Quoting Prathap Kumar Valsan (2019-08-26 01:48:01) > To provide shared last-level-cache isolation to cpu workloads running > concurrently with gpu workloads, the gpu allocation of cache lines needs > to be restricted to certain ways. Currently GPU hardware supports four > class-of-service(CLOS) levels and there is an associated way-mask for > each CLOS. > > Hardware supports reading supported way-mask configuration for GPU using > a bios pcode interface. The supported way-masks and the one currently > active is communicated to userspace via a sysfs file--closctrl. Admin user > can then select a new mask by writing the mask value to the file. > > Note of Caution: Restricting cache ways using this mechanism presents a > larger attack surface for side-channel attacks.
I wonder if this is enough to justify some further protection before enabling? > Example usage: > The active way-mask is highlighted within square brackets. > > cat /sys/class/drm/card0/closctrl > [0xffff] 0xff00 0xc000 0x8000 How about two files for easier scripting interface? /sys/class/drm/card0/llc_clos /sys/class/drm/card0/llc_clos_modes Regards, Joonas _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
