[Qemu-devel] [PATCH v2] accel: default to an actually available accelerator
configure_accelerator() falls back to tcg if no accelerator has been specified. Formerly, we could be sure that tcg is always available; however, with --disable-tcg, this is not longer true, and you are not able to start qemu without explicitly specifying another accelerator on those builds. Instead, choose an accelerator in the order tcg->kvm->hax. Signed-off-by: Cornelia Huck --- RFC->v2: - drop xen from the list of fallbacks - use comma-delimited list of accelerators (much easier) - changed one place in qemu-options.hx that had been missed --- accel/accel.c | 3 +-- qemu-options.hx | 8 +--- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/accel/accel.c b/accel/accel.c index 8ae40e1e13..e8a3121d06 100644 --- a/accel/accel.c +++ b/accel/accel.c @@ -79,8 +79,7 @@ void configure_accelerator(MachineState *ms) accel = qemu_opt_get(qemu_get_machine_opts(), "accel"); if (accel == NULL) { -/* Use the default "accelerator", tcg */ -accel = "tcg"; +accel = "tcg:kvm:hax"; } p = accel; diff --git a/qemu-options.hx b/qemu-options.hx index 9f6e2adfff..2ff88389e0 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -31,7 +31,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ "-machine [type=]name[,prop[=value][,...]]\n" "selects emulated machine ('-machine help' for list)\n" "property accel=accel1[:accel2[:...]] selects accelerator\n" -"supported accelerators are kvm, xen, hax or tcg (default: tcg)\n" +"supported accelerators are kvm, xen, hax or tcg (default: tcg:kvm:hax)\n" "kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n" "vmport=on|off|auto controls emulation of vmport (default: auto)\n" "kvm_shadow_mem=size of KVM shadow MMU in bytes\n" @@ -66,7 +66,8 @@ Supported machine properties are: @table @option @item accel=@var{accels1}[:@var{accels2}[:...]] This is used to enable an accelerator. Depending on the target architecture, -kvm, xen, hax or tcg can be available. By default, tcg is used. If there is +kvm, xen, hax or tcg can be available. By default, the first one available +out of tcg, kvm, hax (in that order) is used. If there is more than one accelerator specified, the next one is used if the previous one fails to initialize. @item kernel_irqchip=on|off @@ -126,7 +127,8 @@ STEXI @item -accel @var{name}[,prop=@var{value}[,...]] @findex -accel This is used to enable an accelerator. Depending on the target architecture, -kvm, xen, hax or tcg can be available. By default, tcg is used. If there is +kvm, xen, hax or tcg can be available. By default, the first one available +out of tcg, kvm, hax (in that order) is used. If there is more than one accelerator specified, the next one is used if the previous one fails to initialize. @table @option -- 2.13.5
Re: [Qemu-devel] [PATCH v2] accel: default to an actually available accelerator
On 13.09.2017 19:29, Cornelia Huck wrote: > configure_accelerator() falls back to tcg if no accelerator has > been specified. Formerly, we could be sure that tcg is always > available; however, with --disable-tcg, this is not longer true, > and you are not able to start qemu without explicitly specifying > another accelerator on those builds. > > Instead, choose an accelerator in the order tcg->kvm->hax. > > Signed-off-by: Cornelia Huck > --- > RFC->v2: > - drop xen from the list of fallbacks > - use comma-delimited list of accelerators (much easier) > - changed one place in qemu-options.hx that had been missed > --- > accel/accel.c | 3 +-- > qemu-options.hx | 8 +--- > 2 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/accel/accel.c b/accel/accel.c > index 8ae40e1e13..e8a3121d06 100644 > --- a/accel/accel.c > +++ b/accel/accel.c > @@ -79,8 +79,7 @@ void configure_accelerator(MachineState *ms) > > accel = qemu_opt_get(qemu_get_machine_opts(), "accel"); > if (accel == NULL) { > -/* Use the default "accelerator", tcg */ > -accel = "tcg"; > +accel = "tcg:kvm:hax"; > } > > p = accel; > diff --git a/qemu-options.hx b/qemu-options.hx > index 9f6e2adfff..2ff88389e0 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -31,7 +31,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ > "-machine [type=]name[,prop[=value][,...]]\n" > "selects emulated machine ('-machine help' for list)\n" > "property accel=accel1[:accel2[:...]] selects > accelerator\n" > -"supported accelerators are kvm, xen, hax or tcg > (default: tcg)\n" > +"supported accelerators are kvm, xen, hax or tcg > (default: tcg:kvm:hax)\n" > "kernel_irqchip=on|off|split controls accelerated > irqchip support (default=off)\n" > "vmport=on|off|auto controls emulation of vmport > (default: auto)\n" > "kvm_shadow_mem=size of KVM shadow MMU in bytes\n" > @@ -66,7 +66,8 @@ Supported machine properties are: > @table @option > @item accel=@var{accels1}[:@var{accels2}[:...]] > This is used to enable an accelerator. Depending on the target architecture, > -kvm, xen, hax or tcg can be available. By default, tcg is used. If there is > +kvm, xen, hax or tcg can be available. By default, the first one available > +out of tcg, kvm, hax (in that order) is used. If there is > more than one accelerator specified, the next one is used if the previous one > fails to initialize. > @item kernel_irqchip=on|off > @@ -126,7 +127,8 @@ STEXI > @item -accel @var{name}[,prop=@var{value}[,...]] > @findex -accel > This is used to enable an accelerator. Depending on the target architecture, > -kvm, xen, hax or tcg can be available. By default, tcg is used. If there is > +kvm, xen, hax or tcg can be available. By default, the first one available > +out of tcg, kvm, hax (in that order) is used. If there is > more than one accelerator specified, the next one is used if the previous one > fails to initialize. > @table @option Reviewed-by: Thomas Huth
Re: [Qemu-devel] [PATCH v2] accel: default to an actually available accelerator
On 09/13/2017 10:29 AM, Cornelia Huck wrote: > configure_accelerator() falls back to tcg if no accelerator has > been specified. Formerly, we could be sure that tcg is always > available; however, with --disable-tcg, this is not longer true, > and you are not able to start qemu without explicitly specifying > another accelerator on those builds. > > Instead, choose an accelerator in the order tcg->kvm->hax. > > Signed-off-by: Cornelia Huck > --- > RFC->v2: > - drop xen from the list of fallbacks > - use comma-delimited list of accelerators (much easier) > - changed one place in qemu-options.hx that had been missed Queued to tcg-next. Thanks, r~
Re: [Qemu-devel] [PATCH v2] accel: default to an actually available accelerator
On Wed, 13 Sep 2017 11:09:04 -0700 Richard Henderson wrote: > On 09/13/2017 10:29 AM, Cornelia Huck wrote: > > configure_accelerator() falls back to tcg if no accelerator has > > been specified. Formerly, we could be sure that tcg is always > > available; however, with --disable-tcg, this is not longer true, > > and you are not able to start qemu without explicitly specifying > > another accelerator on those builds. > > > > Instead, choose an accelerator in the order tcg->kvm->hax. > > > > Signed-off-by: Cornelia Huck > > --- > > RFC->v2: > > - drop xen from the list of fallbacks > > - use comma-delimited list of accelerators (much easier) > > - changed one place in qemu-options.hx that had been missed > > Queued to tcg-next. Thanks, Hm, has this fallen through the cracks?