Re: [libvirt] [PATCH v5 3/3] qemu: Automatically create NVRAM store
On 22.08.2014 14:26, Laszlo Ersek wrote:
one question
On 08/22/14 14:08, Michal Privoznik wrote:
> When using split UEFI image, it may come handy if libvirt manages per
> domain _VARS file automatically. While the _CODE file is RO and can be
> shared among multiple domains, you certainly don't want to do that on
> the _VARS file. This latter one needs to be per domain. So at the
> domain startup process, if it's determined that domain needs _VARS
> file it's copied from this master _VARS file. The location of the
> master file is configurable in qemu.conf.
>
> Temporary, on per domain basis the location of master NVRAM file can
> be overridden by this @template attribute I'm inventing to the
> <nvram/> element. All it does is holding path to the master NVRAM file
> from which local copy is created. If that's the case, the map in
> qemu.conf is not consulted.
>
> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
> ---
> docs/formatdomain.html.in | 11 +-
> docs/schemas/domaincommon.rng | 9 +-
> libvirt.spec.in | 2 +
> src/Makefile.am | 1 +
> src/conf/domain_conf.c | 11 +-
> src/conf/domain_conf.h | 1 +
> src/qemu/libvirtd_qemu.aug | 3 +
> src/qemu/qemu.conf | 14 +++
> src/qemu/qemu_conf.c | 94 ++++++++++++++
> src/qemu/qemu_conf.h | 5 +
> src/qemu/qemu_process.c | 137 +++++++++++++++++++++
> src/qemu/test_libvirtd_qemu.aug.in | 3 +
> tests/domainschemadata/domain-bios-nvram-empty.xml | 40 ++++++
> 13 files changed, 325 insertions(+), 6 deletions(-)
> create mode 100644 tests/domainschemadata/domain-bios-nvram-empty.xml
> @@ -17682,7 +17684,14 @@ virDomainLoaderDefFormat(virBufferPtr buf,
> virBufferAsprintf(buf, " type='%s'>", type);
>
> virBufferEscapeString(buf, "%s</loader>\n", loader->path);
> - virBufferEscapeString(buf, "<nvram>%s</nvram>\n",
loader->nvram);
> + if (loader->nvram || loader->templt) {
> + virBufferAddLit(buf, "<nvram");
> + virBufferEscapeString(buf, " template='%s'",
loader->templt);
Shouldn't you protect this virBufferEscapeString() call with an "if" too?
No, virBufferEscapeString() works slightly different to other virBuffer*
APIs. If any of its 3 arguments is NULL is basically NOP.
So if loader->templt (sigh, I couldn't use template as it's c++ keyword,
but that's different story) is NULL (= it wasn't specified in XML) this
line turns into NOP and doesn't output anything.
> + if (loader->nvram)
> + virBufferEscapeString(buf, ">%s</nvram>\n",
loader->nvram);
> + else
> + virBufferAddLit(buf, "/>\n");
> + }
You were confused by this, weren't you? This is basically to distinguish
cases if nvram path was specified or not. If it was, we need to print
out <nvram>/some/path</nvram> otherwise the partially written nvram
element needs to be enclosed.
> }
Looks good otherwise.
Cool!
Thanks
Laszlo
Michal