s390x: smp: Improve smp code and reset checks

Reviewed-by Thomas Huth <[email protected]>

---
 s390x/smp.c | 42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

s390x/smp.c +23 ~~-19~~

index ab7e46c..8d8e3a5 100644
@@ -22,6 +22,13 @@
 
 static int testflag = 0;
 
+static void wait_for_flag(void)
+{
+	while (!testflag) {
+		mb();
+	}
+}
+
 static void cpu_loop(void)
 {
 	for (;;) {}

@@ -30,20 +37,17 @@ static void cpu_loop(void)
 static void test_func(void)
 {
 	testflag = 1;
-	mb();
 	cpu_loop();
 }
 
 static void test_start(void)
 {
 	struct psw psw;
-	psw.mask =  extract_psw_mask();
+	psw.mask = extract_psw_mask();
 	psw.addr = (unsigned long)test_func;
 
 	smp_cpu_setup(1, psw);
-	while (!testflag) {
-		mb();
-	}
+	wait_for_flag();
 	report(1, "start");
 }

@@ -115,24 +119,24 @@ static void ecall(void)
 	testflag = 1;
 	while (lc->ext_int_code != 0x1202) { mb(); }
 	report(1, "ecall");
-	testflag= 1;
+	testflag = 1;
 }
 
 static void test_ecall(void)
 {
 	struct psw psw;
-	psw.mask =  extract_psw_mask();
+	psw.mask = extract_psw_mask();
 	psw.addr = (unsigned long)ecall;
 
 	report_prefix_push("ecall");
-	testflag= 0;
+	testflag = 0;
 	smp_cpu_destroy(1);
 
 	smp_cpu_setup(1, psw);
-	while (!testflag) { mb(); }
-	testflag= 0;
+	wait_for_flag();
+	testflag = 0;
 	sigp(1, SIGP_EXTERNAL_CALL, 0, NULL);
-	while(!testflag) {mb();}
+	wait_for_flag();
 	smp_cpu_stop(1);
 	report_prefix_pop();
 }

@@ -147,7 +151,7 @@ static void emcall(void)
 	mask = extract_psw_mask();
 	mask |= PSW_MASK_EXT;
 	load_psw_mask(mask);
-	testflag= 1;
+	testflag = 1;
 	while (lc->ext_int_code != 0x1201) { mb(); }
 	report(1, "ecall");
 	testflag = 1;

@@ -156,18 +160,18 @@ static void emcall(void)
 static void test_emcall(void)
 {
 	struct psw psw;
-	psw.mask =  extract_psw_mask();
+	psw.mask = extract_psw_mask();
 	psw.addr = (unsigned long)emcall;
 
 	report_prefix_push("emcall");
-	testflag= 0;
+	testflag = 0;
 	smp_cpu_destroy(1);
 
 	smp_cpu_setup(1, psw);
-	while (!testflag) { mb(); }
-	testflag= 0;
+	wait_for_flag();
+	testflag = 0;
 	sigp(1, SIGP_EMERGENCY_SIGNAL, 0, NULL);
-	while(!testflag) { mb(); }
+	wait_for_flag();
 	smp_cpu_stop(1);
 	report_prefix_pop();
 }

@@ -177,7 +181,7 @@ static void test_reset_initial(void)
 	struct cpu_status *status = alloc_pages(0);
 	struct psw psw;
 
-	psw.mask =  extract_psw_mask();
+	psw.mask = extract_psw_mask();
 	psw.addr = (unsigned long)test_func;
 
 	report_prefix_push("reset initial");

@@ -208,7 +212,7 @@ static void test_reset(void)
 {
 	struct psw psw;
 
-	psw.mask =  extract_psw_mask();
+	psw.mask = extract_psw_mask();
 	psw.addr = (unsigned long)test_func;
 
 	report_prefix_push("cpu reset");

Signature · 1 line

2.20.1

David Hildenbrand

Reviewed-by on v3 1/9

2020-01-20 12:02 UTC #2 lore raw

Re: [kvm-unit-tests PATCH v3 1/9] s390x: smp: Cleanup smp.c

Quoted 17 lines · Janosch Frank

Let's remove a lot of badly formatted code by introducing the wait_for_flag() function.
Also let's remove some stray spaces.
Signed-off-by Janosch Frank <[email protected]>
Reviewed-by Thomas Huth <[email protected]>
Reviewed-by Cornelia Huck <[email protected]>
---
 s390x/smp.c | 42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)
s390x/smp.c +0 -0
index ab7e46c..8d8e3a5 100644

s390x/smp.c line 29

Quoted 8 lines

s390x/smp.c +5 -0

@@ -22,6 +22,13 @@
 
 static int testflag = 0;
 
+static void wait_for_flag(void)
+{
+	while (!testflag) {
+		mb();
+	}

No need for the {}

Signature · 3 lines

Thanks,

David / dhildenb

Janosch Frank

author

2020-01-17 10:46 UTC #3 lore raw

PATCH v3 2/9 s390x: smp: Only use smp_cpu_setup once

Let's stop and start instead of using setup to run a function on a cpu.

Reviewed-by Thomas Huth <[email protected]>

Acked-by David Hildenbrand <[email protected]>

---
 s390x/smp.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

s390x/smp.c +14 -7

index 8d8e3a5..555ed72 100644
@@ -46,7 +46,7 @@ static void test_start(void)
 	psw.mask = extract_psw_mask();
 	psw.addr = (unsigned long)test_func;
 
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 	wait_for_flag();
 	report(1, "start");
 }

@@ -102,6 +102,7 @@ static void test_store_status(void)
 	report(1, "status written");
 	free_pages(status, PAGE_SIZE * 2);
 	report_prefix_pop();
+	smp_cpu_stop(1);
 
 	report_prefix_pop();
 }

@@ -130,9 +131,8 @@ static void test_ecall(void)
 
 	report_prefix_push("ecall");
 	testflag = 0;
-	smp_cpu_destroy(1);
 
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 	wait_for_flag();
 	testflag = 0;
 	sigp(1, SIGP_EXTERNAL_CALL, 0, NULL);

@@ -165,9 +165,8 @@ static void test_emcall(void)
 
 	report_prefix_push("emcall");
 	testflag = 0;
-	smp_cpu_destroy(1);
 
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 	wait_for_flag();
 	testflag = 0;
 	sigp(1, SIGP_EMERGENCY_SIGNAL, 0, NULL);

@@ -185,7 +184,7 @@ static void test_reset_initial(void)
 	psw.addr = (unsigned long)test_func;
 
 	report_prefix_push("reset initial");
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 
 	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
 	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);

@@ -216,7 +215,7 @@ static void test_reset(void)
 	psw.addr = (unsigned long)test_func;
 
 	report_prefix_push("cpu reset");
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 
 	sigp_retry(1, SIGP_CPU_RESET, 0, NULL);
 	report(smp_cpu_stopped(1), "cpu stopped");

@@ -225,6 +224,7 @@ static void test_reset(void)
 
 int main(void)
 {
+	struct psw psw;
 	report_prefix_push("smp");
 
 	if (smp_query_num_cpus() == 1) {

@@ -232,6 +232,12 @@ int main(void)
 		goto done;
 	}
 
+	/* Setting up the cpu to give it a stack and lowcore */
+	psw.mask = extract_psw_mask();
+	psw.addr = (unsigned long)cpu_loop;
+	smp_cpu_setup(1, psw);
+	smp_cpu_stop(1);
+
 	test_start();
 	test_stop();
 	test_stop_store_status();

@@ -240,6 +246,7 @@ int main(void)
 	test_emcall();
 	test_reset();
 	test_reset_initial();
+	smp_cpu_destroy(1);
 
 done:
 	report_prefix_pop();

Signature · 1 line

2.20.1

Janosch Frank

author

2020-01-17 10:46 UTC #4 lore raw

PATCH v3 3/9 s390x: Add cpu id to interrupt error prints

It's good to know which cpu broke the test.

---
 lib/s390x/interrupt.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

lib/s390x/interrupt.c +10 ~~-10~~

index 05f30be..773752a 100644
@@ -107,8 +107,8 @@ static void fixup_pgm_int(void)
 void handle_pgm_int(void)
 {
 	if (!pgm_int_expected)
-		report_abort("Unexpected program interrupt: %d at %#lx, ilen %d\n",
-			     lc->pgm_int_code, lc->pgm_old_psw.addr,
+		report_abort("Unexpected program interrupt: %d on cpu %d at %#lx, ilen %d\n",
+			     lc->pgm_int_code, stap(), lc->pgm_old_psw.addr,
 			     lc->pgm_int_id);
 
 	pgm_int_expected = false;

@@ -119,8 +119,8 @@ void handle_ext_int(void)
 {
 	if (!ext_int_expected &&
 	    lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
-		report_abort("Unexpected external call interrupt (code %#x): at %#lx",
-			     lc->ext_int_code, lc->ext_old_psw.addr);
+		report_abort("Unexpected external call interrupt (code %#x): on cpu %d at %#lx",
+			     stap(), lc->ext_int_code, lc->ext_old_psw.addr);
 		return;
 	}

@@ -137,18 +137,18 @@ void handle_ext_int(void)
 
 void handle_mcck_int(void)
 {
-	report_abort("Unexpected machine check interrupt: at %#lx",
-		     lc->mcck_old_psw.addr);
+	report_abort("Unexpected machine check interrupt: on cpu %d at %#lx",
+		     stap(), lc->mcck_old_psw.addr);
 }
 
 void handle_io_int(void)
 {
-	report_abort("Unexpected io interrupt: at %#lx",
-		     lc->io_old_psw.addr);
+	report_abort("Unexpected io interrupt: on cpu %d at %#lx",
+		     stap(), lc->io_old_psw.addr);
 }
 
 void handle_svc_int(void)
 {
-	report_abort("Unexpected supervisor call interrupt: at %#lx",
-		     lc->svc_old_psw.addr);
+	report_abort("Unexpected supervisor call interrupt: on cpu %d at %#lx",
+		     stap(), lc->svc_old_psw.addr);
 }

Signature · 1 line

2.20.1

Janosch Frank

author

2020-01-17 10:47 UTC #5 lore raw

PATCH v3 4/9 s390x: smp: Rework cpu start and active tracking

The architecture specifies that processing sigp orders may be asynchronous, and this is indeed the case on some hypervisors, so we need to wait until the cpu runs before we return from the setup/start function.

As there was a lot of duplicate code, a common function for cpu restarts has been introduced.

In reply to David Hildenbrand

---
 lib/s390x/smp.c | 50 ++++++++++++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 21 deletions(-)

lib/s390x/smp.c +29 ~~-21~~

index f57f420..84e681d 100644
@@ -104,35 +104,46 @@ int smp_cpu_stop_store_status(uint16_t addr)
 	return rc;
 }
 
+static int smp_cpu_restart_nolock(uint16_t addr, struct psw *psw)
+{
+	int rc;
+	struct cpu *cpu = smp_cpu_from_addr(addr);
+
+	if (!cpu)
+		return -1;
+	if (psw) {
+		cpu->lowcore->restart_new_psw.mask = psw->mask;
+		cpu->lowcore->restart_new_psw.addr = psw->addr;
+	}
+	rc = sigp(addr, SIGP_RESTART, 0, NULL);
+	if (rc)
+		return rc;
+	/*
+	 * The order has been accepted, but the actual restart may not
+	 * have been performed yet, so wait until the cpu is running.
+	 */
+	while (!smp_cpu_running(addr))
+		mb();
+	cpu->active = true;
+	return 0;
+}
+
 int smp_cpu_restart(uint16_t addr)
 {
-	int rc = -1;
-	struct cpu *cpu;
+	int rc;
 
 	spin_lock(&lock);
-	cpu = smp_cpu_from_addr(addr);
-	if (cpu) {
-		rc = sigp(addr, SIGP_RESTART, 0, NULL);
-		cpu->active = true;
-	}
+	rc = smp_cpu_restart_nolock(addr, NULL);
 	spin_unlock(&lock);
 	return rc;
 }
 
 int smp_cpu_start(uint16_t addr, struct psw psw)
 {
-	int rc = -1;
-	struct cpu *cpu;
-	struct lowcore *lc;
+	int rc;
 
 	spin_lock(&lock);
-	cpu = smp_cpu_from_addr(addr);
-	if (cpu) {
-		lc = cpu->lowcore;
-		lc->restart_new_psw.mask = psw.mask;
-		lc->restart_new_psw.addr = psw.addr;
-		rc = sigp(addr, SIGP_RESTART, 0, NULL);
-	}
+	rc = smp_cpu_restart_nolock(addr, &psw);
 	spin_unlock(&lock);
 	return rc;
 }

@@ -192,10 +203,7 @@ int smp_cpu_setup(uint16_t addr, struct psw psw)
 	lc->sw_int_crs[0] = 0x0000000000040000UL;
 
 	/* Start processing */
-	rc = sigp_retry(cpu->addr, SIGP_RESTART, 0, NULL);
-	if (!rc)
-		cpu->active = true;
-
+	smp_cpu_restart_nolock(addr, NULL);
 out:
 	spin_unlock(&lock);
 	return rc;

Signature · 1 line

2.20.1

David Hildenbrand

2020-01-20 12:06 UTC #6 lore raw

Re: [kvm-unit-tests PATCH v3 4/9] s390x: smp: Rework cpu start and active tracking

Quoted 19 lines · Janosch Frank

The architecture specifies that processing sigp orders may be asynchronous, and this is indeed the case on some hypervisors, so we need to wait until the cpu runs before we return from the setup/start function.
As there was a lot of duplicate code, a common function for cpu restarts has been introduced.
Signed-off-by Janosch Frank <[email protected]>
Reviewed-by Cornelia Huck <[email protected]>
---
 lib/s390x/smp.c | 50 ++++++++++++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 21 deletions(-)
lib/s390x/smp.c +0 -0
index f57f420..84e681d 100644

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 110

Quoted 7 lines

lib/s390x/smp.c +4 -0

@@ -104,35 +104,46 @@ int smp_cpu_stop_store_status(uint16_t addr)
 	return rc;
 }
 
+static int smp_cpu_restart_nolock(uint16_t addr, struct psw *psw)
+{
+	int rc;
+	struct cpu *cpu = smp_cpu_from_addr(addr);

I'd exchange these two (reverse christmas tree)

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 113

Quoted 3 lines

lib/s390x/smp.c +3 -0

+
+	if (!cpu)
+		return -1;

-EINVAL?

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 117

Quoted 4 lines

lib/s390x/smp.c +4 -0

+	if (psw) {
+		cpu->lowcore->restart_new_psw.mask = psw->mask;
+		cpu->lowcore->restart_new_psw.addr = psw->addr;
+	}

Does this make sense to have optional? (the other CPU will execute random crap if not set, won't it?)

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 126

Quoted 9 lines

lib/s390x/smp.c +9 -0

+	rc = sigp(addr, SIGP_RESTART, 0, NULL);
+	if (rc)
+		return rc;
+	/*
+	 * The order has been accepted, but the actual restart may not
+	 * have been performed yet, so wait until the cpu is running.
+	 */
+	while (!smp_cpu_running(addr))
+		mb();

Should you make sure to stop the CPU before issuing the restart? Otherwise you will get false positives if it is still running (but hasn't processed the RESTART yet)

Signature · 3 lines

Thanks,

David / dhildenb

Thomas Huth

2020-01-20 13:17 UTC #7 lore raw

Re: [kvm-unit-tests PATCH v3 4/9] s390x: smp: Rework cpu start and active tracking

Quoted 1 line · David Hildenbrand

On 17.01.20 11:46, Janosch Frank wrote:

[...]

Quoted 5 lines

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 113
Quoted 3 lines
lib/s390x/smp.c +3 -0
+
+	if (!cpu)
+		return -1;
-EINVAL?

-ENOERRNOHEADERINKVMUNITTESTS ;-)

Thomas

David Hildenbrand

2020-01-20 13:21 UTC #8 lore raw

Re: [kvm-unit-tests PATCH v3 4/9] s390x: smp: Rework cpu start and active tracking

Quoted 11 lines · Thomas Huth

Quoted 1 line · David Hildenbrand
On 17.01.20 11:46, Janosch Frank wrote:
[...]
Quoted 5 lines
lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 113
Quoted 3 lines
lib/s390x/smp.c +3 -0
+
+	if (!cpu)
+		return -1;
-EINVAL?
-ENOERRNOHEADERINKVMUNITTESTS ;-)

-EDAMMIT :)

Signature · 3 lines

Thanks,

David / dhildenb

Janosch Frank

author

2020-01-20 14:47 UTC #9 lore raw

Re: [kvm-unit-tests PATCH v3 4/9] s390x: smp: Rework cpu start and active tracking

Quoted 23 lines · David Hildenbrand

Quoted 22 lines · Janosch Frank
The architecture specifies that processing sigp orders may be asynchronous, and this is indeed the case on some hypervisors, so we need to wait until the cpu runs before we return from the setup/start function.
As there was a lot of duplicate code, a common function for cpu restarts has been introduced.
Signed-off-by Janosch Frank <[email protected]>
Reviewed-by Cornelia Huck <[email protected]>
---
 lib/s390x/smp.c | 50 ++++++++++++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 21 deletions(-)
lib/s390x/smp.c +0 -0
index f57f420..84e681d 100644
@@ -104,35 +104,46 @@ int smp_cpu_stop_store_status(uint16_t addr)
 	return rc;
 }
 

Quoted 6 lines

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 110
Quoted 4 lines
lib/s390x/smp.c +4 -0
+static int smp_cpu_restart_nolock(uint16_t addr, struct psw *psw)
+{
+	int rc;
+	struct cpu *cpu = smp_cpu_from_addr(addr);
I'd exchange these two (reverse christmas tree)

Christmas is over

Quoted 7 lines

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 113
Quoted 4 lines
lib/s390x/smp.c +3 -0
+
+	if (!cpu)
+		return -1;
-EINVAL?

Quoted 7 lines

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 117
Quoted 4 lines
lib/s390x/smp.c +4 -0
+	if (psw) {
+		cpu->lowcore->restart_new_psw.mask = psw->mask;
+		cpu->lowcore->restart_new_psw.addr = psw->addr;
+	}
Does this make sense to have optional? (the other CPU will execute random crap if not set, won't it?)

Well, I have restarts in the smp test and I don't want to always pass a psw if I know what the last restart psw was.
Simply restarting into test_func or wait_for_flag is certainly no problem.

Quoted 14 lines

lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 126
Quoted 10 lines
lib/s390x/smp.c +9 -0
+	rc = sigp(addr, SIGP_RESTART, 0, NULL);
+	if (rc)
+		return rc;
+	/*
+	 * The order has been accepted, but the actual restart may not
+	 * have been performed yet, so wait until the cpu is running.
+	 */
+	while (!smp_cpu_running(addr))
+		mb();
Should you make sure to stop the CPU before issuing the restart? Otherwise you will get false positives if it is still running (but hasn't processed the RESTART yet)

Good point

David Hildenbrand

2020-01-20 14:53 UTC #10 lore raw

Re: [kvm-unit-tests PATCH v3 4/9] s390x: smp: Rework cpu start and active tracking

Quoted 5 lines

Well, I have restarts in the smp test and I don't want to always pass a psw if I know what the last restart psw was.
Simply restarting into test_func or wait_for_flag is certainly no problem.
Quoted 1 line

Makes sense.

Quoted 16 lines

Quoted 5 lines
Quoted 5 lines
lib/s390x/smp.c +5 -0
+	rc = sigp(addr, SIGP_RESTART, 0, NULL);
+	if (rc)
+		return rc;
+	/*
+	 * The order has been accepted, but the actual restart may not
Quoted 8 lines
lib/s390x/smp.c int smp_cpu_stop_store_status(uint16_t addr) · line 126
Quoted 4 lines
lib/s390x/smp.c +4 -0
+	 * have been performed yet, so wait until the cpu is running.
+	 */
+	while (!smp_cpu_running(addr))
+		mb();
Should you make sure to stop the CPU before issuing the restart? Otherwise you will get false positives if it is still running (but hasn't processed the RESTART yet)
Good point

Signature · 3 lines

Thanks,

David / dhildenb

Janosch Frank

author

2020-01-17 10:47 UTC #11 lore raw

PATCH v3 5/9 s390x: smp: Wait for cpu setup to finish

We store the user provided psw address into restart new, so a psw restart does not lead us through setup again.

Also we wait on smp_cpu_setup() until the cpu has finished setup before returning. This is necessary for z/VM and LPAR where sigp is asynchronous.

---
 lib/s390x/smp.c  | 2 ++
 s390x/cstart64.S | 2 ++
 2 files changed, 4 insertions(+)

lib/s390x/smp.c +2 -0

index 84e681d..9dad146 100644
@@ -204,6 +204,8 @@ int smp_cpu_setup(uint16_t addr, struct psw psw)
 
 	/* Start processing */
 	smp_cpu_restart_nolock(addr, NULL);
+	/* Wait until the cpu has finished setup and started the provided psw */
+	while (lc->restart_new_psw.addr != psw.addr) { mb(); }
 out:
 	spin_unlock(&lock);
 	return rc;

s390x/cstart64.S +2 -0

index 86dd4c4..9af6bb3 100644
@@ -159,6 +159,8 @@ smp_cpu_setup_state:
 	xgr	%r1, %r1
 	lmg     %r0, %r15, GEN_LC_SW_INT_GRS
 	lctlg   %c0, %c0, GEN_LC_SW_INT_CRS
+	/* We should only go once through cpu setup and not for every restart */
+	stg	%r14, GEN_LC_RESTART_NEW_PSW + 8
 	br	%r14
 
 pgm_int:

Signature · 1 line

2.20.1

Cornelia Huck

Reviewed-by on v3 5/9

2020-01-20 11:04 UTC #12 lore raw

Re: [kvm-unit-tests PATCH v3 5/9] s390x: smp: Wait for cpu setup to finish

Quoted 7 lines · On Fri, 17 Jan 2020 05:46:36 -0500 Janosch Frank <[email protected]> wrote:

We store the user provided psw address into restart new, so a psw restart does not lead us through setup again.
Also we wait on smp_cpu_setup() until the cpu has finished setup before returning. This is necessary for z/VM and LPAR where sigp is asynchronous.

Quoted 6 lines

Signed-off-by Janosch Frank <[email protected]>
Reviewed-by David Hildenbrand <[email protected]>
---
 lib/s390x/smp.c  | 2 ++
 s390x/cstart64.S | 2 ++
 2 files changed, 4 insertions(+)

David Hildenbrand

2020-01-20 12:07 UTC #13 lore raw

Re: [kvm-unit-tests PATCH v3 5/9] s390x: smp: Wait for cpu setup to finish

Quoted 19 lines · Janosch Frank

We store the user provided psw address into restart new, so a psw restart does not lead us through setup again.
Also we wait on smp_cpu_setup() until the cpu has finished setup before returning. This is necessary for z/VM and LPAR where sigp is asynchronous.
Signed-off-by Janosch Frank <[email protected]>
Reviewed-by David Hildenbrand <[email protected]>
---
 lib/s390x/smp.c  | 2 ++
 s390x/cstart64.S | 2 ++
 2 files changed, 4 insertions(+)
lib/s390x/smp.c +0 -0
index 84e681d..9dad146 100644

lib/s390x/smp.c int smp_cpu_setup(uint16_t addr, struct psw psw) · line 208

Quoted 5 lines

lib/s390x/smp.c +2 -0

@@ -204,6 +204,8 @@ int smp_cpu_setup(uint16_t addr, struct psw psw)
 
 	/* Start processing */
 	smp_cpu_restart_nolock(addr, NULL);
+	/* Wait until the cpu has finished setup and started the provided psw */
+	while (lc->restart_new_psw.addr != psw.addr) { mb(); }

while (lc->restart_new_psw.addr != psw.addr)

	mb();

Signature · 3 lines

Thanks,

David / dhildenb

Janosch Frank

author

2020-01-17 10:47 UTC #14 lore raw

PATCH v3 6/9 s390x: smp: Loop if secondary cpu returns into cpu setup again

Up to now a secondary cpu could have returned from the function it was executing and ending up somewhere in cstart64.S. This was mostly circumvented by an endless loop in the function that it executed.

Let's add a loop to the end of the cpu setup, so we don't have to rely on added loops in the tests.

---
 s390x/cstart64.S | 2 ++
 1 file changed, 2 insertions(+)

s390x/cstart64.S +2 -0

index 9af6bb3..5fd8d2f 100644
@@ -162,6 +162,8 @@ smp_cpu_setup_state:
 	/* We should only go once through cpu setup and not for every restart */
 	stg	%r14, GEN_LC_RESTART_NEW_PSW + 8
 	br	%r14
+	/* If the function returns, just loop here */
+0:	j	0
 
 pgm_int:
 	SAVE_REGS

Signature · 1 line

2.20.1

Cornelia Huck

2020-01-20 11:27 UTC #15 lore raw

Re: [kvm-unit-tests PATCH v3 6/9] s390x: smp: Loop if secondary cpu returns into cpu setup again

Quoted 17 lines · On Fri, 17 Jan 2020 05:46:37 -0500 Janosch Frank <[email protected]> wrote:

Up to now a secondary cpu could have returned from the function it was executing and ending up somewhere in cstart64.S. This was mostly circumvented by an endless loop in the function that it executed.
Let's add a loop to the end of the cpu setup, so we don't have to rely on added loops in the tests.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/cstart64.S | 2 ++
 1 file changed, 2 insertions(+)
s390x/cstart64.S +0 -0
index 9af6bb3..5fd8d2f 100644

s390x/cstart64.S smp_cpu_setup_state: · line 166

Quoted 5 lines

s390x/cstart64.S +2 -0

@@ -162,6 +162,8 @@ smp_cpu_setup_state:
 	/* We should only go once through cpu setup and not for every restart */
 	stg	%r14, GEN_LC_RESTART_NEW_PSW + 8
 	br	%r14
+	/* If the function returns, just loop here */
+0:	j	0

Would it make sense to e.g. load a disabled wait psw instead? Or does that mess things up elsewhere?

Quoted 3 lines

s390x/cstart64.S +0 -0
 pgm_int:
 	SAVE_REGS

David Hildenbrand

2020-01-20 12:08 UTC #16 lore raw

Re: [kvm-unit-tests PATCH v3 6/9] s390x: smp: Loop if secondary cpu returns into cpu setup again

Quoted 15 lines · Cornelia Huck

Quoted 12 lines · On Fri, 17 Jan 2020 05:46:37 -0500 Janosch Frank <[email protected]> wrote:
Up to now a secondary cpu could have returned from the function it was executing and ending up somewhere in cstart64.S. This was mostly circumvented by an endless loop in the function that it executed.
Let's add a loop to the end of the cpu setup, so we don't have to rely on added loops in the tests.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/cstart64.S | 2 ++
 1 file changed, 2 insertions(+)

Quoted 13 lines

s390x/cstart64.S smp_cpu_setup_state: · line 166
Quoted 10 lines
s390x/cstart64.S +2 -0
index 9af6bb3..5fd8d2f 100644
@@ -162,6 +162,8 @@ smp_cpu_setup_state:
 	/* We should only go once through cpu setup and not for every restart */
 	stg	%r14, GEN_LC_RESTART_NEW_PSW + 8
 	br	%r14
+	/* If the function returns, just loop here */
+0:	j	0
Would it make sense to e.g. load a disabled wait psw instead? Or does that mess things up elsewhere?

I think we can keep it like that for now (simpler than loading a PSW). Overall, I don't care about burning CPU cycles here :)

Signature · 3 lines

Thanks,

David / dhildenb

Janosch Frank

author

2020-01-17 10:47 UTC #17 lore raw

PATCH v3 7/9 s390x: smp: Remove unneeded cpu loops

Now that we have a loop which is executed after we return from the main function of a secondary cpu, we can remove the surplus loops.

---
 s390x/smp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

s390x/smp.c +1 -7

index 555ed72..c12a3db 100644
@@ -29,15 +29,9 @@ static void wait_for_flag(void)
 	}
 }
 
-static void cpu_loop(void)
-{
-	for (;;) {}
-}
-
 static void test_func(void)
 {
 	testflag = 1;
-	cpu_loop();
 }
 
 static void test_start(void)

@@ -234,7 +228,7 @@ int main(void)
 
 	/* Setting up the cpu to give it a stack and lowcore */
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)cpu_loop;
+	psw.addr = (unsigned long)test_func;
 	smp_cpu_setup(1, psw);
 	smp_cpu_stop(1);

Signature · 1 line

2.20.1

Cornelia Huck

2020-01-20 11:30 UTC #18 lore raw

Re: [kvm-unit-tests PATCH v3 7/9] s390x: smp: Remove unneeded cpu loops

Quoted 29 lines · On Fri, 17 Jan 2020 05:46:38 -0500 Janosch Frank <[email protected]> wrote:

Now that we have a loop which is executed after we return from the main function of a secondary cpu, we can remove the surplus loops.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
s390x/smp.c +0 -6
index 555ed72..c12a3db 100644
@@ -29,15 +29,9 @@ static void wait_for_flag(void)
 	}
 }
 
-static void cpu_loop(void)
-{
-	for (;;) {}
-}
-
 static void test_func(void)
 {
 	testflag = 1;
-	cpu_loop();
 }
 
 static void test_start(void)

s390x/smp.c int main(void) · line 231

Quoted 5 lines

s390x/smp.c +1 -1

@@ -234,7 +228,7 @@ int main(void)
 
 	/* Setting up the cpu to give it a stack and lowcore */
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)cpu_loop;
+	psw.addr = (unsigned long)test_func;

Before, you did not set testflag here... intended change?

Quoted 3 lines

s390x/smp.c +0 -0

 	smp_cpu_setup(1, psw);
 	smp_cpu_stop(1);

Janosch Frank

author

2020-01-20 14:42 UTC #19 lore raw

Re: [kvm-unit-tests PATCH v3 7/9] s390x: smp: Remove unneeded cpu loops

Quoted 33 lines · Cornelia Huck

Quoted 30 lines · On Fri, 17 Jan 2020 05:46:38 -0500 Janosch Frank <[email protected]> wrote:
Now that we have a loop which is executed after we return from the main function of a secondary cpu, we can remove the surplus loops.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
s390x/smp.c +0 -6
index 555ed72..c12a3db 100644
@@ -29,15 +29,9 @@ static void wait_for_flag(void)
 	}
 }
 
-static void cpu_loop(void)
-{
-	for (;;) {}
-}
-
 static void test_func(void)
 {
 	testflag = 1;
-	cpu_loop();
 }
 
 static void test_start(void)
@@ -234,7 +228,7 @@ int main(void)
 

Quoted 6 lines

s390x/smp.c int main(void) · line 231
Quoted 4 lines
s390x/smp.c +1 -1
 	/* Setting up the cpu to give it a stack and lowcore */
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)cpu_loop;
+	psw.addr = (unsigned long)test_func;
Before, you did not set testflag here... intended change?

Yes
It is set to 0 before the first test, so it shouldn't matter.

Quoted 5 lines

Quoted 4 lines
s390x/smp.c +0 -0
 	smp_cpu_setup(1, psw);
 	smp_cpu_stop(1);
 

Cornelia Huck

2020-01-20 16:11 UTC #20 lore raw

Re: [kvm-unit-tests PATCH v3 7/9] s390x: smp: Remove unneeded cpu loops

Quoted 41 lines · On Mon, 20 Jan 2020 15:41:52 +0100 Janosch Frank <[email protected]> wrote:

Quoted 33 lines · Cornelia Huck
Quoted 30 lines · On Fri, 17 Jan 2020 05:46:38 -0500 Janosch Frank <[email protected]> wrote:
Now that we have a loop which is executed after we return from the main function of a secondary cpu, we can remove the surplus loops.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
s390x/smp.c +0 -6
index 555ed72..c12a3db 100644
@@ -29,15 +29,9 @@ static void wait_for_flag(void)
 	}
 }
 
-static void cpu_loop(void)
-{
-	for (;;) {}
-}
-
 static void test_func(void)
 {
 	testflag = 1;
-	cpu_loop();
 }
 
 static void test_start(void)
@@ -234,7 +228,7 @@ int main(void)
 
Quoted 6 lines
s390x/smp.c int main(void) · line 231
Quoted 4 lines
s390x/smp.c +1 -1
 	/* Setting up the cpu to give it a stack and lowcore */
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)cpu_loop;
+	psw.addr = (unsigned long)test_func;  
Before, you did not set testflag here... intended change?

Quoted 2 lines

Yes
It is set to 0 before the first test, so it shouldn't matter.

Hm... I got a bit lost in all those changes, so I checked your branch on github, and I don't see it being set to 0 before test_start() is called?

Quoted 8 lines

Quoted 6 lines
Quoted 5 lines
s390x/smp.c +0 -0
 	smp_cpu_setup(1, psw);
 	smp_cpu_stop(1);
 

Janosch Frank

author

2020-01-21 12:46 UTC #21 lore raw

Re: [kvm-unit-tests PATCH v3 7/9] s390x: smp: Remove unneeded cpu loops

Quoted 44 lines · Cornelia Huck

Quoted 41 lines · On Mon, 20 Jan 2020 15:41:52 +0100 Janosch Frank <[email protected]> wrote:
Quoted 39 lines · Cornelia Huck
Quoted 29 lines · On Fri, 17 Jan 2020 05:46:38 -0500 Janosch Frank <[email protected]> wrote:
Now that we have a loop which is executed after we return from the main function of a secondary cpu, we can remove the surplus loops.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
s390x/smp.c +0 -6
index 555ed72..c12a3db 100644
@@ -29,15 +29,9 @@ static void wait_for_flag(void)
 	}
 }
 
-static void cpu_loop(void)
-{
-	for (;;) {}
-}
-
 static void test_func(void)
 {
 	testflag = 1;
-	cpu_loop();
 }
 
 static void test_start(void)
s390x/smp.c int main(void) · line 231
Quoted 5 lines
s390x/smp.c +1 -1
@@ -234,7 +228,7 @@ int main(void)
 
 	/* Setting up the cpu to give it a stack and lowcore */
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)cpu_loop;
+	psw.addr = (unsigned long)test_func;  
Before, you did not set testflag here... intended change?

Quoted 6 lines

Quoted 2 lines
Yes
It is set to 0 before the first test, so it shouldn't matter.
Hm... I got a bit lost in all those changes, so I checked your branch on github, and I don't see it being set to 0 before test_start() is called?

Well, that's because test_start doesn't care about the flag. ecall and emcall are the first users, and they set it to 0 before using it.

Quoted 10 lines

Quoted 9 lines
Quoted 7 lines
Quoted 6 lines
s390x/smp.c +0 -0
 	smp_cpu_setup(1, psw);
 	smp_cpu_stop(1);
 

Cornelia Huck

2020-01-21 12:59 UTC #22 lore raw

Re: [kvm-unit-tests PATCH v3 7/9] s390x: smp: Remove unneeded cpu loops

Quoted 45 lines · On Tue, 21 Jan 2020 13:46:51 +0100 Janosch Frank <[email protected]> wrote:

Quoted 44 lines · Cornelia Huck
Quoted 41 lines · On Mon, 20 Jan 2020 15:41:52 +0100 Janosch Frank <[email protected]> wrote:
Quoted 39 lines · Cornelia Huck
Quoted 29 lines · On Fri, 17 Jan 2020 05:46:38 -0500 Janosch Frank <[email protected]> wrote:
Now that we have a loop which is executed after we return from the main function of a secondary cpu, we can remove the surplus loops.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
s390x/smp.c +0 -6
index 555ed72..c12a3db 100644
@@ -29,15 +29,9 @@ static void wait_for_flag(void)
 	}
 }
 
-static void cpu_loop(void)
-{
-	for (;;) {}
-}
-
 static void test_func(void)
 {
 	testflag = 1;
-	cpu_loop();
 }
 
 static void test_start(void)
s390x/smp.c int main(void) · line 231
Quoted 5 lines
s390x/smp.c +1 -1
@@ -234,7 +228,7 @@ int main(void)
 
 	/* Setting up the cpu to give it a stack and lowcore */
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)cpu_loop;
+	psw.addr = (unsigned long)test_func;    
Before, you did not set testflag here... intended change?

Quoted 8 lines

Quoted 6 lines
Quoted 2 lines
Yes
It is set to 0 before the first test, so it shouldn't matter.
Hm... I got a bit lost in all those changes, so I checked your branch on github, and I don't see it being set to 0 before test_start() is called?
Well, that's because test_start doesn't care about the flag.

But I see a wait_for_flag() in there? What am I missing?

Quoted 14 lines

ecall and emcall are the first users, and they set it to 0 before using it.
Quoted 10 lines
Quoted 9 lines
Quoted 7 lines
Quoted 6 lines
s390x/smp.c +0 -0
 	smp_cpu_setup(1, psw);
 	smp_cpu_stop(1);
 

Janosch Frank

author

2020-01-21 13:08 UTC #23 lore raw

Re: [kvm-unit-tests PATCH v3 7/9] s390x: smp: Remove unneeded cpu loops

Quoted 51 lines · Cornelia Huck

Quoted 48 lines · On Tue, 21 Jan 2020 13:46:51 +0100 Janosch Frank <[email protected]> wrote:
Quoted 47 lines · Cornelia Huck
Quoted 43 lines · On Mon, 20 Jan 2020 15:41:52 +0100 Janosch Frank <[email protected]> wrote:
Quoted 33 lines · Cornelia Huck
Quoted 30 lines · On Fri, 17 Jan 2020 05:46:38 -0500 Janosch Frank <[email protected]> wrote:
Now that we have a loop which is executed after we return from the main function of a secondary cpu, we can remove the surplus loops.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
s390x/smp.c +0 -6
index 555ed72..c12a3db 100644
@@ -29,15 +29,9 @@ static void wait_for_flag(void)
 	}
 }
 
-static void cpu_loop(void)
-{
-	for (;;) {}
-}
-
 static void test_func(void)
 {
 	testflag = 1;
-	cpu_loop();
 }
 
 static void test_start(void)
@@ -234,7 +228,7 @@ int main(void)
 
Quoted 6 lines
s390x/smp.c int main(void) · line 231
Quoted 4 lines
s390x/smp.c +1 -1
 	/* Setting up the cpu to give it a stack and lowcore */
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)cpu_loop;
+	psw.addr = (unsigned long)test_func;    
Before, you did not set testflag here... intended change?
Yes
It is set to 0 before the first test, so it shouldn't matter.

Quoted 9 lines

Quoted 5 lines
Quoted 3 lines
Hm... I got a bit lost in all those changes, so I checked your branch on github, and I don't see it being set to 0 before test_start() is called?
Well, that's because test_start doesn't care about the flag.
But I see a wait_for_flag() in there? What am I missing?
Quoted 1 line
ecall and emcall are the first users, and they set it to 0 before using it.

Well, cpu #1 will update tesflag to 1 in ecall() and emcall()

Quoted 14 lines

Quoted 13 lines
Quoted 11 lines
Quoted 10 lines
Quoted 8 lines
Quoted 7 lines
s390x/smp.c +0 -0
 	smp_cpu_setup(1, psw);
 	smp_cpu_stop(1);
 

Janosch Frank

author

2020-01-17 10:47 UTC #24 lore raw

PATCH v3 8/9 s390x: smp: Test all CRs on initial reset

All CRs are set to 0 and CRs 0 and 14 are set to pre-defined values, so we also need to test 1-13 and 15 for 0.

And while we're at it, let's also set some values to cr 1, 7 and 13, so we can actually be sure that they will be zeroed.

---
 s390x/smp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

s390x/smp.c +17 -1

index c12a3db..1385488 100644
@@ -169,16 +169,30 @@ static void test_emcall(void)
 	report_prefix_pop();
 }
 
+/* Used to dirty registers of cpu #1 before it is reset */
+static void test_func_initial(void)
+{
+	lctlg(1, 0x42000UL);
+	lctlg(7, 0x43000UL);
+	lctlg(13, 0x44000UL);
+	mb();
+	testflag = 1;
+}
+
 static void test_reset_initial(void)
 {
 	struct cpu_status *status = alloc_pages(0);
+	uint64_t nullp[12] = {};
 	struct psw psw;
 
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)test_func;
+	psw.addr = (unsigned long)test_func_initial;
 
 	report_prefix_push("reset initial");
+	testflag = 0;
+	mb();
 	smp_cpu_start(1, psw);
+	wait_for_flag();
 
 	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
 	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);

@@ -189,6 +203,8 @@ static void test_reset_initial(void)
 	report(!status->fpc, "fpc");
 	report(!status->cputm, "cpu timer");
 	report(!status->todpr, "todpr");
+	report(!memcmp(&status->crs[1], nullp, sizeof(status->crs[1]) * 12), "cr1-13 == 0");
+	report(status->crs[15] == 0, "cr15 == 0");
 	report_prefix_pop();
 
 	report_prefix_push("initialized");

Signature · 1 line

2.20.1

Cornelia Huck

Reviewed-by on v3 8/9

2020-01-20 11:44 UTC #25 lore raw

Re: [kvm-unit-tests PATCH v3 8/9] s390x: smp: Test all CRs on initial reset

Quoted 10 lines · On Fri, 17 Jan 2020 05:46:39 -0500 Janosch Frank <[email protected]> wrote:

All CRs are set to 0 and CRs 0 and 14 are set to pre-defined values, so we also need to test 1-13 and 15 for 0.
And while we're at it, let's also set some values to cr 1, 7 and 13, so we can actually be sure that they will be zeroed.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

David Hildenbrand

Reviewed-by on v3 8/9

2020-01-20 12:10 UTC #26 lore raw

Re: [kvm-unit-tests PATCH v3 8/9] s390x: smp: Test all CRs on initial reset

Quoted 32 lines · Janosch Frank

All CRs are set to 0 and CRs 0 and 14 are set to pre-defined values, so we also need to test 1-13 and 15 for 0.
And while we're at it, let's also set some values to cr 1, 7 and 13, so we can actually be sure that they will be zeroed.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)
s390x/smp.c +10 -0
index c12a3db..1385488 100644
@@ -169,16 +169,30 @@ static void test_emcall(void)
 	report_prefix_pop();
 }
 
+/* Used to dirty registers of cpu #1 before it is reset */
+static void test_func_initial(void)
+{
+	lctlg(1, 0x42000UL);
+	lctlg(7, 0x43000UL);
+	lctlg(13, 0x44000UL);
+	mb();
+	testflag = 1;
+}
+
 static void test_reset_initial(void)
 {
 	struct cpu_status *status = alloc_pages(0);

s390x/smp.c static void test_emcall(void) · line 193

Quoted 10 lines

s390x/smp.c +4 -1

+	uint64_t nullp[12] = {};
 	struct psw psw;
 
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)test_func;
+	psw.addr = (unsigned long)test_func_initial;
 
 	report_prefix_push("reset initial");
+	testflag = 0;
+	mb();

maybe use a set_flag() function like

mb();
testflag = val;
mb();

and use it everywhere you set the flag? (e.g., in test_func_initial())

Apart from that

Quoted 15 lines

s390x/smp.c +3 -0

 	smp_cpu_start(1, psw);
+	wait_for_flag();
 
 	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
 	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);

@@ -189,6 +203,8 @@ static void test_reset_initial(void)
 	report(!status->fpc, "fpc");
 	report(!status->cputm, "cpu timer");
 	report(!status->todpr, "todpr");
+	report(!memcmp(&status->crs[1], nullp, sizeof(status->crs[1]) * 12), "cr1-13 == 0");
+	report(status->crs[15] == 0, "cr15 == 0");
 	report_prefix_pop();
 
 	report_prefix_push("initialized");

Signature · 3 lines

Thanks,

David / dhildenb

Janosch Frank

author

2020-01-20 14:49 UTC #27 lore raw

Re: [kvm-unit-tests PATCH v3 8/9] s390x: smp: Test all CRs on initial reset

Quoted 46 lines · David Hildenbrand

Quoted 32 lines · Janosch Frank
All CRs are set to 0 and CRs 0 and 14 are set to pre-defined values, so we also need to test 1-13 and 15 for 0.
And while we're at it, let's also set some values to cr 1, 7 and 13, so we can actually be sure that they will be zeroed.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)
s390x/smp.c +10 -0
index c12a3db..1385488 100644
@@ -169,16 +169,30 @@ static void test_emcall(void)
 	report_prefix_pop();
 }
 
+/* Used to dirty registers of cpu #1 before it is reset */
+static void test_func_initial(void)
+{
+	lctlg(1, 0x42000UL);
+	lctlg(7, 0x43000UL);
+	lctlg(13, 0x44000UL);
+	mb();
+	testflag = 1;
+}
+
 static void test_reset_initial(void)
 {
 	struct cpu_status *status = alloc_pages(0);
s390x/smp.c static void test_emcall(void) · line 193
Quoted 10 lines
s390x/smp.c +4 -1
+	uint64_t nullp[12] = {};
 	struct psw psw;
 
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)test_func;
+	psw.addr = (unsigned long)test_func_initial;
 
 	report_prefix_push("reset initial");
+	testflag = 0;
+	mb();
maybe use a set_flag() function like

Quoted 5 lines

mb();
testflag = val;
mb();
and use it everywhere you set the flag? (e.g., in test_func_initial())

Hmm, so basically a set_test_flag() function in a new patch :) Ok, I'll have a look.

Quoted 22 lines

Apart from that

Quoted 15 lines

s390x/smp.c +3 -0

 	smp_cpu_start(1, psw);
+	wait_for_flag();
 
 	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
 	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);

@@ -189,6 +203,8 @@ static void test_reset_initial(void)
 	report(!status->fpc, "fpc");
 	report(!status->cputm, "cpu timer");
 	report(!status->todpr, "todpr");
+	report(!memcmp(&status->crs[1], nullp, sizeof(status->crs[1]) * 12), "cr1-13 == 0");
+	report(status->crs[15] == 0, "cr15 == 0");
 	report_prefix_pop();
 
 	report_prefix_push("initialized");

David Hildenbrand

2020-01-20 14:53 UTC #28 lore raw

Re: [kvm-unit-tests PATCH v3 8/9] s390x: smp: Test all CRs on initial reset

Quoted 47 lines · Janosch Frank

Quoted 46 lines · David Hildenbrand
Quoted 32 lines · Janosch Frank
All CRs are set to 0 and CRs 0 and 14 are set to pre-defined values, so we also need to test 1-13 and 15 for 0.
And while we're at it, let's also set some values to cr 1, 7 and 13, so we can actually be sure that they will be zeroed.
Signed-off-by Janosch Frank <[email protected]>
---
 s390x/smp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)
s390x/smp.c +10 -0
index c12a3db..1385488 100644
@@ -169,16 +169,30 @@ static void test_emcall(void)
 	report_prefix_pop();
 }
 
+/* Used to dirty registers of cpu #1 before it is reset */
+static void test_func_initial(void)
+{
+	lctlg(1, 0x42000UL);
+	lctlg(7, 0x43000UL);
+	lctlg(13, 0x44000UL);
+	mb();
+	testflag = 1;
+}
+
 static void test_reset_initial(void)
 {
 	struct cpu_status *status = alloc_pages(0);
s390x/smp.c static void test_emcall(void) · line 193
Quoted 10 lines
s390x/smp.c +4 -1
+	uint64_t nullp[12] = {};
 	struct psw psw;
 
 	psw.mask = extract_psw_mask();
-	psw.addr = (unsigned long)test_func;
+	psw.addr = (unsigned long)test_func_initial;
 
 	report_prefix_push("reset initial");
+	testflag = 0;
+	mb();
maybe use a set_flag() function like

Quoted 8 lines

Quoted 5 lines
mb();
testflag = val;
mb();
and use it everywhere you set the flag? (e.g., in test_func_initial())
Hmm, so basically a set_test_flag() function in a new patch :) Ok, I'll have a look.

Sorry that this patch set keeps exploding :)

Signature · 3 lines

Thanks,

David / dhildenb

Janosch Frank

author

2020-01-17 10:47 UTC #29 lore raw

PATCH v3 9/9 s390x: smp: Dirty fpc before initial reset test

Let's dirty the fpc, before we test if the initial reset sets it to 0.

Reviewed-by Thomas Huth <[email protected]>