qemu/pc-bios/s390-ccw/virtio.c
Farhan Ali 99b72e0fbb pc-bios/s390-ccw: Use the ccw bios to start the network boot
We want to use the ccw bios to start final network boot. To do
this we use ccw bios to detect if the boot device is a virtio
network device and retrieve the start address of the
network boot image.

Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-02-28 12:04:48 +01:00

611 lines
16 KiB
C

/*
* Virtio driver bits
*
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at
* your option) any later version. See the COPYING file in the top-level
* directory.
*/
#include "s390-ccw.h"
#include "virtio.h"
#include "virtio-scsi.h"
#define VRING_WAIT_REPLY_TIMEOUT 3
static VRing block[VIRTIO_MAX_VQS];
static char ring_area[VIRTIO_RING_SIZE * VIRTIO_MAX_VQS]
__attribute__((__aligned__(PAGE_SIZE)));
static char chsc_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
static VDev vdev = {
.nr_vqs = 1,
.vrings = block,
.cmd_vr_idx = 0,
.ring_area = ring_area,
.wait_reply_timeout = VRING_WAIT_REPLY_TIMEOUT,
.schid = { .one = 1 },
.scsi_block_size = VIRTIO_SCSI_BLOCK_SIZE,
.blk_factor = 1,
};
VDev *virtio_get_device(void)
{
return &vdev;
}
VirtioDevType virtio_get_device_type(void)
{
return vdev.senseid.cu_model;
}
/* virtio spec v1.0 para 4.3.3.2 */
static long kvm_hypercall(unsigned long nr, unsigned long param1,
unsigned long param2, unsigned long param3)
{
register ulong r_nr asm("1") = nr;
register ulong r_param1 asm("2") = param1;
register ulong r_param2 asm("3") = param2;
register ulong r_param3 asm("4") = param3;
register long retval asm("2");
asm volatile ("diag 2,4,0x500"
: "=d" (retval)
: "d" (r_nr), "0" (r_param1), "r"(r_param2), "d"(r_param3)
: "memory", "cc");
return retval;
}
static long virtio_notify(SubChannelId schid, int vq_idx, long cookie)
{
return kvm_hypercall(KVM_S390_VIRTIO_CCW_NOTIFY, *(u32 *)&schid,
vq_idx, cookie);
}
/***********************************************
* Virtio functions *
***********************************************/
static int drain_irqs(SubChannelId schid)
{
Irb irb = {};
int r = 0;
while (1) {
/* FIXME: make use of TPI, for that enable subchannel and isc */
if (tsch(schid, &irb)) {
/* Might want to differentiate error codes later on. */
if (irb.scsw.cstat) {
r = -EIO;
} else if (irb.scsw.dstat != 0xc) {
r = -EIO;
}
return r;
}
}
}
static int run_ccw(VDev *vdev, int cmd, void *ptr, int len)
{
Ccw1 ccw = {};
CmdOrb orb = {};
Schib schib;
int r;
/* start command processing */
stsch_err(vdev->schid, &schib);
/* enable the subchannel for IPL device */
schib.pmcw.ena = 1;
msch(vdev->schid, &schib);
/* start subchannel command */
orb.fmt = 1;
orb.cpa = (u32)(long)&ccw;
orb.lpm = 0x80;
ccw.cmd_code = cmd;
ccw.cda = (long)ptr;
ccw.count = len;
r = ssch(vdev->schid, &orb);
/*
* XXX Wait until device is done processing the CCW. For now we can
* assume that a simple tsch will have finished the CCW processing,
* but the architecture allows for asynchronous operation
*/
if (!r) {
r = drain_irqs(vdev->schid);
}
return r;
}
static void vring_init(VRing *vr, VqInfo *info)
{
void *p = (void *) info->queue;
debug_print_addr("init p", p);
vr->id = info->index;
vr->num = info->num;
vr->desc = p;
vr->avail = p + info->num * sizeof(VRingDesc);
vr->used = (void *)(((unsigned long)&vr->avail->ring[info->num]
+ info->align - 1) & ~(info->align - 1));
/* Zero out all relevant field */
vr->avail->flags = 0;
vr->avail->idx = 0;
/* We're running with interrupts off anyways, so don't bother */
vr->used->flags = VRING_USED_F_NO_NOTIFY;
vr->used->idx = 0;
vr->used_idx = 0;
vr->next_idx = 0;
vr->cookie = 0;
debug_print_addr("init vr", vr);
}
static bool vring_notify(VRing *vr)
{
vr->cookie = virtio_notify(vr->schid, vr->id, vr->cookie);
return vr->cookie >= 0;
}
static void vring_send_buf(VRing *vr, void *p, int len, int flags)
{
/* For follow-up chains we need to keep the first entry point */
if (!(flags & VRING_HIDDEN_IS_CHAIN)) {
vr->avail->ring[vr->avail->idx % vr->num] = vr->next_idx;
}
vr->desc[vr->next_idx].addr = (ulong)p;
vr->desc[vr->next_idx].len = len;
vr->desc[vr->next_idx].flags = flags & ~VRING_HIDDEN_IS_CHAIN;
vr->desc[vr->next_idx].next = vr->next_idx;
vr->desc[vr->next_idx].next++;
vr->next_idx++;
/* Chains only have a single ID */
if (!(flags & VRING_DESC_F_NEXT)) {
vr->avail->idx++;
}
}
static u64 get_clock(void)
{
u64 r;
asm volatile("stck %0" : "=Q" (r) : : "cc");
return r;
}
ulong get_second(void)
{
return (get_clock() >> 12) / 1000000;
}
static int vr_poll(VRing *vr)
{
if (vr->used->idx == vr->used_idx) {
vring_notify(vr);
yield();
return 0;
}
vr->used_idx = vr->used->idx;
vr->next_idx = 0;
vr->desc[0].len = 0;
vr->desc[0].flags = 0;
return 1; /* vr has been updated */
}
/*
* Wait for the host to reply.
*
* timeout is in seconds if > 0.
*
* Returns 0 on success, 1 on timeout.
*/
static int vring_wait_reply(void)
{
ulong target_second = get_second() + vdev.wait_reply_timeout;
/* Wait for any queue to be updated by the host */
do {
int i, r = 0;
for (i = 0; i < vdev.nr_vqs; i++) {
r += vr_poll(&vdev.vrings[i]);
}
yield();
if (r) {
return 0;
}
} while (!vdev.wait_reply_timeout || (get_second() < target_second));
return 1;
}
int virtio_run(VDev *vdev, int vqid, VirtioCmd *cmd)
{
VRing *vr = &vdev->vrings[vqid];
int i = 0;
do {
vring_send_buf(vr, cmd[i].data, cmd[i].size,
cmd[i].flags | (i ? VRING_HIDDEN_IS_CHAIN : 0));
} while (cmd[i++].flags & VRING_DESC_F_NEXT);
vring_wait_reply();
if (drain_irqs(vr->schid)) {
return -1;
}
return 0;
}
/***********************************************
* Virtio block *
***********************************************/
static int virtio_blk_read_many(VDev *vdev,
ulong sector, void *load_addr, int sec_num)
{
VirtioBlkOuthdr out_hdr;
u8 status;
VRing *vr = &vdev->vrings[vdev->cmd_vr_idx];
/* Tell the host we want to read */
out_hdr.type = VIRTIO_BLK_T_IN;
out_hdr.ioprio = 99;
out_hdr.sector = virtio_sector_adjust(sector);
vring_send_buf(vr, &out_hdr, sizeof(out_hdr), VRING_DESC_F_NEXT);
/* This is where we want to receive data */
vring_send_buf(vr, load_addr, virtio_get_block_size() * sec_num,
VRING_DESC_F_WRITE | VRING_HIDDEN_IS_CHAIN |
VRING_DESC_F_NEXT);
/* status field */
vring_send_buf(vr, &status, sizeof(u8),
VRING_DESC_F_WRITE | VRING_HIDDEN_IS_CHAIN);
/* Now we can tell the host to read */
vring_wait_reply();
if (drain_irqs(vr->schid)) {
/* Well, whatever status is supposed to contain... */
status = 1;
}
return status;
}
int virtio_read_many(ulong sector, void *load_addr, int sec_num)
{
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
return virtio_blk_read_many(&vdev, sector, load_addr, sec_num);
case VIRTIO_ID_SCSI:
return virtio_scsi_read_many(&vdev, sector, load_addr, sec_num);
}
panic("\n! No readable IPL device !\n");
return -1;
}
unsigned long virtio_load_direct(ulong rec_list1, ulong rec_list2,
ulong subchan_id, void *load_addr)
{
u8 status;
int sec = rec_list1;
int sec_num = ((rec_list2 >> 32) & 0xffff) + 1;
int sec_len = rec_list2 >> 48;
ulong addr = (ulong)load_addr;
if (sec_len != virtio_get_block_size()) {
return -1;
}
sclp_print(".");
status = virtio_read_many(sec, (void *)addr, sec_num);
if (status) {
panic("I/O Error");
}
addr += sec_num * virtio_get_block_size();
return addr;
}
int virtio_read(ulong sector, void *load_addr)
{
return virtio_read_many(sector, load_addr, 1);
}
/*
* Other supported value pairs, if any, would need to be added here.
* Note: head count is always 15.
*/
static inline u8 virtio_eckd_sectors_for_block_size(int size)
{
switch (size) {
case 512:
return 49;
case 1024:
return 33;
case 2048:
return 21;
case 4096:
return 12;
}
return 0;
}
VirtioGDN virtio_guessed_disk_nature(void)
{
return vdev.guessed_disk_nature;
}
void virtio_assume_scsi(void)
{
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
vdev.guessed_disk_nature = VIRTIO_GDN_SCSI;
vdev.config.blk.blk_size = VIRTIO_SCSI_BLOCK_SIZE;
vdev.config.blk.physical_block_exp = 0;
vdev.blk_factor = 1;
break;
case VIRTIO_ID_SCSI:
vdev.scsi_block_size = VIRTIO_SCSI_BLOCK_SIZE;
break;
}
}
void virtio_assume_iso9660(void)
{
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
vdev.guessed_disk_nature = VIRTIO_GDN_SCSI;
vdev.config.blk.blk_size = VIRTIO_ISO_BLOCK_SIZE;
vdev.config.blk.physical_block_exp = 0;
vdev.blk_factor = VIRTIO_ISO_BLOCK_SIZE / VIRTIO_SECTOR_SIZE;
break;
case VIRTIO_ID_SCSI:
vdev.scsi_block_size = VIRTIO_ISO_BLOCK_SIZE;
break;
}
}
void virtio_assume_eckd(void)
{
vdev.guessed_disk_nature = VIRTIO_GDN_DASD;
vdev.blk_factor = 1;
vdev.config.blk.physical_block_exp = 0;
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
vdev.config.blk.blk_size = 4096;
break;
case VIRTIO_ID_SCSI:
vdev.config.blk.blk_size = vdev.scsi_block_size;
break;
}
vdev.config.blk.geometry.heads = 15;
vdev.config.blk.geometry.sectors =
virtio_eckd_sectors_for_block_size(vdev.config.blk.blk_size);
}
bool virtio_disk_is_scsi(void)
{
if (vdev.guessed_disk_nature == VIRTIO_GDN_SCSI) {
return true;
}
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
return (vdev.config.blk.geometry.heads == 255)
&& (vdev.config.blk.geometry.sectors == 63)
&& (virtio_get_block_size() == VIRTIO_SCSI_BLOCK_SIZE);
case VIRTIO_ID_SCSI:
return true;
}
return false;
}
bool virtio_disk_is_eckd(void)
{
const int block_size = virtio_get_block_size();
if (vdev.guessed_disk_nature == VIRTIO_GDN_DASD) {
return true;
}
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
return (vdev.config.blk.geometry.heads == 15)
&& (vdev.config.blk.geometry.sectors ==
virtio_eckd_sectors_for_block_size(block_size));
case VIRTIO_ID_SCSI:
return false;
}
return false;
}
bool virtio_ipl_disk_is_valid(void)
{
return virtio_disk_is_scsi() || virtio_disk_is_eckd();
}
int virtio_get_block_size(void)
{
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
return vdev.config.blk.blk_size << vdev.config.blk.physical_block_exp;
case VIRTIO_ID_SCSI:
return vdev.scsi_block_size;
}
return 0;
}
uint8_t virtio_get_heads(void)
{
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
return vdev.config.blk.geometry.heads;
case VIRTIO_ID_SCSI:
return vdev.guessed_disk_nature == VIRTIO_GDN_DASD
? vdev.config.blk.geometry.heads : 255;
}
return 0;
}
uint8_t virtio_get_sectors(void)
{
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
return vdev.config.blk.geometry.sectors;
case VIRTIO_ID_SCSI:
return vdev.guessed_disk_nature == VIRTIO_GDN_DASD
? vdev.config.blk.geometry.sectors : 63;
}
return 0;
}
uint64_t virtio_get_blocks(void)
{
const uint64_t factor = virtio_get_block_size() / VIRTIO_SECTOR_SIZE;
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
return vdev.config.blk.capacity / factor;
case VIRTIO_ID_SCSI:
return vdev.scsi_last_block / factor;
}
return 0;
}
static void virtio_setup_ccw(VDev *vdev)
{
int i, cfg_size = 0;
unsigned char status = VIRTIO_CONFIG_S_DRIVER_OK;
IPL_assert(virtio_is_supported(vdev->schid), "PE");
/* device ID has been established now */
vdev->config.blk.blk_size = 0; /* mark "illegal" - setup started... */
vdev->guessed_disk_nature = VIRTIO_GDN_NONE;
run_ccw(vdev, CCW_CMD_VDEV_RESET, NULL, 0);
switch (vdev->senseid.cu_model) {
case VIRTIO_ID_BLOCK:
vdev->nr_vqs = 1;
vdev->cmd_vr_idx = 0;
cfg_size = sizeof(vdev->config.blk);
break;
case VIRTIO_ID_SCSI:
vdev->nr_vqs = 3;
vdev->cmd_vr_idx = VR_REQUEST;
cfg_size = sizeof(vdev->config.scsi);
break;
default:
panic("Unsupported virtio device\n");
}
IPL_assert(run_ccw(vdev, CCW_CMD_READ_CONF, &vdev->config, cfg_size) == 0,
"Could not get block device configuration");
/*
* Skipping CCW_CMD_READ_FEAT. We're not doing anything fancy, and
* we'll just stop dead anyway if anything does not work like we
* expect it.
*/
for (i = 0; i < vdev->nr_vqs; i++) {
VqInfo info = {
.queue = (unsigned long long) ring_area + (i * VIRTIO_RING_SIZE),
.align = KVM_S390_VIRTIO_RING_ALIGN,
.index = i,
.num = 0,
};
VqConfig config = {
.index = i,
.num = 0,
};
IPL_assert(
run_ccw(vdev, CCW_CMD_READ_VQ_CONF, &config, sizeof(config)) == 0,
"Could not get block device VQ configuration");
info.num = config.num;
vring_init(&vdev->vrings[i], &info);
vdev->vrings[i].schid = vdev->schid;
IPL_assert(run_ccw(vdev, CCW_CMD_SET_VQ, &info, sizeof(info)) == 0,
"Cannot set VQ info");
}
IPL_assert(
run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status)) == 0,
"Could not write status to host");
}
void virtio_setup_device(SubChannelId schid)
{
vdev.schid = schid;
virtio_setup_ccw(&vdev);
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
sclp_print("Using virtio-blk.\n");
if (!virtio_ipl_disk_is_valid()) {
/* make sure all getters but blocksize return 0 for
* invalid IPL disk
*/
memset(&vdev.config.blk, 0, sizeof(vdev.config.blk));
virtio_assume_scsi();
}
break;
case VIRTIO_ID_SCSI:
IPL_assert(vdev.config.scsi.sense_size == VIRTIO_SCSI_SENSE_SIZE,
"Config: sense size mismatch");
IPL_assert(vdev.config.scsi.cdb_size == VIRTIO_SCSI_CDB_SIZE,
"Config: CDB size mismatch");
sclp_print("Using virtio-scsi.\n");
virtio_scsi_setup(&vdev);
break;
default:
panic("\n! No IPL device available !\n");
}
}
bool virtio_is_supported(SubChannelId schid)
{
vdev.schid = schid;
memset(&vdev.senseid, 0, sizeof(vdev.senseid));
/* run sense id command */
if (run_ccw(&vdev, CCW_CMD_SENSE_ID, &vdev.senseid, sizeof(vdev.senseid))) {
return false;
}
if (vdev.senseid.cu_type == 0x3832) {
switch (vdev.senseid.cu_model) {
case VIRTIO_ID_BLOCK:
case VIRTIO_ID_SCSI:
case VIRTIO_ID_NET:
return true;
}
}
return false;
}
int enable_mss_facility(void)
{
int ret;
ChscAreaSda *sda_area = (ChscAreaSda *) chsc_page;
memset(sda_area, 0, PAGE_SIZE);
sda_area->request.length = 0x0400;
sda_area->request.code = 0x0031;
sda_area->operation_code = 0x2;
ret = chsc(sda_area);
if ((ret == 0) && (sda_area->response.code == 0x0001)) {
return 0;
}
return -EIO;
}