Viresh Kumar viresh.kumar@linaro.org writes:
This adds the vhost-user backend driver to support virtio based I2C and SMBUS devices.
vhost-user-i2c --help
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
<snip>
+static VI2cAdapter *vi2c_create_adapter(int32_t bus, uint16_t client_addr[],
int32_t n_client)+{
- VI2cAdapter *adapter;
- char path[20];
If you use:
g_autofree char *path = NULL;
If fact you could also use g_autofree with adapter to make you exit case a little easier.
- uint64_t funcs;
- int32_t fd, i;
- if (bus < 0) {
return NULL;- }
- adapter = g_malloc0(sizeof(*adapter));
g_malloc will abort() on lack of memory so you can skip the check here.
- if (!adapter) {
g_printerr("failed to alloc adapter");return NULL;- }
- snprintf(path, sizeof(path), "/dev/i2c-%d", bus);
- path[sizeof(path) - 1] = '\0';
then this becomes:
path = g_strdup_printf("/dev/i2c-%d", bus);
- fd = open(path, O_RDWR);
- if (fd < 0) {
g_printerr("virtio_i2c: failed to open %s\n", path);goto fail;- }
- adapter->fd = fd;
- adapter->bus = bus;
- if (ioctl(fd, I2C_FUNCS, &funcs) < 0) {
g_printerr("virtio_i2c: failed to get functionality %s: %d\n", path,errno);goto close_fd;- }
- if (funcs & I2C_FUNC_I2C) {
adapter->smbus = false;- } else if (funcs & I2C_FUNC_SMBUS_WORD_DATA) {
adapter->smbus = true;- } else {
g_printerr("virtio_i2c: invalid functionality %lx\n", funcs);goto close_fd;- }
- for (i = 0; i < n_client; i++) {
if (client_addr[i]) {if (!vi2c_set_client_addr(adapter, client_addr[i])) {goto close_fd;}if (adapter->clients[client_addr[i]]) {g_printerr("client addr 0x%x repeat, not allowed.\n",client_addr[i]);goto close_fd;}adapter->clients[client_addr[i]] = true;if (verbose) {g_print("Added client 0x%x to bus %u\n", client_addr[i], bus);}}- }
- if (verbose) {
g_print("Added adapter: bus: %d, func %s\n", bus,adapter->smbus ? "smbus" : "i2c");- }
- return adapter;
This would then be:
return g_steal_pointer(adapter);
+close_fd:
- close(fd);
+fail:
- g_free(adapter);
- return NULL;
+}
+/*
- Virtio I2C device list format.
- <bus>:<client_addr>[:<client_addr>],
- [<bus>:<client_addr>[:<client_addr>]]
- bus (dec): adatper bus number.
e.g. 2 for /dev/i2c-2
- client_addr (hex): address for client device
e.g. 0x1C or 1C
- Example: --device-list="2:0x1c:0x20,3:0x10:0x2c"
- Note: client address can not repeat.
- */
+static int32_t vi2c_parse(VuI2c *i2c) +{
- uint16_t client_addr[MAX_I2C_VDEV];
- int32_t n_adapter = 0, n_client;
- int64_t addr, bus;
- const char *cp, *t;
- while (device_list) {
/* Read <bus>:<client_addr>[:<client_addr>] entries one by one */cp = strsep(&device_list, ",");
The glib approach would be to use g_strsplit(device_list, ",", 0) which you can then iterate over with something like:
for (i = 0; cp[i] != NULL; i++) {
}
g_strfreev(cp);
if (!cp || *cp == '\0') {break;}if (n_adapter == MAX_I2C_ADAPTER) {g_printerr("too many adapter (%d), only support %d\n", n_adapter,MAX_I2C_ADAPTER);goto out;}if (qemu_strtol(cp, &t, 10, &bus) || bus < 0) {g_printerr("Invalid bus number %s\n", cp);goto out;}cp = t;n_client = 0;/* Parse clients <client_addr>[:<client_addr>] entries one byone */
Then this would be:
**dev = g_strsplit(cp[i], ":", 2); if (dev && dev[0]) {
if (dev[1]) { } } g_freestrv(dev);
which would avoid you manually iterating over the string.
while (cp != NULL && *cp != '\0') {if (*cp == ':') {cp++;}if (n_client == MAX_I2C_VDEV) {g_printerr("too many devices (%d), only support %d\n",n_client, MAX_I2C_VDEV);goto out;}if (qemu_strtol(cp, &t, 16, &addr) ||addr < 0 || addr > MAX_I2C_VDEV) {g_printerr("Invalid address %s : %lx\n", cp, addr);goto out;}client_addr[n_client++] = addr;cp = t;if (verbose) {g_print("i2c adapter %ld:0x%lx\n", bus, addr);}}i2c->adapter[n_adapter] = vi2c_create_adapter(bus, client_addr,n_client);if (!i2c->adapter[n_adapter]) {goto out;}n_adapter++;- }
- if (!n_adapter) {
g_printerr("Failed to add any adapters\n");return -1;- }
- i2c->adapter_num = n_adapter;
- if (!vi2c_map_adapters(i2c)) {
return 0;- }
+out:
- vi2c_remove_adapters(i2c);
- return -1;
+}
<snip>
+static void vi2c_handle_ctrl(VuDev *dev, int qidx) +{
- VuVirtq *vq = vu_get_queue(dev, qidx);
- struct virtio_i2c_out_hdr *out_hdr;
- size_t i, count = 0, len, in_hdr_len;
- struct i2c_msg *msgs;
- VuVirtqElement *elem;
- uint8_t status;
- struct {
struct virtio_i2c_in_hdr *in_hdr;VuVirtqElement *elem;size_t size;- } *info;
- /* Count number of messages */
- do {
elem = vu_queue_pop(dev, vq, sizeof(VuVirtqElement));- } while (elem && ++count);
Can you expand on this comment as to why we can't process each message as we come to it?
- if (!count) {
if (verbose) {g_printerr("Virtqueue can't have 0 elements\n");}return;- }
- /* Rewind everything, now that we have counted the number of messages */
- vu_queue_rewind(dev, vq, count);
- if (verbose) {
g_print("Received %ld messages in virtqueue\n", count);- }
- /* Allocate memory for msgs and info */
- msgs = g_malloc0_n(count, sizeof(*msgs) + sizeof(*info));
- if (!msgs) {
g_printerr("failed to allocate space for messages\n");return;- }
g_malloc0_n will abort() or succeed. Could this be a g_new and be typed in some way?
- info = (void *)(msgs + count);
- for (i = 0; i < count; i++) {
elem = vu_queue_pop(dev, vq, sizeof(VuVirtqElement));if (!elem) {g_printerr("Failed to pop element: %ld : %ld\n", i, count);goto out;}
not withstanding the above comment this seems like an assert() because it should never fail?
info[i].elem = elem;info[i].size = sizeof(*info[i].in_hdr);g_debug("%s: got queue (in %d, out %d)", __func__, elem->in_num,elem->out_num);/* Validate size of "out" header */if (elem->out_sg[0].iov_len != sizeof(*out_hdr)) {g_warning("%s: Invalid out hdr %zu : %zu\n", __func__,elem->out_sg[0].iov_len, sizeof(*out_hdr));goto out;}out_hdr = elem->out_sg[0].iov_base;/* Bit 0 is reserved in virtio spec */msgs[i].addr = le16toh(out_hdr->addr) >> 1;/* Read Operation */if (elem->out_num == 1 && elem->in_num == 2) {len = elem->in_sg[0].iov_len;if (!len) {g_warning("%s: Read buffer length can't be zero\n", __func__);goto out;}msgs[i].buf = elem->in_sg[0].iov_base;msgs[i].flags = I2C_M_RD;msgs[i].len = len;info[i].in_hdr = elem->in_sg[1].iov_base;info[i].size += len;in_hdr_len = elem->in_sg[1].iov_len;} else if (elem->out_num == 2 && elem->in_num == 1) {/* Write Operation */len = elem->out_sg[1].iov_len;if (!len) {g_warning("%s: Write buffer length can't be zero\n", __func__);goto out;}msgs[i].buf = elem->out_sg[1].iov_base;msgs[i].flags = 0;msgs[i].len = len;info[i].in_hdr = elem->in_sg[0].iov_base;in_hdr_len = elem->in_sg[0].iov_len;} else {g_warning("%s: Transfer type not supported (in %d, out %d)\n",__func__, elem->in_num, elem->out_num);goto out;}/* Validate size of "in" header */if (in_hdr_len != sizeof(*(info[i].in_hdr))) {g_warning("%s: Invalid in hdr %zu : %zu\n", __func__, in_hdr_len,sizeof(*(info[i].in_hdr)));goto out;}- }
- status = vi2c_xfer(dev, msgs, count);
- for (i = 0; i < count; i++) {
info[i].in_hdr->status = status;vu_queue_push(dev, vq, info[i].elem, info[i].size);- }
- vu_queue_notify(dev, vq);
+out:
- g_free(msgs);
+}
<snip>
diff --git a/tools/vhost-user-i2c/meson.build b/tools/vhost-user-i2c/meson.build new file mode 100644 index 000000000000..f71e9fec7df6 --- /dev/null +++ b/tools/vhost-user-i2c/meson.build @@ -0,0 +1,10 @@ +executable('vhost-user-i2c', files(
- 'main.c'),
- dependencies: [qemuutil, glib, gio],
- install: true,
- install_dir: get_option('libexecdir'))
+configure_file(input: '50-qemu-i2c.json.in',
output: '50-qemu-i2c.json',configuration: config_host,
FYI this now needs to be:
configuration: { 'libexecdir' : get_option('prefix') / get_option('libexecdir') },
to properly pass libexecdir above.
install_dir: qemu_datadir / 'vhost-user')