[kvm-unit-tests PATCH v1 0/2] s390x: Add migration test for guest TOD clock

[kvm-unit-tests PATCH v1 0/2] s390x: Add migration test for guest TOD clock

[Nico Boehr]

The guest TOD clock should be preserved on migration. Add a test to
verify that.

To reduce code duplication, move some of the time-related defined
from the sck test to the library.

Nico Boehr (2):
  lib/s390x: move TOD clock related functions to library
  s390x: add migration TOD clock test

 lib/s390x/asm/time.h  | 48 +++++++++++++++++++++++++++++++++++++++++++
 s390x/Makefile        |  1 +
 s390x/migration-sck.c | 45 ++++++++++++++++++++++++++++++++++++++++
 s390x/sck.c           | 32 -----------------------------
 s390x/unittests.cfg   |  4 ++++
 5 files changed, 98 insertions(+), 32 deletions(-)
 create mode 100644 s390x/migration-sck.c

-- 
2.36.1

[kvm-unit-tests PATCH v1 1/2] lib/s390x: move TOD clock related functions to library

[Nico Boehr]

The TOD-clock related functions can be useful for other tests beside the
sck test, hence move them to the library.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
---
 lib/s390x/asm/time.h | 48 ++++++++++++++++++++++++++++++++++++++++++++
 s390x/sck.c          | 32 -----------------------------
 2 files changed, 48 insertions(+), 32 deletions(-)

diff --git a/lib/s390x/asm/time.h b/lib/s390x/asm/time.h
index 7652a151e87a..81b57e2b4894 100644
--- a/lib/s390x/asm/time.h
+++ b/lib/s390x/asm/time.h
@@ -28,6 +28,54 @@ static inline uint64_t get_clock_ms(void)
 	return get_clock_us() / 1000;
 }
 
+static inline int sck(uint64_t *time)
+{
+	int cc;
+
+	asm volatile(
+		"	sck %[time]\n"
+		"	ipm %[cc]\n"
+		"	srl %[cc],28\n"
+		: [cc] "=d"(cc)
+		: [time] "Q"(*time)
+		: "cc"
+	);
+
+	return cc;
+}
+
+static inline int stck(uint64_t *time)
+{
+	int cc;
+
+	asm volatile(
+		"	stck %[time]\n"
+		"	ipm %[cc]\n"
+		"	srl %[cc],28\n"
+		: [cc] "=d" (cc), [time] "=Q" (*time)
+		:
+		: "cc", "memory"
+	);
+
+	return cc;
+}
+
+static inline int stckf(uint64_t *time)
+{
+	int cc;
+
+	asm volatile(
+		"	stckf %[time]\n"
+		"	ipm %[cc]\n"
+		"	srl %[cc],28\n"
+		: [cc] "=d" (cc), [time] "=Q" (*time)
+		:
+		: "cc", "memory"
+	);
+
+	return cc;
+}
+
 static inline void udelay(unsigned long us)
 {
 	unsigned long startclk = get_clock_us();
diff --git a/s390x/sck.c b/s390x/sck.c
index 88d52b74a586..dff496187602 100644
--- a/s390x/sck.c
+++ b/s390x/sck.c
@@ -12,38 +12,6 @@
 #include <asm/interrupt.h>
 #include <asm/time.h>
 
-static inline int sck(uint64_t *time)
-{
-	int cc;
-
-	asm volatile(
-		"	sck %[time]\n"
-		"	ipm %[cc]\n"
-		"	srl %[cc],28\n"
-		: [cc] "=d"(cc)
-		: [time] "Q"(*time)
-		: "cc"
-	);
-
-	return cc;
-}
-
-static inline int stck(uint64_t *time)
-{
-	int cc;
-
-	asm volatile(
-		"	stck %[time]\n"
-		"	ipm %[cc]\n"
-		"	srl %[cc],28\n"
-		: [cc] "=d" (cc), [time] "=Q" (*time)
-		:
-		: "cc", "memory"
-	);
-
-	return cc;
-}
-
 static void test_priv(void)
 {
 	uint64_t time_to_set_privileged = 0xfacef00dcafe0000,
-- 
2.36.1

[kvm-unit-tests PATCH v1 2/2] s390x: add migration TOD clock test

[Nico Boehr]

On migration, we expect the guest clock value to be preserved. Add a
test to verify this:
- advance the guest TOD by much more than we need to migrate
- migrate the guest
- get the guest TOD

After migration, assert the guest TOD value is at least the value we set
before migration.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
---
 s390x/Makefile        |  1 +
 s390x/migration-sck.c | 45 +++++++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg   |  4 ++++
 3 files changed, 50 insertions(+)
 create mode 100644 s390x/migration-sck.c

diff --git a/s390x/Makefile b/s390x/Makefile
index efd5e0c13102..be8e647bb35f 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -34,6 +34,7 @@ tests += $(TEST_DIR)/migration.elf
 tests += $(TEST_DIR)/pv-attest.elf
 tests += $(TEST_DIR)/migration-cmm.elf
 tests += $(TEST_DIR)/migration-skey.elf
+tests += $(TEST_DIR)/migration-sck.elf
 
 pv-tests += $(TEST_DIR)/pv-diags.elf
 
diff --git a/s390x/migration-sck.c b/s390x/migration-sck.c
new file mode 100644
index 000000000000..701d33f9db5a
--- /dev/null
+++ b/s390x/migration-sck.c
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * SET CLOCK migration tests
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ *  Nico Boehr <nrb@linux.ibm.com>
+ */
+
+#include <libcflat.h>
+#include <asm/time.h>
+#include <bitops.h>
+
+static void test_sck_migration(void)
+{
+	uint64_t now_before_set = 0, now_after_migration, time_to_set, time_to_advance;
+	int cc;
+
+	stckf(&now_before_set);
+
+	/* Advance the clock by a lot more than we might ever need to migrate (60s) */
+	time_to_advance = (60ULL * 1000ULL * 1000ULL << STCK_SHIFT_US);
+	time_to_set = now_before_set + time_to_advance;
+
+	cc = sck(&time_to_set);
+	report(!cc, "setting clock succeeded");
+
+	puts("Please migrate me, then press return\n");
+	(void)getchar();
+
+	cc = stckf(&now_after_migration);
+	report(!cc, "clock still set");
+
+	report(now_after_migration >= time_to_set, "TOD clock value preserved");
+}
+
+int main(void)
+{
+	report_prefix_push("migration-sck");
+
+	test_sck_migration();
+	report_prefix_pop();
+	return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index f7b1fc3dbca1..808e8a28ba96 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -185,3 +185,7 @@ groups = migration
 [migration-skey]
 file = migration-skey.elf
 groups = migration
+
+[migration-sck]
+file = migration-sck.elf
+groups = migration
-- 
2.36.1

Re: [kvm-unit-tests PATCH v1 1/2] lib/s390x: move TOD clock related functions to library

[Claudio Imbrenda]

On Fri, 26 Aug 2022 10:49:43 +0200
Nico Boehr <nrb@linux.ibm.com> wrote:

> The TOD-clock related functions can be useful for other tests beside the
> sck test, hence move them to the library.
> 
> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> ---
>  lib/s390x/asm/time.h | 48 ++++++++++++++++++++++++++++++++++++++++++++
>  s390x/sck.c          | 32 -----------------------------
>  2 files changed, 48 insertions(+), 32 deletions(-)
> 
> diff --git a/lib/s390x/asm/time.h b/lib/s390x/asm/time.h
> index 7652a151e87a..81b57e2b4894 100644
> --- a/lib/s390x/asm/time.h
> +++ b/lib/s390x/asm/time.h
> @@ -28,6 +28,54 @@ static inline uint64_t get_clock_ms(void)
>  	return get_clock_us() / 1000;
>  }
>  
> +static inline int sck(uint64_t *time)
> +{
> +	int cc;
> +
> +	asm volatile(
> +		"	sck %[time]\n"
> +		"	ipm %[cc]\n"
> +		"	srl %[cc],28\n"
> +		: [cc] "=d"(cc)
> +		: [time] "Q"(*time)
> +		: "cc"
> +	);
> +
> +	return cc;
> +}
> +
> +static inline int stck(uint64_t *time)
> +{
> +	int cc;
> +
> +	asm volatile(
> +		"	stck %[time]\n"
> +		"	ipm %[cc]\n"
> +		"	srl %[cc],28\n"
> +		: [cc] "=d" (cc), [time] "=Q" (*time)
> +		:
> +		: "cc", "memory"
> +	);
> +
> +	return cc;
> +}
> +
> +static inline int stckf(uint64_t *time)
> +{
> +	int cc;
> +
> +	asm volatile(
> +		"	stckf %[time]\n"
> +		"	ipm %[cc]\n"
> +		"	srl %[cc],28\n"
> +		: [cc] "=d" (cc), [time] "=Q" (*time)
> +		:
> +		: "cc", "memory"
> +	);
> +
> +	return cc;
> +}

please put these functions before all the other inline functions, and
then fix get_clock_us to use the wrapper instead of the (broken) inline
asm

> +
>  static inline void udelay(unsigned long us)
>  {
>  	unsigned long startclk = get_clock_us();
> diff --git a/s390x/sck.c b/s390x/sck.c
> index 88d52b74a586..dff496187602 100644
> --- a/s390x/sck.c
> +++ b/s390x/sck.c
> @@ -12,38 +12,6 @@
>  #include <asm/interrupt.h>
>  #include <asm/time.h>
>  
> -static inline int sck(uint64_t *time)
> -{
> -	int cc;
> -
> -	asm volatile(
> -		"	sck %[time]\n"
> -		"	ipm %[cc]\n"
> -		"	srl %[cc],28\n"
> -		: [cc] "=d"(cc)
> -		: [time] "Q"(*time)
> -		: "cc"
> -	);
> -
> -	return cc;
> -}
> -
> -static inline int stck(uint64_t *time)
> -{
> -	int cc;
> -
> -	asm volatile(
> -		"	stck %[time]\n"
> -		"	ipm %[cc]\n"
> -		"	srl %[cc],28\n"
> -		: [cc] "=d" (cc), [time] "=Q" (*time)
> -		:
> -		: "cc", "memory"
> -	);
> -
> -	return cc;
> -}
> -
>  static void test_priv(void)
>  {
>  	uint64_t time_to_set_privileged = 0xfacef00dcafe0000,

Re: [kvm-unit-tests PATCH v1 2/2] s390x: add migration TOD clock test

[Claudio Imbrenda]

On Fri, 26 Aug 2022 10:49:44 +0200
Nico Boehr <nrb@linux.ibm.com> wrote:

> On migration, we expect the guest clock value to be preserved. Add a
> test to verify this:
> - advance the guest TOD by much more than we need to migrate
> - migrate the guest
> - get the guest TOD
> 
> After migration, assert the guest TOD value is at least the value we set
> before migration.
> 
> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> ---
>  s390x/Makefile        |  1 +
>  s390x/migration-sck.c | 45 +++++++++++++++++++++++++++++++++++++++++++
>  s390x/unittests.cfg   |  4 ++++
>  3 files changed, 50 insertions(+)
>  create mode 100644 s390x/migration-sck.c
> 
> diff --git a/s390x/Makefile b/s390x/Makefile
> index efd5e0c13102..be8e647bb35f 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -34,6 +34,7 @@ tests += $(TEST_DIR)/migration.elf
>  tests += $(TEST_DIR)/pv-attest.elf
>  tests += $(TEST_DIR)/migration-cmm.elf
>  tests += $(TEST_DIR)/migration-skey.elf
> +tests += $(TEST_DIR)/migration-sck.elf
>  
>  pv-tests += $(TEST_DIR)/pv-diags.elf
>  
> diff --git a/s390x/migration-sck.c b/s390x/migration-sck.c
> new file mode 100644
> index 000000000000..701d33f9db5a
> --- /dev/null
> +++ b/s390x/migration-sck.c
> @@ -0,0 +1,45 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * SET CLOCK migration tests
> + *
> + * Copyright IBM Corp. 2022
> + *
> + * Authors:
> + *  Nico Boehr <nrb@linux.ibm.com>
> + */
> +
> +#include <libcflat.h>
> +#include <asm/time.h>
> +#include <bitops.h>
> +
> +static void test_sck_migration(void)
> +{
> +	uint64_t now_before_set = 0, now_after_migration, time_to_set, time_to_advance;
> +	int cc;
> +
> +	stckf(&now_before_set);
> +
> +	/* Advance the clock by a lot more than we might ever need to migrate (60s) */

maybe give an even bigger value, just to be really sure. like 600s

> +	time_to_advance = (60ULL * 1000ULL * 1000ULL << STCK_SHIFT_US);

you can do * 1000000, and you don't need ULL everywhere; use the braces
to help humans understand what's going on:

time_to_advance = (600ULL * 1000000) << STCK_SHIFT_US;

> +	time_to_set = now_before_set + time_to_advance;
> +
> +	cc = sck(&time_to_set);
> +	report(!cc, "setting clock succeeded");
> +
> +	puts("Please migrate me, then press return\n");
> +	(void)getchar();
> +
> +	cc = stckf(&now_after_migration);
> +	report(!cc, "clock still set");
> +
> +	report(now_after_migration >= time_to_set, "TOD clock value preserved");
> +}
> +
> +int main(void)
> +{
> +	report_prefix_push("migration-sck");
> +
> +	test_sck_migration();
> +	report_prefix_pop();
> +	return report_summary();
> +}
> diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
> index f7b1fc3dbca1..808e8a28ba96 100644
> --- a/s390x/unittests.cfg
> +++ b/s390x/unittests.cfg
> @@ -185,3 +185,7 @@ groups = migration
>  [migration-skey]
>  file = migration-skey.elf
>  groups = migration
> +
> +[migration-sck]
> +file = migration-sck.elf
> +groups = migration

Re: [kvm-unit-tests PATCH v1 1/2] lib/s390x: move TOD clock related functions to library

[Nico Boehr]

Quoting Claudio Imbrenda (2022-10-06 12:50:14)
[...]
> > diff --git a/lib/s390x/asm/time.h b/lib/s390x/asm/time.h
> > index 7652a151e87a..81b57e2b4894 100644
[...]
> > +static inline int sck(uint64_t *time)
[...]
> > +static inline int stck(uint64_t *time)
[...]
> > +static inline int stckf(uint64_t *time)
[...]
> 
> please put these functions before all the other inline functions, and
> then fix get_clock_us to use the wrapper instead of the (broken) inline
> asm

Yes, this makes sense, thanks.