[kvm-unit-tests PATCH 0/2] s390x: Improve console handling

[kvm-unit-tests PATCH 0/2] s390x: Improve console handling

[Janosch Frank]

Console IO is and has been in a state of "works for me". I don't think
that will change soon since there's no need for a proper console
driver when all we want is the ability to print or read a line at a
time.

However since input is only supported on the ASCII console I was
forced to use it on the HMC. The HMC generally does not add a \r on a
\n so each line doesn't necessarily start at column 0. It's time to
finally fix that.

Also, since there are environments that only provide the line-mode
console it's time to add line-mode input to properly support them.

rfc -> v1:
	- Switched to \r\n from \n\r
	- Removed console clear
	- Added truncation logic to maintain 2k limit

Janosch Frank (2):
  lib: s390x: sclp: Add carriage return to line feed
  lib: s390x: sclp: Add line mode input handling

 lib/s390x/sclp-console.c | 193 +++++++++++++++++++++++++++++++++++----
 lib/s390x/sclp.h         |  26 +++++-
 2 files changed, 198 insertions(+), 21 deletions(-)

-- 
2.34.1

[kvm-unit-tests PATCH 1/2] lib: s390x: sclp: Add carriage return to line feed

[Janosch Frank]

Without the \r the output of the HMC ASCII console takes a lot of
additional effort to read in comparison to the line mode console.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/sclp-console.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
index 19c74e46..66572774 100644
--- a/lib/s390x/sclp-console.c
+++ b/lib/s390x/sclp-console.c
@@ -97,14 +97,31 @@ static void sclp_print_ascii(const char *str)
 {
 	int len = strlen(str);
 	WriteEventData *sccb = (void *)_sccb;
+	char *str_dest = (char *)&sccb->msg;
+	int i = 0, j = 0;
 
 	sclp_mark_busy();
 	memset(sccb, 0, sizeof(*sccb));
+
+	/*
+	 * Copy the string over and add a \r to all \n since the HMC
+	 * ASCII console requires it.
+	 */
+	for (; i < len && j < (PAGE_SIZE / 2); i++) {
+		if (str[i] == '\n') {
+			str_dest[j] = '\r';
+			j++;
+		}
+		str_dest[j] = str[i];
+		j++;
+	}
+
+	/* len has changed since we might have added \r */
+	len = j;
 	sccb->h.length = offsetof(WriteEventData, msg) + len;
 	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
 	sccb->ebh.length = sizeof(EventBufferHeader) + len;
 	sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
-	memcpy(&sccb->msg, str, len);
 
 	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
 }
-- 
2.34.1

[kvm-unit-tests PATCH 2/2] lib: s390x: sclp: Add line mode input handling

[Janosch Frank]

Time to add line-mode input so we can use input handling under LPAR if
there's no access to a ASCII console.

Line-mode IO is pretty wild and the documentation could be improved a
lot. Hence I've copied the input parsing functions from the s390-tools
zipl code.

For some reason output is a type 2 event but input is a type 1
event. This also means that the input and output structures are
different from each other.

The input can consist of multiple structures which don't contain text
data before the input text data is reached. Hence we need a bunch of
search functions to retrieve a pointer to the text data.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/sclp-console.c | 174 ++++++++++++++++++++++++++++++++++-----
 lib/s390x/sclp.h         |  26 +++++-
 2 files changed, 180 insertions(+), 20 deletions(-)

diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
index 66572774..15187874 100644
--- a/lib/s390x/sclp-console.c
+++ b/lib/s390x/sclp-console.c
@@ -85,6 +85,41 @@ static uint8_t _ascebc[256] = {
      0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
 };
 
+static const uint8_t _ebcasc[] = {
+    0x00, 0x01, 0x02, 0x03, 0x07, 0x09, 0x07, 0x7F,
+    0x07, 0x07, 0x07, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+    0x10, 0x11, 0x12, 0x13, 0x07, 0x0A, 0x08, 0x07,
+    0x18, 0x19, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
+    0x07, 0x07, 0x1C, 0x07, 0x07, 0x0A, 0x17, 0x1B,
+    0x07, 0x07, 0x07, 0x07, 0x07, 0x05, 0x06, 0x07,
+    0x07, 0x07, 0x16, 0x07, 0x07, 0x07, 0x07, 0x04,
+    0x07, 0x07, 0x07, 0x07, 0x14, 0x15, 0x07, 0x1A,
+    0x20, 0xFF, 0x83, 0x84, 0x85, 0xA0, 0x07, 0x86,
+    0x87, 0xA4, 0x5B, 0x2E, 0x3C, 0x28, 0x2B, 0x21,
+    0x26, 0x82, 0x88, 0x89, 0x8A, 0xA1, 0x8C, 0x07,
+    0x8D, 0xE1, 0x5D, 0x24, 0x2A, 0x29, 0x3B, 0x5E,
+    0x2D, 0x2F, 0x07, 0x8E, 0x07, 0x07, 0x07, 0x8F,
+    0x80, 0xA5, 0x07, 0x2C, 0x25, 0x5F, 0x3E, 0x3F,
+    0x07, 0x90, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
+    0x70, 0x60, 0x3A, 0x23, 0x40, 0x27, 0x3D, 0x22,
+    0x07, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
+    0x68, 0x69, 0xAE, 0xAF, 0x07, 0x07, 0x07, 0xF1,
+    0xF8, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
+    0x71, 0x72, 0xA6, 0xA7, 0x91, 0x07, 0x92, 0x07,
+    0xE6, 0x7E, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
+    0x79, 0x7A, 0xAD, 0xAB, 0x07, 0x07, 0x07, 0x07,
+    0x9B, 0x9C, 0x9D, 0xFA, 0x07, 0x07, 0x07, 0xAC,
+    0xAB, 0x07, 0xAA, 0x7C, 0x07, 0x07, 0x07, 0x07,
+    0x7B, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
+    0x48, 0x49, 0x07, 0x93, 0x94, 0x95, 0xA2, 0x07,
+    0x7D, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
+    0x51, 0x52, 0x07, 0x96, 0x81, 0x97, 0xA3, 0x98,
+    0x5C, 0xF6, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+    0x59, 0x5A, 0xFD, 0x07, 0x99, 0x07, 0x07, 0x07,
+    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+    0x38, 0x39, 0x07, 0x07, 0x9A, 0x07, 0x07, 0x07,
+};
+
 static char lm_buff[120];
 static unsigned char lm_buff_off;
 static struct spinlock lm_buff_lock;
@@ -225,7 +260,8 @@ static void sclp_write_event_mask(int receive_mask, int send_mask)
 
 static void sclp_console_enable_read(void)
 {
-	sclp_write_event_mask(SCLP_EVENT_MASK_MSG_ASCII, SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG);
+	sclp_write_event_mask(SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_OPCMD,
+			      SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG);
 }
 
 static void sclp_console_disable_read(void)
@@ -258,37 +294,137 @@ void sclp_print(const char *str)
 	sclp_print_lm(str);
 }
 
+static char *console_read_ascii(struct EventBufferHeader *ebh, int *len)
+{
+	struct ReadEventDataAsciiConsole *evdata = (void *)ebh;
+	const int max_event_buffer_len = SCCB_SIZE - offsetof(ReadEventDataAsciiConsole, ebh);
+	const int event_buffer_ascii_recv_header_len = offsetof(ReadEventDataAsciiConsole, data);
+
+	assert(ebh->length <= max_event_buffer_len);
+	assert(ebh->length > event_buffer_ascii_recv_header_len);
+
+	*len = ebh->length - event_buffer_ascii_recv_header_len;
+	return evdata->data;
+}
+
+
+static struct gds_vector *sclp_find_gds_vector(void *start, void *end, uint16_t id)
+{
+	struct gds_vector *v;
+
+	for (v = start; (void *)v < end; v = (void *)v + v->length)
+		if (v->gds_id == id)
+			return v;
+	return NULL;
+}
+
+static struct gds_subvector *sclp_eval_selfdeftextmsg(struct gds_subvector *sv)
+{
+	void *end;
+
+	end = (void *)sv + sv->length;
+	for (sv = sv + 1; (void *)sv < end; sv = (void *)sv + sv->length)
+		if (sv->key == 0x30)
+			return sv;
+	return NULL;
+}
+
+static struct gds_subvector *sclp_eval_textcmd(struct gds_vector *v)
+{
+	struct gds_subvector *sv;
+	void *end;
+
+	end = (void *)v + v->length;
+	for (sv = (struct gds_subvector *)(v + 1); (void *)sv < end;
+	     sv = (void *)sv + sv->length)
+		if (sv->key == GDS_KEY_SELFDEFTEXTMSG)
+			return sclp_eval_selfdeftextmsg(sv);
+	return NULL;
+}
+
+static struct gds_subvector *sclp_eval_cpmsu(struct gds_vector *v)
+{
+	void *end;
+
+	end = (void *)v + v->length;
+	for (v = v + 1; (void *)v < end; v = (void *)v + v->length)
+		if (v->gds_id == GDS_ID_TEXTCMD)
+			return sclp_eval_textcmd(v);
+	return NULL;
+}
+
+static struct gds_subvector *sclp_eval_mdsmu(struct gds_vector *v)
+{
+	v = sclp_find_gds_vector(v + 1, (void *)v + v->length, GDS_ID_CPMSU);
+	if (v)
+		return sclp_eval_cpmsu(v);
+	return NULL;
+}
+
+static char *console_read_lm(struct EventBufferHeader *ebh, int *len)
+{
+	struct gds_vector *v = (void *)ebh + sizeof(*ebh);
+	struct gds_subvector *sv;
+
+	v = sclp_find_gds_vector(v, (void *)ebh + ebh->length,
+				 GDS_ID_MDSMU);
+	if (!v)
+		return NULL;
+
+	sv = sclp_eval_mdsmu(v);
+	if (!sv)
+		return NULL;
+
+	*len = sv->length - (sizeof(*sv));
+	return (char *)(sv + 1);
+}
+
+static void ebc_to_asc(char *data, int len)
+{
+	int i;
+
+	 for (i = 0; i < len; i++)
+		 data[i] = _ebcasc[(uint8_t)data[i]];
+}
+
 static int console_refill_read_buffer(void)
 {
-	const int max_event_buffer_len = SCCB_SIZE - offsetof(ReadEventDataAsciiConsole, ebh);
-	ReadEventDataAsciiConsole *sccb = (void *)_sccb;
-	const int event_buffer_ascii_recv_header_len = sizeof(sccb->ebh) + sizeof(sccb->type);
-	int ret = -1;
+	struct SCCBHeader *sccb = (struct SCCBHeader *)_sccb;
+	struct EventBufferHeader *ebh = (void *)_sccb + sizeof(struct SCCBHeader);
+	char *data;
+	int ret = -1, len;
 
 	sclp_console_enable_read();
 
 	sclp_mark_busy();
-	memset(sccb, 0, SCCB_SIZE);
-	sccb->h.length = PAGE_SIZE;
-	sccb->h.function_code = SCLP_UNCONDITIONAL_READ;
-	sccb->h.control_mask[2] = SCLP_CM2_VARIABLE_LENGTH_RESPONSE;
+	memset(_sccb, 0, SCCB_SIZE);
+	sccb->length = PAGE_SIZE;
+	sccb->function_code = SCLP_UNCONDITIONAL_READ;
+	sccb->control_mask[2] = SCLP_CM2_VARIABLE_LENGTH_RESPONSE;
 
 	sclp_service_call(SCLP_CMD_READ_EVENT_DATA, sccb);
 
-	if (sccb->h.response_code == SCLP_RC_NO_EVENT_BUFFERS_STORED ||
-	    sccb->ebh.type != SCLP_EVENT_ASCII_CONSOLE_DATA ||
-	    sccb->type != SCLP_EVENT_ASCII_TYPE_DATA_STREAM_FOLLOWS) {
-		ret = -1;
+	if (sccb->response_code == SCLP_RC_NO_EVENT_BUFFERS_STORED)
+		goto out;
+
+	switch (ebh->type) {
+	case SCLP_EVENT_OP_CMD:
+		data = console_read_lm(ebh, &len);
+		if (data)
+			ebc_to_asc(data, len);
+		break;
+	case SCLP_EVENT_ASCII_CONSOLE_DATA:
+		data = console_read_ascii(ebh, &len);
+		break;
+	default:
 		goto out;
 	}
 
-	assert(sccb->ebh.length <= max_event_buffer_len);
-	assert(sccb->ebh.length > event_buffer_ascii_recv_header_len);
+	if (!data)
+		goto out;
 
-	read_buf_length = sccb->ebh.length - event_buffer_ascii_recv_header_len;
-
-	assert(read_buf_length <= sizeof(read_buf));
-	memcpy(read_buf, sccb->data, read_buf_length);
+	assert(len <= sizeof(read_buf));
+	memcpy(read_buf, data, len);
 
 	read_index = 0;
 	ret = 0;
diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
index 853529bf..c9bb4a71 100644
--- a/lib/s390x/sclp.h
+++ b/lib/s390x/sclp.h
@@ -225,6 +225,7 @@ typedef struct SCCB {
 } __attribute__((packed)) SCCB;
 
 /* SCLP event types */
+#define SCLP_EVENT_OP_CMD			0x01
 #define SCLP_EVENT_ASCII_CONSOLE_DATA           0x1a
 #define SCLP_EVENT_SIGNAL_QUIESCE               0x1d
 
@@ -232,6 +233,7 @@ typedef struct SCCB {
 #define SCLP_EVENT_MASK_SIGNAL_QUIESCE          0x00000008
 #define SCLP_EVENT_MASK_MSG_ASCII               0x00000040
 #define SCLP_EVENT_MASK_MSG          		0x40000000
+#define SCLP_EVENT_MASK_OPCMD          		0x80000000
 
 #define SCLP_UNCONDITIONAL_READ                 0x00
 #define SCLP_SELECTIVE_READ                     0x01
@@ -295,6 +297,23 @@ struct mdb {
 	struct mto mto;
 } __attribute__((packed));
 
+/* vector keys and ids */
+#define GDS_ID_MDSMU		0x1310
+#define GDS_ID_CPMSU		0x1212
+#define GDS_ID_TEXTCMD		0x1320
+#define GDS_KEY_SELFDEFTEXTMSG	0x31
+#define EBC_MDB			0xd4c4c240
+
+struct gds_vector {
+	uint16_t     length;
+	uint16_t     gds_id;
+} __attribute__((packed));
+
+struct gds_subvector {
+	uint8_t      length;
+	uint8_t      key;
+} __attribute__((packed));
+
 typedef struct EventBufferHeader {
 	uint16_t length;
 	uint8_t  type;
@@ -319,12 +338,17 @@ typedef struct ReadEventData {
 
 #define SCLP_EVENT_ASCII_TYPE_DATA_STREAM_FOLLOWS 0
 typedef struct ReadEventDataAsciiConsole {
-	SCCBHeader h;
 	EventBufferHeader ebh;
 	uint8_t type;
 	char data[];
 } __attribute__((packed)) ReadEventDataAsciiConsole;
 
+struct ReadEventDataLMConsole {
+	SCCBHeader h;
+	EventBufferHeader ebh;
+	struct gds_vector v[];
+};
+
 extern char _sccb[];
 void sclp_setup_int(void);
 void sclp_handle_ext(void);
-- 
2.34.1

Re: [kvm-unit-tests PATCH 2/2] lib: s390x: sclp: Add line mode input handling

[Nico Boehr]

Quoting Janosch Frank (2023-07-07 16:54:10)
> Time to add line-mode input so we can use input handling under LPAR if
> there's no access to a ASCII console.
> 
> Line-mode IO is pretty wild and the documentation could be improved a
> lot. Hence I've copied the input parsing functions from the s390-tools
> zipl code.

ZIPL is MIT and the copyright notice is not reproduced here.

NACK.

Please preserve the copyright notice or copy from a GPL-licensed project.