On 11/30/2023 1:08 AM, Edgecombe, Rick P wrote:
On Wed, 2023-11-29 at 22:12 +0800, Yang, Weijiang wrote:
On 11/28/2023 10:58 PM, Edgecombe, Rick P wrote:
On Fri, 2023-11-24 at 00:53 -0500, Yang Weijiang wrote:
+ /*
+ * Set guest's __user_state_size to
fpu_user_cfg.default_size
so that
+ * existing uAPIs can still work.
+ */
+ fpu->guest_perm.__user_state_size =
fpu_user_cfg.default_size;
It seems like an appropriate value, but where does this come into
play
exactly for guest FPUs?
I don't see there's special usage of this field for vCPU in VMM
userspace(QEMU).
Maybe it's mainly for AMX resulted usespace fault handling? For vCPU
thread,
it's only referenced when AMX is enabled via __xfd_enable_feature()
.
In that case the "so that existing uAPIs can still work" comment seems
misleading. Maybe "this doesn't come into play for guest FPUs, but set
it to a reasonable value"?
Ah, I mistook it for uabi_size and added comments. Will reword it properly.
Thank you for bringing it up!
