--- /dev/null
+/*
+ * Copyright (C) International Business Machines Corp., 2005
+ * Author(s): Anthony Liguori <aliguori@us.ibm.com>
+ *
+ * Copyright (C) Red Hat 2007
+ *
+ * Xen Console
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; under version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/select.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <termios.h>
+#include <stdarg.h>
+#include <sys/mman.h>
+
+#include "hw/hw.h"
+#include "sysemu/char.h"
+#include "hw/xen/xen_backend.h"
+
+#include <xen/io/console.h>
+
+struct buffer {
+ uint8_t *data;
+ size_t consumed;
+ size_t size;
+ size_t capacity;
+ size_t max_capacity;
+};
+
+struct XenConsole {
+ struct XenDevice xendev; /* must be first */
+ struct buffer buffer;
+ char console[XEN_BUFSIZE];
+ int ring_ref;
+ void *sring;
+ CharDriverState *chr;
+ int backlog;
+};
+
+static void buffer_append(struct XenConsole *con)
+{
+ struct buffer *buffer = &con->buffer;
+ XENCONS_RING_IDX cons, prod, size;
+ struct xencons_interface *intf = con->sring;
+
+ cons = intf->out_cons;
+ prod = intf->out_prod;
+ xen_mb();
+
+ size = prod - cons;
+ if ((size == 0) || (size > sizeof(intf->out)))
+ return;
+
+ if ((buffer->capacity - buffer->size) < size) {
+ buffer->capacity += (size + 1024);
+ buffer->data = g_realloc(buffer->data, buffer->capacity);
+ }
+
+ while (cons != prod)
+ buffer->data[buffer->size++] = intf->out[
+ MASK_XENCONS_IDX(cons++, intf->out)];
+
+ xen_mb();
+ intf->out_cons = cons;
+ xen_be_send_notify(&con->xendev);
+
+ if (buffer->max_capacity &&
+ buffer->size > buffer->max_capacity) {
+ /* Discard the middle of the data. */
+
+ size_t over = buffer->size - buffer->max_capacity;
+ uint8_t *maxpos = buffer->data + buffer->max_capacity;
+
+ memmove(maxpos - over, maxpos, over);
+ buffer->data = g_realloc(buffer->data, buffer->max_capacity);
+ buffer->size = buffer->capacity = buffer->max_capacity;
+
+ if (buffer->consumed > buffer->max_capacity - over)
+ buffer->consumed = buffer->max_capacity - over;
+ }
+}
+
+static void buffer_advance(struct buffer *buffer, size_t len)
+{
+ buffer->consumed += len;
+ if (buffer->consumed == buffer->size) {
+ buffer->consumed = 0;
+ buffer->size = 0;
+ }
+}
+
+static int ring_free_bytes(struct XenConsole *con)
+{
+ struct xencons_interface *intf = con->sring;
+ XENCONS_RING_IDX cons, prod, space;
+
+ cons = intf->in_cons;
+ prod = intf->in_prod;
+ xen_mb();
+
+ space = prod - cons;
+ if (space > sizeof(intf->in))
+ return 0; /* ring is screwed: ignore it */
+
+ return (sizeof(intf->in) - space);
+}
+
+static int xencons_can_receive(void *opaque)
+{
+ struct XenConsole *con = opaque;
+ return ring_free_bytes(con);
+}
+
+static void xencons_receive(void *opaque, const uint8_t *buf, int len)
+{
+ struct XenConsole *con = opaque;
+ struct xencons_interface *intf = con->sring;
+ XENCONS_RING_IDX prod;
+ int i, max;
+
+ max = ring_free_bytes(con);
+ /* The can_receive() func limits this, but check again anyway */
+ if (max < len)
+ len = max;
+
+ prod = intf->in_prod;
+ for (i = 0; i < len; i++) {
+ intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
+ buf[i];
+ }
+ xen_wmb();
+ intf->in_prod = prod;
+ xen_be_send_notify(&con->xendev);
+}
+
+static void xencons_send(struct XenConsole *con)
+{
+ ssize_t len, size;
+
+ size = con->buffer.size - con->buffer.consumed;
+ if (con->chr)
+ len = qemu_chr_fe_write(con->chr, con->buffer.data + con->buffer.consumed,
+ size);
+ else
+ len = size;
+ if (len < 1) {
+ if (!con->backlog) {
+ con->backlog = 1;
+ xen_be_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_be_printf(&con->xendev, 1, "backlog is gone\n");
+ }
+ }
+}
+
+/* -------------------------------------------------------------------- */
+
+static int con_init(struct XenDevice *xendev)
+{
+ struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
+ char *type, *dom, label[32];
+ int ret = 0;
+ const char *output;
+
+ /* setup */
+ dom = 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);
+ }
+ free(dom);
+
+ type = xenstore_read_str(con->console, "type");
+ if (!type || strcmp(type, "ioemu") != 0) {
+ xen_be_printf(xendev, 1, "not for me (type=%s)\n", type);
+ ret = -1;
+ goto out;
+ }
+
+ output = xenstore_read_str(con->console, "output");
+
+ /* no Xen override, use qemu output device */
+ if (output == NULL) {
+ con->chr = serial_hds[con->xendev.dev];
+ } else {
+ snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
+ con->chr = qemu_chr_new(label, output, NULL);
+ }
+
+ xenstore_store_pv_console_info(con->xendev.dev, con->chr);
+
+out:
+ g_free(type);
+ return ret;
+}
+
+static int con_initialise(struct XenDevice *xendev)
+{
+ 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;
+
+ if (!xendev->dev) {
+ con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom,
+ XC_PAGE_SIZE,
+ PROT_READ|PROT_WRITE,
+ con->ring_ref);
+ } else {
+ con->sring = xc_gnttab_map_grant_ref(xendev->gnttabdev, con->xendev.dom,
+ con->ring_ref,
+ PROT_READ|PROT_WRITE);
+ }
+ if (!con->sring)
+ return -1;
+
+ xen_be_bind_evtchn(&con->xendev);
+ if (con->chr) {
+ if (qemu_chr_fe_claim(con->chr) == 0) {
+ qemu_chr_add_handlers(con->chr, xencons_can_receive,
+ xencons_receive, NULL, con);
+ } else {
+ xen_be_printf(xendev, 0,
+ "xen_console_init error chardev %s already used\n",
+ con->chr->label);
+ con->chr = NULL;
+ }
+ }
+
+ xen_be_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 con_disconnect(struct XenDevice *xendev)
+{
+ struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
+
+ if (!xendev->dev) {
+ return;
+ }
+ if (con->chr) {
+ qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL);
+ qemu_chr_fe_release(con->chr);
+ }
+ xen_be_unbind_evtchn(&con->xendev);
+
+ if (con->sring) {
+ if (!xendev->gnttabdev) {
+ munmap(con->sring, XC_PAGE_SIZE);
+ } else {
+ xc_gnttab_munmap(xendev->gnttabdev, con->sring, 1);
+ }
+ con->sring = NULL;
+ }
+}
+
+static void con_event(struct XenDevice *xendev)
+{
+ struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
+
+ buffer_append(con);
+ if (con->buffer.size - con->buffer.consumed)
+ xencons_send(con);
+}
+
+/* -------------------------------------------------------------------- */
+
+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,
+};
Code Review / kvmfornfv.git / blobdiff