Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-12 Thread Jan Beulich
>>> On 12.01.15 at 15:54, wrote: > On Fri, Jan 9, 2015 at 12:10 PM, Jan Beulich wrote: > On 09.01.15 at 12:45, wrote: >>> At 11:24 + on 09 Jan (1420799087), Jan Beulich wrote: >>> On 09.01.15 at 12:18, wrote: >> > +default: >> > +xfree(buf); >>

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-12 Thread George Dunlap
On Fri, Jan 9, 2015 at 12:10 PM, Jan Beulich wrote: On 09.01.15 at 12:45, wrote: >> At 11:24 + on 09 Jan (1420799087), Jan Beulich wrote: >>> >>> On 09.01.15 at 12:18, wrote: >>> >> > +default: >>> >> > +xfree(buf); >>> >> > +ASSERT(!buf); >>>

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Tim Deegan
At 12:46 + on 09 Jan (1420804005), Andrew Cooper wrote: > On 09/01/15 12:10, Jan Beulich wrote: > On 09.01.15 at 12:45, wrote: > >> At 11:24 + on 09 Jan (1420799087), Jan Beulich wrote: > >> On 09.01.15 at 12:18, wrote: > >> +default: > >> +xfr

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Andrew Cooper
On 09/01/15 12:10, Jan Beulich wrote: On 09.01.15 at 12:45, wrote: >> At 11:24 + on 09 Jan (1420799087), Jan Beulich wrote: >> On 09.01.15 at 12:18, wrote: >> +default: >> +xfree(buf); >> +ASSERT(!buf); looks dodgy... >>> I

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Jan Beulich
>>> On 09.01.15 at 12:45, wrote: > At 11:24 + on 09 Jan (1420799087), Jan Beulich wrote: >> >>> On 09.01.15 at 12:18, wrote: >> >> > +default: >> >> > +xfree(buf); >> >> > +ASSERT(!buf); >> > >> > looks dodgy... >> >> In which way? The "default" i

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Tim Deegan
At 11:24 + on 09 Jan (1420799087), Jan Beulich wrote: > >>> On 09.01.15 at 12:18, wrote: > >> > +default: > >> > +xfree(buf); > >> > +ASSERT(!buf); > > > > looks dodgy... > > In which way? The "default" is supposed to be unreachable, and sits > in

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Jan Beulich
>>> On 09.01.15 at 12:18, wrote: > At 10:56 + on 09 Jan (1420797418), Andrew Cooper wrote: >> On 09/01/15 10:27, Jan Beulich wrote: >> > While the REP MOVS acceleration appears to have helped qemu-traditional >> > based guests, qemu-upstream (or really the respective video BIOSes) >> > doesn't

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Tim Deegan
At 10:56 + on 09 Jan (1420797418), Andrew Cooper wrote: > On 09/01/15 10:27, Jan Beulich wrote: > > While the REP MOVS acceleration appears to have helped qemu-traditional > > based guests, qemu-upstream (or really the respective video BIOSes) > > doesn't appear to benefit from that. Instead th

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Jan Beulich
>>> On 09.01.15 at 11:56, wrote: > On 09/01/15 10:27, Jan Beulich wrote: >> While the REP MOVS acceleration appears to have helped qemu-traditional >> based guests, qemu-upstream (or really the respective video BIOSes) >> doesn't appear to benefit from that. Instead the acceleration added >> here

Re: [Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Andrew Cooper
On 09/01/15 10:27, Jan Beulich wrote: > While the REP MOVS acceleration appears to have helped qemu-traditional > based guests, qemu-upstream (or really the respective video BIOSes) > doesn't appear to benefit from that. Instead the acceleration added > here provides a visible performance improveme

[Xen-devel] [PATCH v2 1/3] x86: also allow REP STOS emulation acceleration

2015-01-09 Thread Jan Beulich
While the REP MOVS acceleration appears to have helped qemu-traditional based guests, qemu-upstream (or really the respective video BIOSes) doesn't appear to benefit from that. Instead the acceleration added here provides a visible performance improvement during very early HVM guest boot. Signed-o