From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KXItB-0002Xn-07 for qemu-devel@nongnu.org; Sun, 24 Aug 2008 12:56:29 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KXItA-0002Wg-7u for qemu-devel@nongnu.org; Sun, 24 Aug 2008 12:56:28 -0400 Received: from [199.232.76.173] (port=55236 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KXItA-0002WZ-4T for qemu-devel@nongnu.org; Sun, 24 Aug 2008 12:56:28 -0400 Received: from yx-out-1718.google.com ([74.125.44.154]:21439) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KXIt9-0007hH-O0 for qemu-devel@nongnu.org; Sun, 24 Aug 2008 12:56:27 -0400 Received: by yx-out-1718.google.com with SMTP id 3so712125yxi.82 for ; Sun, 24 Aug 2008 09:56:27 -0700 (PDT) Message-ID: Date: Sun, 24 Aug 2008 19:56:26 +0300 From: "Blue Swirl" Subject: Re: [Qemu-devel] [PATCH 0/6] Add UUID command-line option In-Reply-To: <48B16860.5010207@qumranet.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080824113258.5652.92531.stgit@gleb-debian.qumranet.com.qumranet.com> <20080824122423.GA6192@minantech.com> <48B15D87.9000000@qumranet.com> <48B16860.5010207@qumranet.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On 8/24/08, Avi Kivity wrote: > Blue Swirl wrote: > > > True, but realistic probing for memory could take some time if there > > is a huge amount of it. > > > > No reason for that. A binary search with a cap of 1TB and a granularity of > 1MB requires only 20 probes. But on real machines there could be gaps between the memory banks, memory banks may be of different sizes and then there are aliasing effects. I doubt you can manage with 20 probes then. > > Moreover, this level of precision would not > > gain anything in Qemu use, it would be unnecessary. If Bochs BIOS was > > aiming to be used as a real, physical PC BIOS in the future, then > > these kind of improvements might be useful. > > > > > > > > Agree, it isn't necessary. > > > > A long time ago on Sparc32, I put the memory size to one of CPU > > registers. That was quick and easy for both sides but dirty. > > > > > > For x86 it seems like an obvious candidate for vmport (and I don't > understand the object to using vmport for uuid). UUID can be used in all machines, so it would be nice if the interface was same. I don't see much benefit in vmport compared to ROM solution.