Re: [Qemu-devel] [PATCH RFC 0/5] kvm/vhost: enable durty logging during memory registration

[Brad Hards <bradh@frogmouth.net>]

On Thu, 7 Apr 2011 06:41:35 am Michael S. Tsirkin wrote:
> As a solution, this adds an explicit flag that
> will enable dirty logging directly when registering
> the ram. kvm then needs a single system call
> to update tables for vga ram, vhost-net can simply ignore it.
I'm not very familiar with QEMU coding style and standards (so this could be 
completely bogus), but I think that the code would be easier if you used a 
integer flag / enum instead of a boolean. That would also give you options for 
additional behaviour changes later too. So instead of passing true/false, pass 
MEM_LOG_DIRTY_PAGES (or whatever you decide to call it).

I can't really comment on the rest of the patch - I'm too clueless. 

> This replaces the RFC patchset 'vga: flag vga ram for notifiers'.
> Warning: compile-tested only.
I compiled and booted my Ubuntu guest (on ubuntu host) which uses Cirrus for 
each step in this patchset. Seems OK to me - I didn't notice appreciable 
speedup, but I wasn't really expecting to.

Brad