Skip to content

powerpc/pseries/vas: Pass hw_cpu_id to node associativity HCALL

Steve Best requested to merge sfbest/centos-stream-9:2131650 into main

Bugzilla: http://bugzilla.redhat.com/2131650

Build Info: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=48509087

Tested: Did sanity boot testing on power 9 (ibm-p9z-16-lp10) system.

commit f3e5d9e53e74d77e711a2c90a91a8b0836a9e0b3 Author: Haren Myneni haren@linux.ibm.com Date: Wed Sep 28 18:57:33 2022 -0700

powerpc/pseries/vas: Pass hw_cpu_id to node associativity HCALL

Generally the hypervisor decides to allocate a window on different
VAS instances. But if user space wishes to allocate on the current VAS
instance where the process is executing, the kernel has to pass
associativity domain IDs to allocate VAS window HCALL.

To determine the associativity domain IDs for the current CPU,
smp_processor_id() is passed to node associativity HCALL which may
return H_P2 (-55) error during DLPAR CPU event. This is because Linux
CPU numbers (smp_processor_id()) are not the same as the hypervisor's
view of CPU numbers.

Fix the issue by passing hard_smp_processor_id() with
VPHN_FLAG_VCPU flag (PAPR 14.11.6.1 H_HOME_NODE_ASSOCIATIVITY).

Fixes: b22f2d88e435 ("powerpc/pseries/vas: Integrate API with open/close windows")
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
[mpe: Update change log to mention Linux vs HV CPU numbers]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/55380253ea0c11341824cd4c0fc6bbcfc5752689.camel@linux.ibm.com

Signed-off-by: Steve Best sbest@redhat.com

Merge request reports