[kvm-unit-tests,v4,08/13] s390x: Add linemode console
diff mbox series

Message ID 20190103100806.9039-9-frankja@linux.ibm.com
State New
Headers show
Series
  • 390x: Add cross hypervisor and disk boot
Related show

Commit Message

Janosch Frank Jan. 3, 2019, 10:08 a.m. UTC
z/VM isn't fond of vt220, so we need line mode when running under z/VM.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/sclp-console.c | 178 ++++++++++++++++++++++++++++++++++++++++++-----
 lib/s390x/sclp.h         |  67 ++++++++++++++++++
 2 files changed, 228 insertions(+), 17 deletions(-)

Comments

Thomas Huth Jan. 3, 2019, 1:11 p.m. UTC | #1
On 2019-01-03 11:08, Janosch Frank wrote:
> z/VM isn't fond of vt220, so we need line mode when running under z/VM.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
[...]
> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
> index 63cf609..408bbaf 100644
> --- a/lib/s390x/sclp.h
> +++ b/lib/s390x/sclp.h
> @@ -179,6 +179,7 @@ typedef struct SCCB {
>  /* SCLP event masks */
>  #define SCLP_EVENT_MASK_SIGNAL_QUIESCE          0x00000008
>  #define SCLP_EVENT_MASK_MSG_ASCII               0x00000040
> +#define SCLP_EVENT_MASK_MSG          		0x40000000
>  
>  #define SCLP_UNCONDITIONAL_READ                 0x00
>  #define SCLP_SELECTIVE_READ                     0x01
> @@ -212,6 +213,72 @@ typedef struct ReadEventData {
>      uint32_t mask;
>  } __attribute__((packed)) ReadEventData;
>  
> +#define MDBTYP_GO               0x0001
> +#define MDBTYP_MTO              0x0004
> +#define EVTYP_MSG               0x02
> +#define LNTPFLGS_CNTLTEXT       0x8000
> +#define LNTPFLGS_LABELTEXT      0x4000
> +#define LNTPFLGS_DATATEXT       0x2000
> +#define LNTPFLGS_ENDTEXT        0x1000
> +#define LNTPFLGS_PROMPTTEXT     0x0800
> +
> +typedef uint32_t sccb_mask_t;
> +
> +/* SCLP line mode console related structures. */
> +
> +struct mto {
> +	u16 length;
> +	u16 type;
> +	u16 line_type_flags;
> +	u8  alarm_control;
> +	u8  _reserved[3];
> +} __attribute__((packed));
> +
> +struct go {
> +	u16 length;
> +	u16 type;
> +	u32 domid;
> +	u8  hhmmss_time[8];
> +	u8  th_time[3];
> +	u8  reserved_0;
> +	u8  dddyyyy_date[7];
> +	u8  _reserved_1;
> +	u16 general_msg_flags;
> +	u8  _reserved_2[10];
> +	u8  originating_system_name[8];
> +	u8  job_guest_name[8];
> +} __attribute__((packed));
> +
> +struct mdb_header {
> +	u16 length;
> +	u16 type;
> +	u32 tag;
> +	u32 revision_code;
> +} __attribute__((packed));
> +
> +struct mdb {
> +	struct mdb_header header;
> +	struct go go;
> +	struct mto mto;
> +} __attribute__((packed));
> +
> +struct evbuf_header {
> +	u16	length;
> +	u8	type;
> +	u8	flags;
> +	u16	_reserved;
> +} __attribute__((packed));
> +
> +struct msg_buf {
> +	struct evbuf_header header;
> +	struct mdb mdb;
> +} __attribute__((packed));
> +
> +struct write_sccb {
> +	struct SCCBHeader header;
> +	struct msg_buf msg;
> +} __packed;
You're using "__attribute__((packed))" for all the other structs, so I'd
suggest to use that for write_sccb, too.

 Thomas
David Hildenbrand Jan. 10, 2019, 12:23 p.m. UTC | #2
On 03.01.19 11:08, Janosch Frank wrote:
> z/VM isn't fond of vt220, so we need line mode when running under z/VM.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  lib/s390x/sclp-console.c | 178 ++++++++++++++++++++++++++++++++++++++++++-----
>  lib/s390x/sclp.h         |  67 ++++++++++++++++++
>  2 files changed, 228 insertions(+), 17 deletions(-)
> 
> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
> index a5ef45f..6b30fab 100644
> --- a/lib/s390x/sclp-console.c
> +++ b/lib/s390x/sclp-console.c
> @@ -11,21 +11,167 @@
>  #include <libcflat.h>
>  #include <string.h>
>  #include <asm/page.h>
> +#include <asm/arch_def.h>
> +#include <asm/io.h>
>  #include "sclp.h"
>  
> +/*
> + * ASCII (IBM PC 437) -> EBCDIC 037
> + */
> +static uint8_t _ascebc[256] = {
> + /*00 NUL   SOH   STX   ETX   EOT   ENQ   ACK   BEL */
> +     0x00, 0x01, 0x02, 0x03, 0x37, 0x2D, 0x2E, 0x2F,
> + /*08  BS    HT    LF    VT    FF    CR    SO    SI */
> + /*              ->NL                               */
> +     0x16, 0x05, 0x15, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
> + /*10 DLE   DC1   DC2   DC3   DC4   NAK   SYN   ETB */
> +     0x10, 0x11, 0x12, 0x13, 0x3C, 0x3D, 0x32, 0x26,
> + /*18 CAN    EM   SUB   ESC    FS    GS    RS    US */
> + /*                               ->IGS ->IRS ->IUS */
> +     0x18, 0x19, 0x3F, 0x27, 0x22, 0x1D, 0x1E, 0x1F,
> + /*20  SP     !     "     #     $     %     &     ' */
> +     0x40, 0x5A, 0x7F, 0x7B, 0x5B, 0x6C, 0x50, 0x7D,
> + /*28   (     )     *     +     ,     -    .      / */
> +     0x4D, 0x5D, 0x5C, 0x4E, 0x6B, 0x60, 0x4B, 0x61,
> + /*30   0     1     2     3     4     5     6     7 */
> +     0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
> + /*38   8     9     :     ;     <     =     >     ? */
> +     0xF8, 0xF9, 0x7A, 0x5E, 0x4C, 0x7E, 0x6E, 0x6F,
> + /*40   @     A     B     C     D     E     F     G */
> +     0x7C, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7,
> + /*48   H     I     J     K     L     M     N     O */
> +     0xC8, 0xC9, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6,
> + /*50   P     Q     R     S     T     U     V     W */
> +     0xD7, 0xD8, 0xD9, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6,
> + /*58   X     Y     Z     [     \     ]     ^     _ */
> +     0xE7, 0xE8, 0xE9, 0xBA, 0xE0, 0xBB, 0xB0, 0x6D,
> + /*60   `     a     b     c     d     e     f     g */
> +     0x79, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
> + /*68   h     i     j     k     l     m     n     o */
> +     0x88, 0x89, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96,
> + /*70   p     q     r     s     t     u     v     w */
> +     0x97, 0x98, 0x99, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6,
> + /*78   x     y     z     {     |     }     ~    DL */
> +     0xA7, 0xA8, 0xA9, 0xC0, 0x4F, 0xD0, 0xA1, 0x07,
> + /*80*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*88*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*90*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*98*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*A0*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*A8*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*B0*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*B8*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*C0*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*C8*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*D0*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*D8*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*E0        sz						*/

That */ somewhat sticks out.

> +     0x3F, 0x59, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*E8*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*F0*/
> +     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
> + /*F8*/
> +     0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
> +};
> +
> +static void sclp_print_ascii(const char *str)
> +{
> +	int len = strlen(str);
> +	WriteEventData *sccb = (void *)_sccb;
> +
> +	sclp_mark_busy();
> +	memset(sccb, 0, sizeof(*sccb));
> +	sccb->h.length = sizeof(WriteEventData) + 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->data, str, len);

Soooo ... what would happen when printing more than 4000 + something
characters? (same applies to lm below)

> +
> +	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
> +}
> +
> +static void sclp_print_lm(const char *str)
> +{
> +	unsigned char *ptr, *end, ch;
> +	unsigned int count, offset, len;
> +	struct write_sccb *sccb;
> +	struct msg_buf *msg;
> +	struct mdb *mdb;
> +	struct mto *mto;
> +	struct go *go;
> +
> +	sclp_mark_busy();
> +	sccb = (struct write_sccb *) _sccb;
> +	end = (unsigned char *) sccb + 4096 - 1;

PAGE_SIZE? (char _sccb[PAGE_SIZE])

> +	memset(sccb, 0, sizeof(*sccb));
> +	ptr = (unsigned char *) &sccb->msg.mdb.mto;
> +	len = strlen(str);
> +	offset = 0;
> +	do {
> +		for (count = sizeof(*mto); offset < len; count++) {
> +			ch = str[offset++];
> +			if ((ch == 0x0a) || (ptr + count > end))
> +				break;
> +			ptr[count] = _ascebc[ch];
> +		}
> +		mto = (struct mto *) ptr;
> +		memset(mto, 0, sizeof(*mto));

Shouldn't this already be 0?

> +		mto->length = count;
> +		mto->type = 4;
> +		mto->line_type_flags = LNTPFLGS_ENDTEXT;
> +		ptr += count;
> +	} while (offset < len && ptr + sizeof(*mto) <= end);
> +	len = ptr - (unsigned char *) sccb;
> +	sccb->header.length = len - offsetof(struct write_sccb, header);
> +	msg = &sccb->msg;
> +	msg->header.type = EVTYP_MSG;
> +	msg->header.length = len - offsetof(struct write_sccb, msg.header);
> +	mdb = &msg->mdb;
> +	mdb->header.type = 1;
> +	mdb->header.tag = 0xD4C4C240;
> +	mdb->header.revision_code = 1;
> +	mdb->header.length = len - offsetof(struct write_sccb, msg.mdb.header);
> +	go = &mdb->go;
> +	go->length = sizeof(*go);
> +	go->type = 1;
> +	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
> +}
> +
> +/*
> + * SCLP needs to be initialized by setting a send and receive mask,
> + * indicating which messages the control program (we) want(s) to
> + * send/receive.
> + */
>  static void sclp_set_write_mask(void)
>  {
>  	WriteEventMask *sccb = (void *)_sccb;
>  
>  	sclp_mark_busy();
> +	memset(_sccb, 0, sizeof(*sccb));
>  	sccb->h.length = sizeof(WriteEventMask);
> -	sccb->mask_length = sizeof(unsigned int);
> -	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
> -	sccb->cp_receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
> -	sccb->send_mask = SCLP_EVENT_MASK_MSG_ASCII;
> -	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII;
> +	sccb->h.function_code = 0;

Already 0'ed out.

> +	sccb->mask_length = sizeof(sccb_mask_t);
> +
> +	/* For now we don't process sclp input. */
> +	sccb->cp_receive_mask = 0;

dito

> +	/* We send ASCII and line mode. */
> +	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG;
>  
>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
> +	assert(sccb->h.response_code == SCLP_RC_NORMAL_COMPLETION);
>  }
>  
>  void sclp_console_setup(void)
> @@ -35,16 +181,14 @@ void sclp_console_setup(void)
>  
>  void sclp_print(const char *str)
>  {
> -	int len = strlen(str);
> -	WriteEventData *sccb = (void *)_sccb;
> -
> -	sclp_mark_busy();
> -	sccb->h.length = sizeof(WriteEventData) + len;
> -	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
> -	sccb->ebh.length = sizeof(EventBufferHeader) + len;
> -	sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
> -	sccb->ebh.flags = 0;
> -	memcpy(sccb->data, str, len);
> -
> -	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
> +	/*
> +	 * z/VM advertises a vt220 console which is not functional:
> +	 * (response code 05F0, "not active because of the state of
> +	 * the machine"). Hence testing the masks would only work if
> +	 * we also use stsi data to distinguish z/VM.
> +	 *
> +	 * Let's rather print on all available consoles.
> +	 */
> +	sclp_print_ascii(str);
> +	sclp_print_lm(str);
>  }
> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
> index 63cf609..408bbaf 100644
> --- a/lib/s390x/sclp.h
> +++ b/lib/s390x/sclp.h
> @@ -179,6 +179,7 @@ typedef struct SCCB {
>  /* SCLP event masks */
>  #define SCLP_EVENT_MASK_SIGNAL_QUIESCE          0x00000008
>  #define SCLP_EVENT_MASK_MSG_ASCII               0x00000040
> +#define SCLP_EVENT_MASK_MSG          		0x40000000
>  
>  #define SCLP_UNCONDITIONAL_READ                 0x00
>  #define SCLP_SELECTIVE_READ                     0x01
> @@ -212,6 +213,72 @@ typedef struct ReadEventData {
>      uint32_t mask;
>  } __attribute__((packed)) ReadEventData;
>  
> +#define MDBTYP_GO               0x0001
> +#define MDBTYP_MTO              0x0004
> +#define EVTYP_MSG               0x02
> +#define LNTPFLGS_CNTLTEXT       0x8000
> +#define LNTPFLGS_LABELTEXT      0x4000
> +#define LNTPFLGS_DATATEXT       0x2000
> +#define LNTPFLGS_ENDTEXT        0x1000
> +#define LNTPFLGS_PROMPTTEXT     0x0800
> +
> +typedef uint32_t sccb_mask_t;
> +
> +/* SCLP line mode console related structures. */
> +
> +struct mto {
> +	u16 length;
> +	u16 type;
> +	u16 line_type_flags;
> +	u8  alarm_control;
> +	u8  _reserved[3];
> +} __attribute__((packed));
> +
> +struct go {
> +	u16 length;
> +	u16 type;
> +	u32 domid;
> +	u8  hhmmss_time[8];
> +	u8  th_time[3];
> +	u8  reserved_0;
> +	u8  dddyyyy_date[7];
> +	u8  _reserved_1;
> +	u16 general_msg_flags;
> +	u8  _reserved_2[10];
> +	u8  originating_system_name[8];
> +	u8  job_guest_name[8];
> +} __attribute__((packed));
> +
> +struct mdb_header {
> +	u16 length;
> +	u16 type;
> +	u32 tag;
> +	u32 revision_code;
> +} __attribute__((packed));
> +
> +struct mdb {
> +	struct mdb_header header;
> +	struct go go;
> +	struct mto mto;
> +} __attribute__((packed));
> +
> +struct evbuf_header {
> +	u16	length;
> +	u8	type;
> +	u8	flags;
> +	u16	_reserved;
> +} __attribute__((packed));
> +
> +struct msg_buf {
> +	struct evbuf_header header;
> +	struct mdb mdb;
> +} __attribute__((packed));
> +
> +struct write_sccb {
> +	struct SCCBHeader header;
> +	struct msg_buf msg;
> +} __packed;
> +
>  extern char _sccb[];
>  void sclp_handle_ext(void);
>  void sclp_wait_busy(void);
> 

I have to trust you on the LM specific parts ;)
Janosch Frank Jan. 10, 2019, 12:34 p.m. UTC | #3
On 10.01.19 13:23, David Hildenbrand wrote:
> On 03.01.19 11:08, Janosch Frank wrote:
>> z/VM isn't fond of vt220, so we need line mode when running under z/VM.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  lib/s390x/sclp-console.c | 178 ++++++++++++++++++++++++++++++++++++++++++-----
>>  lib/s390x/sclp.h         |  67 ++++++++++++++++++
>>  2 files changed, 228 insertions(+), 17 deletions(-)
>>
>> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
>> index a5ef45f..6b30fab 100644
>> --- a/lib/s390x/sclp-console.c
>> +++ b/lib/s390x/sclp-console.c
>> @@ -11,21 +11,167 @@
>>  #include <libcflat.h>
>>  #include <string.h>
>>  #include <asm/page.h>
>> +#include <asm/arch_def.h>
>> +#include <asm/io.h>
>>  #include "sclp.h"
>>  
[...]
>> +
>> +static void sclp_print_ascii(const char *str)
>> +{
>> +	int len = strlen(str);
>> +	WriteEventData *sccb = (void *)_sccb;
>> +
>> +	sclp_mark_busy();
>> +	memset(sccb, 0, sizeof(*sccb));
>> +	sccb->h.length = sizeof(WriteEventData) + 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->data, str, len);
> 
> Soooo ... what would happen when printing more than 4000 + something
> characters? (same applies to lm below)

I wouldn't advise on that, because you'll overwrite memory and sclp
might have a length limit. But that wasn't a problem before, was it?

Do you plan on printing the memory in one go? :-)

> 
>> +
>> +	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>> +}
>> +
>> +static void sclp_print_lm(const char *str)
>> +{
>> +	unsigned char *ptr, *end, ch;
>> +	unsigned int count, offset, len;
>> +	struct write_sccb *sccb;
>> +	struct msg_buf *msg;
>> +	struct mdb *mdb;
>> +	struct mto *mto;
>> +	struct go *go;
>> +
>> +	sclp_mark_busy();
>> +	sccb = (struct write_sccb *) _sccb;
>> +	end = (unsigned char *) sccb + 4096 - 1;
> 
> PAGE_SIZE? (char _sccb[PAGE_SIZE])
> 
>> +	memset(sccb, 0, sizeof(*sccb));
>> +	ptr = (unsigned char *) &sccb->msg.mdb.mto;
>> +	len = strlen(str);
>> +	offset = 0;
>> +	do {
>> +		for (count = sizeof(*mto); offset < len; count++) {
>> +			ch = str[offset++];
>> +			if ((ch == 0x0a) || (ptr + count > end))
>> +				break;
>> +			ptr[count] = _ascebc[ch];
>> +		}
>> +		mto = (struct mto *) ptr;
>> +		memset(mto, 0, sizeof(*mto));
> 
> Shouldn't this already be 0?

Yup

> 
>> +		mto->length = count;
>> +		mto->type = 4;
>> +		mto->line_type_flags = LNTPFLGS_ENDTEXT;
>> +		ptr += count;
>> +	} while (offset < len && ptr + sizeof(*mto) <= end);
>> +	len = ptr - (unsigned char *) sccb;
>> +	sccb->header.length = len - offsetof(struct write_sccb, header);
>> +	msg = &sccb->msg;
>> +	msg->header.type = EVTYP_MSG;
>> +	msg->header.length = len - offsetof(struct write_sccb, msg.header);
>> +	mdb = &msg->mdb;
>> +	mdb->header.type = 1;
>> +	mdb->header.tag = 0xD4C4C240;
>> +	mdb->header.revision_code = 1;
>> +	mdb->header.length = len - offsetof(struct write_sccb, msg.mdb.header);
>> +	go = &mdb->go;
>> +	go->length = sizeof(*go);
>> +	go->type = 1;
>> +	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>> +}
>> +
>> +/*
>> + * SCLP needs to be initialized by setting a send and receive mask,
>> + * indicating which messages the control program (we) want(s) to
>> + * send/receive.
>> + */
>>  static void sclp_set_write_mask(void)
>>  {
>>  	WriteEventMask *sccb = (void *)_sccb;
>>  
>>  	sclp_mark_busy();
>> +	memset(_sccb, 0, sizeof(*sccb));
>>  	sccb->h.length = sizeof(WriteEventMask);
>> -	sccb->mask_length = sizeof(unsigned int);
>> -	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>> -	sccb->cp_receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>> -	sccb->send_mask = SCLP_EVENT_MASK_MSG_ASCII;
>> -	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII;
>> +	sccb->h.function_code = 0;
> 
> Already 0'ed out.

Yes, this one is here to make absolutely clear which function we execute.

> 
>> +	sccb->mask_length = sizeof(sccb_mask_t);
>> +
>> +	/* For now we don't process sclp input. */
>> +	sccb->cp_receive_mask = 0;
> 
> dito

Same
If you want, I'll add a comment instead.

> 
>> +	/* We send ASCII and line mode. */
>> +	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG;
>>  
>>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
>> +	assert(sccb->h.response_code == SCLP_RC_NORMAL_COMPLETION);
>>  }
>>  
>>  void sclp_console_setup(void)
>> @@ -35,16 +181,14 @@ void sclp_console_setup(void)
>>  
>>  void sclp_print(const char *str)
>>  {
>> -	int len = strlen(str);
>> -	WriteEventData *sccb = (void *)_sccb;
>> -
>> -	sclp_mark_busy();
>> -	sccb->h.length = sizeof(WriteEventData) + len;
>> -	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
>> -	sccb->ebh.length = sizeof(EventBufferHeader) + len;
>> -	sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
>> -	sccb->ebh.flags = 0;
>> -	memcpy(sccb->data, str, len);
>> -
>> -	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>> +	/*
>> +	 * z/VM advertises a vt220 console which is not functional:
>> +	 * (response code 05F0, "not active because of the state of
>> +	 * the machine"). Hence testing the masks would only work if
>> +	 * we also use stsi data to distinguish z/VM.
>> +	 *
>> +	 * Let's rather print on all available consoles.
>> +	 */
>> +	sclp_print_ascii(str);
>> +	sclp_print_lm(str);
>>  }
>> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
>> index 63cf609..408bbaf 100644
>> --- a/lib/s390x/sclp.h
>> +++ b/lib/s390x/sclp.h
>> @@ -179,6 +179,7 @@ typedef struct SCCB {
>>  /* SCLP event masks */
>>  #define SCLP_EVENT_MASK_SIGNAL_QUIESCE          0x00000008
>>  #define SCLP_EVENT_MASK_MSG_ASCII               0x00000040
>> +#define SCLP_EVENT_MASK_MSG          		0x40000000
>>  
>>  #define SCLP_UNCONDITIONAL_READ                 0x00
>>  #define SCLP_SELECTIVE_READ                     0x01
>> @@ -212,6 +213,72 @@ typedef struct ReadEventData {
>>      uint32_t mask;
>>  } __attribute__((packed)) ReadEventData;
>>  
>> +#define MDBTYP_GO               0x0001
>> +#define MDBTYP_MTO              0x0004
>> +#define EVTYP_MSG               0x02
>> +#define LNTPFLGS_CNTLTEXT       0x8000
>> +#define LNTPFLGS_LABELTEXT      0x4000
>> +#define LNTPFLGS_DATATEXT       0x2000
>> +#define LNTPFLGS_ENDTEXT        0x1000
>> +#define LNTPFLGS_PROMPTTEXT     0x0800
>> +
>> +typedef uint32_t sccb_mask_t;
>> +
>> +/* SCLP line mode console related structures. */
>> +
>> +struct mto {
>> +	u16 length;
>> +	u16 type;
>> +	u16 line_type_flags;
>> +	u8  alarm_control;
>> +	u8  _reserved[3];
>> +} __attribute__((packed));
>> +
>> +struct go {
>> +	u16 length;
>> +	u16 type;
>> +	u32 domid;
>> +	u8  hhmmss_time[8];
>> +	u8  th_time[3];
>> +	u8  reserved_0;
>> +	u8  dddyyyy_date[7];
>> +	u8  _reserved_1;
>> +	u16 general_msg_flags;
>> +	u8  _reserved_2[10];
>> +	u8  originating_system_name[8];
>> +	u8  job_guest_name[8];
>> +} __attribute__((packed));
>> +
>> +struct mdb_header {
>> +	u16 length;
>> +	u16 type;
>> +	u32 tag;
>> +	u32 revision_code;
>> +} __attribute__((packed));
>> +
>> +struct mdb {
>> +	struct mdb_header header;
>> +	struct go go;
>> +	struct mto mto;
>> +} __attribute__((packed));
>> +
>> +struct evbuf_header {
>> +	u16	length;
>> +	u8	type;
>> +	u8	flags;
>> +	u16	_reserved;
>> +} __attribute__((packed));
>> +
>> +struct msg_buf {
>> +	struct evbuf_header header;
>> +	struct mdb mdb;
>> +} __attribute__((packed));
>> +
>> +struct write_sccb {
>> +	struct SCCBHeader header;
>> +	struct msg_buf msg;
>> +} __packed;
>> +
>>  extern char _sccb[];
>>  void sclp_handle_ext(void);
>>  void sclp_wait_busy(void);
>>
> 
> I have to trust you on the LM specific parts ;)
> 

I trust the ones that developed that in the kernel.
David Hildenbrand Jan. 10, 2019, 12:39 p.m. UTC | #4
On 10.01.19 13:34, Janosch Frank wrote:
> On 10.01.19 13:23, David Hildenbrand wrote:
>> On 03.01.19 11:08, Janosch Frank wrote:
>>> z/VM isn't fond of vt220, so we need line mode when running under z/VM.
>>>
>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>> ---
>>>  lib/s390x/sclp-console.c | 178 ++++++++++++++++++++++++++++++++++++++++++-----
>>>  lib/s390x/sclp.h         |  67 ++++++++++++++++++
>>>  2 files changed, 228 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
>>> index a5ef45f..6b30fab 100644
>>> --- a/lib/s390x/sclp-console.c
>>> +++ b/lib/s390x/sclp-console.c
>>> @@ -11,21 +11,167 @@
>>>  #include <libcflat.h>
>>>  #include <string.h>
>>>  #include <asm/page.h>
>>> +#include <asm/arch_def.h>
>>> +#include <asm/io.h>
>>>  #include "sclp.h"
>>>  
> [...]
>>> +
>>> +static void sclp_print_ascii(const char *str)
>>> +{
>>> +	int len = strlen(str);
>>> +	WriteEventData *sccb = (void *)_sccb;
>>> +
>>> +	sclp_mark_busy();
>>> +	memset(sccb, 0, sizeof(*sccb));
>>> +	sccb->h.length = sizeof(WriteEventData) + 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->data, str, len);
>>
>> Soooo ... what would happen when printing more than 4000 + something
>> characters? (same applies to lm below)
> 
> I wouldn't advise on that, because you'll overwrite memory and sclp
> might have a length limit. But that wasn't a problem before, was it?
> 
> Do you plan on printing the memory in one go? :-)

Won't say it won't happen when somebody debugs/develops tests and gets
strange side effects from printing. Wonder if we should simply cut it
off to the supported size.

(And yes, this is already in existing code)

>>
>>> +		mto->length = count;
>>> +		mto->type = 4;
>>> +		mto->line_type_flags = LNTPFLGS_ENDTEXT;
>>> +		ptr += count;
>>> +	} while (offset < len && ptr + sizeof(*mto) <= end);
>>> +	len = ptr - (unsigned char *) sccb;
>>> +	sccb->header.length = len - offsetof(struct write_sccb, header);
>>> +	msg = &sccb->msg;
>>> +	msg->header.type = EVTYP_MSG;
>>> +	msg->header.length = len - offsetof(struct write_sccb, msg.header);
>>> +	mdb = &msg->mdb;
>>> +	mdb->header.type = 1;
>>> +	mdb->header.tag = 0xD4C4C240;
>>> +	mdb->header.revision_code = 1;
>>> +	mdb->header.length = len - offsetof(struct write_sccb, msg.mdb.header);
>>> +	go = &mdb->go;
>>> +	go->length = sizeof(*go);
>>> +	go->type = 1;
>>> +	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>>> +}
>>> +
>>> +/*
>>> + * SCLP needs to be initialized by setting a send and receive mask,
>>> + * indicating which messages the control program (we) want(s) to
>>> + * send/receive.
>>> + */
>>>  static void sclp_set_write_mask(void)
>>>  {
>>>  	WriteEventMask *sccb = (void *)_sccb;
>>>  
>>>  	sclp_mark_busy();
>>> +	memset(_sccb, 0, sizeof(*sccb));
>>>  	sccb->h.length = sizeof(WriteEventMask);
>>> -	sccb->mask_length = sizeof(unsigned int);
>>> -	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>> -	sccb->cp_receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>> -	sccb->send_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>> -	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>> +	sccb->h.function_code = 0;
>>
>> Already 0'ed out.
> 
> Yes, this one is here to make absolutely clear which function we execute.

Wondering if this should be SCLP_FC_NORMAL_WRITE, too?

> 
>>
>>> +	sccb->mask_length = sizeof(sccb_mask_t);
>>> +
>>> +	/* For now we don't process sclp input. */
>>> +	sccb->cp_receive_mask = 0;
>>
>> dito
> 
> Same
> If you want, I'll add a comment instead.

Whatever you prefer, I guess a comment is enough.
Janosch Frank Jan. 10, 2019, 1:20 p.m. UTC | #5
On 10.01.19 13:39, David Hildenbrand wrote:
> On 10.01.19 13:34, Janosch Frank wrote:
>> On 10.01.19 13:23, David Hildenbrand wrote:
>>> On 03.01.19 11:08, Janosch Frank wrote:
>>>> z/VM isn't fond of vt220, so we need line mode when running under z/VM.
>>>>
>>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>>> ---
>>>>  lib/s390x/sclp-console.c | 178 ++++++++++++++++++++++++++++++++++++++++++-----
>>>>  lib/s390x/sclp.h         |  67 ++++++++++++++++++
>>>>  2 files changed, 228 insertions(+), 17 deletions(-)
>>>>
>>>> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
>>>> index a5ef45f..6b30fab 100644
>>>> --- a/lib/s390x/sclp-console.c
>>>> +++ b/lib/s390x/sclp-console.c
>>>> @@ -11,21 +11,167 @@
>>>>  #include <libcflat.h>
>>>>  #include <string.h>
>>>>  #include <asm/page.h>
>>>> +#include <asm/arch_def.h>
>>>> +#include <asm/io.h>
>>>>  #include "sclp.h"
>>>>  
>> [...]
>>>> +
>>>> +static void sclp_print_ascii(const char *str)
>>>> +{
>>>> +	int len = strlen(str);
>>>> +	WriteEventData *sccb = (void *)_sccb;
>>>> +
>>>> +	sclp_mark_busy();
>>>> +	memset(sccb, 0, sizeof(*sccb));
>>>> +	sccb->h.length = sizeof(WriteEventData) + 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->data, str, len);
>>>
>>> Soooo ... what would happen when printing more than 4000 + something
>>> characters? (same applies to lm below)
>>
>> I wouldn't advise on that, because you'll overwrite memory and sclp
>> might have a length limit. But that wasn't a problem before, was it?
>>
>> Do you plan on printing the memory in one go? :-)
> 
> Won't say it won't happen when somebody debugs/develops tests and gets
> strange side effects from printing. Wonder if we should simply cut it
> off to the supported size.
> 
> (And yes, this is already in existing code)

As the print functions have different max lengths for user data I'd
print a warning and return after 2KB in sclp_print. Anything against that?

It's simple and 2KB ought to be enough for everyone (TM) and nobody
keeps you from calling print multiple times instead.


if (strlen(str) > (1 << 11)) {
		sclp_print_ascii("Warning: Printing is limited to 2KB of data.");
		sclp_print_lm("Warning: Printing is limited to 2KB of data.");
		return;
	}

> 
>>>
>>>> +		mto->length = count;
>>>> +		mto->type = 4;
>>>> +		mto->line_type_flags = LNTPFLGS_ENDTEXT;
>>>> +		ptr += count;
>>>> +	} while (offset < len && ptr + sizeof(*mto) <= end);
>>>> +	len = ptr - (unsigned char *) sccb;
>>>> +	sccb->header.length = len - offsetof(struct write_sccb, header);
>>>> +	msg = &sccb->msg;
>>>> +	msg->header.type = EVTYP_MSG;
>>>> +	msg->header.length = len - offsetof(struct write_sccb, msg.header);
>>>> +	mdb = &msg->mdb;
>>>> +	mdb->header.type = 1;
>>>> +	mdb->header.tag = 0xD4C4C240;
>>>> +	mdb->header.revision_code = 1;
>>>> +	mdb->header.length = len - offsetof(struct write_sccb, msg.mdb.header);
>>>> +	go = &mdb->go;
>>>> +	go->length = sizeof(*go);
>>>> +	go->type = 1;
>>>> +	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>>>> +}
>>>> +
>>>> +/*
>>>> + * SCLP needs to be initialized by setting a send and receive mask,
>>>> + * indicating which messages the control program (we) want(s) to
>>>> + * send/receive.
>>>> + */
>>>>  static void sclp_set_write_mask(void)
>>>>  {
>>>>  	WriteEventMask *sccb = (void *)_sccb;
>>>>  
>>>>  	sclp_mark_busy();
>>>> +	memset(_sccb, 0, sizeof(*sccb));
>>>>  	sccb->h.length = sizeof(WriteEventMask);
>>>> -	sccb->mask_length = sizeof(unsigned int);
>>>> -	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>>> -	sccb->cp_receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>>> -	sccb->send_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>>> -	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>>> +	sccb->h.function_code = 0;
>>>
>>> Already 0'ed out.
>>
>> Yes, this one is here to make absolutely clear which function we execute.
> 
> Wondering if this should be SCLP_FC_NORMAL_WRITE, too?

Yes
I'll also be able to remove msg_buf and write_sccb structs as they are
already defined in WriteEventData. That that has to wait until a proper
level of caffeine is reached to adapt the offset calculations.

> 
>>
>>>
>>>> +	sccb->mask_length = sizeof(sccb_mask_t);
>>>> +
>>>> +	/* For now we don't process sclp input. */
>>>> +	sccb->cp_receive_mask = 0;
>>>
>>> dito
>>
>> Same
>> If you want, I'll add a comment instead.
> 
> Whatever you prefer, I guess a comment is enough.

So this one has a comment.
I changed the above one to the constant, so both should be fine.

> 
>
David Hildenbrand Jan. 10, 2019, 1:24 p.m. UTC | #6
On 10.01.19 14:20, Janosch Frank wrote:
> On 10.01.19 13:39, David Hildenbrand wrote:
>> On 10.01.19 13:34, Janosch Frank wrote:
>>> On 10.01.19 13:23, David Hildenbrand wrote:
>>>> On 03.01.19 11:08, Janosch Frank wrote:
>>>>> z/VM isn't fond of vt220, so we need line mode when running under z/VM.
>>>>>
>>>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>>>> ---
>>>>>  lib/s390x/sclp-console.c | 178 ++++++++++++++++++++++++++++++++++++++++++-----
>>>>>  lib/s390x/sclp.h         |  67 ++++++++++++++++++
>>>>>  2 files changed, 228 insertions(+), 17 deletions(-)
>>>>>
>>>>> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
>>>>> index a5ef45f..6b30fab 100644
>>>>> --- a/lib/s390x/sclp-console.c
>>>>> +++ b/lib/s390x/sclp-console.c
>>>>> @@ -11,21 +11,167 @@
>>>>>  #include <libcflat.h>
>>>>>  #include <string.h>
>>>>>  #include <asm/page.h>
>>>>> +#include <asm/arch_def.h>
>>>>> +#include <asm/io.h>
>>>>>  #include "sclp.h"
>>>>>  
>>> [...]
>>>>> +
>>>>> +static void sclp_print_ascii(const char *str)
>>>>> +{
>>>>> +	int len = strlen(str);
>>>>> +	WriteEventData *sccb = (void *)_sccb;
>>>>> +
>>>>> +	sclp_mark_busy();
>>>>> +	memset(sccb, 0, sizeof(*sccb));
>>>>> +	sccb->h.length = sizeof(WriteEventData) + 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->data, str, len);
>>>>
>>>> Soooo ... what would happen when printing more than 4000 + something
>>>> characters? (same applies to lm below)
>>>
>>> I wouldn't advise on that, because you'll overwrite memory and sclp
>>> might have a length limit. But that wasn't a problem before, was it?
>>>
>>> Do you plan on printing the memory in one go? :-)
>>
>> Won't say it won't happen when somebody debugs/develops tests and gets
>> strange side effects from printing. Wonder if we should simply cut it
>> off to the supported size.
>>
>> (And yes, this is already in existing code)
> 
> As the print functions have different max lengths for user data I'd
> print a warning and return after 2KB in sclp_print. Anything against that?
> 
> It's simple and 2KB ought to be enough for everyone (TM) and nobody
> keeps you from calling print multiple times instead.
> 
> 
> if (strlen(str) > (1 << 11)) {
> 		sclp_print_ascii("Warning: Printing is limited to 2KB of data.");
> 		sclp_print_lm("Warning: Printing is limited to 2KB of data.");
> 		return;
> 	}

Yes, something like that might be the best thing to do!

Patch
diff mbox series

diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
index a5ef45f..6b30fab 100644
--- a/lib/s390x/sclp-console.c
+++ b/lib/s390x/sclp-console.c
@@ -11,21 +11,167 @@ 
 #include <libcflat.h>
 #include <string.h>
 #include <asm/page.h>
+#include <asm/arch_def.h>
+#include <asm/io.h>
 #include "sclp.h"
 
+/*
+ * ASCII (IBM PC 437) -> EBCDIC 037
+ */
+static uint8_t _ascebc[256] = {
+ /*00 NUL   SOH   STX   ETX   EOT   ENQ   ACK   BEL */
+     0x00, 0x01, 0x02, 0x03, 0x37, 0x2D, 0x2E, 0x2F,
+ /*08  BS    HT    LF    VT    FF    CR    SO    SI */
+ /*              ->NL                               */
+     0x16, 0x05, 0x15, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+ /*10 DLE   DC1   DC2   DC3   DC4   NAK   SYN   ETB */
+     0x10, 0x11, 0x12, 0x13, 0x3C, 0x3D, 0x32, 0x26,
+ /*18 CAN    EM   SUB   ESC    FS    GS    RS    US */
+ /*                               ->IGS ->IRS ->IUS */
+     0x18, 0x19, 0x3F, 0x27, 0x22, 0x1D, 0x1E, 0x1F,
+ /*20  SP     !     "     #     $     %     &     ' */
+     0x40, 0x5A, 0x7F, 0x7B, 0x5B, 0x6C, 0x50, 0x7D,
+ /*28   (     )     *     +     ,     -    .      / */
+     0x4D, 0x5D, 0x5C, 0x4E, 0x6B, 0x60, 0x4B, 0x61,
+ /*30   0     1     2     3     4     5     6     7 */
+     0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
+ /*38   8     9     :     ;     <     =     >     ? */
+     0xF8, 0xF9, 0x7A, 0x5E, 0x4C, 0x7E, 0x6E, 0x6F,
+ /*40   @     A     B     C     D     E     F     G */
+     0x7C, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7,
+ /*48   H     I     J     K     L     M     N     O */
+     0xC8, 0xC9, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6,
+ /*50   P     Q     R     S     T     U     V     W */
+     0xD7, 0xD8, 0xD9, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6,
+ /*58   X     Y     Z     [     \     ]     ^     _ */
+     0xE7, 0xE8, 0xE9, 0xBA, 0xE0, 0xBB, 0xB0, 0x6D,
+ /*60   `     a     b     c     d     e     f     g */
+     0x79, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ /*68   h     i     j     k     l     m     n     o */
+     0x88, 0x89, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96,
+ /*70   p     q     r     s     t     u     v     w */
+     0x97, 0x98, 0x99, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6,
+ /*78   x     y     z     {     |     }     ~    DL */
+     0xA7, 0xA8, 0xA9, 0xC0, 0x4F, 0xD0, 0xA1, 0x07,
+ /*80*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*88*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*90*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*98*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*A0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*A8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*B0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*B8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*C0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*C8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*D0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*D8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*E0        sz						*/
+     0x3F, 0x59, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*E8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*F0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*F8*/
+     0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
+};
+
+static void sclp_print_ascii(const char *str)
+{
+	int len = strlen(str);
+	WriteEventData *sccb = (void *)_sccb;
+
+	sclp_mark_busy();
+	memset(sccb, 0, sizeof(*sccb));
+	sccb->h.length = sizeof(WriteEventData) + 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->data, str, len);
+
+	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
+}
+
+static void sclp_print_lm(const char *str)
+{
+	unsigned char *ptr, *end, ch;
+	unsigned int count, offset, len;
+	struct write_sccb *sccb;
+	struct msg_buf *msg;
+	struct mdb *mdb;
+	struct mto *mto;
+	struct go *go;
+
+	sclp_mark_busy();
+	sccb = (struct write_sccb *) _sccb;
+	end = (unsigned char *) sccb + 4096 - 1;
+	memset(sccb, 0, sizeof(*sccb));
+	ptr = (unsigned char *) &sccb->msg.mdb.mto;
+	len = strlen(str);
+	offset = 0;
+	do {
+		for (count = sizeof(*mto); offset < len; count++) {
+			ch = str[offset++];
+			if ((ch == 0x0a) || (ptr + count > end))
+				break;
+			ptr[count] = _ascebc[ch];
+		}
+		mto = (struct mto *) ptr;
+		memset(mto, 0, sizeof(*mto));
+		mto->length = count;
+		mto->type = 4;
+		mto->line_type_flags = LNTPFLGS_ENDTEXT;
+		ptr += count;
+	} while (offset < len && ptr + sizeof(*mto) <= end);
+	len = ptr - (unsigned char *) sccb;
+	sccb->header.length = len - offsetof(struct write_sccb, header);
+	msg = &sccb->msg;
+	msg->header.type = EVTYP_MSG;
+	msg->header.length = len - offsetof(struct write_sccb, msg.header);
+	mdb = &msg->mdb;
+	mdb->header.type = 1;
+	mdb->header.tag = 0xD4C4C240;
+	mdb->header.revision_code = 1;
+	mdb->header.length = len - offsetof(struct write_sccb, msg.mdb.header);
+	go = &mdb->go;
+	go->length = sizeof(*go);
+	go->type = 1;
+	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
+}
+
+/*
+ * SCLP needs to be initialized by setting a send and receive mask,
+ * indicating which messages the control program (we) want(s) to
+ * send/receive.
+ */
 static void sclp_set_write_mask(void)
 {
 	WriteEventMask *sccb = (void *)_sccb;
 
 	sclp_mark_busy();
+	memset(_sccb, 0, sizeof(*sccb));
 	sccb->h.length = sizeof(WriteEventMask);
-	sccb->mask_length = sizeof(unsigned int);
-	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
-	sccb->cp_receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
-	sccb->send_mask = SCLP_EVENT_MASK_MSG_ASCII;
-	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII;
+	sccb->h.function_code = 0;
+	sccb->mask_length = sizeof(sccb_mask_t);
+
+	/* For now we don't process sclp input. */
+	sccb->cp_receive_mask = 0;
+	/* We send ASCII and line mode. */
+	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG;
 
 	sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
+	assert(sccb->h.response_code == SCLP_RC_NORMAL_COMPLETION);
 }
 
 void sclp_console_setup(void)
@@ -35,16 +181,14 @@  void sclp_console_setup(void)
 
 void sclp_print(const char *str)
 {
-	int len = strlen(str);
-	WriteEventData *sccb = (void *)_sccb;
-
-	sclp_mark_busy();
-	sccb->h.length = sizeof(WriteEventData) + len;
-	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
-	sccb->ebh.length = sizeof(EventBufferHeader) + len;
-	sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
-	sccb->ebh.flags = 0;
-	memcpy(sccb->data, str, len);
-
-	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
+	/*
+	 * z/VM advertises a vt220 console which is not functional:
+	 * (response code 05F0, "not active because of the state of
+	 * the machine"). Hence testing the masks would only work if
+	 * we also use stsi data to distinguish z/VM.
+	 *
+	 * Let's rather print on all available consoles.
+	 */
+	sclp_print_ascii(str);
+	sclp_print_lm(str);
 }
diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
index 63cf609..408bbaf 100644
--- a/lib/s390x/sclp.h
+++ b/lib/s390x/sclp.h
@@ -179,6 +179,7 @@  typedef struct SCCB {
 /* SCLP event masks */
 #define SCLP_EVENT_MASK_SIGNAL_QUIESCE          0x00000008
 #define SCLP_EVENT_MASK_MSG_ASCII               0x00000040
+#define SCLP_EVENT_MASK_MSG          		0x40000000
 
 #define SCLP_UNCONDITIONAL_READ                 0x00
 #define SCLP_SELECTIVE_READ                     0x01
@@ -212,6 +213,72 @@  typedef struct ReadEventData {
     uint32_t mask;
 } __attribute__((packed)) ReadEventData;
 
+#define MDBTYP_GO               0x0001
+#define MDBTYP_MTO              0x0004
+#define EVTYP_MSG               0x02
+#define LNTPFLGS_CNTLTEXT       0x8000
+#define LNTPFLGS_LABELTEXT      0x4000
+#define LNTPFLGS_DATATEXT       0x2000
+#define LNTPFLGS_ENDTEXT        0x1000
+#define LNTPFLGS_PROMPTTEXT     0x0800
+
+typedef uint32_t sccb_mask_t;
+
+/* SCLP line mode console related structures. */
+
+struct mto {
+	u16 length;
+	u16 type;
+	u16 line_type_flags;
+	u8  alarm_control;
+	u8  _reserved[3];
+} __attribute__((packed));
+
+struct go {
+	u16 length;
+	u16 type;
+	u32 domid;
+	u8  hhmmss_time[8];
+	u8  th_time[3];
+	u8  reserved_0;
+	u8  dddyyyy_date[7];
+	u8  _reserved_1;
+	u16 general_msg_flags;
+	u8  _reserved_2[10];
+	u8  originating_system_name[8];
+	u8  job_guest_name[8];
+} __attribute__((packed));
+
+struct mdb_header {
+	u16 length;
+	u16 type;
+	u32 tag;
+	u32 revision_code;
+} __attribute__((packed));
+
+struct mdb {
+	struct mdb_header header;
+	struct go go;
+	struct mto mto;
+} __attribute__((packed));
+
+struct evbuf_header {
+	u16	length;
+	u8	type;
+	u8	flags;
+	u16	_reserved;
+} __attribute__((packed));
+
+struct msg_buf {
+	struct evbuf_header header;
+	struct mdb mdb;
+} __attribute__((packed));
+
+struct write_sccb {
+	struct SCCBHeader header;
+	struct msg_buf msg;
+} __packed;
+
 extern char _sccb[];
 void sclp_handle_ext(void);
 void sclp_wait_busy(void);