From 125a3d3fac51571b8ede0d0599618c6ecd975ea8 Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda Date: Tue, 23 Jun 2026 17:33:29 +0200 Subject: [PATCH] KVM: s390: selftests: Fix cmma selftest The existing cmma selftest depended on the host allocating page tables for all present memslots. Since the gmap rewrite, memory that is not accessed by the guest might not have page tables allocated yet. This caused the test to fail due to a mismatch in the assertion. Fix by having the guest access also the second half of the test memslot, thus guaranteeing that its page tables are present. Fixes: e38c884df921 ("KVM: s390: Switch to new gmap") Signed-off-by: Claudio Imbrenda Message-ID: <20260623153331.233784-9-imbrenda@linux.ibm.com> --- tools/testing/selftests/kvm/s390/cmma_test.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/testing/selftests/kvm/s390/cmma_test.c b/tools/testing/selftests/kvm/s390/cmma_test.c index e39a724fe860..15d81b2ed7ad 100644 --- a/tools/testing/selftests/kvm/s390/cmma_test.c +++ b/tools/testing/selftests/kvm/s390/cmma_test.c @@ -34,16 +34,22 @@ static char cmma_value_buf[MAIN_PAGE_COUNT + TEST_DATA_PAGE_COUNT]; /** * Dirty CMMA attributes of exactly one page in the TEST_DATA memslot, * so use_cmma goes on and the CMMA related ioctls do something. + * Touch the page at offset 1M inside TEST_DATA to make sure its page + * tables are allocated in the host. */ static void guest_do_one_essa(void) { asm volatile( /* load TEST_DATA_START_GFN into r1 */ + " xgr 1,1\n" " llilf 1,%[start_gfn]\n" /* calculate the address from the gfn */ " sllg 1,1,12(0)\n" /* set the first page in TEST_DATA memslot to STABLE */ " .insn rrf,0xb9ab0000,2,1,1,0\n" + " agfi 1,0x100000\n" + /* also touch the first page of the second MB of TEST_DATA */ + " .insn rrf,0xb9ab0000,2,1,1,0\n" /* hypercall */ " diag 0,0,0x501\n" "0: j 0b"