gpui/blade: Allow forcing use of a specific GPU with ZED_DEVICE_ID env var

[probably-neb]

Workaround for users affected by #25899

Thanks to the work done by @kvark in kvark/blade#210, we have the ability to tell Vulkan (through blade) a specific GPU to use.

This will hopefully allow some of the users affected by #25899 to use Zed by allowing them to use a specific GPU, if the primary/default GPU will not work

Release Notes:

• Added the ability to specify which GPU Zed uses on Linux by setting the ZED_DEVICE_ID environment variable. You can obtain the device ID of your GPU by running lspci -nn | grep VGA which will output each GPU on one line like:

  08:00.0 VGA compatible controller [0300]: NVIDIA Corporation GA104 [GeForce RTX 3070] [10de:2484] (rev a1)
  

  where the device ID here is 2484. This value is in hexadecimal, so to force Zed to use this specific GPU you would set the environment variable like so:

  ZED_DEVICE_ID=0x2484
  

  Make sure to export the variable if you choose to define it globally in a .bashrc or similar

[knweiss]

I am wondering: Shouldn’t this rather use the VENDORID:DEVICEID combination (“10de:2484” in the example) instead of only the DEVICEID? As far as I know the DEVICEID is only unique per vendor.

[probably-neb]

Wow, thanks for catching that @knweiss. I had no idea device ID was not unique. Will get this fixed! (PRs also welcome :) )

[kvark]

Technically, yes. But the chance of getting a single node with multiple GPUs with the same ID are quite low.

[probably-neb]

If and when you add the ability to specify the vendor ID when initializing the context @kvark, I will make sure we support passing it. Agreed it is very unlikely to occur, especially for Zed where most cases this flag is needed is when there is an iGPU as well as a discrete GPU