From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Bug: cpu0 unhandled rdmsr: 0x1900 and inject_general_protection Date: Sun, 11 Nov 2007 12:04:07 +0200 Message-ID: <4736D397.30600@qumranet.com> References: <1194523650.20087.16.camel@hephaestion> <473308F0.4050504@qumranet.com> <1194617153.30982.5.camel@hephaestion> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel To: TJ Return-path: In-Reply-To: <1194617153.30982.5.camel@hephaestion> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org TJ wrote: > Avi, thanks. The patch fixes the issue for the XO image and there are no > more MSR read errors. > > I'm still not sure why when starting the image with kvm enabled the > drawing of the GRUB screen is so painfully slow, but without kvm it is > fast. > > Grub probably uses one of the 4-bit vga modes which cannot be direct mapped. This means that every pixel access is a 5-10 microsecond vmexit. Xen uses some form of mmio buffering to reduce this costs (mmio exits under Xen are even more expensive). Something like this can be added to kvm to speed up vga writes. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/