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 <cohuck@redhat.com>
---
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
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 <cohuck@redhat.com> > --- > 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 <thuth@redhat.com>
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 <cohuck@redhat.com> > --- > 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~
On Wed, 13 Sep 2017 11:09:04 -0700 Richard Henderson <richard.henderson@linaro.org> 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 <cohuck@redhat.com> > > --- > > 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?
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