From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:48591) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QFpdn-0000zj-Ge for qemu-devel@nongnu.org; Fri, 29 Apr 2011 11:30:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QFpdl-0007d0-V4 for qemu-devel@nongnu.org; Fri, 29 Apr 2011 11:29:59 -0400 Received: from fmmailgate01.web.de ([217.72.192.221]:49622) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QFpdl-0007c8-Nd for qemu-devel@nongnu.org; Fri, 29 Apr 2011 11:29:57 -0400 Message-ID: <4DBAD942.6080001@siemens.com> Date: Fri, 29 Apr 2011 17:29:06 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <20110429031437.3796.49456.stgit@s20.home> <20110429150640.GB27816@redhat.com> In-Reply-To: <20110429150640.GB27816@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: jan.kiszka@siemens.com Subject: Re: [Qemu-devel] [PATCH] Fix phys memory client - pass guest physical address not region offset List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Alex Williamson , qemu-devel@nongnu.org On 2011-04-29 17:06, Michael S. Tsirkin wrote: > On Thu, Apr 28, 2011 at 09:15:23PM -0600, Alex Williamson wrote: >> When we're trying to get a newly registered phys memory client updated >> with the current page mappings, we end up passing the region offset >> (a ram_addr_t) as the start address rather than the actual guest >> physical memory address (target_phys_addr_t). If your guest has less >> than 3.5G of memory, these are coincidentally the same thing. If I think this broke even with < 3.5G as phys_offset also encodes the memory type while region_offset does not. So everything became RAMthis way, no MMIO was announced. >> there's more, the region offset for the memory above 4G starts over >> at 0, so the set_memory client will overwrite it's lower memory entries. >> >> Instead, keep track of the guest phsyical address as we're walking the >> tables and pass that to the set_memory client. >> >> Signed-off-by: Alex Williamson > > Acked-by: Michael S. Tsirkin > > Given all this, can yo tell how much time does > it take to hotplug a device with, say, a 40G RAM guest? Why not collect pages of identical types and report them as one chunk once the type changes? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux