qemu: command: Don't skip 'readonly' and throttling info for empty drive

In commit f80eae8c2ae I was too agresive in removing properties of
-drive for empty drives. It turns out that qemu actually persists the
state of 'readonly' and the throttling information even for the empty
drive.

Removing 'readonly' thus made qemu open any subsequent images added via
the 'change' command as RW which was forbidden by selinux thanks to the
restrictive sVirt label for readonly media.

Fix this by formating the property again and bump the tests and leave a
note detailing why the rest of the properties needs to be skipped.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 811024f0756263e3315d7205ac934180c9b56c2c..374836a35e385e0a9268ce24d92fb43d3595ed2c 100644 (file)
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1773,10 +1773,18 @@ qemuBuildDriveStr(virDomainDiskDefPtr disk,
         }
     }
 
+    if (disk->src->readonly)
+        virBufferAddLit(&opt, ",readonly=on");
+
+    /* qemu rejects some parameters for an empty -drive, so we need to skip
+     * them in that case:
+     * cache: modifies properties of the format driver which is not present
+     * copy_on_read: really only works for floppies
+     * discard: modifies properties of format driver
+     * detect_zeroes: works but really depends on discard so it's useless
+     * iomode: setting it to 'native' requires a specific cache mode
+     */
     if (!virStorageSourceIsEmpty(disk->src)) {
-        if (disk->src->readonly)
-            virBufferAddLit(&opt, ",readonly=on");
-
         if (disk->cachemode) {
             virBufferAsprintf(&opt, ",cache=%s",
                               qemuDiskCacheV2TypeToString(disk->cachemode));
@@ -1801,10 +1809,10 @@ qemuBuildDriveStr(virDomainDiskDefPtr disk,
             virBufferAsprintf(&opt, ",aio=%s",
                               virDomainDiskIoTypeToString(disk->iomode));
         }
-
-        qemuBuildDiskThrottling(disk, &opt);
     }
 
+    qemuBuildDiskThrottling(disk, &opt);
+
     if (virBufferCheckError(&opt) < 0)
         goto error;
 

diff --git a/tests/qemuxml2argvdata/disk-cdrom.args b/tests/qemuxml2argvdata/disk-cdrom.args
index a9f60aa47776d9101c3247ea103e9d525cb17aba..4823ae82de9ba551ffb65e8809011e582d6ee274 100644 (file)
--- a/tests/qemuxml2argvdata/disk-cdrom.args
+++ b/tests/qemuxml2argvdata/disk-cdrom.args
@@ -27,7 +27,7 @@ bootindex=1 \
 -drive file=/root/boot.iso,format=raw,if=none,id=drive-ide0-0-1,media=cdrom,\
 readonly=on \
 -device ide-drive,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 \
--drive if=none,id=drive-ide0-1-0,media=cdrom \
+-drive if=none,id=drive-ide0-1-0,media=cdrom,readonly=on \
 -device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 \
--drive if=none,id=drive-ide0-1-1,media=cdrom \
+-drive if=none,id=drive-ide0-1-1,media=cdrom,readonly=on \
 -device ide-drive,bus=ide.1,unit=1,drive=drive-ide0-1-1,id=ide0-1-1

diff --git a/tests/qemuxml2argvdata/disk-cdrom.x86_64-2.12.0.args b/tests/qemuxml2argvdata/disk-cdrom.x86_64-2.12.0.args
index a39d920f67cc582aeb0a2b7796f25c111807b6e6..2fe84177b86f8a805a62b6d013a33c49ed893fee 100644 (file)
--- a/tests/qemuxml2argvdata/disk-cdrom.x86_64-2.12.0.args
+++ b/tests/qemuxml2argvdata/disk-cdrom.x86_64-2.12.0.args
@@ -28,10 +28,10 @@ file=/tmp/lib/domain--1-QEMUGuest1/master-key.aes \
 -device ide-hd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 \
 -drive file=/root/boot.iso,format=raw,if=none,id=drive-ide0-0-1,readonly=on \
 -device ide-cd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 \
--drive if=none,id=drive-ide0-1-0 \
+-drive if=none,id=drive-ide0-1-0,readonly=on \
 -device ide-cd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0,\
 write-cache=on \
--drive if=none,id=drive-ide0-1-1 \
+-drive if=none,id=drive-ide0-1-1,readonly=on \
 -device ide-cd,bus=ide.1,unit=1,drive=drive-ide0-1-1,id=ide0-1-1 \
 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,\
 resourcecontrol=deny \

diff --git a/tests/qemuxml2argvdata/disk-cdrom.x86_64-latest.args b/tests/qemuxml2argvdata/disk-cdrom.x86_64-latest.args
index 029ae23dfa3a138e5926229376429ce7d39c969d..9b9451f435c8ca7eb6053a34ec85cde96847e73f 100644 (file)
--- a/tests/qemuxml2argvdata/disk-cdrom.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/disk-cdrom.x86_64-latest.args
@@ -28,10 +28,10 @@ file=/tmp/lib/domain--1-QEMUGuest1/master-key.aes \
 -device ide-hd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 \
 -drive file=/root/boot.iso,format=raw,if=none,id=drive-ide0-0-1,readonly=on \
 -device ide-cd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 \
--drive if=none,id=drive-ide0-1-0 \
+-drive if=none,id=drive-ide0-1-0,readonly=on \
 -device ide-cd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0,\
 write-cache=on \
--drive if=none,id=drive-ide0-1-1 \
+-drive if=none,id=drive-ide0-1-1,readonly=on \
 -device ide-cd,bus=ide.1,unit=1,drive=drive-ide0-1-1,id=ide0-1-1 \
 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,\
 resourcecontrol=deny \