Re: [libvirt] [PATCH 1/2] xenFormatNet: correct `type=netfront' to 'type=vif' to match libxl

On 05/12/2016 09:55 PM, Jim Fehlig wrote: > Joao Martins wrote: >> On 05/12/2016 12:54 AM, Jim Fehlig wrote: >>> On 04/21/2016 05:10 AM, Chunyan Liu wrote: >>>> According to current xl.cfg docs and xl codes, it uses type=vif >>>> instead of type=netfront. >>>> >>>> Currently after domxml-to-native, libvirt xml model=netfront will be >>>> converted to xl type=netfront. This has no problem before, xen codes >>>> for a long time just check type=ioemu, if not, set type to _VIF. >>>> >>>> Since libxl uses parse_nic_config to avoid duplicate codes, it >>>> compares 'type=vif' and 'type=ioemu' for valid parameters, others >>>> are considered as invalid, thus we have problem with type=netfront >>>> in xl config file. >>>> #xl create sles12gm-hvm.orig >>>> Parsing config from sles12gm-hvm.orig >>>> Invalid parameter `type'. >>>> >>>> Correct the convertion in libvirt, so that it matchs libxl codes >>>> and also xl.cfg. >>>> >>>> Signed-off-by: Chunyan Liu <cyliu(a)suse.com&gt; >>>> --- >>>> src/xenconfig/xen_common.c | 38 ++++++++++++++++++++++++-------------- >>>> src/xenconfig/xen_common.h | 7 ++++--- >>>> src/xenconfig/xen_xl.c | 4 ++-- >>>> src/xenconfig/xen_xm.c | 8 ++++---- >>>> 4 files changed, 34 insertions(+), 23 deletions(-) >>>> >>>> diff --git a/src/xenconfig/xen_common.c b/src/xenconfig/xen_common.c >>>> index e1d9cf6..f54d6b6 100644 >>>> --- a/src/xenconfig/xen_common.c >>>> +++ b/src/xenconfig/xen_common.c >>>> @@ -801,9 +801,8 @@ xenParseCharDev(virConfPtr conf, virDomainDefPtr def) >>>> return -1; >>>> } >>>> >>>> - >>>> static int >>>> -xenParseVif(virConfPtr conf, virDomainDefPtr def) >>>> +xenParseVif(virConfPtr conf, virDomainDefPtr def, const char *vif_typename) >>>> { >>>> char *script = NULL; >>>> virDomainNetDefPtr net = NULL; >>>> @@ -942,7 +941,7 @@ xenParseVif(virConfPtr conf, virDomainDefPtr def) >>>> VIR_STRDUP(net->model, model) < 0) >>>> goto cleanup; >>>> >>>> - if (!model[0] && type[0] && STREQ(type, "netfront") && >>>> + if (!model[0] && type[0] && STREQ(type, vif_typename) && >>>> VIR_STRDUP(net->model, "netfront") < 0) >>>> goto cleanup; >>>> >>>> @@ -1042,11 +1041,17 @@ xenParseGeneralMeta(virConfPtr conf, virDomainDefPtr def, virCapsPtr caps) >>>> >>>> /* >>>> * A convenience function for parsing all config common to both XM and XL >>>> + * >>>> + * vif_typename: type name for a paravirtualized network could >>>> + * be different for xm and xl. For xm, it uses type=netfront; >>>> + * for xl, it uses type=vif. So, for xm, should pass "netfront"; >>>> + * for xl, should pass "vif". >>>> */ >>>> int >>>> xenParseConfigCommon(virConfPtr conf, >>>> virDomainDefPtr def, >>>> - virCapsPtr caps) >>>> + virCapsPtr caps, >>>> + const char *vif_typename) >>> One thing I didn't recall when suggesting this approach is that xenParseVif() is >>> called in xenParseConfigCommon(). I was thinking it was called from >>> xen_{xl,xm}.c and the extra parameter would only be added to the >>> xen{Format,Parse}Vif functions. I don't particularly like seeing the device >>> specific parameter added to the common functions, but wont object if others are >>> fine with it. Any other opinions on that? Joao? >> That's a good point - probably we can avoid it by using >> xen{Format,Parse}Vif (with the signature change Chunyan proposes) individually >> on xenParseXM and xenParseXL. > Nod. > >> And there wouldn't be any xenParseConfigCommon >> with device-specific parameters (as vif being one of the many devices that the >> routine is handling). The vif config is the same between xm and xl, with the >> small difference wrt to the validation on xen libxl side - so having in >> xen_common.c makes sense. > Nod again :-). > >>> And one reason I wont object is that the alternative (calling >>> xen{Format,Parse}Vif from xen_{xl,xm}.c) is a rather large change since all the >>> tests/{xl,xm}configdata/ files would need to be adjusted. >> Hm, perhaps I fail to see what the large change would be. We would keep the same >> interface (i.e. model=netfront as valid on libvirt-side and converting to >> type="vif" where applicable (libxl)) then the xml and .cfg won't change. >> Furthermore, we only use e1000 which is valid for both cases and Chunyan adds >> one test case to cover this series. So may be the adjustment you suggest above >> wouldn't be as cumbersome as to change all the tests/{xl,xm}configdata files? > On the Parse side we would be fine, but on the Format side 'vif =' would now be > emitted after xenFormatConfigCommon executed. So the xl.cfg output would change > from e.g. > Ah, totally missed that out: it looks a large change. I think XL vif won't diverge from XM anytime soon unless we start adding support for more qemu-ish features on xen libxl (e.g. vhostuser, or even block "target" field equivalent).

I am fine with the approach on the patch, but the way you suggested is indeed more correct.