diff mbox series

[v2,kvmtool,28/30] arm/fdt: Remove 'linux,pci-probe-only' property

Message ID 20200123134805.1993-29-alexandru.elisei@arm.com (mailing list archive)
State New, archived
Headers show
Series Add reassignable BARs and PCIE 1.1 support | expand

Commit Message

Alexandru Elisei Jan. 23, 2020, 1:48 p.m. UTC
From: Julien Thierry <julien.thierry@arm.com>

PCI now supports configurable BARs. Get rid of the no longer needed,
Linux-only, fdt property.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
 arm/fdt.c | 1 -
 1 file changed, 1 deletion(-)

Comments

Andre Przywara Feb. 7, 2020, 4:51 p.m. UTC | #1
On Thu, 23 Jan 2020 13:48:03 +0000
Alexandru Elisei <alexandru.elisei@arm.com> wrote:

Hi,

> From: Julien Thierry <julien.thierry@arm.com>
> 
> PCI now supports configurable BARs. Get rid of the no longer needed,
> Linux-only, fdt property.

\o/

> Signed-off-by: Julien Thierry <julien.thierry@arm.com>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre.

> ---
>  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) {
Andre Przywara Feb. 7, 2020, 5:38 p.m. UTC | #2
On Thu, 23 Jan 2020 13:48:03 +0000
Alexandru Elisei <alexandru.elisei@arm.com> wrote:

Hi,

> From: Julien Thierry <julien.thierry@arm.com>
> 
> 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?

Cheers,
Andre

> Signed-off-by: Julien Thierry <julien.thierry@arm.com>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> ---
>  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) {
Alexandru Elisei March 10, 2020, 4:04 p.m. UTC | #3
Hi,

On 2/7/20 5:38 PM, Andre Przywara wrote:
> On Thu, 23 Jan 2020 13:48:03 +0000
> Alexandru Elisei <alexandru.elisei@arm.com> wrote:
>
> Hi,
>
>> From: Julien Thierry <julien.thierry@arm.com>
>>
>> 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@arm.com>
>> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
>> ---
>>  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) {
diff mbox series

Patch

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) {