From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH] xl, e820_host, PV passthrough: Fix guests crashing when memory == maxmem Date: Fri, 24 May 2013 15:57:41 +0100 Message-ID: <519F7FE5.6060809@eu.citrix.com> References: <1369402576-2958-1-git-send-email-konrad.wilk@oracle.com> <1369403904.17830.201.camel@zakaz.uk.xensource.com> <20130524145131.GG4404@phenom.dumpdata.com> <1369407312.17830.202.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1369407312.17830.202.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: Konrad Rzeszutek Wilk , xen-devel@lists.xensource.com, david.vrabel@citrix.com, christian@holpert.de, Konrad Rzeszutek Wilk List-Id: xen-devel@lists.xenproject.org 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 >>>> Signed-off-by: Konrad Rzeszutek Wilk >>> Acked-by: Ian Campbell >> 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