Re: [libvirt] [PATCH v2 06/12] qemu: Generate cmd line at startup

On 02/21/2018 01:11 PM, Michal Privoznik wrote: > This is the easier part. All we need to do here is put -object > pr-manger-helper,id=$alias,path=$socketPath and then just > reference the object in -drive file.pr-manger=$alias. s/manger/manager/ My fingers usually the same way though as manger > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > src/qemu/qemu_command.c | 40 ++++++++++++++++++++++ > .../disk-virtio-scsi-reservations-not-managed.args | 28 +++++++++++++++ > .../disk-virtio-scsi-reservations.args | 29 ++++++++++++++++ > tests/qemuxml2argvtest.c | 8 +++++ > 4 files changed, 105 insertions(+) > create mode 100644 tests/qemuxml2argvdata/disk-virtio-scsi-reservations-not-managed.args > create mode 100644 tests/qemuxml2argvdata/disk-virtio-scsi-reservations.args > > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index fa0aa5d5c..069d60d35 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -1514,6 +1514,20 @@ qemuDiskSourceGetProps(virStorageSourcePtr src) > } > > > +static void > +qemuBuildDriveSourcePR(virBufferPtr buf, > + virStorageSourcePtr src) > +{ > + qemuDomainStorageSourcePrivatePtr srcPriv = QEMU_DOMAIN_STORAGE_SOURCE_PRIVATE(src); > + qemuDomainDiskPRDPtr prd = srcPriv->prd; > + > + if (!prd || !prd->alias) > + return; > + > + virBufferAsprintf(buf, ",file.pr-manager=%s", prd->alias); > +} > + > + > static int > qemuBuildDriveSourceStr(virDomainDiskDefPtr disk, > virQEMUCapsPtr qemuCaps, > @@ -1590,6 +1604,8 @@ qemuBuildDriveSourceStr(virDomainDiskDefPtr disk, > > if (disk->src->debug) > virBufferAsprintf(buf, ",file.debug=%d", disk->src->debugLevel); > + > + qemuBuildDriveSourcePR(buf, disk->src); > } else { > if (!(source = virQEMUBuildDriveCommandlineFromJSON(srcprops))) > goto cleanup; > @@ -9789,6 +9805,28 @@ qemuBuildPanicCommandLine(virCommandPtr cmd, > } > > > +static void > +qemuBuildMasterPRCommandLine(virCommandPtr cmd, > + const virDomainDef *def) > +{ > + size_t i; > + > + for (i = 0; i < def->ndisks; i++) { > + const virDomainDiskDef *disk = def->disks[i]; > + qemuDomainStorageSourcePrivatePtr srcPriv = QEMU_DOMAIN_STORAGE_SOURCE_PRIVATE(disk->src); > + qemuDomainDiskPRDPtr prd = srcPriv->prd; > + virBuffer buf = VIR_BUFFER_INITIALIZER; > + > + if (!prd || !prd->alias) > + continue; > + > + virBufferAsprintf(&buf, "pr-manager-helper,id=%s,path=%s", prd->alias, prd->path); > + virCommandAddArg(cmd, "-object"); > + virCommandAddArgBuffer(cmd, &buf); What happens when there's more than one disk using the managed mode where you have a "static" alias and path, wouldn't there be multiple lines with: -object pr-manager-helper,id=pr-helper0,path=/tmp/lib/domain--1-QEMUGuest1/pr-helper0.sock

? And how is QEMU going to react to that? IOW: Shouldn't this code know it's already created an object for that case and not generate another one? The other one : -object pr-manager-helper,id=pr-helper-sdb,path=/path/to/qemu-pr-helper.sock I get, but I'm still not thrilled with "sdb" as opposed to the disk->info.alias of "scsi0-0-0-0" more commonly used. IIRC, there's no guarantee that what libvirt calls "sdb" ends up being "sdb" on the guest. My vague recollection of the algorithm that "automagically" generates the address based on sda, sdb, sdc, etc. So "sdb" IIRC would related to an address that would create an alias using "0-0-1"; whereas, "sda" would create that "0-0-0" value.