After the execution of __tilerelease(), AMX component will be in INIT state. Therefore, execution of XSAVEC saving the AMX state into memory will cause the xstate_bv[18] cleared in xheader. However, the xcomp_bv[18] will remain set. Fix the error in comment. Also, update xsavec() to XSAVEC because xcomp_bv[18] is set due to the instruction, not the function. Finally, use XTILEDATA instead 'bit 18' in comments.
Cc: Jim Mattson jmattson@google.com Cc: Venkatesh Srinivas venkateshs@google.com Cc: Aaron Lewis aaronlewis@google.com Signed-off-by: Mingwei Zhang mizhang@google.com --- tools/testing/selftests/kvm/x86_64/amx_test.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c index bb9dc0008f43..16c857c1052e 100644 --- a/tools/testing/selftests/kvm/x86_64/amx_test.c +++ b/tools/testing/selftests/kvm/x86_64/amx_test.c @@ -190,7 +190,10 @@ static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg, GUEST_SYNC(4); __tilerelease(); GUEST_SYNC(5); - /* bit 18 not in the XCOMP_BV after xsavec() */ + /* + * After XSAVEC, XTILEDATA is cleared in the xstate_bv but is set in + * the xcomp_bv. + */ xstate->header.xstate_bv = XFEATURE_MASK_XTILEDATA; __xsavec(xstate, XFEATURE_MASK_XTILEDATA); GUEST_ASSERT(!(xstate->header.xstate_bv & XFEATURE_MASK_XTILEDATA));