Re: [Qemu-devel] [Xen-devel] [PATCH 2/2] xen:i386:pc_piix: create isa bridge specific to IGD passthrough

[Chen, Tiejun]

On 2014/8/28 8:56, Chen, Tiejun wrote:
+     */
+    dev = pci_create_simple(bus, PCI_DEVFN(0x1f, 0),
+                            "xen-igd-passthrough-isa-bridge");
+    if (dev) {
+        r = xen_host_pci_device_get(&hdev, 0, 0, PCI_DEVFN(0x1f,
0), 0);
+        if (!r) {
+            pci_config_set_vendor_id(dev->config, hdev.vendor_id);
+            pci_config_set_device_id(dev->config, hdev.device_id);

Can you, instead, implement the reverse logic, probing
the card and supplying the correct device id for PCH?


Here what is your so-called reverse logic as I already asked you
previously? Do you mean I should list all PCHs with a combo illustrated
with the vendor/device id in advance? Then look up if we can find a

Michael,


Ping.

Thanks
Tiejun

Could you explain this exactly? Then I can try follow-up your idea ASAP
if this is necessary and possible.

Michel,

Could you give us some explanation for your "reverse logic" when you're 
free?

Thanks
Tiejun


Thanks
Tiejun

matched PCH? If yes, what is that benefit you expect in passthrough
case? Shouldn't we pass these info to VM directly in passthrough case?

Thanks
Tiejun