[Patch] avoid unnecessary loading NIC rom.

[Patch] avoid unnecessary loading NIC rom.

[Akio Takebe]

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Hi,

When we don't specify PXE boot in guest configuration file,
it is not necessary for hvmloader to load PXE option ROM.
This patch avoid unncessary loading the rom.
It can save shadow memory area for option ROMs.

Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com>

Best Regards,

Akio Takebe

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diff -r a76b4e00e186 tools/firmware/hvmloader/hvmloader.c
--- a/tools/firmware/hvmloader/hvmloader.c	Tue Dec 16 13:14:25 2008 +0000
+++ b/tools/firmware/hvmloader/hvmloader.c	Thu Dec 18 22:38:18 2008 +0900
@@ -423,19 +423,28 @@
 {
     uint8_t devfn;
     uint16_t class, vendor_id, device_id;
+    uint16_t bootdev;
+    uint16_t seq_nr;
 
-    for ( devfn = 0; devfn < 128; devfn++ )
-    {
-        class     = pci_readw(devfn, PCI_CLASS_DEVICE);
-        vendor_id = pci_readw(devfn, PCI_VENDOR_ID);
-        device_id = pci_readw(devfn, PCI_DEVICE_ID);
+    for (seq_nr=0; seq_nr<3; seq_nr++ ){
+        bootdev = cmos_inb(0x3d);
+        bootdev |= ((cmos_inb(0x38) & 0xf0) << 4);
+        bootdev >>= 4 * seq_nr;
+        bootdev &= 0xf;
+	if ( bootdev == 4 ){
+            for ( devfn = 0; devfn < 128; devfn++ ){
+                class     = pci_readw(devfn, PCI_CLASS_DEVICE);
+                vendor_id = pci_readw(devfn, PCI_VENDOR_ID);
+                device_id = pci_readw(devfn, PCI_DEVICE_ID);
 
-        /* We're only interested in NICs. */
-        if ( (vendor_id != 0xffff) &&
-             (device_id != 0xffff) &&
-             (class == 0x0200) )
-            return scan_option_rom(
-                devfn, vendor_id, device_id, etherboot, copy_rom_dest);
+                /* We're only interested in NICs. */
+                if ( (vendor_id != 0xffff) &&
+                     (device_id != 0xffff) &&
+                     (class == 0x0200) )
+                    return scan_option_rom(devfn, vendor_id, 
+                               device_id, etherboot, copy_rom_dest);
+            }
+        }
     }
 
     return 0;

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Re: [Patch] avoid unnecessary loading NIC rom.

[Keir Fraser]

On 18/12/2008 13:45, "Akio Takebe" <takebe_akio@jp.fujitsu.com> wrote:

> When we don't specify PXE boot in guest configuration file,
> it is not necessary for hvmloader to load PXE option ROM.
> This patch avoid unncessary loading the rom.
> It can save shadow memory area for option ROMs.

There's a 'F10 to select boot device' option in rombios, so you can't
determine this in hvmloader.

 -- Keir

Re: [Patch] avoid unnecessary loading NIC rom.

[Akio Takebe]

Keir Fraser wrote:
> On 18/12/2008 13:45, "Akio Takebe" <takebe_akio@jp.fujitsu.com> wrote:
> 
>> When we don't specify PXE boot in guest configuration file,
>> it is not necessary for hvmloader to load PXE option ROM.
>> This patch avoid unncessary loading the rom.
>> It can save shadow memory area for option ROMs.
> 
> There's a 'F10 to select boot device' option in rombios, so you can't
> determine this in hvmloader.
Exactly. But if gPXE rom is loaded,
hvmloader cannot load some option ROMs of raal PCI cards.
I suspect we don't use F10 option for PXE boot.
Do you have good idea?

Best Regards,

Akio Takebe

Re: [Patch] avoid unnecessary loading NIC rom.

[Keir Fraser]

On 18/12/2008 14:50, "Akio Takebe" <takebe_akio@jp.fujitsu.com> wrote:

>> There's a 'F10 to select boot device' option in rombios, so you can't
>> determine this in hvmloader.
> Exactly. But if gPXE rom is loaded,
> hvmloader cannot load some option ROMs of raal PCI cards.
> I suspect we don't use F10 option for PXE boot.
> Do you have good idea?

Not really. Perhaps scan_etherboot_nic() after pci_load_option_roms(), so
the latter takes priority?

 -- Keir

Re: [Patch] avoid unnecessary loading NIC rom.

[Keir Fraser]

On 18/12/2008 14:55, "Keir Fraser" <keir.fraser@eu.citrix.com> wrote:

>>> There's a 'F10 to select boot device' option in rombios, so you can't
>>> determine this in hvmloader.
>> Exactly. But if gPXE rom is loaded,
>> hvmloader cannot load some option ROMs of raal PCI cards.
>> I suspect we don't use F10 option for PXE boot.
>> Do you have good idea?
> 
> Not really. Perhaps scan_etherboot_nic() after pci_load_option_roms(), so the
> latter takes priority?

Another possibility is to let option ROMs load up to 0xe9000 rather than
just 0xe0000. There's nothing in the range 0xe0000-0xe9000 right now; it's
36kB of wasted space.

 -- Keir

Re: [Patch] avoid unnecessary loading NIC rom.

[Akio Takebe]

Keir Fraser wrote:
> On 18/12/2008 14:55, "Keir Fraser" <keir.fraser@eu.citrix.com> wrote:
> 
>>>> There's a 'F10 to select boot device' option in rombios, so you can't
>>>> determine this in hvmloader.
>>> Exactly. But if gPXE rom is loaded,
>>> hvmloader cannot load some option ROMs of raal PCI cards.
>>> I suspect we don't use F10 option for PXE boot.
>>> Do you have good idea?
>> Not really. Perhaps scan_etherboot_nic() after pci_load_option_roms(), so the
>> latter takes priority?
> 
> Another possibility is to let option ROMs load up to 0xe9000 rather than
> just 0xe0000. There's nothing in the range 0xe0000-0xe9000 right now; it's
> 36kB of wasted space.
> 
OK. I'll try to use the range 0xe0000-0xe9000.
The range seems to be OK in BBS spec.

Best Regards,

Akio Takebe