lkml.org 
[lkml]   [2021]   [Feb]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 8/9] vfio/pci: use x86 naming instead of igd
From
Date
On 2/1/21 12:14 PM, Cornelia Huck wrote:
> On Mon, 1 Feb 2021 16:28:27 +0000
> Max Gurtovoy <mgurtovoy@nvidia.com> wrote:
>
>> This patch doesn't change any logic but only align to the concept of
>> vfio_pci_core extensions. Extensions that are related to a platform
>> and not to a specific vendor of PCI devices should be part of the core
>> driver. Extensions that are specific for PCI device vendor should go
>> to a dedicated vendor vfio-pci driver.
>
> My understanding is that igd means support for Intel graphics, i.e. a
> strict subset of x86. If there are other future extensions that e.g.
> only make sense for some devices found only on AMD systems, I don't
> think they should all be included under the same x86 umbrella.
>
> Similar reasoning for nvlink, that only seems to cover support for some
> GPUs under Power, and is not a general platform-specific extension IIUC.
>
> We can arguably do the zdev -> s390 rename (as zpci appears only on
> s390, and all PCI devices will be zpci on that platform), although I'm
> not sure about the benefit.

As far as I can tell, there isn't any benefit for s390 it's just
"re-branding" to match the platform name rather than the zdev moniker,
which admittedly perhaps makes it more clear to someone outside of s390
that any PCI device on s390 is a zdev/zpci type, and thus will use this
extension to vfio_pci(_core). This would still be true even if we added
something later that builds atop it (e.g. a platform-specific device
like ism-vfio-pci). Or for that matter, mlx5 via vfio-pci on s390x uses
these zdev extensions today and would need to continue using them in a
world where mlx5-vfio-pci.ko exists.

I guess all that to say: if such a rename matches the 'grand scheme' of
this design where we treat arch-level extensions to vfio_pci(_core) as
"vfio_pci_(arch)" then I'm not particularly opposed to the rename. But
by itself it's not very exciting :)

>
>>
>> For now, x86 extensions will include only igd.
>>
>> Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
>> ---
>> drivers/vfio/pci/Kconfig | 13 ++++++-------
>> drivers/vfio/pci/Makefile | 2 +-
>> drivers/vfio/pci/vfio_pci_core.c | 2 +-
>> drivers/vfio/pci/vfio_pci_private.h | 2 +-
>> drivers/vfio/pci/{vfio_pci_igd.c => vfio_pci_x86.c} | 0
>> 5 files changed, 9 insertions(+), 10 deletions(-)
>> rename drivers/vfio/pci/{vfio_pci_igd.c => vfio_pci_x86.c} (100%)
>
> (...)
>
>> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
>> index c559027def2d..e0e258c37fb5 100644
>> --- a/drivers/vfio/pci/vfio_pci_core.c
>> +++ b/drivers/vfio/pci/vfio_pci_core.c
>> @@ -328,7 +328,7 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
>>
>> if (vfio_pci_is_vga(pdev) &&
>> pdev->vendor == PCI_VENDOR_ID_INTEL &&
>> - IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
>> + IS_ENABLED(CONFIG_VFIO_PCI_X86)) {
>> ret = vfio_pci_igd_init(vdev);
>
> This one explicitly checks for Intel devices, so I'm not sure why you
> want to generalize this to x86?
>
>> if (ret && ret != -ENODEV) {
>> pci_warn(pdev, "Failed to setup Intel IGD regions\n");
>

\
 
 \ /
  Last update: 2021-02-01 18:53    [W:0.100 / U:22.612 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site