Re: [libvirt] [PATCH 8/9] libxl: pass cmdline to HVM guests

On Fri, Mar 20, 2015 at 11:18:36AM -0600, Jim Fehlig wrote: > Marek Marczykowski-Górecki wrote: > >> Signed-off-by: Marek Marczykowski-Górecki <marmarek(a)invisiblethingslab.com&gt; >> --- >> src/libxl/libxl_conf.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c >> index 8ec3c75..d78d2b2 100644 >> --- a/src/libxl/libxl_conf.c >> +++ b/src/libxl/libxl_conf.c >> @@ -735,6 +735,14 @@ libxlMakeDomBuildInfo(virDomainDefPtr def, >> libxl_defbool_set(&b_info->device_model_stubdomain, >> def->stubdomain == VIR_TRISTATE_BOOL_YES); >> >> + if (def->os.cmdline && def->os.cmdline[0]) { >> + b_info->extra_hvm = virStringSplit(def->os.cmdline, " ", 0); >> >> > What is the difference between b_info->extra_hvm and b_info->cmdline? > How are these two reconciled in libxl? I.e., what if they contained > In short, I don't think you should use that field at all. b_info->extra_hvm contains the parameters passed to QEMU specifically for HVM guest. Those parameters are not meant to be kernel command line. That field is introduced so that user can append arbitrary parameters to QEMU. I think it's only a stopgap for things we have not implemented in libxl or things we don't want to put into libxl. In reality I think it is rarely used.