From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Steven Hand" Subject: Re: Re: [PATCH][HVM] fix VNIF restore failure on HVMguestwith heavy workload Date: Wed, 11 Apr 2007 17:54:08 +0100 Message-ID: <060501c77c5a$07b60a20$4333710a@Violet> References: <0E6B8CEB89DCFE40A52F80EB8F97D99D013F1FC0@pdsmsx413.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 8bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Zhao, Fan" , Keir Fraser , "Zhai, Edwin" Cc: Steven Hand , Tim Deegan , Ian Pratt , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Just FYI - this is something I tested successfully last week. Not sure if anything has been changed in recent changesets but worth checking up - can you post the output from /var/log/xen/xend.log ? Secondly: there is a known issue with save/restore of ballooned domains (HVM or PV) where the balloning is done from within the guest (e.g. by echoing to /proc/xen/balloon). Since this doesn't update the memory target within xenstore, you'll end up 'reverting' the guest memory size to that last set via xm mem-set. The 'fix' is not to do that, i.e. only use the xm or XenAPI to request ballooning. cheers, S. ----- Original Message ----- From: "Zhao, Fan" To: "Keir Fraser" ; "Zhai, Edwin" Cc: "Tim Deegan" ; "Ian Pratt" ; Sent: Wednesday, April 11, 2007 5:24 PM Subject: RE: [Xen-devel] Re: [PATCH][HVM] fix VNIF restore failure on HVMguestwith heavy workload Hi Keir, I noticed that with cset 14773, if I use xm mem-set to adjust the memory of hvm guest with balloon driver by xm mem-set, and then save the guest, the xm save will fail, so does xm migrate. A white window will pop up, and the guest still exists through xm li. So will your great fixes also include the fixing for this issue? Thanks! Best regards, Fan -----Original Message----- From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Keir Fraser Sent: 2007Äê4ÔÂ11ÈÕ 16:57 To: Zhai, Edwin Cc: Tim Deegan; Ian Pratt; xen-devel@lists.xensource.com Subject: Re: [Xen-devel] Re: [PATCH][HVM] fix VNIF restore failure on HVMguest with heavy workload FYI, the next changeset worth testing or fixing is r14795:6e7ef794cdbc. I've made a *lot* of changes in the last 24 hours. I've tried a few save/restores under block and net load with no observed problems. -- Keir On 11/4/07 08:20, "Zhai, Edwin" wrote: > On Tue, Apr 10, 2007 at 08:16:04PM +0100, Keir Fraser wrote: >> On 10/4/07 17:47, "Zhai, Edwin" wrote: >> >>> [PATCH][HVM] fix VNIF restore failure on HVM guest with heavy workload >>> >>> Signed-off-by: Zhai Edwin >>> >>> VNIF has many intrs when save/restore with net workload, so need keep >>> handler >>> from intrs >> >> What happens if an interrupt is being processed during save/restore? It >> would be nice to know what the underlying bug is! > > If an pseudo PCI intr occurred after xen_suspend on cpu0, there is > definitely > a > crash. I copy this code from original PV driver code. > >> >> That said, it may well make sense to somehow disable interrupt handling >> across save/restore. Unfortunately your patch is insufficient since we >> could >> handle event-channel interrupts on any VCPU (the irq's affinity can be >> changed outside our control if it is routed through the virtual IOAPIC, >> and >> if e.g. the userspace irqbalance daemon is running). >> >> I wanted to use stop_machine_run() but unfortunately it isn't exported to >> modules. :-( irq_disable() may do the right thing for us though. > > SMP is a headache for PV drv save/restore on HVM. Even we disable intr on > all > cpus, PV driver on other cpu may still access low level service after > xen_suspend on cpu0. > > smp_suspend is used for PV drv on PV domain, which is not suitable for HVM > as > we > need the transparency to guest. > > Do we need lightweight stop_machine_run in this case, i.e. make other cpu > sleep? > > >> >> -- Keir >> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel