Re: [PATCH v10 1/3] ioreq-server: add support for multiple servers

["Jan Beulich" <JBeulich@suse.com>]

>>> On 02.06.14 at 10:34, <Paul.Durrant@citrix.com> wrote:
>>  -----Original Message-----
>> From: Jan Beulich [mailto:JBeulich@suse.com]
>> Sent: 02 June 2014 09:05
>> To: Paul Durrant
>> Cc: Ian Jackson; Stefano Stabellini; xen-devel@lists.xen.org 
>> Subject: Re: [PATCH v10 1/3] ioreq-server: add support for multiple servers
>> 
>> >>> On 22.05.14 at 12:38, <paul.durrant@citrix.com> wrote:
>> > The previous single ioreq server that was created on demand now
>> > becomes the default server and an API is created to allow secondary
>> > servers, which handle specific IO ranges or PCI devices, to be added.
>> >
>> > When the guest issues an IO the list of secondary servers is checked
>> > for a matching IO range or PCI device. If none is found then the IO
>> > is passed to the default server.
>> >
>> > Secondary servers use guest pages to communicate with emulators, in
>> > the same way as the default server. These pages need to be in the
>> > guest physmap otherwise there is no suitable reference that can be
>> > queried by an emulator in order to map them. Therefore a pool of
>> > pages in the current E820 reserved region, just below the special
>> > pages is used. Secondary servers allocate from and free to this pool
>> > as they are created and destroyed.
>> >
>> > The size of the pool is currently hardcoded in the domain build at a
>> > value of 8. This should be sufficient for now and both the location and
>> > size of the pool can be modified in future without any need to change the
>> > API.
>> >
>> > Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
>> > Acked-by: Ian Campbell <ian.campbell@citrix.com>
>> 
>> I committed and pushed this, but I had to fix up two build errors
>> with XSM enabled. Please in the future make sure patches you
>> submit build in all relevant modes.
>> 
> 
> Apologies. I didn't realise I had to explicitly enable it in the build.

In fact any XSM changes would need to be tested both ways - with
in enabled (non-default) and disabled (default).

Jan