/******************************************************************************
* xend.c
*
- * The grand Xen daemon. For now it's just a console concentrator.
+ * The grand Xen daemon. For now it's just a virtual-console concentrator.
*
* Copyright (c) 2004, K A Fraser
*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <xc.h>
+
+/* NB. The following should be kept in sync with the kernel's evtchn driver. */
+#define EVTCHN_DEV_NAME "/dev/xen/evtchn"
+#define EVTCHN_DEV_MAJOR 10
+#define EVTCHN_DEV_MINOR 200
+#define PORT_NORMAL 0x0000 /* A standard event notification. */
+#define PORT_DISCONNECT 0x8000 /* A port-disconnect notification. */
+#define PORTIDX_MASK 0x7fff /* Strip subtype to obtain port index. */
+#define EVTCHN_RESET _IO('E', 1) /* Clear notification buffer. Clear errors. */
+
+/* Error macros. */
+#define ERROR(_f, _a...) \
+ fprintf ( stderr, "ERROR: " _f "\n" , ## _a );
+#define SYS_ERROR(_f, _a...) \
+ fprintf ( stderr, "ERROR: " _f " [errno=%d (%s)]\n" , \
+ ## _a , errno , strerror(errno) );
+#define HINT(_f, _a...) \
+ fprintf ( stderr, "Hint: " _f "\n" , ## _a );
+#define ROOT_HINT() HINT("You must execute this daemon as root.")
+#define DOM0_HINT() HINT("You must execute this daemon " \
+ "on a privileged Xenolinux instance (e.g., DOM0).")
+
+/* The following is to be shared with guest kernels. */
+typedef struct {
+ u8 cmd_type; /* echoed in response */
+ u8 cmd_subtype; /* echoed in response */
+ u8 id; /* echoed in response */
+ u8 length; /* number of bytes in 'msg' */
+ unsigned char msg[60]; /* command-specific message data */
+} control_msg_t;
+#define CONTROL_RING_SIZE 8
+typedef unsigned int CONTROL_RING_IDX;
+#define MASK_CONTROL_IDX(_i) ((_i)&(CONTROL_RING_SIZE-1))
+typedef struct {
+ control_msg_t tx_ring[CONTROL_RING_SIZE]; /* guest -> DOM0 */
+ control_msg_t rx_ring[CONTROL_RING_SIZE]; /* DOM0 -> guest */
+ CONTROL_RING_IDX tx_req_prod, tx_resp_prod;
+ CONTROL_RING_IDX rx_req_prod, rx_resp_prod;
+} control_comms_t;
+#define CMD_CONSOLE 0
+#define CMD_CONSOLE_DATA 0
+
+#define PAGE_SHIFT 12
+#define PAGE_SIZE (1<<PAGE_SHIFT)
+
+typedef struct {
+ u64 dom;
+ control_comms_t *comms;
+ CONTROL_RING_IDX tx_req_cons, tx_resp_prod;
+ CONTROL_RING_IDX rx_req_cons, rx_resp_prod;
+} portinfo_t;
+
+static portinfo_t portinfo[1024];
+
+static control_comms_t *map_comms(int fd, unsigned long pfn)
+{
+ char *vaddr = mmap(NULL, PAGE_SIZE, PROT_READ|PROT_WRITE,
+ MAP_SHARED, fd, pfn << PAGE_SHIFT);
+ if ( vaddr == MAP_FAILED )
+ return NULL;
+ return (control_comms_t *)(vaddr + 2048);
+}
+
+static void unmap_comms(int fd, control_comms_t *c)
+{
+ char *vaddr = (char *)c - 2048;
+ (void)munmap(vaddr, PAGE_SIZE);
+}
+
+#define PORT_CHUNK 4
int main(int argc, char **argv)
{
+ int fd, memfd, xch, chunk;
+ unsigned int bytes, i, port, portid, status;
+ u64 domid;
+ u16 buf[PORT_CHUNK];
+
+ if ( (fd = open(EVTCHN_DEV_NAME, O_RDWR)) == -1 )
+ {
+ SYS_ERROR("Could not open '%s'", EVTCHN_DEV_NAME);
+ ROOT_HINT();
+ HINT("On a non-devfs system you must run 'mknod %s c %d %d'.",
+ EVTCHN_DEV_NAME, EVTCHN_DEV_MAJOR, EVTCHN_DEV_MINOR);
+ exit(1);
+ }
+
+ if ( (memfd = open("/dev/mem", O_RDWR)) == -1 )
+ {
+ SYS_ERROR("Could not open '/dev/mem'");
+ ROOT_HINT();
+ exit(1);
+ }
+
+ if ( (xch = xc_interface_open()) == -1 )
+ {
+ SYS_ERROR("Could not open Xen control interface");
+ ROOT_HINT();
+ DOM0_HINT();
+ exit(1);
+ }
+
+ while ( (bytes = read(fd, buf, sizeof(buf))) == -1 )
+ {
+ if ( errno == EINTR )
+ continue;
+ SYS_ERROR("Unexpected error reading '%s'.", EVTCHN_DEV_NAME);
+ exit(1);
+ }
+
+ if ( (bytes == 0) || ((bytes & 1) != 0) )
+ {
+ ERROR("Short or bad read length (%d bytes) from '%s'.",
+ bytes, EVTCHN_DEV_NAME);
+ exit(1);
+ }
+
+ chunk = bytes / 2;
+ for ( i = 0; i < chunk; i++ )
+ {
+ port = buf[i] & PORTIDX_MASK;
+ if ( buf[i] & PORT_DISCONNECT )
+ {
+ if ( portinfo[port].comms == NULL )
+ continue;
+ unmap_comms(memfd, portinfo[port].comms);
+ portinfo[port].comms = NULL;
+ (void)write(fd, &buf[i], sizeof(u16));
+ (void)xc_evtchn_close(xch, DOMID_SELF, port);
+ }
+ else
+ {
+ if ( portinfo[port].comms == NULL )
+ {
+ xc_dominfo_t info;
+ xc_evtchn_status(xch, DOMID_SELF, port,
+ &domid, &portid, &status);
+
+ if ( (status == EVTCHNSTAT_closed) ||
+ ((status == EVTCHNSTAT_disconnected) && (portid == 0)) )
+ {
+ /* Cleanup sanity: we'll be the grim reaper. */
+ (void)write(fd, &buf[i], sizeof(u16)); /* PORT_NORMAL */
+ buf[i] |= PORT_DISCONNECT;
+ (void)write(fd, &buf[i], sizeof(u16)); /* PORT_DISCON */
+ continue;
+ }
+
+ /* We only deal with initial ports (id == 0). */
+ if ( portid != 0 )
+ continue;
+
+ xc_domain_getinfo(xch, domid, 1, &info);
+ portinfo[port].comms =
+ map_comms(memfd, info.shared_info_frame);
+ portinfo[port].dom = domid;
+ portinfo[port].tx_req_cons = 0;
+ portinfo[port].tx_resp_prod = 0;
+ portinfo[port].rx_req_cons = 0;
+ portinfo[port].rx_resp_prod = 0;
+ }
+
+ do {
+ xc_evtchn_send(xch, port);
+ write(fd, &buf[i], sizeof(u16));
+ } while ( 0 );
+ }
+ }
+
+ (void)xc_interface_close(xch);
+ (void)close(memfd);
+ (void)close(fd);
+
return 0;
}
projects / xen.git / commitdiff