Re: [PATCH v2 0/7] Add virtio gpu userptr support
From: Huang, Honglei1
Date: Tue Apr 01 2025 - 21:48:02 EST
On 2025/3/30 3:56, Demi Marie Obenour wrote:
On 3/21/25 4:00 AM, Honglei Huang wrote:
From: Honglei Huang <Honglei1.Huang@xxxxxxx>
Hello,
This series add virtio gpu userptr support and add libhsakmt capset.
The userptr feature is used for let host access guest user space memory,
this feature is used for GPU compute use case, to enable ROCm/OpenCL native
context. It should be pointed out that we are not to implement SVM here,
this is just a buffer based userptr implementation.
The libhsakmt capset is used for ROCm context, libhsakmt is like the role
of libdrm in Mesa.
Patches 1-2 add libhsakmt capset and userptr blob resource flag.
libhsakmt and userptr are orthogonal from each other.
Should the libhsakmt context be a separate patch series?
I will separate libhsakmt capset patch into another patch series.
Patches 3-5 implement basic userptr feature, in some popular bench marks,
it has an efficiency of about 70% compared to bare metal in OpenCL API.
Patch 6 adds interval tree to manage userptrs and prevent duplicate creation.
V2: - Split add HSAKMT context and blob userptr resource to two patches.
- Remove MMU notifier related patches, cause use not moveable user space
memory with MMU notifier is not a good idea.
- Remove HSAKMT context check when create context, let all the context
support the userptr feature.
- Remove MMU notifier related content in cover letter.
- Add more comments for patch 6 in cover letter.
I have not looked at the implementation, but thanks for removing the MMU
notifier support. Should the interval tree be added before the feature
is exposed to userspace? That would prevent users who are doing kernel
bisects from temporarily exposing a buggy feature to userspace.
Ok I will add interval tree patch before introduce the feature into user
space in next version. Really thanks for the review.