Re: [Qemu-devel] [v2][PATCH 4/8] xen, gfx passthrough: reserve 00:02.0 for INTEL IGD

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, May 22, 2014 at 08:44:41AM +0200, Gerd Hoffmann wrote:
>   Hi,
> 
> > > Another useful thing would be to not create the xen platform device in case
> > > "-nodefaults" was specified on the command line (that switch turns off a bunch
> > > of other devices present by default: vga, nic, cdrom, ...).
> > 
> > Currently looks 'xen-platform' itself can't be created, not those devices existed on that.
> 
> The error message looks more like libxl tries to hot-unplug the xen
> platform device.
> 
> Attached patch (untested!) hooks up the xen platform device to the
> default device code we have in qemu.  Two effects:
> 
>   (1) As mentioned above the device will not be created in case
>       -nodefaults  is specified on the command line.
>   (2) Autocreating the device is also turned off in case xen-platform
>       is added manually via -device.
> 
> With the patch applied you should be able to move the xen-platform
> device to some other place with a simple 'qemu -device
> xen-platform,addr=$slot'.
> 
> cheers,
>   Gerd
> 

> >From 405349bf38fc05653bfb8c971c61796e981eee98 Mon Sep 17 00:00:00 2001
> From: Gerd Hoffmann <kraxel@redhat.com>
> Date: Thu, 22 May 2014 08:34:28 +0200
> Subject: [PATCH] xen: make xen-platform a default device
> 
> ---

Looks good to me, though Sob is missing.
Can some Xen folks pls ack this one? I'll queue it up then.

>  hw/i386/pc_piix.c    | 2 +-
>  include/hw/xen/xen.h | 1 +
>  vl.c                 | 3 +++
>  3 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index eaf3e61..f987d03 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -385,7 +385,7 @@ static void pc_xen_hvm_init(QEMUMachineInitArgs *args)
>      pc_init_pci(args);
>  
>      bus = pci_find_primary_bus();
> -    if (bus != NULL) {
> +    if (bus != NULL && default_xenplatform) {
>          pci_create_simple(bus, -1, "xen-platform");
>      }
>  }
> diff --git a/include/hw/xen/xen.h b/include/hw/xen/xen.h
> index 85fda3d..b350413 100644
> --- a/include/hw/xen/xen.h
> +++ b/include/hw/xen/xen.h
> @@ -20,6 +20,7 @@ enum xen_mode {
>  
>  extern uint32_t xen_domid;
>  extern enum xen_mode xen_mode;
> +extern int default_xenplatform;
>  
>  extern bool xen_allowed;
>  
> diff --git a/vl.c b/vl.c
> index 709d8cd..673148e 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -226,6 +226,7 @@ static int default_floppy = 1;
>  static int default_cdrom = 1;
>  static int default_sdcard = 1;
>  static int default_vga = 1;
> +int default_xenplatform = 1;
>  
>  static struct {
>      const char *driver;
> @@ -247,6 +248,7 @@ static struct {
>      { .driver = "isa-cirrus-vga",       .flag = &default_vga       },
>      { .driver = "vmware-svga",          .flag = &default_vga       },
>      { .driver = "qxl-vga",              .flag = &default_vga       },
> +    { .driver = "xen-platform",         .flag = &default_xenplatform },
>  };
>  
>  static QemuOptsList qemu_rtc_opts = {
> @@ -4101,6 +4103,7 @@ int main(int argc, char **argv, char **envp)
>          default_monitor = 0;
>          default_net = 0;
>          default_vga = 0;
> +        default_xenplatform = 0;
>      }
>  
>      if (is_daemonized()) {
> -- 
> 1.8.3.1
>