[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 0/6] Add UUID command-line option
From: |
Blue Swirl |
Subject: |
Re: [Qemu-devel] [PATCH 0/6] Add UUID command-line option |
Date: |
Sun, 24 Aug 2008 15:45:51 +0300 |
On 8/24/08, Gleb Natapov <address@hidden> wrote:
> On Sun, Aug 24, 2008 at 03:01:22PM +0300, Blue Swirl wrote:
> > On 8/24/08, Gleb Natapov <address@hidden> wrote:
> > > Hello,
> > >
> > > This is one more try to push this patch series into qemu. This time
> > > I don't use vmport interface. Instead I implemented simple communication
> > > channel between qemu and BIOS using IO port. I decided not to use
> > > firmware interface since current users of the interface may depend on
> > > exact structure layout, so it doesn't look like a good idea to add
> > > arbitrary fields there. Also I don't want to copy the whole ROM into
> BIOS
> > > just to access one field of it. IO channel is implemented by the first
> > > patch of the series. Patches 2-5 implement UUID related stuff. Patch 6
> > > passes host CPU frequency to fill in SM BIOS table.
> > >
> > > Please comment.
> >
> > I disagree about not using the firmware interface. The structure can
> > be extended and even new versions defined, all structure users are
> > open source.
>
> It is hard enough to change interface between qemu and bochs BIOS. How
> complex it will be to simultaneously change interface for several boot
> loaders.
This is because no Qemu developer has commit rights to Bochs, and
Bochs releases too infrequently. With commit rights, synchronizing a
commit would not be too difficult. And this should be needed only if
the common interface changes incompatibly.
> > UUID is not architecture specific, so it should use the
> > main structure instead if the architecture specific substructure
> > (nvram_arch*). Adding UUID to unused fields will not break anything.
>
> Most info in ohwcfg_v3_t are not needed (or can be obtained by other
> means) by PC BIOS, so there is no point in coping the whole structure
> into BIOS. Of cause BIOS don't have to copy entire ohwcfg_v3_t, but
For example, Bochs seems to use i440fx registers to determine the
available physical memory. This could be changed to use the
configuration structure instead. It's a matter of taste, but I would
find this an improvement.
> access only required fields by reading only specific offsets, but then the
> interface will be exactly like the one I proposed with only difference
> that instead of specifying magic value (like 1 for reading UUID in my
> patch series), BIOS will have to specify magic offset (like 0xE0).
There is no need for a magic offset, ohwcfg_v3_t is designed to be
included even from asm.
- Re: [Qemu-devel] [PATCH 3/6] Add "info uuid" command to monitor., (continued)
- Re: [Qemu-devel] [PATCH 0/6] Add UUID command-line option, Avi Kivity, 2008/08/24
- Re: [Qemu-devel] [PATCH 0/6] Add UUID command-line option, Blue Swirl, 2008/08/24
- Re: [Qemu-devel] [PATCH 0/6] Add UUID command-line option, Avi Kivity, 2008/08/24
- Re: [Qemu-devel] [PATCH 0/6] Add UUID command-line option, Blue Swirl, 2008/08/24
- Re: [Qemu-devel] [PATCH 0/6] Add UUID command-line option, Avi Kivity, 2008/08/25