On 30/06/2022 20:12, Zanoni, Paulo R wrote:
Can you please explain what happens when we try to write to a range
that's bound as read-only?
It will be mapped as read-only in device page table. Hence any
write access will fail. I would expect a CAT error reported.
What's a CAT error? Does this lead to machine freeze or a GPU hang?
Let's make sure we document this.
Catastrophic error.
Reading the documentation, it seems the behavior depends on the context
type.
With the Legacy 64bit context type, writes are ignored (BSpec 531) :
- "For legacy context, the access rights are not applicable and
should not be considered during page walk."
For Advanced 64bit context type, I think the HW will generate a pagefault.
-Lionel
