[libvirt PATCH 12/18] qemu: populate <audio> element with default config

[Daniel P. Berrangé]

On Wed, Mar 03, 2021 at 06:18:28PM +0000, Daniel P. Berrangé wrote:
> Currently the QEMU driver secretly sets the QEMU_AUDIO_DRV env variable
> 
>  - VNC - set to "none", unless passthrough of host env variable is set
>  - SPICE - always set to "spice"
>  - SDL - always passthrough host env
>  - No graphics - set to "none", unless passthrough of host env variable is set
> 
> The setting of the QEMU_AUDIO_DRV env variable is done in the code which
> configures graphics.
> 
> If no <audio> element is present, we now auto-populate <audio> elements
> to reflect this historical default config. This avoids need to set audio
> env when processing graphics.
> 
> Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>


> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
> index bb14fe2e33..59071068c3 100644
> --- a/src/qemu/qemu_domain.c
> +++ b/src/qemu/qemu_domain.c
> @@ -3573,9 +3573,112 @@ qemuDomainDefAddImplicitInputDevice(virDomainDef *def)
>      return 0;
>  }
>  
> +static int
> +qemuDomainDefAddDefaultAudioBackend(virQEMUDriverPtr driver,
> +                                    virDomainDefPtr def)
> +{
> +    size_t i;
> +    bool addAudio = false;
> +    bool audioPassthrough = false;
> +    virDomainAudioType audioBackend = VIR_DOMAIN_AUDIO_TYPE_NONE;

This var should be a plain 'int' otherwise the later....

> +    g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
> +
> +    if (def->naudios > 0) {
> +        return 0;
> +    }
> +
> +    for (i = 0; i < def->ngraphics; i++) {
> +        virDomainGraphicsDefPtr graph = def->graphics[i];
> +
> +        switch ((virDomainGraphicsType)graph->type) {
> +        case VIR_DOMAIN_GRAPHICS_TYPE_VNC:
> +            if (cfg->vncAllowHostAudio) {
> +                audioPassthrough = true;
> +            } else {
> +                audioPassthrough = false;
> +                audioBackend = VIR_DOMAIN_AUDIO_TYPE_NONE;
> +            }
> +            addAudio = true;
> +            break;
> +        case VIR_DOMAIN_GRAPHICS_TYPE_SPICE:
> +            audioPassthrough = false;
> +            audioBackend = VIR_DOMAIN_AUDIO_TYPE_SPICE;
> +            addAudio = true;
> +            break;
> +        case VIR_DOMAIN_GRAPHICS_TYPE_SDL:
> +            audioPassthrough = true;
> +            addAudio = true;
> +            break;
> +
> +        case VIR_DOMAIN_GRAPHICS_TYPE_RDP:
> +        case VIR_DOMAIN_GRAPHICS_TYPE_DESKTOP:
> +        case VIR_DOMAIN_GRAPHICS_TYPE_EGL_HEADLESS:
> +            break;
> +        case VIR_DOMAIN_GRAPHICS_TYPE_LAST:
> +        default:
> +            virReportEnumRangeError(virDomainGraphicsType, graph->type);
> +            return -1;
> +        }
> +    }
> +
> +    if (!def->ngraphics) {
> +        if (cfg->nogfxAllowHostAudio) {
> +            audioPassthrough = true;
> +        } else {
> +            audioPassthrough = false;
> +            audioBackend = VIR_DOMAIN_AUDIO_TYPE_NONE;
> +        }
> +        addAudio = true;
> +    }
> +
> +    if (addAudio && audioPassthrough) {
> +        const char *audioenv = g_getenv("QEMU_AUDIO_DRV");
> +        if (audioenv == NULL) {
> +            addAudio = false;
> +        } else {
> +            /*
> +             * QEMU audio driver names are mostly the same as
> +             * libvirt XML audio backend names
> +             */
> +            if (STREQ(audioenv, "pa")) {
> +                audioBackend = VIR_DOMAIN_AUDIO_TYPE_PULSEAUDIO;
> +            } else {
> +                if ((audioBackend = virDomainAudioTypeTypeFromString(audioenv)) < 0) {


...check here causes warning from clang about comparing an unsigned
enum type to -1.

> +                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> +                                   _("unknown QEMU_AUDIO_DRV setting %s"), audioenv);
> +                    return -1;
> +                }
> +            }
> +        }
> +    }



Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|