On Tue, May 21, 2013 at 08:27:09AM -0700, Stephen Hemminger wrote: > On Tue, 21 May 2013 13:01:18 +0300 > Gleb Natapov <gleb@xxxxxxxxxx> wrote: > > > On Tue, May 21, 2013 at 11:50:30AM +0200, Joerg Roedel wrote: > > > Hey Stephen, > > > > > > On Mon, May 20, 2013 at 02:24:31PM -0700, Stephen Hemminger wrote: > > > > ioperm() inheritance across threads is different in KVM then when run > > > > on physical hardware. The following program runs on physical hardware > > > > but get SEGV under KVM. > > > > > > > > It appears that the I/O permission bits are not shared between threads > > > > in the same way. > > > > > > Is this specific to SVM or do you see it on VMX too? My first guess > > > would be that the KVM instruction emulator does not check to > > > IO-permissions correctly, but that would affect VMX and SVM. > > > > > The program segfaults on physical hardware: > > # ./a.out > > joining > > waiting > > beeping > > Segmentation fault > > > > -- > > Gleb. > > The program had timing races, changing it slightly shows that. > # ./beep > beeping > done > oo > # ./beep --pre > joining > beeping > Segmentation fault > # ./beep --post > beeping > joining > done > oo > # > And I get the same in a VM on Intel host. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
