[kvm-unit-tests GIT PULL 5/9] s390x: css: implementing Set CHannel Monitor

[Janosch Frank <frankja@linux.ibm.com>]

From: Pierre Morel <pmorel@linux.ibm.com>

We implement the call of the Set CHannel Monitor instruction,
starting the monitoring of the all Channel Sub System, and
initializing channel subsystem monitoring.

Initial tests report the presence of the extended measurement block
feature, and verify the error reporting of the hypervisor for SCHM.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/kvm/1615545714-13747-5-git-send-email-pmorel@linux.ibm.com/
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/css.h | 12 ++++++++++++
 s390x/css.c     | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/lib/s390x/css.h b/lib/s390x/css.h
index 7dddb422..7158423c 100644
--- a/lib/s390x/css.h
+++ b/lib/s390x/css.h
@@ -309,6 +309,7 @@ struct chsc_scsc {
 	uint8_t reserved[9];
 	struct chsc_header res;
 	uint32_t res_fmt;
+#define CSSC_EXTENDED_MEASUREMENT_BLOCK 48
 	uint64_t general_char[255];
 	uint64_t chsc_char[254];
 };
@@ -359,6 +360,17 @@ bool chsc(void *p, uint16_t code, uint16_t len);
 #define css_test_general_feature(bit) test_bit_inv(bit, chsc_scsc->general_char)
 #define css_test_chsc_feature(bit) test_bit_inv(bit, chsc_scsc->chsc_char)
 
+#define SCHM_DCTM	1 /* activate Device Connection TiMe */
+#define SCHM_MBU	2 /* activate Measurement Block Update */
+
+static inline void schm(void *mbo, unsigned int flags)
+{
+	register void *__gpr2 asm("2") = mbo;
+	register long __gpr1 asm("1") = flags;
+
+	asm("schm" : : "d" (__gpr2), "d" (__gpr1));
+}
+
 bool css_enable_mb(int sid, uint64_t mb, uint16_t mbi, uint16_t flg, bool fmt1);
 bool css_disable_mb(int schid);
 
diff --git a/s390x/css.c b/s390x/css.c
index a4778338..af68266d 100644
--- a/s390x/css.c
+++ b/s390x/css.c
@@ -141,6 +141,40 @@ static void css_init(void)
 	report(get_chsc_scsc(), "Store Channel Characteristics");
 }
 
+static void test_schm(void)
+{
+	if (css_test_general_feature(CSSC_EXTENDED_MEASUREMENT_BLOCK))
+		report_info("Extended measurement block available");
+
+	/* bits 59-63 of MB address must be 0  if MBU is defined */
+	report_prefix_push("Unaligned operand");
+	expect_pgm_int();
+	schm((void *)0x01, SCHM_MBU);
+	check_pgm_int_code(PGM_INT_CODE_OPERAND);
+	report_prefix_pop();
+
+	/* bits 36-61 of register 1 (flags) must be 0 */
+	report_prefix_push("Bad flags");
+	expect_pgm_int();
+	schm(NULL, 0xfffffffc);
+	check_pgm_int_code(PGM_INT_CODE_OPERAND);
+	report_prefix_pop();
+
+	/* SCHM is a privilege operation */
+	report_prefix_push("Privilege");
+	enter_pstate();
+	expect_pgm_int();
+	schm(NULL, SCHM_MBU);
+	check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
+	report_prefix_pop();
+
+	/* Normal operation */
+	report_prefix_push("Normal operation");
+	schm(NULL, SCHM_MBU);
+	report(1, "SCHM call without address");
+	report_prefix_pop();
+}
+
 static struct {
 	const char *name;
 	void (*func)(void);
@@ -150,6 +184,7 @@ static struct {
 	{ "enumerate (stsch)", test_enumerate },
 	{ "enable (msch)", test_enable },
 	{ "sense (ssch/tsch)", test_sense },
+	{ "measurement block (schm)", test_schm },
 	{ NULL, NULL }
 };
 
-- 
2.30.2