Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (27 commits)
  lguest: use __PAGE_KERNEL instead of _PAGE_KERNEL
  lguest: Use explicit includes rateher than indirect
  lguest: get rid of lg variable assignments
  lguest: change gpte_addr header
  lguest: move changed bitmap to lg_cpu
  lguest: move last_pages to lg_cpu
  lguest: change last_guest to last_cpu
  lguest: change spte_addr header
  lguest: per-vcpu lguest pgdir management
  lguest: make pending notifications per-vcpu
  lguest: makes special fields be per-vcpu
  lguest: per-vcpu lguest task management
  lguest: replace lguest_arch with lg_cpu_arch.
  lguest: make registers per-vcpu
  lguest: make emulate_insn receive a vcpu struct.
  lguest: map_switcher_in_guest() per-vcpu
  lguest: per-vcpu interrupt processing.
  lguest: per-vcpu lguest timers
  lguest: make hypercalls use the vcpu struct
  lguest: make write() operation smp aware
  ...

Manual conflict resolved (maybe even correctly, who knows) in
drivers/lguest/x86/core.c

1 files changed, 43 insertions, 6 deletions

diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index 9b0e322118b5..6c8a2386cd50 100644
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -79,6 +79,9 @@ static void *guest_base;
 /* The maximum guest physical address allowed, and maximum possible. */
 static unsigned long guest_limit, guest_max;
 
+/* a per-cpu variable indicating whose vcpu is currently running */
+static unsigned int __thread cpu_id;
+
 /* This is our list of devices. */
 struct device_list
 {
@@ -153,6 +156,9 @@ struct virtqueue
         void (*handle_output)(int fd, struct virtqueue *me);
 };
 
+/* Remember the arguments to the program so we can "reboot" */
+static char **main_args;
+
 /* Since guest is UP and we don't run at the same time, we don't need barriers.
  * But I include them in the code in case others copy it. */
 #define wmb()
@@ -554,7 +560,7 @@ static void wake_parent(int pipefd, int lguest_fd)
                         else
                                 FD_CLR(-fd - 1, &devices.infds);
                 } else /* Send LHREQ_BREAK command. */
-                        write(lguest_fd, args, sizeof(args));
+                        pwrite(lguest_fd, args, sizeof(args), cpu_id);
         }
 }
 
@@ -1489,7 +1495,9 @@ static void setup_block_file(const char *filename)
 
         /* Create stack for thread and run it */
         stack = malloc(32768);
-        if (clone(io_thread, stack + 32768, CLONE_VM, dev) == -1)
+        /* SIGCHLD - We dont "wait" for our cloned thread, so prevent it from
+         * becoming a zombie. */
+        if (clone(io_thread, stack + 32768,  CLONE_VM | SIGCHLD, dev) == -1)
                 err(1, "Creating clone");
 
         /* We don't need to keep the I/O thread's end of the pipes open. */
@@ -1499,7 +1507,21 @@ static void setup_block_file(const char *filename)
         verbose("device %u: virtblock %llu sectors\n",
                 devices.device_num, cap);
 }
-/* That's the end of device setup. */
+/* That's the end of device setup. :*/
+
+/* Reboot */
+static void __attribute__((noreturn)) restart_guest(void)
+{
+        unsigned int i;
+
+        /* Closing pipes causes the waker thread and io_threads to die, and
+         * closing /dev/lguest cleans up the Guest.  Since we don't track all
+         * open fds, we simply close everything beyond stderr. */
+        for (i = 3; i < FD_SETSIZE; i++)
+                close(i);
+        execv(main_args[0], main_args);
+        err(1, "Could not exec %s", main_args[0]);
+}
 
 /*L:220 Finally we reach the core of the Launcher, which runs the Guest, serves
  * its input and output, and finally, lays it to rest. */
@@ -1511,7 +1533,8 @@ static void __attribute__((noreturn)) run_guest(int lguest_fd)
                 int readval;
 
                 /* We read from the /dev/lguest device to run the Guest. */
-                readval = read(lguest_fd, &notify_addr, sizeof(notify_addr));
+                readval = pread(lguest_fd, &notify_addr,
+                                sizeof(notify_addr), cpu_id);
 
                 /* One unsigned long means the Guest did HCALL_NOTIFY */
                 if (readval == sizeof(notify_addr)) {
@@ -1521,16 +1544,23 @@ static void __attribute__((noreturn)) run_guest(int lguest_fd)
                 /* ENOENT means the Guest died.  Reading tells us why. */
                 } else if (errno == ENOENT) {
                         char reason[1024] = { 0 };
-                        read(lguest_fd, reason, sizeof(reason)-1);
+                        pread(lguest_fd, reason, sizeof(reason)-1, cpu_id);
                         errx(1, "%s", reason);
+                /* ERESTART means that we need to reboot the guest */
+                } else if (errno == ERESTART) {
+                        restart_guest();
                 /* EAGAIN means the Waker wanted us to look at some input.
                  * Anything else means a bug or incompatible change. */
                 } else if (errno != EAGAIN)
                         err(1, "Running guest failed");
 
+                /* Only service input on thread for CPU 0. */
+                if (cpu_id != 0)
+                        continue;
+
                 /* Service input, then unset the BREAK to release the Waker. */
                 handle_input(lguest_fd);
-                if (write(lguest_fd, args, sizeof(args)) < 0)
+                if (pwrite(lguest_fd, args, sizeof(args), cpu_id) < 0)
                         err(1, "Resetting break");
         }
 }
@@ -1571,6 +1601,12 @@ int main(int argc, char *argv[])
         /* If they specify an initrd file to load. */
         const char *initrd_name = NULL;
 
+        /* Save the args: we "reboot" by execing ourselves again. */
+        main_args = argv;
+        /* We don't "wait" for the children, so prevent them from becoming
+         * zombies. */
+        signal(SIGCHLD, SIG_IGN);
+
         /* First we initialize the device list.  Since console and network
          * device receive input from a file descriptor, we keep an fdset
          * (infds) and the maximum fd number (max_infd) with the head of the
@@ -1582,6 +1618,7 @@ int main(int argc, char *argv[])
         devices.lastdev = &devices.dev;
         devices.next_irq = 1;
 
+        cpu_id = 0;
         /* We need to know how much memory so we can set up the device
          * descriptor and memory pages for the devices as we parse the command
          * line.  So we quickly look through the arguments to find the amount