Hi,
On 2/7/20 5:38 PM, Andre Przywara wrote:
> On Thu, 23 Jan 2020 13:48:03 +0000
> Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
>
> Hi,
>
>> From: Julien Thierry <julien.thierry@xxxxxxx>
>>
>> PCI now supports configurable BARs. Get rid of the no longer needed,
>> Linux-only, fdt property.
> I was just wondering: what is the x86 story here?
> Does the x86 kernel never reassign BARs? Or is this dependent on something else?
> I see tons of pci kernel command line parameters for pci=, maybe one of them would explicitly allow reassigning?
I only see pci=conf1, can you post your kernel command line? Here's mine:
[ 0.000000] Command line: noapic noacpi pci=conf1 reboot=k panic=1
i8042.direct=1 i8042.dumbkbd=1 i8042.nopnp=1 earlyprintk=serial i8042.noaux=1
console=ttyS0 earlycon root=/dev/vda1
Just for pci=conf1, from Documentation/admin-guide/kernel-parameters.txt:
"conf1 [X86] Force use of PCI Configuration Access
Mechanism 1 (config address in IO port 0xCF8,
data in IO port 0xCFC, both 32-bit)."
But you have a point, I haven't seen an x86 guest reassign BARs, I assumed it's
because it trusts the BIOS allocation. I'll try to figure out why this happens
(maybe I need a special kernel parameter).
Thanks,
Alex
>
> Cheers,
> Andre
>
>> Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
>> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
>> ---
>> arm/fdt.c | 1 -
>> 1 file changed, 1 deletion(-)
>>
>> diff --git a/arm/fdt.c b/arm/fdt.c
>> index c80e6da323b6..02091e9e0bee 100644
>> --- a/arm/fdt.c
>> +++ b/arm/fdt.c
>> @@ -130,7 +130,6 @@ static int setup_fdt(struct kvm *kvm)
>>
>> /* /chosen */
>> _FDT(fdt_begin_node(fdt, "chosen"));
>> - _FDT(fdt_property_cell(fdt, "linux,pci-probe-only", 1));
>>
>> /* Pass on our amended command line to a Linux kernel only. */
>> if (kvm->cfg.firmware_filename) {
