From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=41843 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OHEhD-0005FG-2H for qemu-devel@nongnu.org; Wed, 26 May 2010 07:22:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OHEh6-0002OY-Re for qemu-devel@nongnu.org; Wed, 26 May 2010 07:22:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48417) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OHEh6-0002OL-E3 for qemu-devel@nongnu.org; Wed, 26 May 2010 07:22:40 -0400 Message-ID: <4BFD0479.90609@redhat.com> Date: Wed, 26 May 2010 13:22:33 +0200 From: Gerd Hoffmann MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] all vga: refuse hotplugging. References: <1274863397-15005-1-git-send-email-kraxel@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefano Stabellini Cc: "qemu-devel@nongnu.org" On 05/26/10 12:59, Stefano Stabellini wrote: > On Wed, 26 May 2010, Gerd Hoffmann wrote: >> Try to pci hotplug a vga card, watch qemu die with hw_error(). >> This patch fixes it. >> > > Do you know the reason why we get hw_error()? Because the card tries to register the legacy vga ports which are already taken by the primary card. I also don't know whenever you can pci hot-plug hardware which uses non-pci ressources at all. > Theoretically vga hotplug should be possible at least for secondary > graphic cards (even though I suspect most operating systems wouldn't > cope). Yes. Assuming the virtual hardware in question can actually act as secondary, i.e. is fully programmable without the legacy vga ports. The standard vga can't. The cirrus looks doable, at least you can access the vga ports using the mmio bar. cheers, Gerd