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qemu/pc-bios/s390-ccw/virtio.c

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/*
* 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:
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;
}
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