On Thu, 17 Dec 2015 16:09:23 -0200 Eduardo Habkost <ehabk...@redhat.com> wrote:
> On Wed, Dec 16, 2015 at 11:26:20PM +0100, Igor Mammedov wrote: > > On Wed, 16 Dec 2015 17:39:02 -0200 > > Eduardo Habkost <ehabk...@redhat.com> wrote: > > > > > On Wed, Dec 16, 2015 at 05:54:25PM +0100, Igor Mammedov wrote: > > > > On Tue, 15 Dec 2015 14:08:09 +0530 > > > > Bharata B Rao <bhar...@linux.vnet.ibm.com> wrote: > > > > > > > > > On Mon, Dec 14, 2015 at 03:29:49PM -0200, Eduardo Habkost wrote: > > > > > > On Thu, Dec 10, 2015 at 11:45:37AM +0530, Bharata B Rao wrote: > > > > > > > Storing CPU typename in MachineState lets us to create CPU > > > > > > > threads for all architectures in uniform manner from > > > > > > > arch-neutral code. > > > > > > > > > > > > > > TODO: Touching only i386 and spapr targets for now > > > > > > > > > > > > > > Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com> > > > > > > > > > > > > Suggestions: > > > > > > > > > > > > * Name the field "cpu_base_type" to indicate it is the base CPU > > > > > > class name, not the actual CPU class name used when creating > > > > > > CPUs. > > > > > > * Put it in MachineClass, as it may be useful for code that > > > > > > runs before machine->init(), in the future. > > > > > > > > > > Ok. > > > > > > > > > > > * Maybe make it a CPUClass* field instead of a string? > > > > > > > > > > In the current use case, this base cpu type string is being passed > > > > > to cpu_generic_init(const char *typename, const char *cpu_model) > > > > > to create boot time CPUs with given typename and cpu_mode. So for > > > > > now the string makes sense for use case. > > > > > > > > > > Making it CPUClass* would necessiate more changes to > > > > > cpu_generic_init(). > > > > how about actually leaving it as "cpu_type" and putting in it > > > > actual cpu type that could be used with device_add(). > > > > > > > > that would get rid of keeping and passing around intermediate > > > > cpu_model. > > > > > > Makes sense. We only need to save both typename and cpu_model > > > today because cpu_generic_init() currently encapsulates three > > > steps: CPU class lookup + CPU creation + CPU feature parsing. But > > > we shouldn't need to redo CPU class lookup every time. > > BTW: Eduardo do you know if QEMU could somehow provide a list of > > supported CPU types (i.e. not cpumodels) to libvirt? > > Not sure I understand the question. Could you clarify what you > mean by "supported CPU types", and what's the problem it would > solve? device_add TYPE, takes only type name so I'd like to kep it that way and make sure that libvirt/user can list cpu types that hi would be able to use with device_add/-device. for PC they are generated from cpu_model with help of x86_cpu_type_name() > > > > > > > > We could just split cpu_model once, and save the resulting > > > CPUClass* + featurestr, instead of saving the full cpu_model > > > string and parsing it again every time. > > isn't featurestr as x86/sparc specific? > > > > Could we have field in x86_cpu_class/sparc_cpu_class for it and set it > > when cpu_model is parsed? > > That way generic cpu_model parser would handle only cpu names and > > target specific overrides would handle both. > > I always assumed we want to have a generic CPU model + featurestr > mechanism that could be reused by multiple architectures. I've thought the opposite way, that we wanted to faze out featurestr in favor of generic option parsing of generic device, i.e. -device TYPE,option=X,... but we would have to keep compatibility with old CLI that supplies cpu definition via -cpu cpu_model,featurestr so cpu_model translated into "cpu_type" field make sense for every target but featurestr is x86/sparc specific and I'd prefer to keep it that way and do not introduce it to other targets.
