Re: [SeaBIOS] [PATCH 2/3] vgahooks: Register 155f vga hooks for Xen Intel passthrough devices

[Kevin O'Connor]

On Mon, Jan 30, 2012 at 01:55:55PM +0000, [e-mail] wrote:
> From: Julian Pidancet
>
> Some Intel VGA option ROMs require some 155f hooks implemented in the
> BIOS.
> Signed-off-by: Julian Pidancet
>
> src/vgahooks.c |   20 +++++++++++++++++++-
>  1 files changed, 19 insertions(+), 1 deletions(-)
>
> diff --git a/src/vgahooks.c b/src/vgahooks.c
> index a8f667c..ca12e31 100644
> --- a/src/vgahooks.c
> +++ b/src/vgahooks.c
> @@ -11,6 +11,7 @@
>  #include "pci_ids.h" // PCI_VENDOR_ID_VIA
>  #include "util.h" // handle_155f
>  #include "config.h" // CONFIG_*
> +#include "xen.h" // usingXen
>
> #define VH_VIA 1
>  #define VH_INTEL 2
> @@ -228,6 +229,15 @@ getac_setup(struct pci_device *pci)
>  {
>  }
>
> +static void
> +xen_vgapt_setup(struct pci_device *pci)
> +{
> if (pci->vendor == 0x8086 && pci->class == 0x300) {
>    VGAHookHandlerType = VH_INTEL;
>    IntelDisplayType = BOOT_DISPLAY_DEFAULT;
>    IntelDisplayId = 3;
> }
>
> +}
>
> /****************************************************************
> Entry and setup
>
> @@ -254,7 +264,15 @@ handle_155f(struct bregs *regs)
>  void
>  vgahook_setup(struct pci_device *pci)
>  {
> if (!CONFIG_VGAHOOKS || !CBvendor || !CBpart)
> if (!CONFIG_VGAHOOKS)
>    return;
> if (usingXen()) {
>    xen_vgapt_setup(pci);
>    return;
> }
> if (!CBvendor || !CBpart)
>     return;

Is Xen passthrough special, or will the same thing occur on KVM
passthrough?  If the 155f hooks are needed on Intel VGA cards, I
wouldn't tie it to Xen - we can just turn it on by default and enable
it if the VGA card is recognized as Intel based.

-Kevin