Allow specifying zero discard granularity for block devices

That allows for disabling discard in a way that some guest
OSes (e.g. Windows) understand and do not try to trim the disk.

Resolves: https://issues.redhat.com/browse/RHEL-72006
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index bfc62b62705f5466b7d8e71858be29b3ea01242d..ba0d4a7b128c0aff1de2191f216142eec4543313 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -8554,6 +8554,8 @@ virDomainDiskDefParseXML(virDomainXMLOption *xmlopt,
     }
 
     if ((blockioNode = virXPathNode("./blockio", ctxt))) {
+        int tmp = 0;
+
         if (virXMLPropUInt(blockioNode, "logical_block_size", 10, VIR_XML_PROP_NONE,
                            &def->blockio.logical_block_size) < 0)
             return NULL;
@@ -8562,9 +8564,11 @@ virDomainDiskDefParseXML(virDomainXMLOption *xmlopt,
                            &def->blockio.physical_block_size) < 0)
             return NULL;
 
-        if (virXMLPropUInt(blockioNode, "discard_granularity", 10, VIR_XML_PROP_NONE,
-                           &def->blockio.discard_granularity) < 0)
+        if ((tmp = virXMLPropUInt(blockioNode, "discard_granularity", 10, VIR_XML_PROP_NONE,
+                                  &def->blockio.discard_granularity)) < 0)
             return NULL;
+        if (tmp > 0)
+            def->blockio.discard_granularity_specified = true;
     }
 
     if ((driverNode = virXPathNode("./driver", ctxt))) {
@@ -23102,7 +23106,7 @@ virDomainDiskBlockIoDefFormat(virBuffer *buf,
 {
     if (def->blockio.logical_block_size > 0 ||
         def->blockio.physical_block_size > 0 ||
-        def->blockio.discard_granularity > 0) {
+        def->blockio.discard_granularity_specified) {
         virBufferAddLit(buf, "<blockio");
         if (def->blockio.logical_block_size > 0) {
             virBufferAsprintf(buf,
@@ -23114,7 +23118,7 @@ virDomainDiskBlockIoDefFormat(virBuffer *buf,
                               " physical_block_size='%u'",
                               def->blockio.physical_block_size);
         }
-        if (def->blockio.discard_granularity > 0) {
+        if (def->blockio.discard_granularity_specified) {
             virBufferAsprintf(buf,
                               " discard_granularity='%u'",
                               def->blockio.discard_granularity);

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 6997cf7c09be51339fb8136c7862705f57cd4af8..6008ec66d3fe6bb7b4f2a7857434056814e45002 100644 (file)
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -560,6 +560,7 @@ struct _virDomainDiskDef {
         unsigned int logical_block_size;
         unsigned int physical_block_size;
         unsigned int discard_granularity;
+        bool discard_granularity_specified;
     } blockio;
 
     virDomainBlockIoTuneInfo blkdeviotune;

diff --git a/src/conf/domain_validate.c b/src/conf/domain_validate.c
index b28af7fa5618c2066129e27320114f9740490382..8f7259a0e1eddabc1e86e97ca6e9188d6ef551f1 100644 (file)
--- a/src/conf/domain_validate.c
+++ b/src/conf/domain_validate.c
@@ -462,7 +462,7 @@ virDomainDiskVhostUserValidate(const virDomainDiskDef *disk)
 
     if (disk->blockio.logical_block_size > 0 ||
         disk->blockio.physical_block_size > 0 ||
-        disk->blockio.discard_granularity > 0) {
+        disk->blockio.discard_granularity_specified) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                        _("blockio is not supported with vhostuser disk"));
         return -1;

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 7658cc4d395ae8781fb4d71db4b952577fa360b7..fc6ce4dd914310d1a8d1dc417b50f23658ee8fe9 100644 (file)
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1899,7 +1899,6 @@ qemuBuildDiskDeviceProps(const virDomainDef *def,
                               "S:loadparm", bootLoadparm,
                               "p:logical_block_size", logical_block_size,
                               "p:physical_block_size", physical_block_size,
-                              "p:discard_granularity", discard_granularity,
                               "A:wwn", &wwn,
                               "p:rotation_rate", disk->rotation_rate,
                               "S:vendor", disk->vendor,
@@ -1917,6 +1916,12 @@ qemuBuildDiskDeviceProps(const virDomainDef *def,
                               NULL) < 0)
         return NULL;
 
+    if (disk->blockio.discard_granularity_specified &&
+        virJSONValueObjectAdd(&props,
+                              "u:discard_granularity", discard_granularity,
+                              NULL) < 0)
+        return NULL;
+
     return g_steal_pointer(&props);
 }
 

diff --git a/tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.args b/tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.args
new file mode 100644 (file)
index 0000000..0e477c6
--- /dev/null
+++ b/tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.args
@@ -0,0 +1,37 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc,usb=off,dump-guest-core=off,memory-backend=pc.ram,acpi=off \
+-accel tcg \
+-cpu qemu64 \
+-m size=219136k \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-boot strict=on \
+-device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \
+-blockdev '{"driver":"host_device","filename":"/dev/HostVG/QEMUGuest1","node-name":"libvirt-2-storage","read-only":true}' \
+-device '{"driver":"ide-cd","bus":"ide.0","unit":1,"drive":"libvirt-2-storage","id":"ide0-0-1"}' \
+-blockdev '{"driver":"file","filename":"/tmp/idedisk.img","node-name":"libvirt-1-storage","read-only":false}' \
+-device '{"driver":"ide-hd","bus":"ide.0","unit":2,"drive":"libvirt-1-storage","id":"ide0-0-2","bootindex":1,"logical_block_size":512,"physical_block_size":512,"discard_granularity":0}' \
+-audiodev '{"id":"audio1","driver":"none"}' \
+-device '{"driver":"virtio-balloon-pci","id":"balloon0","bus":"pci.0","addr":"0x2"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on

diff --git a/tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.xml b/tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.xml
new file mode 100644 (file)
index 0000000..94cff1c
--- /dev/null
+++ b/tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.xml
@@ -0,0 +1,48 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='custom' match='exact' check='none'>
+    <model fallback='forbid'>qemu64</model>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <disk type='block' device='cdrom'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <readonly/>
+      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
+    </disk>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source file='/tmp/idedisk.img'/>
+      <blockio logical_block_size='512' physical_block_size='512' discard_granularity='0'/>
+      <target dev='hdc' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='2'/>
+    </disk>
+    <controller type='usb' index='0' model='piix3-uhci'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+    </controller>
+    <controller type='ide' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
+    </controller>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <audio id='1' type='none'/>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
+    </memballoon>
+  </devices>
+</domain>

diff --git a/tests/qemuxmlconfdata/disk-blockio-no-discard.xml b/tests/qemuxmlconfdata/disk-blockio-no-discard.xml
new file mode 100644 (file)
index 0000000..6000223
--- /dev/null
+++ b/tests/qemuxmlconfdata/disk-blockio-no-discard.xml
@@ -0,0 +1,32 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <disk type='block' device='cdrom'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
+    </disk>
+    <disk type='file' device='disk'>
+      <source file='/tmp/idedisk.img'/>
+      <target dev='hdc' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='2'/>
+      <blockio logical_block_size='512' physical_block_size='512' discard_granularity='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxmlconftest.c b/tests/qemuxmlconftest.c
index 9fba98429019c471dc7b950b5f0dd50f0b4bd669..ae8efd58f8ac201f12be863d88b14fcb8397af59 100644 (file)
--- a/tests/qemuxmlconftest.c
+++ b/tests/qemuxmlconftest.c
@@ -1694,6 +1694,7 @@ mymain(void)
     DO_TEST_CAPS_LATEST("disk-ide-wwn");
     DO_TEST_CAPS_LATEST("disk-geometry");
     DO_TEST_CAPS_LATEST("disk-blockio");
+    DO_TEST_CAPS_LATEST("disk-blockio-no-discard");
 
     driver.config->storageUseNbdkit = 1;
     DO_TEST_CAPS_LATEST_NBDKIT("disk-cdrom-network-nbdkit", QEMU_NBDKIT_CAPS_PLUGIN_CURL);