Re: Priority of -accel

2020-01-14 Thread Daniel P . Berrangé
On Tue, Jan 14, 2020 at 06:49:45PM +0100, Christophe de Dinechin wrote: > > > > On 13 Jan 2020, at 17:25, Paolo Bonzini wrote: > > > > On 13/01/20 17:17, Markus Armbruster wrote: > >> Perfect opportunity to change the default to something more useful. > > > > I am not sure acutally if it's tha

Re: Priority of -accel

2020-01-14 Thread Christophe de Dinechin
> On 13 Jan 2020, at 17:25, Paolo Bonzini wrote: > > On 13/01/20 17:17, Markus Armbruster wrote: >> Perfect opportunity to change the default to something more useful. > > I am not sure acutally if it's that more useful, now that we have > sanctioned qemu-kvm as the fast alternative. OK, hal

Re: Priority of -accel

2020-01-14 Thread Paolo Bonzini
On 14/01/20 09:59, Markus Armbruster wrote: > Paolo Bonzini writes: > >> On 13/01/20 17:17, Markus Armbruster wrote: >>> Perfect opportunity to change the default to something more useful. >> >> I am not sure acutally if it's that more useful, now that we have >> sanctioned qemu-kvm as the fast a

Re: Priority of -accel

2020-01-14 Thread Markus Armbruster
Paolo Bonzini writes: > On 13/01/20 17:17, Markus Armbruster wrote: >> Perfect opportunity to change the default to something more useful. > > I am not sure acutally if it's that more useful, now that we have > sanctioned qemu-kvm as the fast alternative. If there is a fast alternative, why ship

Re: Priority of -accel

2020-01-13 Thread Paolo Bonzini
On 13/01/20 17:17, Markus Armbruster wrote: > Perfect opportunity to change the default to something more useful. I am not sure acutally if it's that more useful, now that we have sanctioned qemu-kvm as the fast alternative. Particularly it would be confusing for qemu-system-x86_64 to use hardwar

Re: Priority of -accel

2020-01-13 Thread Paolo Bonzini
On 13/01/20 17:14, Christophe de Dinechin wrote: > % ./x86_64-softmmu/qemu-system-x86_64 > qemu-system-x86_64: invalid accelerator kvm > qemu-system-x86_64: falling back to tcg That is a bug, Richard Henderson has posted patches to fix it. Paolo

Re: Priority of -accel

2020-01-13 Thread Markus Armbruster
Paolo Bonzini writes: > On 07/01/20 14:55, Christophe de Dinechin wrote: >> So what about ranking the accelerators, so that all combinaisons >> -accel=kvm:tcg, -accel=tcg:kvm, -accel kvm -accel tcg, etc would > > (I assume you mean "-machine accel=kvm:tcg" and "-machine accel=tcg:kvm" > for the f

Re: Priority of -accel

2020-01-13 Thread Christophe de Dinechin
> On 13 Jan 2020, at 15:39, Markus Armbruster wrote: > > Thomas Huth writes: 'any' is a russian roulette, you don't want it to return 'qtest' ;) >>> >>> We could make it return "qtest" only on April 1st ;-P >> >> ... or we finally dare to let QEMU chose the "best" accelerator by

Re: Priority of -accel

2020-01-13 Thread Markus Armbruster
Thomas Huth writes: > On 07/01/2020 15.27, Daniel P. Berrangé wrote: >> On Tue, Jan 07, 2020 at 03:20:40PM +0100, Philippe Mathieu-Daudé wrote: >>> On 1/7/20 3:14 PM, Thomas Huth wrote: On 07/01/2020 13.54, Daniel P. Berrangé wrote: > On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzi

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-10 Thread Peter Maydell
On Wed, 8 Jan 2020 at 11:00, Peter Maydell wrote: > > On Wed, 8 Jan 2020 at 10:40, Alex Bennée wrote: > > Thomas Huth writes: > > > What about "-accel any" or "-accel fastest" or something similar? > > > > "any" is just ambiguous, "fastest" is just begging for me to find a > > micro-benchmark th

Re: Priority of -accel

2020-01-08 Thread Thomas Huth
On 08/01/2020 14.24, Paolo Bonzini wrote: > On 08/01/20 14:10, Daniel P. Berrangé wrote: >> On Wed, Jan 08, 2020 at 01:41:59PM +0100, Paolo Bonzini wrote: >>> On 08/01/20 11:58, Thomas Huth wrote: > "-accel default" could be considered to have vibes of Do The Right > Thing (tm) and could in

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-08 Thread Paolo Bonzini
On 08/01/20 14:10, Daniel P. Berrangé wrote: > On Wed, Jan 08, 2020 at 01:41:59PM +0100, Paolo Bonzini wrote: >> On 08/01/20 11:58, Thomas Huth wrote: "-accel default" could be considered to have vibes of Do The Right Thing (tm) and could in time actually become so! >>> >>> "-accel defaul

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-08 Thread Daniel P . Berrangé
On Wed, Jan 08, 2020 at 01:41:59PM +0100, Paolo Bonzini wrote: > On 08/01/20 11:58, Thomas Huth wrote: > >> "-accel default" could be considered to have vibes of Do The Right > >> Thing (tm) and could in time actually become so! > > > > "-accel default" sounds like the default behavior that you'd a

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-08 Thread Paolo Bonzini
On 08/01/20 11:58, Thomas Huth wrote: >> "-accel default" could be considered to have vibes of Do The Right >> Thing (tm) and could in time actually become so! > > "-accel default" sounds like the default behavior that you'd also get if > you don't use this option at all ... what about "-accel auto

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-08 Thread Peter Maydell
On Wed, 8 Jan 2020 at 10:40, Alex Bennée wrote: > Thomas Huth writes: > > What about "-accel any" or "-accel fastest" or something similar? > > "any" is just ambiguous, "fastest" is just begging for me to find a > micro-benchmark that TCG outperforms on ;-) > > "-accel default" could be considere

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-08 Thread Thomas Huth
On 08/01/2020 11.39, Alex Bennée wrote: > > Thomas Huth writes: > >> On 07/01/2020 13.54, Daniel P. Berrangé wrote: >>> On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: On 07/01/20 13:18, Thomas Huth wrote: > I don't think we need a separate priority parameter here. But IM

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-08 Thread Alex Bennée
Thomas Huth writes: > On 07/01/2020 13.54, Daniel P. Berrangé wrote: >> On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: >>> On 07/01/20 13:18, Thomas Huth wrote: I don't think we need a separate priority parameter here. But IMHO it's really rather common practice to pr

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-08 Thread Kevin Wolf
Am 07.01.2020 um 18:43 hat Christophe de Dinechin geschrieben: > > It would break backwards compatibility for "-machine accel=tcg:kvm", > > which so far meant "use TCG if compiled in, otherwise use KVM". This is > > not something I would have a problem with... except that "tcg:kvm" is > > the defa

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Peter Maydell
On Tue, 7 Jan 2020 at 17:44, Christophe de Dinechin wrote: > > On 7 Jan 2020, at 15:37, Paolo Bonzini wrote: > > It would break backwards compatibility for "-machine accel=tcg:kvm", > > which so far meant "use TCG if compiled in, otherwise use KVM". This is > > not something I would have a probl

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Christophe de Dinechin
> On 7 Jan 2020, at 15:37, Paolo Bonzini wrote: > > On 07/01/20 14:55, Christophe de Dinechin wrote: >> So what about ranking the accelerators, so that all combinaisons >> -accel=kvm:tcg, -accel=tcg:kvm, -accel kvm -accel tcg, etc would > > (I assume you mean "-machine accel=kvm:tcg" and "-ma

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Thomas Huth
On 07/01/2020 15.37, Paolo Bonzini wrote: > On 07/01/20 14:55, Christophe de Dinechin wrote: >> So what about ranking the accelerators, so that all combinaisons >> -accel=kvm:tcg, -accel=tcg:kvm, -accel kvm -accel tcg, etc would > > (I assume you mean "-machine accel=kvm:tcg" and "-machine accel=t

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Paolo Bonzini
On 07/01/20 14:55, Christophe de Dinechin wrote: > So what about ranking the accelerators, so that all combinaisons > -accel=kvm:tcg, -accel=tcg:kvm, -accel kvm -accel tcg, etc would (I assume you mean "-machine accel=kvm:tcg" and "-machine accel=tcg:kvm" for the first two. This is the "older" wa

Re: Priority of -accel

2020-01-07 Thread Daniel P . Berrangé
On Tue, Jan 07, 2020 at 03:20:40PM +0100, Philippe Mathieu-Daudé wrote: > On 1/7/20 3:14 PM, Thomas Huth wrote: > > On 07/01/2020 13.54, Daniel P. Berrangé wrote: > > > On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: > > > > On 07/01/20 13:18, Thomas Huth wrote: > > > > > I don't thi

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Thomas Huth
On 07/01/2020 13.54, Daniel P. Berrangé wrote: > On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: >> On 07/01/20 13:18, Thomas Huth wrote: >>> I don't think we need a separate priority parameter here. But IMHO it's >>> really rather common practice to prioritize the last option. So w

Re: Priority of -accel

2020-01-07 Thread Philippe Mathieu-Daudé
On 1/7/20 3:14 PM, Thomas Huth wrote: On 07/01/2020 13.54, Daniel P. Berrangé wrote: On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: On 07/01/20 13:18, Thomas Huth wrote: I don't think we need a separate priority parameter here. But IMHO it's really rather common practice to p

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Christophe de Dinechin
> On 7 Jan 2020, at 11:14, Paolo Bonzini wrote: > > On 07/01/20 11:03, Thomas Huth wrote: >>> >>> vm = QEMUMachine(iotests.qemu_prog) >>> -vm.add_args('-machine', 'accel=kvm:tcg') >>> +vm.add_args('-accel', 'kvm', '-accel', 'tcg') >> Looking at this, I wonder whether we really want the "-acce

Re: Priority of -accel

2020-01-07 Thread Thomas Huth
On 07/01/2020 15.27, Daniel P. Berrangé wrote: > On Tue, Jan 07, 2020 at 03:20:40PM +0100, Philippe Mathieu-Daudé wrote: >> On 1/7/20 3:14 PM, Thomas Huth wrote: >>> On 07/01/2020 13.54, Daniel P. Berrangé wrote: On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: > On 07/01/20

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Daniel P . Berrangé
On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: > On 07/01/20 13:18, Thomas Huth wrote: > > I don't think we need a separate priority parameter here. But IMHO it's > > really rather common practice to prioritize the last option. So while > > it might be more "self-explanatory" to a

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Daniel P . Berrangé
On Tue, Jan 07, 2020 at 03:14:52PM +0100, Thomas Huth wrote: > On 07/01/2020 13.54, Daniel P. Berrangé wrote: > > On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: > >> On 07/01/20 13:18, Thomas Huth wrote: > >>> I don't think we need a separate priority parameter here. But IMHO it's >

Re: Priority of -accel

2020-01-07 Thread Philippe Mathieu-Daudé
On 1/7/20 1:18 PM, Thomas Huth wrote: On 07/01/2020 11.14, Paolo Bonzini wrote: On 07/01/20 11:03, Thomas Huth wrote: vm = QEMUMachine(iotests.qemu_prog) -vm.add_args('-machine', 'accel=kvm:tcg') +vm.add_args('-accel', 'kvm', '-accel', 'tcg') Looking at this, I wonder whether we really wa

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Kevin Wolf
Am 07.01.2020 um 13:18 hat Thomas Huth geschrieben: > On 07/01/2020 11.14, Paolo Bonzini wrote: > > On 07/01/20 11:03, Thomas Huth wrote: > >>> > >>> vm = QEMUMachine(iotests.qemu_prog) > >>> -vm.add_args('-machine', 'accel=kvm:tcg') > >>> +vm.add_args('-accel', 'kvm', '-accel', 'tcg') > >> Look

Re: Priority of -accel

2020-01-07 Thread Philippe Mathieu-Daudé
On Tue, Jan 7, 2020 at 1:34 PM Philippe Mathieu-Daudé wrote: > On 1/7/20 1:18 PM, Thomas Huth wrote: > > On 07/01/2020 11.14, Paolo Bonzini wrote: > >> On 07/01/20 11:03, Thomas Huth wrote: > > vm = QEMUMachine(iotests.qemu_prog) > -vm.add_args('-machine', 'accel=kvm:tcg') >

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Paolo Bonzini
On 07/01/20 13:18, Thomas Huth wrote: > I don't think we need a separate priority parameter here. But IMHO it's > really rather common practice to prioritize the last option. So while > it might be more "self-explanatory" to a CLI newbie if the first > occurrence got the highest priority, it might

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Thomas Huth
On 07/01/2020 11.14, Paolo Bonzini wrote: > On 07/01/20 11:03, Thomas Huth wrote: >>> >>> vm = QEMUMachine(iotests.qemu_prog) >>> -vm.add_args('-machine', 'accel=kvm:tcg') >>> +vm.add_args('-accel', 'kvm', '-accel', 'tcg') >> Looking at this, I wonder whether we really want the "-accel" option t

Re: Priority of -accel (was: [PATCH] tests/qemu-iotests: Update tests to recent desugarized -accel option)

2020-01-07 Thread Paolo Bonzini
On 07/01/20 11:03, Thomas Huth wrote: >> >> vm = QEMUMachine(iotests.qemu_prog) >> -vm.add_args('-machine', 'accel=kvm:tcg') >> +vm.add_args('-accel', 'kvm', '-accel', 'tcg') > Looking at this, I wonder whether we really want the "-accel" option to > prioritize the accelerators in the order of a