From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [RFC 02/29] xen/arm: don't allow dom0 to access to vpl011 UART0 memory range Date: Mon, 29 Apr 2013 16:19:17 +0100 Message-ID: <517E8F75.4080407@linaro.org> References: <1367247479.3142.323.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1367247479.3142.323.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: Anthony Perard , "patches@linaro.org" , Stefano Stabellini , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 04/29/2013 03:57 PM, Ian Campbell wrote: > On Mon, 2013-04-29 at 00:01 +0100, Julien Grall wrote: >> As vpl011 UART is not initialized for dom 0, when the domain tries to access to >> this range, a segfault will occur in Xen. The right behaviour should be a data >> abort for the guest. >> >> Signed-off-by: Julien Grall > > Acked-by: Ian Campbell > > However I wonder if the provision of a vpl011 UART isn't something which > should be made platform specific. > > It's really a workaround for DEBUG_LL in a kernel which is configured > for vexpress, I expect Arndale has different serial ports? Right. I'm currently working on a patch for linux to enable early printk for Arm. For the moment it's doesn't impact the Arndale board because this range is already mapped to a physical address. By the way, I think vpl011 is useless with Stefano's patch series for SMP. He moved xenvm out of versatile express platform. -- Julien