From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v2 1/1] tools: Handle xc_maxmem adjustments Date: Wed, 15 Apr 2015 10:53:13 +0100 Message-ID: <552E3509.8010107@citrix.com> References: <20150414175437.GB11717@zion.uk.xensource.com> <1429049186-27343-1-git-send-email-dslutz@verizon.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1429049186-27343-1-git-send-email-dslutz@verizon.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: Don Slutz , xen-devel@lists.xen.org Cc: Wei Liu , Ian Campbell , Stefano Stabellini , Ian Jackson , Shriram Rajagopalan , Yang Hongyang List-Id: xen-devel@lists.xenproject.org On 14/04/15 23:06, Don Slutz wrote: > This fixes an issue where "xl save" followed by "xl restore" reports: > "xc: error: Failed to allocate memory for batch.!: Internal error" > > One of the ways to get into this state is to have more then 4 e1000 > nics configured. > > Signed-off-by: Don Slutz I still don't think this is the correct solution, although I will concede that this is a far better patch than v1. Going back to the original problem, why does Qemu need to change maxmem in the first place? You talk about e1000 option roms, but the option roms themselves must be allocated in an appropriate PCI bridge window. As a result, there is necessarily already ram backing, which can be ballooned back in. Currently, all ram behind the PCI MMIO is ballooned out hvmloader but still accounted to the domain, and otherwise wasted. ~Andrew