Re: [Qemu-devel] [PATCH v3 5/6] vga: Use linear mapping + dirty logging in chain 4 memory access mode

[Jan Kiszka]

On 2011-08-25 09:19, Avi Kivity wrote:
> On 08/22/2011 08:12 PM, Jan Kiszka wrote:
>> Most VGA memory access modes require MMIO handling as they demand weird
>> logic to get a byte from or into the video RAM. However, there is one
>> exception: chain 4 mode with all memory planes enabled for writing. This
>> mode actually allows lineary mapping, which can then be combined with
>> dirty logging to accelerate KVM.
>>
>> This patch accelerates specifically VBE accesses like they are used by
>> grub in graphical mode. Not only the standard VGA adapter benefits from
>> this, also vmware and spice in VGA mode.
>>
>>
> 
> On which version of grub does this work?  This isn't having any effect 
> on my Fedora grub.

It's both grub1 (0.97) in graphical mode as used by OpenSUSE 11.4 and
grub2 (1.99-rc1) of Ubuntu 11.04.

Is Fedora's grub still slow or was it already fast before? Which Fedora?

Jan

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