Received: from eggs.gnu.org ([2001:4830:134:3::10]:41318) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dsBTx-0007qh-KT for qemu-devel@nongnu.org; Wed, 13 Sep 2017 13:29:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dsBTu-0002jG-89 for qemu-devel@nongnu.org; Wed, 13 Sep 2017 13:29:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45716) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dsBTu-0002hM-0Z for qemu-devel@nongnu.org; Wed, 13 Sep 2017 13:29:46 -0400 From: Cornelia Huck Date: Wed, 13 Sep 2017 19:29:41 +0200 Message-Id: <20170913172941.5470-1-cohuck@redhat.com> Subject: [Qemu-devel] [PATCH v2] accel: default to an actually available accelerator List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: lvivier@redhat.com, pbonzini@redhat.com, thuth@redhat.com, mreitz@redhat.com, kwolf@redhat.com, richard.henderson@linaro.org, peter.maydell@linaro.org, Cornelia Huck 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