From owner-freebsd-virtualization@FreeBSD.ORG Sun Nov 23 06:04:14 2014 Return-Path: Delivered-To: freebsd-virtualization@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 2B05DD7E for ; Sun, 23 Nov 2014 06:04:14 +0000 (UTC) Received: from SNT004-OMC1S44.hotmail.com (snt004-omc1s44.hotmail.com [65.54.61.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (Client CN "*.outlook.com", Issuer "MSIT Machine Auth CA 2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 027F9A86 for ; Sun, 23 Nov 2014 06:04:13 +0000 (UTC) Received: from SNT150-W46 ([65.55.90.9]) by SNT004-OMC1S44.hotmail.com over TLS secured channel with Microsoft SMTPSVC(7.5.7601.22751); Sat, 22 Nov 2014 22:04:07 -0800 X-TMN: [xqO8FCU1jsEs+CwOXOy2uet9zJlF5KkwBZ/dRBivYz4=] X-Originating-Email: [mrashutosh@hotmail.com] Message-ID: From: Ashutosh Kumar To: Subject: RE: 'repz' instruction not supported. Date: Sun, 23 Nov 2014 06:04:06 +0000 Importance: Normal In-Reply-To: References: , , , MIME-Version: 1.0 X-OriginalArrivalTime: 23 Nov 2014 06:04:07.0332 (UTC) FILETIME=[4AA38E40:01D006E3] Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.18-1 Cc: freebsd-virtualization@freebsd.org X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 Nov 2014 06:04:14 -0000 Thanks. Will share the code sometime this week with you. Regards Ashutosh > Date: Fri=2C 21 Nov 2014 11:22:06 -0800 > Subject: Re: 'repz' instruction not supported. > From: neelnatu@gmail.com > To: mrashutosh@hotmail.com > CC: freebsd-virtualization@freebsd.org >=20 > Hi Ashutosh=2C >=20 > On Fri=2C Nov 21=2C 2014 at 2:07 AM=2C Ashutosh Kumar wrote: > > Yes you are right 'repz' prefixes is added to the =91cmps=92 and 'scas' > > instructions. > > > > The actual opcode is =93F3 A5=94 which is =91rep movs=92 (disassembly i= s showing > > =91repz=92). > > > > > > > > Yes the guest is emitting these instructions to access MMIO (local apic= ) > > >=20 > Bummer. >=20 > I was hoping that it was a prefix stuck by the compiler for > optimization (that could be ignored): > http://repzret.org/p/repzret/ >=20 > In any case=2C 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. >=20 > best > Neel >=20 > > > > > > Regards > > Ashutosh > > > > > >> Date: Fri=2C 21 Nov 2014 00:08:15 -0800 > >> Subject: Re: 'repz' instruction not supported. > >> From: neelnatu@gmail.com > >> To: mrashutosh@hotmail.com > >> CC: freebsd-virtualization@freebsd.org > > > >> > >> Hi Ashutosh=2C > >> > >> On Wed=2C Nov 19=2C 2014 at 10:30 PM=2C Ashutosh Kumar > >> 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 > >> > _______________________________________________ > >> > freebsd-virtualization@freebsd.org mailing list > >> > http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > >> > To unsubscribe=2C send any mail to > >> > "freebsd-virtualization-unsubscribe@freebsd.org" =