Re: [kvm-unit-tests PATCH v3 1/4] lib: s390x: add support for SCLP console read

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, 20 Apr 2022 15:45:54 +0200
Nico Boehr <nrb@xxxxxxxxxxxxx> wrote:

> Add a basic implementation for reading from the SCLP ASCII console. The goal of
> this is to support migration tests on s390x. To know when the migration has been
> finished, we need to listen for a newline on our console.
> 
> Hence, this implementation is focused on the SCLP ASCII console of QEMU and
> currently won't work under e.g. LPAR.
> 
> Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx>
> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>

Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>

> ---
>  lib/s390x/sclp-console.c | 79 +++++++++++++++++++++++++++++++++++++---
>  lib/s390x/sclp.h         |  8 ++++
>  s390x/Makefile           |  1 +
>  3 files changed, 82 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
> index fa36a6a42381..8c4bf68cbbab 100644
> --- a/lib/s390x/sclp-console.c
> +++ b/lib/s390x/sclp-console.c
> @@ -89,6 +89,10 @@ static char lm_buff[120];
>  static unsigned char lm_buff_off;
>  static struct spinlock lm_buff_lock;
>  
> +static char read_buf[4096];
> +static int read_index = sizeof(read_buf) - 1;
> +static int read_buf_end = 0;
> +
>  static void sclp_print_ascii(const char *str)
>  {
>  	int len = strlen(str);
> @@ -185,7 +189,7 @@ static void sclp_print_lm(const char *str)
>   * indicating which messages the control program (we) want(s) to
>   * send/receive.
>   */
> -static void sclp_set_write_mask(void)
> +static void sclp_write_event_mask(int receive_mask, int send_mask)
>  {
>  	WriteEventMask *sccb = (void *)_sccb;
>  
> @@ -195,18 +199,27 @@ static void sclp_set_write_mask(void)
>  	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
>  	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;
> +	sccb->cp_receive_mask = receive_mask;
> +	sccb->cp_send_mask = send_mask;
>  
>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
>  	assert(sccb->h.response_code == SCLP_RC_NORMAL_COMPLETION);
>  }
>  
> +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);
> +}
> +
> +static void sclp_console_disable_read(void)
> +{
> +	sclp_write_event_mask(0, SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG);
> +}
> +
>  void sclp_console_setup(void)
>  {
> -	sclp_set_write_mask();
> +	/* We send ASCII and line mode. */
> +	sclp_write_event_mask(0, SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG);
>  }
>  
>  void sclp_print(const char *str)
> @@ -227,3 +240,57 @@ void sclp_print(const char *str)
>  	sclp_print_ascii(str);
>  	sclp_print_lm(str);
>  }
> +
> +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;
> +
> +	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;
> +
> +	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;
> +		goto out;
> +	}
> +
> +	assert(sccb->ebh.length <= max_event_buffer_len);
> +	assert(sccb->ebh.length > event_buffer_ascii_recv_header_len);
> +
> +	read_buf_end = sccb->ebh.length - event_buffer_ascii_recv_header_len;
> +
> +	assert(read_buf_end <= sizeof(read_buf));
> +	memcpy(read_buf, sccb->data, read_buf_end);
> +
> +	read_index = 0;
> +	ret = 0;
> +
> +out:
> +	sclp_console_disable_read();
> +
> +	return ret;
> +}
> +
> +int __getchar(void)
> +{
> +	int ret;
> +
> +	if (read_index >= read_buf_end) {
> +		ret = console_refill_read_buffer();
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	return read_buf[read_index++];
> +}
> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
> index fead007a6037..e48a5a3df20b 100644
> --- a/lib/s390x/sclp.h
> +++ b/lib/s390x/sclp.h
> @@ -313,6 +313,14 @@ typedef struct ReadEventData {
>  	uint32_t mask;
>  } __attribute__((packed)) 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;
> +
>  extern char _sccb[];
>  void sclp_setup_int(void);
>  void sclp_handle_ext(void);
> diff --git a/s390x/Makefile b/s390x/Makefile
> index c11f6efbd767..f38f442b9cb1 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -75,6 +75,7 @@ cflatobjs += lib/alloc_phys.o
>  cflatobjs += lib/alloc_page.o
>  cflatobjs += lib/vmalloc.o
>  cflatobjs += lib/alloc_phys.o
> +cflatobjs += lib/getchar.o
>  cflatobjs += lib/s390x/io.o
>  cflatobjs += lib/s390x/stack.o
>  cflatobjs += lib/s390x/sclp.o




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux