[kvm-unit-tests PATCH v2 5/9] s390x: smp: add tests for SET_PREFIX

Nico Boehr
2022-03-23T17:03:39Z

We cover the following cases:

- running CPU
- illegal CPU id

The order should be rejected in both cases.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
s390x/smp.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)

diff --git a/s390x/smp.c b/s390x/smp.c
index 344f508a245d..36014e809f2e 100644
--- a/s390x/smp.c
+++ b/s390x/smp.c
@@ -55,6 +55,8 @@ static uint8_t expected_vec_contents[NUM_VEC_REGISTERS][VEC_REGISTER_SIZE];
static struct gs_cb gs_cb;
static struct gs_epl gs_epl;

+static uint32_t cpu1_prefix;
+
static int memisset(void *s, int c, size_t n)
{
uint8_t *p = s;
@@ -537,6 +539,76 @@ out:
report_prefix_pop();
}

+static void loop(void)
+{
+ while (1)
+ ;
+}
+
+static void stpx_and_set_flag(void)
+{
+ asm volatile (
+ " stpx %[prefix]\n"
+ : [prefix] "=Q" (cpu1_prefix)
+ :
+ :
+ );
+
+ set_flag(1);
+}
+
+static void test_set_prefix(void)
+{
+ struct lowcore *new_lc = alloc_pages_flags(1, AREA_DMA31);
+ struct cpu *cpu1 = smp_cpu_from_idx(1);
+ uint32_t status = 0;
+ struct psw new_psw;
+ int cc;
+
+ report_prefix_push("set prefix");
+
+ assert(new_lc);
+
+ memcpy(new_lc, cpu1->lowcore, sizeof(struct lowcore));
+ new_lc->restart_new_psw.addr = (unsigned long)loop;
+
+ report_prefix_push("running");
+ set_flag(0);
+ new_psw.addr = (unsigned long)stpx_and_set_flag;
+ new_psw.mask = extract_psw_mask();
+ smp_cpu_start(1, new_psw);
+ wait_for_flag();
+ cpu1_prefix = 0xFFFFFFFF;
+
+ cc = smp_sigp(1, SIGP_SET_PREFIX, (unsigned long)new_lc, &status);
+ report(cc == 1, "CC = 1");
+ report(status == SIGP_STATUS_INCORRECT_STATE, "status = INCORRECT_STATE");
+
+ /*
+ * If the prefix of the other CPU was changed it will enter an endless
+ * loop. Otherwise, it should eventually set the flag.
+ */
+ smp_cpu_stop(1);
+ set_flag(0);
+ smp_cpu_restart(1);
+ wait_for_flag();
+ report(cpu1_prefix == (uint64_t)cpu1->lowcore, "prefix unchanged");
+
+ report_prefix_pop();
+
+ report_prefix_push("invalid CPU address");
+
+ cc = sigp(INVALID_CPU_ADDRESS, SIGP_SET_PREFIX, (unsigned long)new_lc, &status);
+ report(cc == 3, "CC = 3");
+
+ report_prefix_pop();
+
+ free_pages(new_lc);
+
+ report_prefix_pop();
+
+}
+
static void ecall(void)
{
unsigned long mask;
@@ -729,6 +801,7 @@ int main(void)
test_store_adtl_status_vector();
test_store_adtl_status_gs();
test_store_adtl_status();
+ test_set_prefix();
test_ecall();
test_emcall();
test_sense_running();
--
2.31.1