On 7/22/22 18:23, Daniel P. Berrangé wrote: > Normally when an UEFI firmware is marked as read-only, an associated > NVRAM file will be created. Some builds of UEFI firmware, however, wish > to remain stateless and so will be read-only, but never have any NVRAM > file. To represent this concept a 'stateless' tristate bool attribute > is introduced on the <loader/> element. > > There are rather a large number of permutations to consider. > > With default firmware selection > > * <os/> > > => Historic default, no change > > * <os> > <loader stateless='yes'/> > </os> > > => Explicit version of historic default, no change > > * <os> > <loader stateless='no'/> > </os> > > => Invalid, bios is always stateless > > With manual legacy BIOS selection > > * <os> > <loader>/path/to/seabios</loader> > ... > </os> > > => Historic default, no change > > * <os> > <loader stateless='yes'>/path/to/seabios</loader> > ... > </os> > > => Explicit version of historic default, no change > > * <os> > <loader stateless='no'>/path/to/seabios</loader> > ... > </os> > > => Invalid, bios is always stateless > > With manual UEFI selection > > * <os> > <loader type='pflash'>/path/to/edk2</loader> > ... > </os> > > => Historic default, no change > > * <os> > <loader type='pflash' stateless='yes'>/path/to/edk2</loader> > ... > </os> > > => Skip auto-filling NVRAM / template > > * <os> > <loader type='pflash' stateless='no'>/path/to/edk2</loader> > ... > </os> > > => Explicit version of historic default, no change > > With automatic firmware selection > > * <os firmware='bios'/> > > => Historic default, no change > > * <os firmware='bios'> > <loader stateless='yes'/> > </os> > > => Explicit version of historic default, no change > > * <os firmware='bios'> > <loader stateless='no'/> > </os> > > => Invalid, bios is always stateless > > * <os firmware='uefi'/> > > => Historic default, no change > > * <os firmware='uefi'> > <loader stateless='yes'/> > </os> > > => Skip auto-filling NVRAM / template > > * <os firmware='uefi'> > <loader stateless='no'/> > </os> > > => Explicit version of historic default, no change > > Signed-off-by: Daniel P. Berrangé <berrange@xxxxxxxxxx> > --- > docs/formatdomain.rst | 9 ++++- > src/conf/domain_conf.c | 9 +++++ > src/conf/domain_conf.h | 1 + > src/conf/domain_validate.c | 26 ++++++++++++++ > src/conf/schemas/domaincommon.rng | 5 +++ > ...-auto-bios-not-stateless.x86_64-latest.err | 1 + > .../firmware-auto-bios-not-stateless.xml | 18 ++++++++++ > ...are-auto-bios-stateless.x86_64-latest.args | 32 +++++++++++++++++ > .../firmware-auto-bios-stateless.xml | 18 ++++++++++ > .../firmware-manual-bios-not-stateless.err | 1 + > .../firmware-manual-bios-not-stateless.xml | 15 ++++++++ > .../firmware-manual-bios-stateless.args | 30 ++++++++++++++++ > .../firmware-manual-bios-stateless.xml | 15 ++++++++ > ...nual-efi-nvram-stateless.x86_64-latest.err | 1 + > .../firmware-manual-efi-nvram-stateless.xml | 21 ++++++++++++ > ...nvram-template-stateless.x86_64-latest.err | 1 + > ...re-manual-efi-nvram-template-stateless.xml | 19 +++++++++++ > tests/qemuxml2argvtest.c | 8 +++++ > ...ware-auto-bios-stateless.x86_64-latest.xml | 34 +++++++++++++++++++ > .../firmware-manual-bios-stateless.xml | 25 ++++++++++++++ > .../firmware-manual-bios.xml | 25 ++++++++++++++ > tests/qemuxml2xmltest.c | 3 ++ > 22 files changed, 316 insertions(+), 1 deletion(-) > create mode 100644 tests/qemuxml2argvdata/firmware-auto-bios-not-stateless.x86_64-latest.err > create mode 100644 tests/qemuxml2argvdata/firmware-auto-bios-not-stateless.xml > create mode 100644 tests/qemuxml2argvdata/firmware-auto-bios-stateless.x86_64-latest.args > create mode 100644 tests/qemuxml2argvdata/firmware-auto-bios-stateless.xml > create mode 100644 tests/qemuxml2argvdata/firmware-manual-bios-not-stateless.err > create mode 100644 tests/qemuxml2argvdata/firmware-manual-bios-not-stateless.xml > create mode 100644 tests/qemuxml2argvdata/firmware-manual-bios-stateless.args > create mode 100644 tests/qemuxml2argvdata/firmware-manual-bios-stateless.xml > create mode 100644 tests/qemuxml2argvdata/firmware-manual-efi-nvram-stateless.x86_64-latest.err > create mode 100644 tests/qemuxml2argvdata/firmware-manual-efi-nvram-stateless.xml > create mode 100644 tests/qemuxml2argvdata/firmware-manual-efi-nvram-template-stateless.x86_64-latest.err > create mode 100644 tests/qemuxml2argvdata/firmware-manual-efi-nvram-template-stateless.xml > create mode 100644 tests/qemuxml2xmloutdata/firmware-auto-bios-stateless.x86_64-latest.xml > create mode 100644 tests/qemuxml2xmloutdata/firmware-manual-bios-stateless.xml > create mode 100644 tests/qemuxml2xmloutdata/firmware-manual-bios.xml > > diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst > index 3ea094e64c..4199abfd1a 100644 > --- a/docs/formatdomain.rst > +++ b/docs/formatdomain.rst > @@ -242,7 +242,11 @@ harddisk, cdrom, network) determining where to obtain/find the boot image. > firmwares may implement the Secure boot feature. Attribute ``secure`` can be > used to tell the hypervisor that the firmware is capable of Secure Boot feature. > It cannot be used to enable or disable the feature itself in the firmware. > - :since:`Since 2.1.0` > + :since:`Since 2.1.0`. If the loader is marked as read-only, then with UEFI it > + is assumed that there will be a writable NVRAM available. In some cases, > + however, it may be desirable for the loader to run without any NVRAM, discarding > + any config changes on shutdown. The ``stateless`` flag can be used to control > + this behaviour, when set to ``no`` NVRAM will never be created. The ``stateless` flag (:since:since 8.6.0) can be used ... Or something among those lines, to make it obvious when the attribute was added. > ``nvram`` > Some UEFI firmwares may want to use a non-volatile memory to store some > variables. In the host, this is represented as a file and the absolute path Michal
