On 05/10/2018 16:13, Thomas Huth wrote:
> When compiling with "--disable-tcg", we currently still use "tcg"
> as default accelerator. "kvm" should be used in this case instead.
> Also, some downstream distros provide QEMU binaries which have "kvm"
> in their names (e.g. "qemu-kvm" on RHEL or "kvm" on Ubuntu) that use
> KVM by default - and some users might want to do something similar
> with upstream binaries, too. Accomodate them by using "kvm:tcg" as
> default when we detect such a binary name.
>
> Signed-off-by: Thomas Huth <th...@redhat.com>
> ---
> accel/accel.c | 18 +++++++++++++++---
> include/sysemu/accel.h | 2 +-
> vl.c | 2 +-
> 3 files changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/accel/accel.c b/accel/accel.c
> index 966b2d8..9be195c 100644
> --- a/accel/accel.c
> +++ b/accel/accel.c
> @@ -68,7 +68,7 @@ static int accel_init_machine(AccelClass *acc, MachineState
> *ms)
> return ret;
> }
>
> -void configure_accelerator(MachineState *ms)
> +void configure_accelerator(MachineState *ms, const char *progname)
> {
> const char *accel;
> char **accel_list, **tmp;
> @@ -79,8 +79,20 @@ void configure_accelerator(MachineState *ms)
>
> accel = qemu_opt_get(qemu_get_machine_opts(), "accel");
> if (accel == NULL) {
> - /* Use the default "accelerator", tcg */
> - accel = "tcg";
> + /* Select the default accelerator */
> + int pnlen = strlen(progname);
> + if (pnlen >= 3 && g_str_equal(&progname[pnlen - 3], "kvm")) {
> + /* If the program name ends with "kvm", we prefer KVM */
> + accel = "kvm:tcg";
> + } else {
> +#if defined(CONFIG_TCG)
> + accel = "tcg";
OK until here.
> +#elif defined(CONFIG_KVM)
> + accel = "kvm";
I'm not sure "kvm" here is necessary.
> +#else
> +#error "No default accelerator available"
> +#endif
> + }
> }
>
> accel_list = g_strsplit(accel, ":", 0);
> diff --git a/include/sysemu/accel.h b/include/sysemu/accel.h
> index 637358f..285899e 100644
> --- a/include/sysemu/accel.h
> +++ b/include/sysemu/accel.h
> @@ -66,7 +66,7 @@ typedef struct AccelClass {
>
> extern unsigned long tcg_tb_size;
>
> -void configure_accelerator(MachineState *ms);
> +void configure_accelerator(MachineState *ms, const char *progname);
> /* Register accelerator specific global properties */
> void accel_register_compat_props(AccelState *accel);
> /* Called just before os_setup_post (ie just before drop OS privs) */
> diff --git a/vl.c b/vl.c
> index 0388852..757246a 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -4220,7 +4220,7 @@ int main(int argc, char **argv, char **envp)
> exit(1);
> }
>
> - configure_accelerator(current_machine);
> + configure_accelerator(current_machine, argv[0]);
>
> if (!qtest_enabled() && machine_class->deprecation_reason) {
> error_report("Machine type '%s' is deprecated: %s",
>
