On Fri, 5 Oct 2018 16:13:12 +0200
Thomas Huth <th...@redhat.com> 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.
Heh, we haven't had that discussion for some time ;)
>
> 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";
Ends, or also starts?
(In general, that approach probably makes more sense than the current
default.)
> + } else {
> +#if defined(CONFIG_TCG)
> + accel = "tcg";
> +#elif defined(CONFIG_KVM)
> + accel = "kvm";
> +#else
> +#error "No default accelerator available"
So, we can't configure a qemu with neither tcg nor kvm, but for example
with hax or xen? (Is that possible today?)
> +#endif
> + }
> }
>
> accel_list = g_strsplit(accel, ":", 0);
ISTR that we had a suggestion last time that we should provide
qemu-kvm, qemu-tcg, etc. binaries...
