David Scott wrote:

...

Something like the attached, which seems to work well for me when specifying driverName = qemu, e.g.

<disk type='file' device='disk'> <driver name='qemu'/> <source file='/var/lib/xen/images/sles11sp2-pv/disk0.raw'/> <target dev='xvda' bus='xen'/> </disk>

This also works for me!

Good to hear. I'll send the patch to the libvirt list.

On a related note, what do you think about the attached patch? It allows the user to select a non-default qemu via the <emulator> element. My domain XML looked like this:

<devices> <emulator>/usr/lib/xen/bin/qemu-system-i386</emulator>

IMO, the possible emulators should be exposed in the capabilities. E.g. on a machine with both kvm and qemu, both emulators are shown as possibilities for an hvm, x86_64 guest # virsh capabilities ... <guest> <os_type>hvm</os_type> <arch name='x86_64'> <wordsize>64</wordsize> <domain type='qemu'> <emulator>/usr/bin/qemu-system-x86_64</emulator> <machine>pc-1.1</machine> <machine canonical='pc-1.1'>pc</machine> <machine>pc-1.0</machine> <machine>pc-0.15</machine> <machine>pc-0.14</machine> <machine>pc-0.13</machine> <machine>pc-0.12</machine> <machine>pc-0.11</machine> <machine>pc-0.10</machine> <machine>isapc</machine> </domain> <domain type='kvm'> <emulator>/usr/bin/qemu-kvm</emulator> <machine>pc-1.1</machine> <machine canonical='pc-1.1'>pc</machine> <machine>pc-1.0</machine> <machine>pc-0.15</machine> <machine>pc-0.14</machine> <machine>pc-0.13</machine> <machine>pc-0.12</machine> <machine>pc-0.11</machine> <machine>pc-0.10</machine> <machine>isapc</machine> </domain> .... </guest> ...

<disk device="disk" type="network"> <driver name='qemu'/> <source protocol="rbd" name="rbd:rbd/ubuntu1204.img"/> <target dev="hda"/> </disk> <graphics type="vnc" port="-1" autoport="yes" listen="0.0.0.0"/> </devices>

Now that upstream qemu is the default in xen-4.3, it seems useful to be able to select the traditional qemu for older VMs.

Agreed. And reporting that both emulators exist via the capabilities would be helpful for users.

Also I backported this to my xen-4.2 system and used this patch + your patch + the previous 'stat()' fix to successfully start a VM on ceph storage via libvirt + libxl (my quest is almost complete!)

Nice!

diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index f549a5d..abbd3c0 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -811,6 +811,30 @@ libxlMakeCapabilities(libxl_ctx *ctx) }

int +libxlMakeEmulator(virDomainDefPtr def, libxl_domain_config *d_config) +{ + /* No explicit override means use the default */ + if (!def->emulator) { + return 0; + } + if (strstr(def->emulator, "/qemu-system-")) { + d_config->b_info.device_model_version = + LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN; + return 0; + }

Here we could check the requested emulator against the capabilities, and then do the proper mapping for device_model_version. Do you have time for an upstream libvirt patch to expose the possible emulators in the capabilities, along with this patch allowing the user to specify one? Regards, Jim

+ if (strstr(def->emulator, "/qemu-dm")) { + d_config->b_info.device_model_version = + LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL; + return 0; + } + virReportError(VIR_ERR_INTERNAL_ERROR, + _("libxenlight doesn't support emulator '%s'"), + def->emulator); + return -1; +} + + +int libxlBuildDomainConfig(libxlDriverPrivatePtr driver, virDomainDefPtr def, libxl_domain_config *d_config) { @@ -834,6 +858,10 @@ libxlBuildDomainConfig(libxlDriverPrivatePtr driver, goto error; }

+ if (libxlMakeEmulator(def, d_config) < 0) { + goto error; + } + d_config->on_reboot = def->onReboot; d_config->on_poweroff = def->onPoweroff; d_config->on_crash = def->onCrash;

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