Re: [qemu PATCH v4 3/4] nvdimm, acpi: support NFIT platform capabilities

On Tue, Jun 05, 2018 at 06:25:27PM +0300, Michael S. Tsirkin wrote: > On Mon, May 21, 2018 at 10:32:02AM -0600, Ross Zwisler wrote: > > Add a machine command line option to allow the user to control the Platform > > Capabilities Structure in the virtualized NFIT. This Platform Capabilities > > Structure was added in ACPI 6.2 Errata A. > > > > Signed-off-by: Ross Zwisler <ross.zwisler(a)linux.intel.com&gt; > > I tried playing with it and encoding the capabilities is > quite awkward. > > Can we add bits for specific capabilities instead of nvdimm-cap? > > How about: > > "cpu-flush-on-power-loss-cap" > "memory-flush-on-power-loss-cap" > "byte-addressable-mirroring-cap" Hmmm...I don't like that as much because: a) It's very verbose. Looking at my current qemu command line few other options require that many characters, and you'd commonly be defining more than one of these for a given VM. b) It means that the QEMU will need to be updated if/when new flags are added, because we'll have to have new options for each flag. The current implementation is more future-proof because you can specify any flags value you want. However, if you feel strongly about this, I'll make the change.