vfio/igd: correctly calculate stolen memory size for gen 9 and later

We have to update the calculation of the stolen memory size because
we've seen devices using values of 0xf0 and above for the graphics mode
select field. The new calculation was taken from the linux kernel [1].

[1] 7c626ce4ba/arch/x86/kernel/early-quirks.c (L455-L460)

Signed-off-by: Corvin Köhne <c.koehne@beckhoff.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Corvin Köhne 2024-08-28 15:43:28 +02:00 committed by Cédric Le Goater
parent 971ca22f04
commit 8719224166

View File

@ -488,11 +488,18 @@ static int igd_get_stolen_mb(int gen, uint32_t gmch)
gms = (gmch >> 8) & 0xff;
}
if (gms > 0x10) {
error_report("Unsupported IGD GMS value 0x%x", gms);
return 0;
if (gen < 9) {
if (gms > 0x10) {
error_report("Unsupported IGD GMS value 0x%x", gms);
return 0;
}
return gms * 32;
} else {
if (gms < 0xf0)
return gms * 32;
else
return gms * 4 + 4;
}
return gms * 32;
}
void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)