On 4/9/2025 3:53 AM, Christoph Hellwig wrote:
On Tue, Apr 08, 2025 at 05:08:35PM -0700, Roman Kisel wrote:
The device bit that indicates that the device is capable of I/O
with private pages lets avoid excessive copying in the Hyper-V
SCSI driver.
Set that bit equal to the confidential external memory one to
not bounce buffer
Drivers have absolutely no business telling this. The need for bounce
buffering or not is a platform/IOMMU decision and not one specific to
a certain device or driver.
Seemed to work although I cannot claim nothing is going to be broken
ever. It did appear from the code that one could have this per-device
bit.
As I understand, you're saying this is architecturally broken. Do you
think a broader set of changes would improve the implementation?
--
Thank you,
Roman
