From: David Woodhouse <d...@amazon.co.uk> This allows (non-primary) console devices to be created on the command line and hotplugged.
Signed-off-by: David Woodhouse <d...@amazon.co.uk> Reviewed-by: Paul Durrant <p...@xen.org> --- hw/char/trace-events | 8 + hw/char/xen_console.c | 532 +++++++++++++++++++++++++++--------- hw/xen/xen-legacy-backend.c | 1 - 3 files changed, 411 insertions(+), 130 deletions(-) diff --git a/hw/char/trace-events b/hw/char/trace-events index babf4d35ea..7a398c82a5 100644 --- a/hw/char/trace-events +++ b/hw/char/trace-events @@ -105,3 +105,11 @@ cadence_uart_baudrate(unsigned baudrate) "baudrate %u" # sh_serial.c sh_serial_read(char *id, unsigned size, uint64_t offs, uint64_t val) " %s size %d offs 0x%02" PRIx64 " -> 0x%02" PRIx64 sh_serial_write(char *id, unsigned size, uint64_t offs, uint64_t val) "%s size %d offs 0x%02" PRIx64 " <- 0x%02" PRIx64 + +# xen_console.c +xen_console_connect(unsigned int idx, unsigned int ring_ref, unsigned int port, unsigned int limit) "idx %u ring_ref %u port %u limit %u" +xen_console_disconnect(unsigned int idx) "idx %u" +xen_console_unrealize(unsigned int idx) "idx %u" +xen_console_realize(unsigned int idx, const char *chrdev) "idx %u chrdev %s" +xen_console_device_create(unsigned int idx) "idx %u" +xen_console_device_destroy(unsigned int idx) "idx %u" diff --git a/hw/char/xen_console.c b/hw/char/xen_console.c index 810dae3f44..4a419dc287 100644 --- a/hw/char/xen_console.c +++ b/hw/char/xen_console.c @@ -20,15 +20,20 @@ */ #include "qemu/osdep.h" +#include "qemu/cutils.h" #include <sys/select.h> #include <termios.h> #include "qapi/error.h" #include "sysemu/sysemu.h" #include "chardev/char-fe.h" -#include "hw/xen/xen-legacy-backend.h" - +#include "hw/xen/xen-backend.h" +#include "hw/xen/xen-bus-helper.h" +#include "hw/qdev-properties.h" +#include "hw/qdev-properties-system.h" #include "hw/xen/interface/io/console.h" +#include "hw/xen/interface/io/xs_wire.h" +#include "trace.h" struct buffer { uint8_t *data; @@ -39,16 +44,22 @@ struct buffer { }; struct XenConsole { - struct XenLegacyDevice xendev; /* must be first */ + struct XenDevice xendev; /* must be first */ + XenEventChannel *event_channel; + int dev; struct buffer buffer; - char console[XEN_BUFSIZE]; - int ring_ref; + char *fe_path; + unsigned int ring_ref; void *sring; CharBackend chr; int backlog; }; +typedef struct XenConsole XenConsole; + +#define TYPE_XEN_CONSOLE_DEVICE "xen-console" +OBJECT_DECLARE_SIMPLE_TYPE(XenConsole, XEN_CONSOLE_DEVICE) -static void buffer_append(struct XenConsole *con) +static bool buffer_append(XenConsole *con) { struct buffer *buffer = &con->buffer; XENCONS_RING_IDX cons, prod, size; @@ -60,7 +71,7 @@ static void buffer_append(struct XenConsole *con) size = prod - cons; if ((size == 0) || (size > sizeof(intf->out))) - return; + return false; if ((buffer->capacity - buffer->size) < size) { buffer->capacity += (size + 1024); @@ -73,7 +84,7 @@ static void buffer_append(struct XenConsole *con) xen_mb(); intf->out_cons = cons; - xen_pv_send_notify(&con->xendev); + xen_device_notify_event_channel(XEN_DEVICE(con), con->event_channel, NULL); if (buffer->max_capacity && buffer->size > buffer->max_capacity) { @@ -89,6 +100,7 @@ static void buffer_append(struct XenConsole *con) if (buffer->consumed > buffer->max_capacity - over) buffer->consumed = buffer->max_capacity - over; } + return true; } static void buffer_advance(struct buffer *buffer, size_t len) @@ -100,7 +112,7 @@ static void buffer_advance(struct buffer *buffer, size_t len) } } -static int ring_free_bytes(struct XenConsole *con) +static int ring_free_bytes(XenConsole *con) { struct xencons_interface *intf = con->sring; XENCONS_RING_IDX cons, prod, space; @@ -118,13 +130,13 @@ static int ring_free_bytes(struct XenConsole *con) static int xencons_can_receive(void *opaque) { - struct XenConsole *con = opaque; + XenConsole *con = opaque; return ring_free_bytes(con); } static void xencons_receive(void *opaque, const uint8_t *buf, int len) { - struct XenConsole *con = opaque; + XenConsole *con = opaque; struct xencons_interface *intf = con->sring; XENCONS_RING_IDX prod; int i, max; @@ -141,10 +153,10 @@ static void xencons_receive(void *opaque, const uint8_t *buf, int len) } xen_wmb(); intf->in_prod = prod; - xen_pv_send_notify(&con->xendev); + xen_device_notify_event_channel(XEN_DEVICE(con), con->event_channel, NULL); } -static void xencons_send(struct XenConsole *con) +static bool xencons_send(XenConsole *con) { ssize_t len, size; @@ -159,174 +171,436 @@ static void xencons_send(struct XenConsole *con) if (len < 1) { if (!con->backlog) { con->backlog = 1; - xen_pv_printf(&con->xendev, 1, - "backlog piling up, nobody listening?\n"); } } else { buffer_advance(&con->buffer, len); if (con->backlog && len == size) { con->backlog = 0; - xen_pv_printf(&con->xendev, 1, "backlog is gone\n"); } } + return len > 0; } /* -------------------------------------------------------------------- */ -static int store_con_info(struct XenConsole *con) +static bool con_event(void *_xendev) { - Chardev *cs = qemu_chr_fe_get_driver(&con->chr); - char *pts = NULL; - char *dom_path; - g_autoptr(GString) path = NULL; + XenConsole *con = XEN_CONSOLE_DEVICE(_xendev); + bool done_something; + + if (xen_device_backend_get_state(&con->xendev) != XenbusStateConnected) { + return false; + } + + done_something = buffer_append(con); + + if (con->buffer.size - con->buffer.consumed) { + done_something |= xencons_send(con); + } + return done_something; +} + +/* -------------------------------------------------------------------- */ + +static bool xen_console_connect(XenDevice *xendev, Error **errp) +{ + XenConsole *con = XEN_CONSOLE_DEVICE(xendev); + unsigned int port, limit; + + if (xen_device_frontend_scanf(xendev, "ring-ref", "%u", + &con->ring_ref) != 1) { + error_setg(errp, "failed to read ring-ref"); + return false; + } - /* Only continue if we're talking to a pty. */ - if (!CHARDEV_IS_PTY(cs)) { - return 0; + if (xen_device_frontend_scanf(xendev, "port", "%u", &port) != 1) { + error_setg(errp, "failed to read remote port"); + return false; } - pts = cs->filename + 4; - dom_path = qemu_xen_xs_get_domain_path(xenstore, xen_domid); - if (!dom_path) { - return 0; + if (xen_device_frontend_scanf(xendev, "limit", "%u", &limit) == 1) { + con->buffer.max_capacity = limit; } - path = g_string_new(dom_path); - free(dom_path); + con->event_channel = xen_device_bind_event_channel(xendev, port, + con_event, + con, + errp); + if (!con->event_channel) { + return false; + } - if (con->xendev.dev) { - g_string_append_printf(path, "/device/console/%d", con->xendev.dev); + if (!con->dev) { + xen_pfn_t mfn = (xen_pfn_t)con->ring_ref; + con->sring = qemu_xen_foreignmem_map(xendev->frontend_id, NULL, + PROT_READ | PROT_WRITE, + 1, &mfn, NULL); + if (!con->sring) { + error_setg(errp, "failed to map console page"); + return false; + } } else { - g_string_append(path, "/console"); + con->sring = xen_device_map_grant_refs(xendev, + &con->ring_ref, 1, + PROT_READ | PROT_WRITE, + errp); + if (!con->sring) { + error_prepend(errp, "failed to map grant ref: "); + return false; + } } - g_string_append(path, "/tty"); - if (xenstore_write_str(con->console, path->str, pts)) { - fprintf(stderr, "xenstore_write_str for '%s' fail", path->str); - return -1; + trace_xen_console_connect(con->dev, con->ring_ref, port, + con->buffer.max_capacity); + + qemu_chr_fe_set_handlers(&con->chr, xencons_can_receive, + xencons_receive, NULL, NULL, con, NULL, + true); + return true; +} + +static void xen_console_disconnect(XenDevice *xendev, Error **errp) +{ + XenConsole *con = XEN_CONSOLE_DEVICE(xendev); + + trace_xen_console_disconnect(con->dev); + + qemu_chr_fe_set_handlers(&con->chr, NULL, NULL, NULL, NULL, + con, NULL, true); + + if (con->event_channel) { + xen_device_unbind_event_channel(xendev, con->event_channel, + errp); + con->event_channel = NULL; + } + + if (con->sring) { + if (!con->dev) { + qemu_xen_foreignmem_unmap(con->sring, 1); + } else { + xen_device_unmap_grant_refs(xendev, con->sring, + &con->ring_ref, 1, errp); + } + con->sring = NULL; } - return 0; } -static int con_init(struct XenLegacyDevice *xendev) +static void xen_console_frontend_changed(XenDevice *xendev, + enum xenbus_state frontend_state, + Error **errp) { - struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); - char *type, *dom, label[32]; - int ret = 0; - const char *output; - - /* setup */ - dom = qemu_xen_xs_get_domain_path(xenstore, con->xendev.dom); - if (!xendev->dev) { - snprintf(con->console, sizeof(con->console), "%s/console", dom); - } else { - snprintf(con->console, sizeof(con->console), "%s/device/console/%d", dom, xendev->dev); + ERRP_GUARD(); + enum xenbus_state backend_state = xen_device_backend_get_state(xendev); + + switch (frontend_state) { + case XenbusStateInitialised: + case XenbusStateConnected: + if (backend_state == XenbusStateConnected) { + break; + } + + xen_console_disconnect(xendev, errp); + if (*errp) { + break; + } + + if (!xen_console_connect(xendev, errp)) { + xen_device_backend_set_state(xendev, XenbusStateClosing); + break; + } + + xen_device_backend_set_state(xendev, XenbusStateConnected); + break; + + case XenbusStateClosing: + xen_device_backend_set_state(xendev, XenbusStateClosing); + break; + + case XenbusStateClosed: + case XenbusStateUnknown: + xen_console_disconnect(xendev, errp); + if (*errp) { + break; + } + + xen_device_backend_set_state(xendev, XenbusStateClosed); + break; + + default: + break; } - free(dom); +} - type = xenstore_read_str(con->console, "type"); - if (!type || strcmp(type, "ioemu") != 0) { - xen_pv_printf(xendev, 1, "not for me (type=%s)\n", type); - ret = -1; - goto out; +static char *xen_console_get_name(XenDevice *xendev, Error **errp) +{ + XenConsole *con = XEN_CONSOLE_DEVICE(xendev); + + if (con->dev == -1) { + XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); + char fe_path[XENSTORE_ABS_PATH_MAX + 1]; + char *value; + int idx = 1; + + /* Theoretically we could go up to INT_MAX here but that's overkill */ + while (idx < 100) { + snprintf(fe_path, sizeof(fe_path), + "/local/domain/%u/device/console/%u", + xendev->frontend_id, idx); + value = qemu_xen_xs_read(xenbus->xsh, XBT_NULL, fe_path, NULL); + if (!value) { + if (errno == ENOENT) { + con->dev = idx; + goto found; + } + error_setg(errp, "cannot read %s: %s", fe_path, + strerror(errno)); + return NULL; + } + free(value); + idx++; + } + error_setg(errp, "cannot find device index for console device"); + return NULL; } + found: + return g_strdup_printf("%u", con->dev); +} + +static void xen_console_unrealize(XenDevice *xendev) +{ + XenConsole *con = XEN_CONSOLE_DEVICE(xendev); + + trace_xen_console_unrealize(con->dev); - output = xenstore_read_str(con->console, "output"); + /* Disconnect from the frontend in case this has not already happened */ + xen_console_disconnect(xendev, NULL); - /* no Xen override, use qemu output device */ - if (output == NULL) { - if (con->xendev.dev) { - qemu_chr_fe_init(&con->chr, serial_hd(con->xendev.dev), - &error_abort); + qemu_chr_fe_deinit(&con->chr, false); +} + +static void xen_console_realize(XenDevice *xendev, Error **errp) +{ + ERRP_GUARD(); + XenConsole *con = XEN_CONSOLE_DEVICE(xendev); + Chardev *cs = qemu_chr_fe_get_driver(&con->chr); + unsigned int u; + + if (!cs) { + error_setg(errp, "no backing character device"); + return; + } + + if (con->dev == -1) { + error_setg(errp, "no device index provided"); + return; + } + + /* + * The Xen primary console is special. The ring-ref is actually a GFN to + * be mapped directly as foreignmem (not a grant ref), and the guest port + * was allocated *for* the guest by the toolstack. The guest gets these + * through HVMOP_get_param and can use the console long before it's got + * XenStore up and running. We cannot create those for a Xen guest. + */ + if (!con->dev) { + if (xen_device_frontend_scanf(xendev, "ring-ref", "%u", &u) != 1 || + xen_device_frontend_scanf(xendev, "port", "%u", &u) != 1) { + error_setg(errp, "cannot create primary Xen console"); + return; } + } + + trace_xen_console_realize(con->dev, object_get_typename(OBJECT(cs))); + + if (CHARDEV_IS_PTY(cs)) { + /* Strip the leading 'pty:' */ + xen_device_frontend_printf(xendev, "tty", "%s", cs->filename + 4); + } + + /* No normal PV driver initialization for the primary console */ + if (!con->dev) { + xen_console_connect(xendev, errp); + } +} + +static char *console_frontend_path(struct qemu_xs_handle *xenstore, + unsigned int dom_id, unsigned int dev) +{ + if (!dev) { + return g_strdup_printf("/local/domain/%u/console", dom_id); } else { - snprintf(label, sizeof(label), "xencons%d", con->xendev.dev); - qemu_chr_fe_init(&con->chr, - /* - * FIXME: sure we want to support implicit - * muxed monitors here? - */ - qemu_chr_new_mux_mon(label, output, NULL), - &error_abort); + return g_strdup_printf("/local/domain/%u/device/console/%u", dom_id, + dev); } +} - store_con_info(con); +static char *xen_console_get_frontend_path(XenDevice *xendev, Error **errp) +{ + XenConsole *con = XEN_CONSOLE_DEVICE(xendev); + XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); + char *ret = console_frontend_path(xenbus->xsh, xendev->frontend_id, + con->dev); -out: - g_free(type); + if (!ret) { + error_setg(errp, "failed to create frontend path"); + } return ret; } -static int con_initialise(struct XenLegacyDevice *xendev) + +static Property xen_console_properties[] = { + DEFINE_PROP_CHR("chardev", XenConsole, chr), + DEFINE_PROP_INT32("idx", XenConsole, dev, -1), + DEFINE_PROP_END_OF_LIST(), +}; + +static void xen_console_class_init(ObjectClass *class, void *data) { - struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); - int limit; - - if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1) - return -1; - if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1) - return -1; - if (xenstore_read_int(con->console, "limit", &limit) == 0) - con->buffer.max_capacity = limit; + DeviceClass *dev_class = DEVICE_CLASS(class); + XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class); + + xendev_class->backend = "console"; + xendev_class->device = "console"; + xendev_class->get_name = xen_console_get_name; + xendev_class->realize = xen_console_realize; + xendev_class->frontend_changed = xen_console_frontend_changed; + xendev_class->unrealize = xen_console_unrealize; + xendev_class->get_frontend_path = xen_console_get_frontend_path; + + device_class_set_props(dev_class, xen_console_properties); +} - if (!xendev->dev) { - xen_pfn_t mfn = con->ring_ref; - con->sring = qemu_xen_foreignmem_map(con->xendev.dom, NULL, - PROT_READ | PROT_WRITE, - 1, &mfn, NULL); - } else { - con->sring = xen_be_map_grant_ref(xendev, con->ring_ref, - PROT_READ | PROT_WRITE); - } - if (!con->sring) - return -1; +static const TypeInfo xen_console_type_info = { + .name = TYPE_XEN_CONSOLE_DEVICE, + .parent = TYPE_XEN_DEVICE, + .instance_size = sizeof(XenConsole), + .class_init = xen_console_class_init, +}; - xen_be_bind_evtchn(&con->xendev); - qemu_chr_fe_set_handlers(&con->chr, xencons_can_receive, - xencons_receive, NULL, NULL, con, NULL, true); - - xen_pv_printf(xendev, 1, - "ring mfn %d, remote port %d, local port %d, limit %zd\n", - con->ring_ref, - con->xendev.remote_port, - con->xendev.local_port, - con->buffer.max_capacity); - return 0; +static void xen_console_register_types(void) +{ + type_register_static(&xen_console_type_info); } -static void con_disconnect(struct XenLegacyDevice *xendev) +type_init(xen_console_register_types) + +/* Called to instantiate a XenConsole when the backend is detected. */ +static void xen_console_device_create(XenBackendInstance *backend, + QDict *opts, Error **errp) { - struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); + ERRP_GUARD(); + XenBus *xenbus = xen_backend_get_bus(backend); + const char *name = xen_backend_get_name(backend); + unsigned long number; + char *fe = NULL, *type = NULL, *output = NULL; + char label[32]; + XenDevice *xendev = NULL; + XenConsole *con; + Chardev *cd = NULL; + struct qemu_xs_handle *xsh = xenbus->xsh; + + if (qemu_strtoul(name, NULL, 10, &number) || number > INT_MAX) { + error_setg(errp, "failed to parse name '%s'", name); + goto fail; + } - qemu_chr_fe_deinit(&con->chr, false); - xen_pv_unbind_evtchn(&con->xendev); + trace_xen_console_device_create(number); - if (con->sring) { - if (!xendev->dev) { - qemu_xen_foreignmem_unmap(con->sring, 1); - } else { - xen_be_unmap_grant_ref(xendev, con->sring, con->ring_ref); + fe = console_frontend_path(xsh, xen_domid, number); + if (fe == NULL) { + error_setg(errp, "failed to generate frontend path"); + goto fail; + } + + if (xs_node_scanf(xsh, XBT_NULL, fe, "type", errp, "%ms", &type) != 1) { + error_prepend(errp, "failed to read console device type: "); + goto fail; + } + + if (strcmp(type, "ioemu")) { + error_setg(errp, "declining to handle console type '%s'", + type); + goto fail; + } + + xendev = XEN_DEVICE(qdev_new(TYPE_XEN_CONSOLE_DEVICE)); + con = XEN_CONSOLE_DEVICE(xendev); + + con->dev = number; + + snprintf(label, sizeof(label), "xencons%ld", number); + + if (xs_node_scanf(xsh, XBT_NULL, fe, "output", NULL, "%ms", &output) == 1) { + /* + * FIXME: sure we want to support implicit + * muxed monitors here? + */ + cd = qemu_chr_new_mux_mon(label, output, NULL); + if (!cd) { + error_setg(errp, "console: No valid chardev found at '%s': ", + output); + goto fail; } - con->sring = NULL; + } else if (number) { + cd = serial_hd(number); + if (!cd) { + error_prepend(errp, "console: No serial device #%ld found: ", + number); + goto fail; + } + } else { + /* No 'output' node on primary console: use null. */ + cd = qemu_chr_new(label, "null", NULL); + if (!cd) { + error_setg(errp, "console: failed to create null device"); + goto fail; + } + } + + if (!qemu_chr_fe_init(&con->chr, cd, errp)) { + error_prepend(errp, "console: failed to initialize backing chardev: "); + goto fail; + } + + if (qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { + xen_backend_set_device(backend, xendev); + goto done; + } + + error_prepend(errp, "realization of console device %lu failed: ", + number); + + fail: + if (xendev) { + object_unparent(OBJECT(xendev)); } + done: + g_free(fe); + free(type); + free(output); } -static void con_event(struct XenLegacyDevice *xendev) +static void xen_console_device_destroy(XenBackendInstance *backend, + Error **errp) { - struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); + ERRP_GUARD(); + XenDevice *xendev = xen_backend_get_device(backend); + XenConsole *con = XEN_CONSOLE_DEVICE(xendev); - buffer_append(con); - if (con->buffer.size - con->buffer.consumed) - xencons_send(con); -} + trace_xen_console_device_destroy(con->dev); -/* -------------------------------------------------------------------- */ + object_unparent(OBJECT(xendev)); +} -struct XenDevOps xen_console_ops = { - .size = sizeof(struct XenConsole), - .flags = DEVOPS_FLAG_IGNORE_STATE|DEVOPS_FLAG_NEED_GNTDEV, - .init = con_init, - .initialise = con_initialise, - .event = con_event, - .disconnect = con_disconnect, +static const XenBackendInfo xen_console_backend_info = { + .type = "console", + .create = xen_console_device_create, + .destroy = xen_console_device_destroy, }; + +static void xen_console_register_backend(void) +{ + xen_backend_register(&xen_console_backend_info); +} + +xen_backend_init(xen_console_register_backend); diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c index 4ded3cec23..124dd5f3d6 100644 --- a/hw/xen/xen-legacy-backend.c +++ b/hw/xen/xen-legacy-backend.c @@ -623,7 +623,6 @@ void xen_be_init(void) xen_set_dynamic_sysbus(); - xen_be_register("console", &xen_console_ops); xen_be_register("vkbd", &xen_kbdmouse_ops); #ifdef CONFIG_VIRTFS xen_be_register("9pfs", &xen_9pfs_ops); -- 2.34.1