Joerg Roedel wrote: > On Thu, Mar 22, 2007 at 01:40:26PM +0200, Avi Kivity wrote: > >> Joerg Roedel wrote: >> >>> Right. But it is possible for userspace to enable monitor bit for the >>> guest. Without virtualization of these 2 instructions the guest would >>> idle in the guest state after calling mwait and prevent other processes >>> and guests from running in that time. >>> >> Won't an interrupt during mwait cause a vmexit? >> > > Yes, an interrupt would cause an vmexit. But depending on the HZ value > of the host it may be a lot of time until the next interrupt. And over > time this will sum up and slow down other tasks. >
Well, a guest can cause exactly the same effect with cli spin: jmp spin without executing any instructions that are not reported by cpuid. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- 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