Success with pv guest and ATI Radeon HD4550

[Geoffrey McRae <geoff@spacevs.com>]

Hi All,

This is just a heads up on the steps involved in getting a HD4550 
working with the ATI driver as a pv guest on a Dom0 with no IOMMU 
support. The main issue with making this work was providing a way for 
the guest to read the vga bios.

[    2.127078] [drm] Initialized drm 1.1.0 20060810
[    2.140666] snd_hda_intel 0000:00:00.1: Xen PCI mapped GSI19 to IRQ51
[    2.140950] snd_hda_intel 0000:00:00.1: Handle VGA-switcheroo audio 
client
[    2.143196] [drm] radeon kernel modesetting enabled.
[    2.143856] radeon 0000:00:00.0: Xen PCI mapped GSI18 to IRQ53
[    2.144583] [drm] initializing kernel modesetting (RV710 
0x1002:0x9540 0x1043:0x0298).
[    2.144608] [drm] register mmio base: 0xFBDF0000
[    2.144612] [drm] register mmio size: 65536
[    2.144693] radeon 0000:00:00.0: Invalid ROM contents
[    2.144703] radeon 0000:00:00.0: Invalid ROM contents
[    2.144707] [drm:radeon_get_bios] *ERROR* Unable to locate a BIOS ROM
[    2.144712] radeon 0000:00:00.0: Fatal error during GPU init
[    2.144717] [drm] radeon: finishing device.
[    2.144720] [TTM] Memory type 2 has not been initialized

To resolve this I dumped the BIOS on dom0 to a file and copied it into 
the guest, then patched radeon_bios.c to provide a means to load it from 
userspace with the following result.


[  997.220370] [drm] radeon kernel modesetting enabled.
[  997.220743] xen:events: xen_bind_pirq_gsi_to_irq: returning irq 53 
for gsi 18
[  997.220753] radeon 0000:00:00.0: Xen PCI mapped GSI18 to IRQ53
[  997.221304] [drm] initializing kernel modesetting (RV710 
0x1002:0x9540 0x1043:0x0298).
[  997.221329] [drm] register mmio base: 0xFBDF0000
[  997.221333] [drm] register mmio size: 65536
[  997.222605] radeon 0000:00:00.0: firmware: direct-loading firmware 
radeon.bios
[  997.222652] ATOM BIOS: 9540.11.17.0.18.AS02
[  997.222691] radeon 0000:00:00.0: VRAM: 512M 0x0000000000000000 - 
0x000000001FFFFFFF (512M used)
[  997.222702] radeon 0000:00:00.0: GTT: 1024M 0x0000000020000000 - 
0x000000005FFFFFFF
[  997.222708] Failed to add WC MTRR for 
[00000000d0000000-00000000dfffffff]; performance may suffer.
[  997.222713] [drm] Detected VRAM RAM=512M, BAR=256M
[  997.222717] [drm] RAM width 64bits DDR
[  997.222815] [TTM] Zone  kernel: Available graphics memory: 509996 kiB
[  997.222821] [TTM] Initializing pool allocator
[  997.222829] [TTM] Initializing DMA pool allocator
[  997.222862] [drm] radeon: 512M of VRAM memory ready
[  997.222866] [drm] radeon: 1024M of GTT memory ready.
[  997.222884] [drm] Loading RV710 Microcode
[  997.231622] radeon 0000:00:00.0: firmware: direct-loading firmware 
radeon/RV710_pfp.bin
[  997.249253] radeon 0000:00:00.0: firmware: direct-loading firmware 
radeon/RV710_me.bin
[  997.272966] radeon 0000:00:00.0: firmware: direct-loading firmware 
radeon/R700_rlc.bin
[  997.290901] radeon 0000:00:00.0: firmware: direct-loading firmware 
radeon/RV710_smc.bin
[  997.290915] [drm] Internal thermal controller without fan control
[  997.291866] [drm] radeon: dpm initialized
[  997.306236] radeon 0000:00:00.0: firmware: direct-loading firmware 
radeon/RV710_uvd.bin
[  997.306409] [drm] GART: num cpu pages 262144, num gpu pages 262144
[  997.320178] [drm] PCIE GART of 1024M enabled (table at 
0x000000000025D000).
[  997.320240] radeon 0000:00:00.0: WB enabled
[  997.320246] radeon 0000:00:00.0: fence driver on ring 0 use gpu addr 
0x0000000020000c00 and cpu addr 0xffff88003c79cc00
[  997.320253] radeon 0000:00:00.0: fence driver on ring 3 use gpu addr 
0x0000000020000c0c and cpu addr 0xffff88003c79cc0c
[  997.323053] radeon 0000:00:00.0: fence driver on ring 5 use gpu addr 
0x000000000005c598 and cpu addr 0xffffc9000031c598
[  997.323060] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[  997.323063] [drm] Driver supports precise vblank timestamp query.
[  997.323067] radeon 0000:00:00.0: radeon: MSI limited to 32-bit
[  997.323285] radeon 0000:00:00.0: radeon: using MSI.
[  997.323322] [drm] radeon: irq initialized.
[  997.369642] [drm] ring test on 0 succeeded in 1 usecs
[  997.369651] [drm] ring test on 3 succeeded in 2 usecs
[  997.564145] [drm] ring test on 5 succeeded in 1 usecs
[  997.564153] [drm] UVD initialized successfully.
[  997.564580] [drm] ib test on ring 0 succeeded in 0 usecs
[  997.564614] [drm] ib test on ring 3 succeeded in 0 usecs
[  997.723870] [drm] ib test on ring 5 succeeded
[  997.724326] [drm] Radeon Display Connectors
[  997.724332] [drm] Connector 0:
[  997.724335] [drm]   VGA-1
[  997.724338] [drm]   DDC: 0x7e40 0x7e40 0x7e44 0x7e44 0x7e48 0x7e48 
0x7e4c 0x7e4c
[  997.724342] [drm]   Encoders:
[  997.724345] [drm]     CRT2: INTERNAL_KLDSCP_DAC2
[  997.724348] [drm] Connector 1:
[  997.724350] [drm]   HDMI-A-1
[  997.724353] [drm]   HPD1
[  997.724355] [drm]   DDC: 0x7e50 0x7e50 0x7e54 0x7e54 0x7e58 0x7e58 
0x7e5c 0x7e5c
[  997.724359] [drm]   Encoders:
[  997.724362] [drm]     DFP1: INTERNAL_UNIPHY
[  997.724365] [drm] Connector 2:
[  997.724367] [drm]   DVI-I-1
[  997.724369] [drm]   HPD4
[  997.724372] [drm]   DDC: 0x7f10 0x7f10 0x7f14 0x7f14 0x7f18 0x7f18 
0x7f1c 0x7f1c
[  997.724376] [drm]   Encoders:
[  997.724378] [drm]     CRT1: INTERNAL_KLDSCP_DAC1
[  997.724382] [drm]     DFP2: INTERNAL_UNIPHY2
[  997.779239] [drm] fb mappable at 0xD045E000
[  997.779245] [drm] vram apper at 0xD0000000
[  997.779251] [drm] size 5242880
[  997.779253] [drm] fb depth is 24
[  997.779255] [drm]    pitch is 5120
[  997.779366] fbcon: radeondrmfb (fb0) is primary device
[  997.792290] Console: switching to colour frame buffer device 160x64
[  997.805919] radeon 0000:00:00.0: fb0: radeondrmfb frame buffer device
[  997.806021] radeon 0000:00:00.0: registered panic notifier
[  997.820118] [drm] Initialized radeon 2.39.0 20080528 for 0000:00:00.0 
on minor 0

The changes made were in `drivers/gpu/drm/radeon/radeon_bios.c` where I 
added the following method, and a call to it in `radeon_get_bios`

static bool radeon_load_bios(struct radeon_device *rdev)
{
         const struct firmware *fw;
         if (request_firmware(&fw, "radeon.bios", rdev->dev) != 0)
                 return false;

         rdev->bios = kmalloc(fw->size, GFP_KERNEL);
         if (!rdev->bios) {
                 release_firmware(fw);
                 DRM_ERROR("Unable to allocate bios\n");
                 return false;
         }

         memcpy(rdev->bios, fw->data, fw->size);
         release_firmware(fw);
         return true;
}

I hope this helps anyone else trying find a way to just pass the bios 
into the driver without having to resort to hvm. It would be nice to see 
a patch to `drivers/pci/rom.c` that does the same thing, but chooses a 
bios name based on the pci device instead, allowing the opportunity to 
override the pci rom with any provided file both for testing/debugging 
and corner cases like this one here.

Kind Regards,
Geoffrey McRae (gnif)