From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.30) id 1BLu3S-0008Vg-QS for qemu-devel@nongnu.org; Thu, 06 May 2004 21:21:34 -0400 Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.30) id 1BLu1W-0007wT-76 for qemu-devel@nongnu.org; Thu, 06 May 2004 21:20:05 -0400 Received: from [216.148.227.85] (helo=rwcrmhc12.comcast.net) by monty-python.gnu.org with esmtp (Exim 4.30) id 1BLu1V-0007vM-M7 for qemu-devel@nongnu.org; Thu, 06 May 2004 21:19:33 -0400 From: Jason Gress Subject: Re: [Qemu-devel] Impractical ideas? Date: Thu, 6 May 2004 20:34:39 -0500 References: <1083880377.29521.3876.camel@rapid> <1083881490.3560.1143.camel@aragorn> In-Reply-To: <1083881490.3560.1143.camel@aragorn> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200405062034.39658.jasong@ccgr.org> Reply-To: jasong@ccgr.org, 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 Thursday 06 May 2004 05:11 pm, John R. Hogerhuis wrote: > Of course, there is already something in real life that can get you most > of this if you can afford to rent one: a logic analyzer with built-in > disassembler. > > To buy one is *a lot* unless you get an old one like I have which is > only useful mainly for instrumenting older systems. > > I guess we're getting really sci-fi now, but maybe you should just make > it pass-through everything to underlying OS, and the front end would be > a virtual logic analyzer. > > Of course thinking about the cool timing diagrams a logic analyzer gives > you, I think I'm realizing what the real problem is here: timing. > Virtual drivers incorporate knowledge of timing of the real devices in > their operation. Without that buffer between you and the bare metal, I > think the live guest driver just ain't gonna work. Counterarguments? > I hate to feed the fire ;), but it would seem that drivers couldn't use too much timing information as they can never expect a certain time for anything. Example: If I had a 50MHz FSB, won't most PCI cards still work even though most systems run at 66MHz? (Think old Pentiums) Also I would think that in the case of, say a PCI Gigabit ethernet or HDD controller hogging the bandwidth on a PCI bus that a video card (or whatever) would still work properly even though the delays may go up on a 'real' system in those cases. So, in conclusion, I would think that timing may not be all 'that' important. ;) > -- John. > Jason > > > > _______________________________________________ > Qemu-devel mailing list > Qemu-devel@nongnu.org > http://mail.nongnu.org/mailman/listinfo/qemu-devel