Re: [libvirt] [PATCH] libxl: support dom0

On 07/06/2015 03:46 PM, Jim Fehlig wrote: > In Xen, dom0 is really just another domain that supports ballooning, > adding/removing devices, changing vcpu configuration, etc. This patch > adds support to the libxl driver for managing dom0. Note that the > legacy xend driver has long supported managing dom0. > > Operations that are not supported on dom0 are filtered in libvirt > where a sensible error is reported. Errors from libxl are not > always helpful. E.g., attempting a save on dom0 results in > > 2015-06-23 15:25:05 MDT libxl: debug: > libxl_dom.c:1570:libxl__toolstack_save: domain=0 toolstack data size=8 > 2015-06-23 15:25:05 MDT libxl: debug: > libxl.c:979:do_libxl_domain_suspend: ao 0x7f7e68000b70: inprogress: > poller=0x7f7e68000930, flags=i > 2015-06-23 15:25:05 MDT libxl-save-helper: debug: starting save: Success > 2015-06-23 15:25:05 MDT xc: detail: xc_domain_save_suse: starting save > of domid 0 > 2015-06-23 15:25:05 MDT xc: error: Couldn't map live_shinfo (3 = No > such process): Internal error > 2015-06-23 15:25:05 MDT xc: detail: Save exit of domid 0 with errno=3 > 2015-06-23 15:25:05 MDT libxl-save-helper: debug: complete r=1: No > such process > 2015-06-23 15:25:05 MDT libxl: error: > libxl_dom.c:1876:libxl__xc_domain_save_done: saving domain: domain did > not respond to suspend request: No such process > 2015-06-23 15:25:05 MDT libxl: error: > libxl_dom.c:2033:remus_teardown_done: Remus: failed to teardown device > for guest with domid 0, rc -8 > > Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; > --- > src/libxl/libxl_driver.c | 95 > ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 95 insertions(+) > > diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c > index 149ef70..d0b76ac 100644 > --- a/src/libxl/libxl_driver.c > +++ b/src/libxl/libxl_driver.c > @@ -79,6 +79,15 @@ VIR_LOG_INIT("libxl.libxl_driver"); > /* Number of Xen scheduler parameters */ > #define XEN_SCHED_CREDIT_NPARAM 2 > +#define LIBXL_CHECK_DOM0_GOTO(name, > label) \ > + do > { \ > + if (STREQ_NULLABLE(name, "Domain-0")) > { \ > + virReportError(VIR_ERR_OPERATION_INVALID, > "%s", \ > + _("Domain-0 does not support requested > operation")); \ > + goto > label; \ > + > } \ > + } while (0) > + > static libxlDriverPrivatePtr libxl_driver; > @@ -501,6 +510,62 @@ const struct libxl_event_hooks ev_hooks = { > }; > static int > +libxlAddDom0(libxlDriverPrivatePtr driver) > +{ > + libxlDriverConfigPtr cfg = libxlDriverConfigGet(driver); > + virDomainDefPtr def = NULL; > + virDomainObjPtr vm = NULL; > + virDomainDefPtr oldDef = NULL; > + libxl_dominfo d_info; > + int ret = -1; > + > + libxl_dominfo_init(&d_info); > + > + /* Ensure we have a dom0 */ > + if (libxl_domain_info(cfg->ctx, &d_info, 0) != 0) { > + virReportError(VIR_ERR_INTERNAL_ERROR, > + "%s", _("unable to get Domain-0 information > from libxenlight")); > + goto cleanup; > + } > + > + if (!(def = virDomainDefNew())) > + goto cleanup; > + > + def->id = 0; > + def->virtType = VIR_DOMAIN_VIRT_XEN; > + if (VIR_STRDUP(def->name, "Domain-0") < 0) > + goto cleanup; > + > + def->os.type = VIR_DOMAIN_OSTYPE_XEN; > + > + if (virUUIDParse("00000000-0000-0000-0000-000000000000", > def->uuid) < 0) > + goto cleanup; > + > + vm->def->vcpus = d_info.vcpu_online; > + vm->def->maxvcpus = d_info.vcpu_max_id + 1; > + vm->def->mem.cur_balloon = d_info.current_memkb; > + vm->def->mem.max_balloon = d_info.max_memkb; Opps. Before sending the patch, but after testing it again, I moved the call to libxl_domain_info to the beginning of this function. I also moved setting the vcpu and memory info earlier, but > + > + if (!(vm = virDomainObjListAdd(driver->domains, def, > + driver->xmlopt, > + 0, > + &oldDef))) > + goto cleanup; > + > + def = NULL; > + ret = 0; before getting a virDomainObj - ouch. Consider the following obvious fix squashed in diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index d0b76ac..c0dd00b 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -541,18 +541,19 @@ libxlAddDom0(libxlDriverPrivatePtr driver) if (virUUIDParse("00000000-0000-0000-0000-000000000000", def->uuid) < 0) goto cleanup; + if (!(vm = virDomainObjListAdd(driver->domains, def, + driver->xmlopt, + 0, + &oldDef))) + goto cleanup; + + def = NULL; + vm->def->vcpus = d_info.vcpu_online; vm->def->maxvcpus = d_info.vcpu_max_id + 1; vm->def->mem.cur_balloon = d_info.current_memkb; vm->def->mem.max_balloon = d_info.max_memkb; - if (!(vm = virDomainObjListAdd(driver->domains, def, - driver->xmlopt, - 0, - &oldDef))) - goto cleanup; - - def = NULL; ret = 0; cleanup: Regards, Jim