Thanks. Will share the code sometime this week with you. Regards Ashutosh
> Date: Fri, 21 Nov 2014 11:22:06 -0800 > Subject: Re: 'repz' instruction not supported. > From: [email protected] > To: [email protected] > CC: [email protected] > > Hi Ashutosh, > > On Fri, Nov 21, 2014 at 2:07 AM, Ashutosh Kumar <[email protected]> > wrote: > > Yes you are right 'repz' prefixes is added to the ‘cmps’ and 'scas' > > instructions. > > > > The actual opcode is “F3 A5” which is ‘rep movs’ (disassembly is showing > > ‘repz’). > > > > > > > > Yes the guest is emitting these instructions to access MMIO (local apic) > > > > Bummer. > > I was hoping that it was a prefix stuck by the compiler for > optimization (that could be ignored): > http://repzret.org/p/repzret/ > > In any case, the primitives you will need to emulate MOVS exist in > vmm_instruction_emul.c. I don't have any plans to work on this but > would be happy to review/submit the patch that does the emulation. > > best > Neel > > > > > > > Regards > > Ashutosh > > > > > >> Date: Fri, 21 Nov 2014 00:08:15 -0800 > >> Subject: Re: 'repz' instruction not supported. > >> From: [email protected] > >> To: [email protected] > >> CC: [email protected] > > > >> > >> Hi Ashutosh, > >> > >> On Wed, Nov 19, 2014 at 10:30 PM, Ashutosh Kumar <[email protected]> > >> wrote: > >> > Hi > >> > We have found that emulation of 'repz' instruction is not supported in > >> > bhyve. This is causing VM_EXIT for Guest OS. Do we have plans to add > >> > support > >> > for instructions like 'repz'. > >> > > >> > >> 'repz' is actually an instruction prefix. The two instructions with > >> which 'repz' is allowed are 'cmps' and 'scas'. Both these instructions > >> typically don't need to be emulated since they operate on strings in > >> "regular" guest memory. > >> > >> Is your guest emitting these instructions to access MMIO? Can you > >> share an objdump with the offending instructions? > >> > >> best > >> Neel > >> > >> > RegardsAshutosh > >> > _______________________________________________ > >> > [email protected] mailing list > >> > http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > >> > To unsubscribe, send any mail to > >> > "[email protected]" _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization To unsubscribe, send any mail to "[email protected]"
