[SeaBIOS] Re: [PATCH v3] optionrom: disallow int19 redirect for pnp roms.

[Matt DeVillier]

verified working here, thanks Gerd

On Tue, May 21, 2019 at 12:41 AM Gerd Hoffmann  wrote:
> Check whenever pnp roms attempt to redirect int19, and in case it does
> log a message and undo the redirect.
>
> A pnp rom should not need this, we have BEVs and BCVs for that.
> Nevertheless there are roms in the wild which are redirecting int19.
> At least some BIOS implementations for physical hardware have a config
> option in the setup to allow/disallow int19 redirections, so just not
> allowing this seems to be the way to deal with this situation.
>
> Buglink: https://bugzilla.redhat.com//show_bug.cgi?id=1642135
> Signed-off-by: Gerd Hoffmann
>
> src/optionroms.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/src/optionroms.c b/src/optionroms.c
> index fc992f649fe1..e906ab97f433 100644
> --- a/src/optionroms.c
> +++ b/src/optionroms.c
> @@ -8,6 +8,7 @@
>  #include "bregs.h" // struct bregs
>  #include "config.h" // CONFIG_*
>  #include "farptr.h" // FLATPTR_TO_SEG
> +#include "biosvar.h" // GET_IVT
>  #include "hw/pci.h" // pci_config_readl
>  #include "hw/pcidevice.h" // foreachpci
>  #include "hw/pci_ids.h" // PCI_CLASS_DISPLAY_VGA
> @@ -308,6 +309,19 @@ fail:
>      return NULL;
>  }
>
> +static int boot_irq_captured(void)
> +{
> return GET_IVT(0x19).segoff != FUNC16(entry_19_official).segoff;
>
> +}
>
> +static void boot_irq_restore(void)
> +{
> struct segoff_s seabios;
> seabios = FUNC16(entry_19_official);
> SET_IVT(0x19, seabios);
>
> +}
>
> // Attempt to map and initialize the option rom on a given PCI device.
>  static void
>  init_pcirom(struct pci_device *pci, int isvga, u64 *sources)
> @@ -327,8 +341,18 @@ init_pcirom(struct pci_device *pci, int isvga, u64
> *sources)
>      if (! rom)
>          // No ROM present.
>          return;
> int irq_was_captured = boot_irq_captured();
> struct pnp_data *pnp = get_pnp_rom(rom);
> setRomSource(sources, rom, RS_PCIROM | (u32)pci);
> init_optionrom(rom, pci->bdf, isvga);
> if (boot_irq_captured() && !irq_was_captured &&
>    !file && !isvga && pnp) {
>    // This PCI rom is misbehaving - recapture the boot irqs
>    char *desc = MAKE_FLATPTR(FLATPTR_TO_SEG(rom), pnp->productname);
>    dprintf(1, "PnP optionrom \"%s\" (bdf %pP) captured int19,
>
> restoring\n",
>            desc, pci);
>    boot_irq_restore();
> }
>
> }