From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: KVM: x86: ignore access permissions for hypercall patching Date: Fri, 12 Mar 2010 08:07:21 +0200 Message-ID: <20100312060721.GB20657@redhat.com> References: <1266414330-27444-1-git-send-email-avi@redhat.com> <1266414330-27444-14-git-send-email-avi@redhat.com> <4B925E66.5@canonical.com> <4B937AF5.5020004@redhat.com> <4B950542.2030306@canonical.com> <4B9505E6.1040501@redhat.com> <4B956283.10706@canonical.com> <20100311211605.GA20718@amt.cnet> <20100312055600.GA20657@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stefan Bader , kvm@vger.kernel.org, Avi Kivity To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:12092 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752633Ab0CLGHY (ORCPT ); Fri, 12 Mar 2010 01:07:24 -0500 Content-Disposition: inline In-Reply-To: <20100312055600.GA20657@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Mar 12, 2010 at 07:56:00AM +0200, Gleb Natapov wrote: > On Thu, Mar 11, 2010 at 06:16:05PM -0300, Marcelo Tosatti wrote: > > > > Ignore access permissions while patching hypercall instructions. > > Otherwise KVM injects a page fault when trying to patch vmcall > > on read-only text regions: > > > > Freeing initrd memory: 8843k freed > > Freeing unused kernel memory: 660k freed > > Write protecting the kernel text: 4780k > > Write protecting the kernel read-only data: 1912k > > BUG: unable to handle kernel paging request at c01292e3 > > IP: [] kvm_leave_lazy_mmu+0x43/0x70 > > *pde = 00910067 *pte = 00129161 > > Oops: 0003 [#1] SMP > > > > CC: stable@kernel.org > > Reported-by: Stefan Bader > > Signed-off-by: Marcelo Tosatti > > > My emulator patch series introduce kvm_write_guest_virt_system(). May be > used it here (only compile tested). > Ignore that, it will not work. -- Gleb.