On 9/24/26 7:17 PM, Jason Gunthorpe wrote:
On Thu, Sep 24, 2026 at 07:03:56PM -0500, Mario Limonciello wrote:
On 9/24/26 5:50 PM, Jason Gunthorpe wrote:
On Mon, Sep 07, 2026 at 11:12:06PM -0500, Mario Limonciello wrote:
+EXPORT_SYMBOL_GPL(amd_iommu_enable_perfopt);
Last time we hardwired the GPU and IOMMU drivers together it was a
huge mess to undo.
Why does the GPU driver have to request this? Why can't the iommu
driver know that this is a special device that can use this magic fast
path and then auto set it when identity is asked for?
The reason was to allow an "opt-out" path on the GPU driver.
This seems like a very poor reason for doing this given the past
negative experiances.
Jason
I guess I don't have the context of what happened in the past. Could
you fill me in? I'm not against it being automatic when in identity
mode. I'll just need to come up with a way to check it's the GPU inside
of an APU not a dGPU connected to the APU.
