Re: [PATCH v8 05/13] libxl: Load guest BIOS from file

[Wei Liu <wei.liu2@citrix.com>]

On Mon, Aug 22, 2016 at 04:09:07PM +0100, Andrew Cooper wrote:
> On 22/08/16 15:26, Wei Liu wrote:
> > On Mon, Aug 22, 2016 at 02:26:11PM +0100, Andrew Cooper wrote:
> >> On 22/08/16 14:13, Wei Liu wrote:
> >>> On Fri, Aug 19, 2016 at 03:43:00PM +0100, Andrew Cooper wrote:
> >>>> On 18/08/16 15:13, Wei Liu wrote:
> >>>>> From: Anthony PERARD <anthony.perard@citrix.com>
> >>>>>
> >>>>> The path to the BIOS blob can be overriden by the xl's
> >>>>> bios_path_override option, or provided by u.hvm.bios_firmware in the
> >>>>> domain_build_info struct by other libxl user.
> >>>>>
> >>>>> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
> >>>>> Acked-by: Wei Liu <wei.liu2@citrix.com>
> >>>> This introduces a regression, but I am not sure how best to fix it.
> >>>>
> >>>> [root@xrtuk-09-12 xen-test-framework]# xl -vvv create -p
> >>>> tests/selftest/test-hvm32-selftest.cfg
> >>>> Parsing config from tests/selftest/test-hvm32-selftest.cfg
> >>>> libxl: debug: libxl_create.c:1603:do_domain_create: ao 0xa6b9f0: create:
> >>>> how=(nil) callback=(nil) poller=0xa6c120
> >>>> libxl: debug: libxl_create.c:959:initiate_domain_create: running bootloader
> >>>> libxl: debug: libxl_bootloader.c:324:libxl__bootloader_run: not a PV
> >>>> domain, skipping bootloader
> >>>> libxl: debug: libxl_event.c:686:libxl__ev_xswatch_deregister: watch
> >>>> w=0xa6cc30: deregister unregistered
> >>>> libxl: debug: libxl_numa.c:483:libxl__get_numa_candidate: New best NUMA
> >>>> placement candidate found: nr_nodes=1, nr_cpus=12, nr_vcpus=17,
> >>>> free_memkb=30611
> >>>> libxl: detail: libxl_dom.c:182:numa_place_domain: NUMA placement
> >>>> candidate with 1 nodes, 12 cpus and 30611 KB free selected
> >>>> domainbuilder: detail: xc_dom_allocate: cmdline="(null)", features="(null)"
> >>>> domainbuilder: detail: xc_dom_kernel_file:
> >>>> filename="/opt/xen-test-framework/tests/selftest/test-hvm32-selftest"
> >>>> domainbuilder: detail: xc_dom_malloc_filemap    : 1090 kB
> >>>> libxl: debug: libxl_dom.c:874:libxl__load_hvm_firmware_module: Loading
> >>>> BIOS: /usr/libexec/xen/boot/bios.bin
> >>>> libxl: error: libxl_dom.c:882:libxl__load_hvm_firmware_module: failed to
> >>>> read BIOS file: No such file or directory
> >>>>
> >>>> In this case, tools have been built with ./configure --disable-seabios
> >>>>
> >>>> As a result, /usr/libexec/xen/boot/bios.bin (name altered a patch sent
> >>>> separately) isn't built or installed.
> >>>>
> >>>> I think libxl needs to logic to determine which firmware to use based on
> >>>> the available CONFIG_* options it was built with.
> >>> I don' quite follow here.
> >>>
> >>> Do you mean if user hasn't specified any bios= option, (s)he gets
> >>> whatever available?
> >>>
> >>> I think we should stick with the seabios-default behaviour to avoid
> >>> surprising breakage.
> >>>
> >>> If you don't want any bois, maybe we should provide a bios=none option?
> >> XenServer is built with ./configure --disable-seabios because we don't
> >> use it (yet).  This means that SeaBIOS is not built, installed, or
> >> available.
> >>
> >> Because of this change, libxl unconditionally assumes the presence of
> >> SeaBIOS, and tries to use the installed seabios binary.
> > Right, this needs fixing.
> >
> > We can restore the behaviour in libxl -- if you specify a not available
> > bios, libxl won't complain, hvmloader will crash in the same way as
> > before.
> 
> HVMLoader works fine.  I am not sure how you got this idea.
> 

Huh? If you don't embed seabios or ovmf in hvmloader and then specify
bios=seabios or bios=ovmf in guest config file, I'm sure it will crash
when trying to load bios.

Wei.

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