/* * 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 <xs.h> #include <xen/io/console.h> #include <xenctrl.h> #include "hw.h" #include "sysemu.h" #include "qemu-char.h" #include "xen_backend.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 = qemu_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 = qemu_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_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; /* setup */ dom = xs_get_domain_path(xenstore, con->xendev.dom); snprintf(con->console, sizeof(con->console), "%s/console", dom); 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); return -1; } if (!serial_hds[con->xendev.dev]) xen_be_printf(xendev, 1, "WARNING: serial line %d not configured\n", con->xendev.dev); else con->chr = serial_hds[con->xendev.dev]; return 0; } static int con_connect(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; con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom, XC_PAGE_SIZE, PROT_READ|PROT_WRITE, con->ring_ref); if (!con->sring) return -1; xen_be_bind_evtchn(&con->xendev); if (con->chr) qemu_chr_add_handlers(con->chr, xencons_can_receive, xencons_receive, NULL, con); 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 (con->chr) qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL); xen_be_unbind_evtchn(&con->xendev); if (con->sring) { munmap(con->sring, XC_PAGE_SIZE); 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, .init = con_init, .connect = con_connect, .event = con_event, .disconnect = con_disconnect, };