On Thu, 2006-12-21 at 11:20 +0200, Avi Kivity wrote: > Jeremy Katz wrote: > > Currently, kvm ends up just using the standard qemu cpu initialization. > > This means that all x86_64 virtual machines appear to have an > > AuthenticAMD (AMD64) processor. This ends up causing a problem when > > booting some x86_64 Linux kernels as they attempt to do AMD64 specific > > initialization for things like performance counters. Since those MSRs > > aren't supported on the Intel host, the virtual machine is halted. > > > > The attached patch makes it so that we check the actual cpu type of the > > host and then provide the same cpu type for the virtual machine. > > Windows crashes immediately with this patch (STOP: 0x7E (0xc0000005 > 0xF724879C 0xF7A168DC 0xF7A165D8) for those who know how to decode > BSODs), so either it's doing too much or not enough.
32 or 64 bit and what are you running for the host? There's definitely more that _could_ be mirrored. > Note that we support migration from Intel to AMD and vice versa, so it > would be good to supply a command line parameter to set the cpuid (to a > least common denominator CPU). The problem is that with current CPUs, I don't know that there really is a least common denominator anymore. Both Intel and AMD have their own implementation of a number of things which aren't "core" bits -- performance counters, things to handle microcode updates, etc. :-/ Are there any docs for the current state of migration? Depending on how it's done, this may not at least make things any "worse" for the migration case since we're only changing things at CPU startup, not runtime calls to cpuid. Jeremy ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
