[Qemu-devel] Re: [PATCH v2 9/9] Add -kvm option

[Anthony Liguori <aliguori@us.ibm.com>]

Glauber Costa wrote:
> This option deprecates --enable-kvm. It is a more flexible option,
> that makes use of qemu-opts, and allow us to pass on options to enable or
> disable kernel irqchip, for example.
>   

With proper qdev support, you could select kvm device models based on 
-device so I think this option isn't all that useful.

What I'd like to see in the interim is a kvm specific machine type 
that's defaulted to if kvm is enabled.  I think this would be useful not 
only for enabling things like in-kernel apic, but also for selecting a 
default cpu model.

> Signed-off-by: Glauber Costa <glommer@redhat.com>
> ---
>  kvm-all.c       |    1 +
>  kvm.h           |    1 +
>  qemu-config.c   |   16 ++++++++++++++++
>  qemu-config.h   |    1 +
>  qemu-options.hx |   13 +++++++++----
>  vl.c            |   11 +++++++++++
>  6 files changed, 39 insertions(+), 4 deletions(-)
>
> diff --git a/kvm-all.c b/kvm-all.c
> index f33354d..b31d085 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -51,6 +51,7 @@ typedef struct KVMSlot
>  typedef struct kvm_dirty_log KVMDirtyLog;
>
>  int kvm_allowed = 0;
> +int kvm_use_kernel_chip = 0;
>
>  struct KVMState
>  {
> diff --git a/kvm.h b/kvm.h
> index f0c9201..49a2b56 100644
> --- a/kvm.h
> +++ b/kvm.h
> @@ -20,6 +20,7 @@
>
>  #ifdef CONFIG_KVM
>  extern int kvm_allowed;
> +extern int kvm_use_kernel_chip;
>
>  #define kvm_enabled() (kvm_allowed)
>  #else
> diff --git a/qemu-config.c b/qemu-config.c
> index bafaea2..9461766 100644
> --- a/qemu-config.c
> +++ b/qemu-config.c
> @@ -184,12 +184,28 @@ QemuOptsList qemu_rtc_opts = {
>      },
>  };
>
> +QemuOptsList qemu_kvm_opts = {
> +    .name = "kvm",
> +    .head = QTAILQ_HEAD_INITIALIZER(qemu_kvm_opts.head),
> +    .desc = {
> +        {
> +            .name = "irqchip-in-kernel",
> +            .type = QEMU_OPT_BOOL,
> +        },{
> +            .name = "enabled",
> +            .type = QEMU_OPT_BOOL,
> +        },
> +        { /* end if list */ }
> +    },
> +};
> +
>  static QemuOptsList *lists[] = {
>      &qemu_drive_opts,
>      &qemu_chardev_opts,
>      &qemu_device_opts,
>      &qemu_net_opts,
>      &qemu_rtc_opts,
> +    &qemu_kvm_opts,
>      NULL,
>  };
>
> diff --git a/qemu-config.h b/qemu-config.h
> index cdad5ac..58cead2 100644
> --- a/qemu-config.h
> +++ b/qemu-config.h
> @@ -6,6 +6,7 @@ extern QemuOptsList qemu_chardev_opts;
>  extern QemuOptsList qemu_device_opts;
>  extern QemuOptsList qemu_net_opts;
>  extern QemuOptsList qemu_rtc_opts;
> +extern QemuOptsList qemu_kvm_opts;
>
>  int qemu_set_option(const char *str);
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 3dd76b3..1cb8431 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1431,15 +1431,20 @@ Set the filename for the BIOS.
>  ETEXI
>
>  #ifdef CONFIG_KVM
> -DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
> -    "-enable-kvm     enable KVM full virtualization support\n")
> -#endif
> +HXCOMM Options deprecated by -kvm
> +DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, "")
> +
> +DEF("kvm", HAS_ARG, QEMU_OPTION_kvm, \
> +    "-kvm enable=on|off,irqchip-in-kernel=on|off\n" \
> +    "                enable KVM full virtualization support\n")
>  STEXI
> -@item -enable-kvm
> +@item -kvm [enable=on|off][,irqchip-in-kernel=on|off]
>  Enable KVM full virtualization support. This option is only available
>  if KVM support is enabled when compiling.
>  ETEXI
>
> +#endif
> +
>  #ifdef CONFIG_XEN
>  DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
>      "-xen-domid id   specify xen guest domain id\n")
> diff --git a/vl.c b/vl.c
> index afe01af..a6f9eb7 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -5353,6 +5353,17 @@ int main(int argc, char **argv, char **envp)
>              case QEMU_OPTION_enable_kvm:
>                  kvm_allowed = 1;
>                  break;
> +            case QEMU_OPTION_kvm:
> +
> +                opts = qemu_opts_parse(&qemu_kvm_opts, optarg, NULL);
> +                if (!opts) {
> +                    fprintf(stderr, "parse error: %s\n", optarg);
> +                    exit(1);
> +                }
> +
> +                kvm_allowed = qemu_opt_get_bool(opts, "enabled", 1);
> +                kvm_use_kernel_chip = qemu_opt_get_bool(opts, "irqchip-in-kernel", 1);
> +                break;
>  #endif
>              case QEMU_OPTION_usb:
>                  usb_enabled = 1;
>   


-- 
Regards,

Anthony Liguori