Re: [libvirt] [PATCH] qemu: add support for -device pvpanic

On 11/27/13 09:41, Hu Tao wrote: > qemu removes the builtin pvpanic device for all qemu versions since 1.7, > in order to support <on_crash>, '-device pvpanic' has to be added to > qemu command line. > > Signed-off-by: Hu Tao <hutao(a)cn.fujitsu.com&gt; > --- > src/qemu/qemu_capabilities.c | 8 ++++++++ > src/qemu/qemu_capabilities.h | 2 ++ > src/qemu/qemu_command.c | 4 ++++ > 3 files changed, 14 insertions(+) > > diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c > index 548b988..7783997 100644 > --- a/src/qemu/qemu_capabilities.c > +++ b/src/qemu/qemu_capabilities.c > @@ -243,6 +243,8 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST, > "virtio-mmio", > "ich9-intel-hda", > "kvm-pit-lost-tick-policy", > + > + "pvpanic", /* 160 */ > ); > > struct _virQEMUCaps { > @@ -1198,6 +1200,9 @@ virQEMUCapsComputeCmdFlags(const char *help, > virQEMUCapsSet(qemuCaps, QEMU_CAPS_VNC_SHARE_POLICY); > } > > + if (version >= 1005000) > + virQEMUCapsSet(qemuCaps, QEMU_CAPS_PVPANIC); > + Hard coding the version number is not a good idea. Libvirt uses qmp monitor queries to determine supported devices. Please add this in the virQEMUCapsObjectTypes structure instead, which will do the qmp detection for you.

> return 0; > } > > @@ -2561,6 +2566,9 @@ virQEMUCapsInitQMPMonitor(virQEMUCapsPtr qemuCaps, > if (qemuCaps->version >= 1006000) > virQEMUCapsSet(qemuCaps, QEMU_CAPS_DEVICE_VIDEO_PRIMARY); > > + if (qemuCaps->version >= 1005000) > + virQEMUCapsSet(qemuCaps, QEMU_CAPS_PVPANIC); > + Same here ... this should be autoprobed by a function using the structure above. > if (virQEMUCapsProbeQMPCommands(qemuCaps, mon) < 0) > goto cleanup; > if (virQEMUCapsProbeQMPEvents(qemuCaps, mon) < 0) > diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h > index 02d47c6..06d2fac 100644 > --- a/src/qemu/qemu_capabilities.h > +++ b/src/qemu/qemu_capabilities.h > @@ -199,6 +199,8 @@ enum virQEMUCapsFlags { > QEMU_CAPS_DEVICE_ICH9_INTEL_HDA = 158, /* -device ich9-intel-hda */ > QEMU_CAPS_KVM_PIT_TICK_POLICY = 159, /* kvm-pit.lost_tick_policy */ > > + QEMU_CAPS_PVPANIC = 160, /* -device pvpanic */ > + > QEMU_CAPS_LAST, /* this must always be the last item */ > }; > > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index 763417f..b1307a3 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -9588,6 +9588,10 @@ qemuBuildCommandLine(virConnectPtr conn, > goto error; > } > > + if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_PVPANIC)) { > + virCommandAddArgList(cmd, "-device", "pvpanic", NULL); > + } > + I remember discussions saying that it's NOT a good idea to enable this stuff always. As a result, this device is not being added by qemu as you described above. Shouldn't we only add this if the user enables <on_crash> actions?