From 680ee0e7d18866c4f41774dd8368902470a14a07 Mon Sep 17 00:00:00 2001 From: Martin Kletzander Date: Thu, 17 Jul 2025 15:12:40 +0200 Subject: [PATCH] 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 Reviewed-by: Peter Krempa --- src/conf/domain_conf.c | 12 +++-- src/conf/domain_conf.h | 1 + src/conf/domain_validate.c | 2 +- src/qemu/qemu_command.c | 7 ++- ...disk-blockio-no-discard.x86_64-latest.args | 37 ++++++++++++++ .../disk-blockio-no-discard.x86_64-latest.xml | 48 +++++++++++++++++++ .../disk-blockio-no-discard.xml | 32 +++++++++++++ tests/qemuxmlconftest.c | 1 + 8 files changed, 134 insertions(+), 6 deletions(-) create mode 100644 tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.args create mode 100644 tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/disk-blockio-no-discard.xml diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index bfc62b6270..ba0d4a7b12 100644 --- 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.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 6997cf7c09..6008ec66d3 100644 --- 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 b28af7fa56..8f7259a0e1 100644 --- 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 7658cc4d39..fc6ce4dd91 100644 --- 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 index 0000000000..0e477c6e40 --- /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 index 0000000000..94cff1ce6a --- /dev/null +++ b/tests/qemuxmlconfdata/disk-blockio-no-discard.x86_64-latest.xml @@ -0,0 +1,48 @@ + + QEMUGuest1 + c7a5fdbd-edaf-9455-926a-d65c16db1809 + 219136 + 219136 + 1 + + hvm + + + + qemu64 + + + destroy + restart + destroy + + /usr/bin/qemu-system-x86_64 + + + + + +
+ + + + + + +
+ + +
+ + +
+ + + + +