Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6 and git://git.infradea...

[pandora-kernel.git] / Documentation / virtual / lguest / lguest.c

diff --git a/Documentation/virtual/lguest/lguest.c b/Documentation/virtual/lguest/lguest.c
index cd9d6af..d928c13 100644 (file)
--- a/Documentation/virtual/lguest/lguest.c
+++ b/Documentation/virtual/lguest/lguest.c
@@ -51,7 +51,7 @@
 #include <asm/bootparam.h>
 #include "../../../include/linux/lguest_launcher.h"
 /*L:110
- * We can ignore the 42 include files we need for this program, but I do want
+ * We can ignore the 43 include files we need for this program, but I do want
  * to draw attention to the use of kernel-style types.
  *
  * As Linus said, "C is a Spartan language, and so should your naming be."  I
@@ -65,7 +65,6 @@ typedef uint16_t u16;
 typedef uint8_t u8;
 /*:*/
 
-#define PAGE_PRESENT 0x7       /* Present, RW, Execute */
 #define BRIDGE_PFX "bridge:"
 #ifndef SIOCBRADDIF
 #define SIOCBRADDIF    0x89a2          /* add interface to bridge      */
@@ -861,8 +860,10 @@ static void console_output(struct virtqueue *vq)
        /* writev can return a partial write, so we loop here. */
        while (!iov_empty(iov, out)) {
                int len = writev(STDOUT_FILENO, iov, out);
-               if (len <= 0)
-                       err(1, "Write to stdout gave %i", len);
+               if (len <= 0) {
+                       warn("Write to stdout gave %i (%d)", len, errno);
+                       break;
+               }
                iov_consume(iov, out, len);
        }
 
@@ -898,7 +899,7 @@ static void net_output(struct virtqueue *vq)
         * same format: what a coincidence!
         */
        if (writev(net_info->tunfd, iov, out) < 0)
-               errx(1, "Write to tun failed?");
+               warnx("Write to tun failed (%d)?", errno);
 
        /*
         * Done with that one; wait_for_vq_desc() will send the interrupt if
@@ -955,7 +956,7 @@ static void net_input(struct virtqueue *vq)
         */
        len = readv(net_info->tunfd, iov, in);
        if (len <= 0)
-               err(1, "Failed to read from tun.");
+               warn("Failed to read from tun (%d).", errno);
 
        /*
         * Mark that packet buffer as used, but don't interrupt here.  We want
@@ -1093,9 +1094,10 @@ static void update_device_status(struct device *dev)
                warnx("Device %s configuration FAILED", dev->name);
                if (dev->running)
                        reset_device(dev);
-       } else if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK) {
-               if (!dev->running)
-                       start_device(dev);
+       } else {
+               if (dev->running)
+                       err(1, "Device %s features finalized twice", dev->name);
+               start_device(dev);
        }
 }
 
@@ -1120,25 +1122,11 @@ static void handle_output(unsigned long addr)
                        return;
                }
 
-               /*
-                * Devices *can* be used before status is set to DRIVER_OK.
-                * The original plan was that they would never do this: they
-                * would always finish setting up their status bits before
-                * actually touching the virtqueues.  In practice, we allowed
-                * them to, and they do (eg. the disk probes for partition
-                * tables as part of initialization).
-                *
-                * If we see this, we start the device: once it's running, we
-                * expect the device to catch all the notifications.
-                */
+               /* Devices should not be used before features are finalized. */
                for (vq = i->vq; vq; vq = vq->next) {
                        if (addr != vq->config.pfn*getpagesize())
                                continue;
-                       if (i->running)
-                               errx(1, "Notification on running %s", i->name);
-                       /* This just calls create_thread() for each virtqueue */
-                       start_device(i);
-                       return;
+                       errx(1, "Notification on %s before setup!", i->name);
                }
        }
 
@@ -1370,7 +1358,7 @@ static void setup_console(void)
  * --sharenet=<name> option which opens or creates a named pipe.  This can be
  * used to send packets to another guest in a 1:1 manner.
  *
- * More sopisticated is to use one of the tools developed for project like UML
+ * More sophisticated is to use one of the tools developed for project like UML
  * to do networking.
  *
  * Faster is to do virtio bonding in kernel.  Doing this 1:1 would be
@@ -1380,7 +1368,7 @@ static void setup_console(void)
  * multiple inter-guest channels behind one interface, although it would
  * require some manner of hotplugging new virtio channels.
  *
- * Finally, we could implement a virtio network switch in the kernel.
+ * Finally, we could use a virtio network switch in the kernel, ie. vhost.
 :*/
 
 static u32 str2ip(const char *ipaddr)
@@ -2008,6 +1996,9 @@ int main(int argc, char *argv[])
        /* We use a simple helper to copy the arguments separated by spaces. */
        concat((char *)(boot + 1), argv+optind+2);
 
+       /* Set kernel alignment to 16M (CONFIG_PHYSICAL_ALIGN) */
+       boot->hdr.kernel_alignment = 0x1000000;
+
        /* Boot protocol version: 2.07 supports the fields for lguest. */
        boot->hdr.version = 0x207;
 
@@ -2017,10 +2008,7 @@ int main(int argc, char *argv[])
        /* Tell the entry path not to try to reload segment registers. */
        boot->hdr.loadflags |= KEEP_SEGMENTS;
 
-       /*
-        * We tell the kernel to initialize the Guest: this returns the open
-        * /dev/lguest file descriptor.
-        */
+       /* We tell the kernel to initialize the Guest. */
        tell_kernel(start);
 
        /* Ensure that we terminate if a device-servicing child dies. */