-hd0"}}

+{ "execute": "device_del", "arguments": {"id": "scsi-hd1"}}

+{ "execute": "device_del", "arguments": {"id": "scsi0"}}

+{ "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 432d981..701cb5c 100644

--- a/tests/qemu-iotests/240.out

+++ b/tests/qemu-iotests/240.out

@@ -15,4 +15,20 @@ QMP_VERSION

 {"return": {}}

 {"return": {}}

 {"return": {}}

+

+=== Attach two SCSI disks using the same block device and the same iothread ===

+

+Testing:

+QMP_VERSION

+{"return": {}}

+{"return": {}}

+{"return": {}}

+{"return": {}}

+{"return": {}}

+{"return": {}}

+{"return": {}}

+{"return": {}}

+{"return": {}}

+{"return": {}}

+{"return": {}}

 *** done

-- 

1.8.3.1