Re: [PATCH] xl, e820_host, PV passthrough: Fix guests crashing when memory == maxmem

[George Dunlap <george.dunlap@eu.citrix.com>]

On 24/05/13 15:55, Ian Campbell wrote:
> On Fri, 2013-05-24 at 10:51 -0400, Konrad Rzeszutek Wilk wrote:
>> On Fri, May 24, 2013 at 02:58:24PM +0100, Ian Campbell wrote:
>>> On Fri, 2013-05-24 at 09:36 -0400, Konrad Rzeszutek Wilk wrote:
>>>> The code had an obvious bug where it would assume that the balloon
>>>> amount would always be _something_ and add an E820_RAM entry at the
>>>> end of the E820 array. The added E820_RAM would contain the balloon amount
>>>> plus the delta of memory that had to be subtracted b/c of the various
>>>> E820 entries. That assumption is certainly true when maxmem != mem,
>>>> but if guest config has maxmem = memory that is incorrect (as balloon
>>>> value is zero). The end result is that the E820 that is constructed
>>>> is missing a swath of "delta" memory and in most cases ends up with
>>>> only one E820_RAM entry that is of 512MB size on many Intel systems.
>>>>
>>>> Reported-by: Christian Holpert <christian@holpert.de>
>>>> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
>>> Acked-by: Ian Campbell <ian.campbell@citrix.com>
>> George,
>> Would you be OK putting this in Xen 4.3? It is only exposed if a user
>>   1) launches a PV guest
>>   2). Has in the guest config: pci=['blabla']\ne820_host=1
>>   3). Is not that freq used as only a couple of people seem to use it
> TBH I was just going to commit it as an obvious bug fix in my next sweep
> of my queue (probably on Tuesday at this rate...)
>
> I guess George has until then to object ;-)

Sounds like a bug fix -- no objections. :-)

  -George