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

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

arch/x86/lguest/boot.c

@@ -67,6 +67,7 @@
 #include <asm/mce.h>
 #include <asm/io.h>
 #include <asm/i387.h>
+#include <asm/reboot.h>		/* for struct machine_ops */
 
 /*G:010 Welcome to the Guest!
  *
@@ -813,7 +814,7 @@ static void lguest_safe_halt(void)
  * rather than virtual addresses, so we use __pa() here. */
 static void lguest_power_off(void)
 {
-	hcall(LHCALL_CRASH, __pa("Power down"), 0, 0);
+	hcall(LHCALL_SHUTDOWN, __pa("Power down"), LGUEST_SHUTDOWN_POWEROFF, 0);
 }
 
 /*
@@ -823,7 +824,7 @@ static void lguest_power_off(void)
  */
 static int lguest_panic(struct notifier_block *nb, unsigned long l, void *p)
 {
-	hcall(LHCALL_CRASH, __pa(p), 0, 0);
+	hcall(LHCALL_SHUTDOWN, __pa(p), LGUEST_SHUTDOWN_POWEROFF, 0);
 	/* The hcall won't return, but to keep gcc happy, we're "done". */
 	return NOTIFY_DONE;
 }
@@ -927,6 +928,11 @@ static unsigned lguest_patch(u8 type, u16 clobber, void *ibuf,
 	return insn_len;
 }
 
+static void lguest_restart(char *reason)
+{
+	hcall(LHCALL_SHUTDOWN, __pa(reason), LGUEST_SHUTDOWN_RESTART, 0);
+}
+
 /*G:030 Once we get to lguest_init(), we know we're a Guest.  The pv_ops
  * structures in the kernel provide points for (almost) every routine we have
  * to override to avoid privileged instructions. */
@@ -1060,6 +1066,7 @@ __init void lguest_init(void)
 	 * the Guest routine to power off. */
 	pm_power_off = lguest_power_off;
 
+	machine_ops.restart = lguest_restart;
 	/* Now we're set up, call start_kernel() in init/main.c and we proceed
 	 * to boot as normal.  It never returns. */
 	start_kernel();

drivers/Makefile

@@ -72,7 +72,7 @@ obj-$(CONFIG_ISDN)		+= isdn/
 obj-$(CONFIG_EDAC)		+= edac/
 obj-$(CONFIG_MCA)		+= mca/
 obj-$(CONFIG_EISA)		+= eisa/
-obj-$(CONFIG_LGUEST_GUEST)	+= lguest/
+obj-y				+= lguest/
 obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
 obj-$(CONFIG_CPU_IDLE)		+= cpuidle/
 obj-$(CONFIG_MMC)		+= mmc/

drivers/lguest/core.c

@@ -151,43 +151,43 @@ int lguest_address_ok(const struct lguest *lg,
 /* This routine copies memory from the Guest.  Here we can see how useful the
  * kill_lguest() routine we met in the Launcher can be: we return a random
  * value (all zeroes) instead of needing to return an error. */
-void __lgread(struct lguest *lg, void *b, unsigned long addr, unsigned bytes)
+void __lgread(struct lg_cpu *cpu, void *b, unsigned long addr, unsigned bytes)
 {
-	if (!lguest_address_ok(lg, addr, bytes)
-	    || copy_from_user(b, lg->mem_base + addr, bytes) != 0) {
+	if (!lguest_address_ok(cpu->lg, addr, bytes)
+	    || copy_from_user(b, cpu->lg->mem_base + addr, bytes) != 0) {
 		/* copy_from_user should do this, but as we rely on it... */
 		memset(b, 0, bytes);
-		kill_guest(lg, "bad read address %#lx len %u", addr, bytes);
+		kill_guest(cpu, "bad read address %#lx len %u", addr, bytes);
 	}
 }
 
 /* This is the write (copy into guest) version. */
-void __lgwrite(struct lguest *lg, unsigned long addr, const void *b,
+void __lgwrite(struct lg_cpu *cpu, unsigned long addr, const void *b,
 	       unsigned bytes)
 {
-	if (!lguest_address_ok(lg, addr, bytes)
-	    || copy_to_user(lg->mem_base + addr, b, bytes) != 0)
-		kill_guest(lg, "bad write address %#lx len %u", addr, bytes);
+	if (!lguest_address_ok(cpu->lg, addr, bytes)
+	    || copy_to_user(cpu->lg->mem_base + addr, b, bytes) != 0)
+		kill_guest(cpu, "bad write address %#lx len %u", addr, bytes);
 }
 /*:*/
 
 /*H:030 Let's jump straight to the the main loop which runs the Guest.
  * Remember, this is called by the Launcher reading /dev/lguest, and we keep
  * going around and around until something interesting happens. */
-int run_guest(struct lguest *lg, unsigned long __user *user)
+int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 {
 	/* We stop running once the Guest is dead. */
-	while (!lg->dead) {
+	while (!cpu->lg->dead) {
 		/* First we run any hypercalls the Guest wants done. */
-		if (lg->hcall)
-			do_hypercalls(lg);
+		if (cpu->hcall)
+			do_hypercalls(cpu);
 
 		/* It's possible the Guest did a NOTIFY hypercall to the
 		 * Launcher, in which case we return from the read() now. */
-		if (lg->pending_notify) {
-			if (put_user(lg->pending_notify, user))
+		if (cpu->pending_notify) {
+			if (put_user(cpu->pending_notify, user))
 				return -EFAULT;
-			return sizeof(lg->pending_notify);
+			return sizeof(cpu->pending_notify);
 		}
 
 		/* Check for signals */
@@ -195,13 +195,13 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
 			return -ERESTARTSYS;
 
 		/* If Waker set break_out, return to Launcher. */
-		if (lg->break_out)
+		if (cpu->break_out)
 			return -EAGAIN;
 
 		/* Check if there are any interrupts which can be delivered
 		 * now: if so, this sets up the hander to be executed when we
 		 * next run the Guest. */
-		maybe_do_interrupt(lg);
+		maybe_do_interrupt(cpu);
 
 		/* All long-lived kernel loops need to check with this horrible
 		 * thing called the freezer.  If the Host is trying to suspend,
@@ -210,12 +210,12 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
 
 		/* Just make absolutely sure the Guest is still alive.  One of
 		 * those hypercalls could have been fatal, for example. */
-		if (lg->dead)
+		if (cpu->lg->dead)
 			break;
 
 		/* If the Guest asked to be stopped, we sleep.  The Guest's
 		 * clock timer or LHCALL_BREAK from the Waker will wake us. */
-		if (lg->halted) {
+		if (cpu->halted) {
 			set_current_state(TASK_INTERRUPTIBLE);
 			schedule();
 			continue;
@@ -226,15 +226,17 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
 		local_irq_disable();
 
 		/* Actually run the Guest until something happens. */
-		lguest_arch_run_guest(lg);
+		lguest_arch_run_guest(cpu);
 
 		/* Now we're ready to be interrupted or moved to other CPUs */
 		local_irq_enable();
 
 		/* Now we deal with whatever happened to the Guest. */
-		lguest_arch_handle_trap(lg);
+		lguest_arch_handle_trap(cpu);
 	}
 
+	if (cpu->lg->dead == ERR_PTR(-ERESTART))
+		return -ERESTART;
 	/* The Guest is dead => "No such file or directory" */
 	return -ENOENT;
 }
@@ -253,7 +255,7 @@ static int __init init(void)
 
 	/* Lguest can't run under Xen, VMI or itself.  It does Tricky Stuff. */
 	if (paravirt_enabled()) {
-		printk("lguest is afraid of %s\n", pv_info.name);
+		printk("lguest is afraid of being a guest\n");
 		return -EPERM;
 	}
 

drivers/lguest/hypercalls.c

@@ -23,13 +23,14 @@
 #include <linux/uaccess.h>
 #include <linux/syscalls.h>
 #include <linux/mm.h>
+#include <linux/ktime.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include "lg.h"
 
 /*H:120 This is the core hypercall routine: where the Guest gets what it wants.
  * Or gets killed.  Or, in the case of LHCALL_CRASH, both. */
-static void do_hcall(struct lguest *lg, struct hcall_args *args)
+static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 {
 	switch (args->arg0) {
 	case LHCALL_FLUSH_ASYNC:
@@ -39,60 +40,62 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
 	case LHCALL_LGUEST_INIT:
 		/* You can't get here unless you're already initialized.  Don't
 		 * do that. */
-		kill_guest(lg, "already have lguest_data");
+		kill_guest(cpu, "already have lguest_data");
 		break;
-	case LHCALL_CRASH: {
-		/* Crash is such a trivial hypercall that we do it in four
+	case LHCALL_SHUTDOWN: {
+		/* Shutdown is such a trivial hypercall that we do it in four
 		 * lines right here. */
 		char msg[128];
 		/* If the lgread fails, it will call kill_guest() itself; the
 		 * kill_guest() with the message will be ignored. */
-		__lgread(lg, msg, args->arg1, sizeof(msg));
+		__lgread(cpu, msg, args->arg1, sizeof(msg));
 		msg[sizeof(msg)-1] = '\0';
-		kill_guest(lg, "CRASH: %s", msg);
+		kill_guest(cpu, "CRASH: %s", msg);
+		if (args->arg2 == LGUEST_SHUTDOWN_RESTART)
+			cpu->lg->dead = ERR_PTR(-ERESTART);
 		break;
 	}
 	case LHCALL_FLUSH_TLB:
 		/* FLUSH_TLB comes in two flavors, depending on the
 		 * argument: */
 		if (args->arg1)
-			guest_pagetable_clear_all(lg);
+			guest_pagetable_clear_all(cpu);
 		else
-			guest_pagetable_flush_user(lg);
+			guest_pagetable_flush_user(cpu);
 		break;
 
 	/* All these calls simply pass the arguments through to the right
 	 * routines. */
 	case LHCALL_NEW_PGTABLE:
-		guest_new_pagetable(lg, args->arg1);
+		guest_new_pagetable(cpu, args->arg1);
 		break;
 	case LHCALL_SET_STACK:
-		guest_set_stack(lg, args->arg1, args->arg2, args->arg3);
+		guest_set_stack(cpu, args->arg1, args->arg2, args->arg3);
 		break;
 	case LHCALL_SET_PTE:
-		guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
+		guest_set_pte(cpu, args->arg1, args->arg2, __pte(args->arg3));
 		break;
 	case LHCALL_SET_PMD:
-		guest_set_pmd(lg, args->arg1, args->arg2);
+		guest_set_pmd(cpu->lg, args->arg1, args->arg2);
 		break;
 	case LHCALL_SET_CLOCKEVENT:
-		guest_set_clockevent(lg, args->arg1);
+		guest_set_clockevent(cpu, args->arg1);
 		break;
 	case LHCALL_TS:
 		/* This sets the TS flag, as we saw used in run_guest(). */
-		lg->ts = args->arg1;
+		cpu->ts = args->arg1;
 		break;
 	case LHCALL_HALT:
 		/* Similarly, this sets the halted flag for run_guest(). */
-		lg->halted = 1;
+		cpu->halted = 1;
 		break;
 	case LHCALL_NOTIFY:
-		lg->pending_notify = args->arg1;
+		cpu->pending_notify = args->arg1;
 		break;
 	default:
 		/* It should be an architecture-specific hypercall. */
-		if (lguest_arch_do_hcall(lg, args))
-			kill_guest(lg, "Bad hypercall %li\n", args->arg0);
+		if (lguest_arch_do_hcall(cpu, args))
+			kill_guest(cpu, "Bad hypercall %li\n", args->arg0);
 	}
 }
 /*:*/
@@ -104,13 +107,13 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
  * Guest put them in the ring, but we also promise the Guest that they will
  * happen before any normal hypercall (which is why we check this before
  * checking for a normal hcall). */
-static void do_async_hcalls(struct lguest *lg)
+static void do_async_hcalls(struct lg_cpu *cpu)
 {
 	unsigned int i;
 	u8 st[LHCALL_RING_SIZE];
 
 	/* For simplicity, we copy the entire call status array in at once. */
-	if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)))
+	if (copy_from_user(&st, &cpu->lg->lguest_data->hcall_status, sizeof(st)))
 		return;
 
 	/* We process "struct lguest_data"s hcalls[] ring once. */
@@ -119,7 +122,7 @@ static void do_async_hcalls(struct lguest *lg)
 		/* We remember where we were up to from last time.  This makes
 		 * sure that the hypercalls are done in the order the Guest
 		 * places them in the ring. */
-		unsigned int n = lg->next_hcall;
+		unsigned int n = cpu->next_hcall;
 
 		/* 0xFF means there's no call here (yet). */
 		if (st[n] == 0xFF)
@@ -127,65 +130,65 @@ static void do_async_hcalls(struct lguest *lg)
 
 		/* OK, we have hypercall.  Increment the "next_hcall" cursor,
 		 * and wrap back to 0 if we reach the end. */
-		if (++lg->next_hcall == LHCALL_RING_SIZE)
-			lg->next_hcall = 0;
+		if (++cpu->next_hcall == LHCALL_RING_SIZE)
+			cpu->next_hcall = 0;
 
 		/* Copy the hypercall arguments into a local copy of
 		 * the hcall_args struct. */
-		if (copy_from_user(&args, &lg->lguest_data->hcalls[n],
+		if (copy_from_user(&args, &cpu->lg->lguest_data->hcalls[n],
 				   sizeof(struct hcall_args))) {
-			kill_guest(lg, "Fetching async hypercalls");
+			kill_guest(cpu, "Fetching async hypercalls");
 			break;
 		}
 
 		/* Do the hypercall, same as a normal one. */
-		do_hcall(lg, &args);
+		do_hcall(cpu, &args);
 
 		/* Mark the hypercall done. */
-		if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) {
-			kill_guest(lg, "Writing result for async hypercall");
+		if (put_user(0xFF, &cpu->lg->lguest_data->hcall_status[n])) {
+			kill_guest(cpu, "Writing result for async hypercall");
 			break;
 		}
 
 		/* Stop doing hypercalls if they want to notify the Launcher:
 		 * it needs to service this first. */
-		if (lg->pending_notify)
+		if (cpu->pending_notify)
 			break;
 	}
 }
 
 /* Last of all, we look at what happens first of all.  The very first time the
  * Guest makes a hypercall, we end up here to set things up: */
-static void initialize(struct lguest *lg)
+static void initialize(struct lg_cpu *cpu)
 {
 	/* You can't do anything until you're initialized.  The Guest knows the
 	 * rules, so we're unforgiving here. */
-	if (lg->hcall->arg0 != LHCALL_LGUEST_INIT) {
-		kill_guest(lg, "hypercall %li before INIT", lg->hcall->arg0);
+	if (cpu->hcall->arg0 != LHCALL_LGUEST_INIT) {
+		kill_guest(cpu, "hypercall %li before INIT", cpu->hcall->arg0);
 		return;
 	}
 
-	if (lguest_arch_init_hypercalls(lg))
-		kill_guest(lg, "bad guest page %p", lg->lguest_data);
+	if (lguest_arch_init_hypercalls(cpu))
+		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
 
 	/* The Guest tells us where we're not to deliver interrupts by putting
 	 * the range of addresses into "struct lguest_data". */
-	if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start)
-	    || get_user(lg->noirq_end, &lg->lguest_data->noirq_end))
-		kill_guest(lg, "bad guest page %p", lg->lguest_data);
+	if (get_user(cpu->lg->noirq_start, &cpu->lg->lguest_data->noirq_start)
+	    || get_user(cpu->lg->noirq_end, &cpu->lg->lguest_data->noirq_end))
+		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
 
 	/* We write the current time into the Guest's data page once so it can
 	 * set its clock. */
-	write_timestamp(lg);
+	write_timestamp(cpu);
 
 	/* page_tables.c will also do some setup. */
-	page_table_guest_data_init(lg);
+	page_table_guest_data_init(cpu);
 
 	/* This is the one case where the above accesses might have been the
 	 * first write to a Guest page.  This may have caused a copy-on-write
 	 * fault, but the old page might be (read-only) in the Guest
 	 * pagetable. */
-	guest_pagetable_clear_all(lg);
+	guest_pagetable_clear_all(cpu);
 }
 
 /*H:100
@@ -194,27 +197,27 @@ static void initialize(struct lguest *lg)
  * Remember from the Guest, hypercalls come in two flavors: normal and
  * asynchronous.  This file handles both of types.
  */
-void do_hypercalls(struct lguest *lg)
+void do_hypercalls(struct lg_cpu *cpu)
 {
 	/* Not initialized yet?  This hypercall must do it. */
-	if (unlikely(!lg->lguest_data)) {
+	if (unlikely(!cpu->lg->lguest_data)) {
 		/* Set up the "struct lguest_data" */
-		initialize(lg);
+		initialize(cpu);
 		/* Hcall is done. */
-		lg->hcall = NULL;
+		cpu->hcall = NULL;
 		return;
 	}
 
 	/* The Guest has initialized.
 	 *
 	 * Look in the hypercall ring for the async hypercalls: */
-	do_async_hcalls(lg);
+	do_async_hcalls(cpu);
 
 	/* If we stopped reading the hypercall ring because the Guest did a
 	 * NOTIFY to the Launcher, we want to return now.  Otherwise we do
 	 * the hypercall. */
-	if (!lg->pending_notify) {
-		do_hcall(lg, lg->hcall);
+	if (!cpu->pending_notify) {
+		do_hcall(cpu, cpu->hcall);
 		/* Tricky point: we reset the hcall pointer to mark the
 		 * hypercall as "done".  We use the hcall pointer rather than
 		 * the trap number to indicate a hypercall is pending.
@@ -225,16 +228,17 @@ void do_hypercalls(struct lguest *lg)
 		 * Launcher, the run_guest() loop will exit without running the
 		 * Guest.  When it comes back it would try to re-run the
 		 * hypercall. */
-		lg->hcall = NULL;
+		cpu->hcall = NULL;
 	}
 }
 
 /* This routine supplies the Guest with time: it's used for wallclock time at
  * initial boot and as a rough time source if the TSC isn't available. */
-void write_timestamp(struct lguest *lg)
+void write_timestamp(struct lg_cpu *cpu)
 {
 	struct timespec now;
 	ktime_get_real_ts(&now);
-	if (copy_to_user(&lg->lguest_data->time, &now, sizeof(struct timespec)))
-		kill_guest(lg, "Writing timestamp");
+	if (copy_to_user(&cpu->lg->lguest_data->time,
+			 &now, sizeof(struct timespec)))
+		kill_guest(cpu, "Writing timestamp");
 }

drivers/lguest/lg.h

@@ -8,6 +8,7 @@
 #include <linux/lguest.h>
 #include <linux/lguest_launcher.h>
 #include <linux/wait.h>
+#include <linux/hrtimer.h>
 #include <linux/err.h>
 #include <asm/semaphore.h>
 
@@ -38,58 +39,72 @@ struct lguest_pages
 #define CHANGED_GDT_TLS		4 /* Actually a subset of CHANGED_GDT */
 #define CHANGED_ALL	        3
 
-/* The private info the thread maintains about the guest. */
-struct lguest
-{
-	/* At end of a page shared mapped over lguest_pages in guest.  */
-	unsigned long regs_page;
-	struct lguest_regs *regs;
-	struct lguest_data __user *lguest_data;
+struct lguest;
+
+struct lg_cpu {
+	unsigned int id;
+	struct lguest *lg;
 	struct task_struct *tsk;
 	struct mm_struct *mm; 	/* == tsk->mm, but that becomes NULL on exit */
-	u32 pfn_limit;
-	/* This provides the offset to the base of guest-physical
-	 * memory in the Launcher. */
-	void __user *mem_base;
-	unsigned long kernel_address;
+
 	u32 cr2;
-	int halted;
 	int ts;
-	u32 next_hcall;
 	u32 esp1;
 	u8 ss1;
 
+	/* Bitmap of what has changed: see CHANGED_* above. */
+	int changed;
+
+	unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
+
+	/* At end of a page shared mapped over lguest_pages in guest.  */
+	unsigned long regs_page;
+	struct lguest_regs *regs;
+
+	struct lguest_pages *last_pages;
+
+	int cpu_pgd; /* which pgd this cpu is currently using */
+
 	/* If a hypercall was asked for, this points to the arguments. */
 	struct hcall_args *hcall;
+	u32 next_hcall;
+
+	/* Virtual clock device */
+	struct hrtimer hrt;
 
 	/* Do we need to stop what we're doing and return to userspace? */
 	int break_out;
 	wait_queue_head_t break_wq;
+	int halted;
 
-	/* Bitmap of what has changed: see CHANGED_* above. */
-	int changed;
-	struct lguest_pages *last_pages;
+	/* Pending virtual interrupts */
+	DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
+
+	struct lg_cpu_arch arch;
+};
+
+/* The private info the thread maintains about the guest. */
+struct lguest
+{
+	struct lguest_data __user *lguest_data;
+	struct lg_cpu cpus[NR_CPUS];
+	unsigned int nr_cpus;
+
+	u32 pfn_limit;
+	/* This provides the offset to the base of guest-physical
+	 * memory in the Launcher. */
+	void __user *mem_base;
+	unsigned long kernel_address;
 
-	/* We keep a small number of these. */
-	u32 pgdidx;
 	struct pgdir pgdirs[4];
 
 	unsigned long noirq_start, noirq_end;
-	unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
 
 	unsigned int stack_pages;
 	u32 tsc_khz;
 
 	/* Dead? */
 	const char *dead;
-
-	struct lguest_arch arch;
-
-	/* Virtual clock device */
-	struct hrtimer hrt;
-
-	/* Pending virtual interrupts */
-	DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
 };
 
 extern struct mutex lguest_lock;
@@ -97,26 +112,26 @@ extern struct mutex lguest_lock;
 /* core.c: */
 int lguest_address_ok(const struct lguest *lg,
 		      unsigned long addr, unsigned long len);
-void __lgread(struct lguest *, void *, unsigned long, unsigned);
-void __lgwrite(struct lguest *, unsigned long, const void *, unsigned);
+void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
+void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
 
 /*H:035 Using memory-copy operations like that is usually inconvient, so we
  * have the following helper macros which read and write a specific type (often
  * an unsigned long).
  *
  * This reads into a variable of the given type then returns that. */
-#define lgread(lg, addr, type)						\
-	({ type _v; __lgread((lg), &_v, (addr), sizeof(_v)); _v; })
+#define lgread(cpu, addr, type)						\
+	({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })
 
 /* This checks that the variable is of the given type, then writes it out. */
-#define lgwrite(lg, addr, type, val)				\
+#define lgwrite(cpu, addr, type, val)				\
 	do {							\
 		typecheck(type, val);				\
-		__lgwrite((lg), (addr), &(val), sizeof(val));	\
+		__lgwrite((cpu), (addr), &(val), sizeof(val));	\
 	} while(0)
 /* (end of memory access helper routines) :*/
 
-int run_guest(struct lguest *lg, unsigned long __user *user);
+int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
 
 /* Helper macros to obtain the first 12 or the last 20 bits, this is only the
  * first step in the migration to the kernel types.  pte_pfn is already defined
@@ -126,52 +141,53 @@ int run_guest(struct lguest *lg, unsigned long __user *user);
 #define pgd_pfn(x)	(pgd_val(x) >> PAGE_SHIFT)
 
 /* interrupts_and_traps.c: */
-void maybe_do_interrupt(struct lguest *lg);
-int deliver_trap(struct lguest *lg, unsigned int num);
-void load_guest_idt_entry(struct lguest *lg, unsigned int i, u32 low, u32 hi);
-void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages);
-void pin_stack_pages(struct lguest *lg);
+void maybe_do_interrupt(struct lg_cpu *cpu);
+int deliver_trap(struct lg_cpu *cpu, unsigned int num);
+void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
+			  u32 low, u32 hi);
+void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
+void pin_stack_pages(struct lg_cpu *cpu);
 void setup_default_idt_entries(struct lguest_ro_state *state,
 			       const unsigned long *def);
-void copy_traps(const struct lguest *lg, struct desc_struct *idt,
+void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
 		const unsigned long *def);
-void guest_set_clockevent(struct lguest *lg, unsigned long delta);
-void init_clockdev(struct lguest *lg);
+void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
+void init_clockdev(struct lg_cpu *cpu);
 bool check_syscall_vector(struct lguest *lg);
 int init_interrupts(void);
 void free_interrupts(void);
 
 /* segments.c: */
 void setup_default_gdt_entries(struct lguest_ro_state *state);
-void setup_guest_gdt(struct lguest *lg);
-void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num);
-void guest_load_tls(struct lguest *lg, unsigned long tls_array);
-void copy_gdt(const struct lguest *lg, struct desc_struct *gdt);
-void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt);
+void setup_guest_gdt(struct lg_cpu *cpu);
+void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num);
+void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
+void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
+void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
 
 /* page_tables.c: */
 int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
 void free_guest_pagetable(struct lguest *lg);
-void guest_new_pagetable(struct lguest *lg, unsigned long pgtable);
+void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
-void guest_pagetable_clear_all(struct lguest *lg);
-void guest_pagetable_flush_user(struct lguest *lg);
-void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
+void guest_pagetable_clear_all(struct lg_cpu *cpu);
+void guest_pagetable_flush_user(struct lg_cpu *cpu);
+void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
 		   unsigned long vaddr, pte_t val);
-void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages);
-int demand_page(struct lguest *info, unsigned long cr2, int errcode);
-void pin_page(struct lguest *lg, unsigned long vaddr);
-unsigned long guest_pa(struct lguest *lg, unsigned long vaddr);
-void page_table_guest_data_init(struct lguest *lg);
+void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
+int demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
+void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
+unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
+void page_table_guest_data_init(struct lg_cpu *cpu);
 
 /* <arch>/core.c: */
 void lguest_arch_host_init(void);
 void lguest_arch_host_fini(void);
-void lguest_arch_run_guest(struct lguest *lg);
-void lguest_arch_handle_trap(struct lguest *lg);
-int lguest_arch_init_hypercalls(struct lguest *lg);
-int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args);
-void lguest_arch_setup_regs(struct lguest *lg, unsigned long start);
+void lguest_arch_run_guest(struct lg_cpu *cpu);
+void lguest_arch_handle_trap(struct lg_cpu *cpu);
+int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
+int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
+void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start);
 
 /* <arch>/switcher.S: */
 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
@@ -181,8 +197,8 @@ int lguest_device_init(void);
 void lguest_device_remove(void);
 
 /* hypercalls.c: */
-void do_hypercalls(struct lguest *lg);
-void write_timestamp(struct lguest *lg);
+void do_hypercalls(struct lg_cpu *cpu);
+void write_timestamp(struct lg_cpu *cpu);
 
 /*L:035
  * Let's step aside for the moment, to study one important routine that's used
@@ -208,12 +224,12 @@ void write_timestamp(struct lguest *lg);
  * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
  * } while(0)".
  */
-#define kill_guest(lg, fmt...)					\
+#define kill_guest(cpu, fmt...)					\
 do {								\
-	if (!(lg)->dead) {					\
-		(lg)->dead = kasprintf(GFP_ATOMIC, fmt);	\
-		if (!(lg)->dead)				\
-			(lg)->dead = ERR_PTR(-ENOMEM);		\
+	if (!(cpu)->lg->dead) {					\
+		(cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt);	\
+		if (!(cpu)->lg->dead)				\
+			(cpu)->lg->dead = ERR_PTR(-ENOMEM);	\
 	}							\
 } while(0)
 /* (End of aside) :*/

drivers/lguest/lguest_user.c

@@ -6,6 +6,7 @@
 #include <linux/uaccess.h>
 #include <linux/miscdevice.h>
 #include <linux/fs.h>
+#include <linux/sched.h>
 #include "lg.h"
 
 /*L:055 When something happens, the Waker process needs a way to stop the
@@ -13,7 +14,7 @@
  * LHREQ_BREAK and the value "1" to /dev/lguest to do this.  Once the Launcher
  * has done whatever needs attention, it writes LHREQ_BREAK and "0" to release
  * the Waker. */
-static int break_guest_out(struct lguest *lg, const unsigned long __user *input)
+static int break_guest_out(struct lg_cpu *cpu, const unsigned long __user*input)
 {
 	unsigned long on;
 
@@ -22,21 +23,21 @@ static int break_guest_out(struct lguest *lg, const unsigned long __user *input)
 		return -EFAULT;
 
 	if (on) {
-		lg->break_out = 1;
+		cpu->break_out = 1;
 		/* Pop it out of the Guest (may be running on different CPU) */
-		wake_up_process(lg->tsk);
+		wake_up_process(cpu->tsk);
 		/* Wait for them to reset it */
-		return wait_event_interruptible(lg->break_wq, !lg->break_out);
+		return wait_event_interruptible(cpu->break_wq, !cpu->break_out);
 	} else {
-		lg->break_out = 0;
-		wake_up(&lg->break_wq);
+		cpu->break_out = 0;
+		wake_up(&cpu->break_wq);
 		return 0;
 	}
 }
 
 /*L:050 Sending an interrupt is done by writing LHREQ_IRQ and an interrupt
  * number to /dev/lguest. */
-static int user_send_irq(struct lguest *lg, const unsigned long __user *input)
+static int user_send_irq(struct lg_cpu *cpu, const unsigned long __user *input)
 {
 	unsigned long irq;
 
@@ -46,7 +47,7 @@ static int user_send_irq(struct lguest *lg, const unsigned long __user *input)
 		return -EINVAL;
 	/* Next time the Guest runs, the core code will see if it can deliver
 	 * this interrupt. */
-	set_bit(irq, lg->irqs_pending);
+	set_bit(irq, cpu->irqs_pending);
 	return 0;
 }
 
@@ -55,13 +56,21 @@ static int user_send_irq(struct lguest *lg, const unsigned long __user *input)
 static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
 {
 	struct lguest *lg = file->private_data;
+	struct lg_cpu *cpu;
+	unsigned int cpu_id = *o;
 
 	/* You must write LHREQ_INITIALIZE first! */
 	if (!lg)
 		return -EINVAL;
 
+	/* Watch out for arbitrary vcpu indexes! */
+	if (cpu_id >= lg->nr_cpus)
+		return -EINVAL;
+
+	cpu = &lg->cpus[cpu_id];
+
 	/* If you're not the task which owns the Guest, go away. */
-	if (current != lg->tsk)
+	if (current != cpu->tsk)
 		return -EPERM;
 
 	/* If the guest is already dead, we indicate why */
@@ -81,11 +90,53 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
 
 	/* If we returned from read() last time because the Guest notified,
 	 * clear the flag. */
-	if (lg->pending_notify)
-		lg->pending_notify = 0;
+	if (cpu->pending_notify)
+		cpu->pending_notify = 0;
 
 	/* Run the Guest until something interesting happens. */
-	return run_guest(lg, (unsigned long __user *)user);
+	return run_guest(cpu, (unsigned long __user *)user);
+}
+
+static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip)
+{
+	if (id >= NR_CPUS)
+		return -EINVAL;
+
+	cpu->id = id;
+	cpu->lg = container_of((cpu - id), struct lguest, cpus[0]);
+	cpu->lg->nr_cpus++;
+	init_clockdev(cpu);
+
+	/* We need a complete page for the Guest registers: they are accessible
+	 * to the Guest and we can only grant it access to whole pages. */
+	cpu->regs_page = get_zeroed_page(GFP_KERNEL);
+	if (!cpu->regs_page)
+		return -ENOMEM;
+
+	/* We actually put the registers at the bottom of the page. */
+	cpu->regs = (void *)cpu->regs_page + PAGE_SIZE - sizeof(*cpu->regs);
+
+	/* Now we initialize the Guest's registers, handing it the start
+	 * address. */
+	lguest_arch_setup_regs(cpu, start_ip);
+
+	/* Initialize the queue for the waker to wait on */
+	init_waitqueue_head(&cpu->break_wq);
+
+	/* We keep a pointer to the Launcher task (ie. current task) for when
+	 * other Guests want to wake this one (inter-Guest I/O). */
+	cpu->tsk = current;
+
+	/* We need to keep a pointer to the Launcher's memory map, because if
+	 * the Launcher dies we need to clean it up.  If we don't keep a
+	 * reference, it is destroyed before close() is called. */
+	cpu->mm = get_task_mm(cpu->tsk);
+
+	/* We remember which CPU's pages this Guest used last, for optimization
+	 * when the same Guest runs on the same CPU twice. */
+	cpu->last_pages = NULL;
+
+	return 0;
 }
 
 /*L:020 The initialization write supplies 4 pointer sized (32 or 64 bit)
@@ -134,15 +185,10 @@ static int initialize(struct file *file, const unsigned long __user *input)
 	lg->mem_base = (void __user *)(long)args[0];
 	lg->pfn_limit = args[1];
 
-	/* We need a complete page for the Guest registers: they are accessible
-	 * to the Guest and we can only grant it access to whole pages. */
-	lg->regs_page = get_zeroed_page(GFP_KERNEL);
-	if (!lg->regs_page) {
-		err = -ENOMEM;
+	/* This is the first cpu */
+	err = lg_cpu_start(&lg->cpus[0], 0, args[3]);
+	if (err)
 		goto release_guest;
-	}
-	/* We actually put the registers at the bottom of the page. */
-	lg->regs = (void *)lg->regs_page + PAGE_SIZE - sizeof(*lg->regs);
 
 	/* Initialize the Guest's shadow page tables, using the toplevel
 	 * address the Launcher gave us.  This allocates memory, so can
@@ -151,28 +197,6 @@ static int initialize(struct file *file, const unsigned long __user *input)
 	if (err)
 		goto free_regs;
 
-	/* Now we initialize the Guest's registers, handing it the start
-	 * address. */
-	lguest_arch_setup_regs(lg, args[3]);
-
-	/* The timer for lguest's clock needs initialization. */
-	init_clockdev(lg);
-
-	/* We keep a pointer to the Launcher task (ie. current task) for when
-	 * other Guests want to wake this one (inter-Guest I/O). */
-	lg->tsk = current;
-	/* We need to keep a pointer to the Launcher's memory map, because if
-	 * the Launcher dies we need to clean it up.  If we don't keep a
-	 * reference, it is destroyed before close() is called. */
-	lg->mm = get_task_mm(lg->tsk);
-
-	/* Initialize the queue for the waker to wait on */
-	init_waitqueue_head(&lg->break_wq);
-
-	/* We remember which CPU's pages this Guest used last, for optimization
-	 * when the same Guest runs on the same CPU twice. */
-	lg->last_pages = NULL;
-
 	/* We keep our "struct lguest" in the file's private_data. */
 	file->private_data = lg;
 
@@ -182,7 +206,8 @@ static int initialize(struct file *file, const unsigned long __user *input)
 	return sizeof(args);
 
 free_regs:
-	free_page(lg->regs_page);
+	/* FIXME: This should be in free_vcpu */
+	free_page(lg->cpus[0].regs_page);
 release_guest:
 	kfree(lg);
 unlock:
@@ -202,30 +227,37 @@ static ssize_t write(struct file *file, const char __user *in,
 	struct lguest *lg = file->private_data;
 	const unsigned long __user *input = (const unsigned long __user *)in;
 	unsigned long req;
+	struct lg_cpu *uninitialized_var(cpu);
+	unsigned int cpu_id = *off;
 
 	if (get_user(req, input) != 0)
 		return -EFAULT;
 	input++;
 
 	/* If you haven't initialized, you must do that first. */
-	if (req != LHREQ_INITIALIZE && !lg)
+	if (req != LHREQ_INITIALIZE) {
+		if (!lg || (cpu_id >= lg->nr_cpus))
 			return -EINVAL;
+		cpu = &lg->cpus[cpu_id];
+		if (!cpu)
+			return -EINVAL;
+	}
 
 	/* Once the Guest is dead, all you can do is read() why it died. */
 	if (lg && lg->dead)
 		return -ENOENT;
 
 	/* If you're not the task which owns the Guest, you can only break */
-	if (lg && current != lg->tsk && req != LHREQ_BREAK)
+	if (lg && current != cpu->tsk && req != LHREQ_BREAK)
 		return -EPERM;
 
 	switch (req) {
 	case LHREQ_INITIALIZE:
 		return initialize(file, input);
 	case LHREQ_IRQ:
-		return user_send_irq(lg, input);
+		return user_send_irq(cpu, input);
 	case LHREQ_BREAK:
-		return break_guest_out(lg, input);
+		return break_guest_out(cpu, input);
 	default:
 		return -EINVAL;
 	}
@@ -241,6 +273,7 @@ static ssize_t write(struct file *file, const char __user *in,
 static int close(struct inode *inode, struct file *file)
 {
 	struct lguest *lg = file->private_data;
+	unsigned int i;
 
 	/* If we never successfully initialized, there's nothing to clean up */
 	if (!lg)
@@ -249,19 +282,23 @@ static int close(struct inode *inode, struct file *file)
 	/* We need the big lock, to protect from inter-guest I/O and other
 	 * Launchers initializing guests. */
 	mutex_lock(&lguest_lock);
-	/* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
-	hrtimer_cancel(&lg->hrt);
+
 	/* Free up the shadow page tables for the Guest. */
 	free_guest_pagetable(lg);
-	/* Now all the memory cleanups are done, it's safe to release the
-	 * Launcher's memory management structure. */
-	mmput(lg->mm);
+
+	for (i = 0; i < lg->nr_cpus; i++) {
+		/* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
+		hrtimer_cancel(&lg->cpus[i].hrt);
+		/* We can free up the register page we allocated. */
+		free_page(lg->cpus[i].regs_page);
+		/* Now all the memory cleanups are done, it's safe to release
+		 * the Launcher's memory management structure. */
+		mmput(lg->cpus[i].mm);
+	}
 	/* If lg->dead doesn't contain an error code it will be NULL or a
 	 * kmalloc()ed string, either of which is ok to hand to kfree(). */
 	if (!IS_ERR(lg->dead))
 		kfree(lg->dead);
-	/* We can free up the register page we allocated. */
-	free_page(lg->regs_page);
 	/* We clear the entire structure, which also marks it as free for the
 	 * next user. */
 	memset(lg, 0, sizeof(*lg));

drivers/lguest/segments.c

@@ -58,7 +58,7 @@ static int ignored_gdt(unsigned int num)
  * Protection Fault in the Switcher when it restores a Guest segment register
  * which tries to use that entry.  Then we kill the Guest for causing such a
  * mess: the message will be "unhandled trap 256". */
-static void fixup_gdt_table(struct lguest *lg, unsigned start, unsigned end)
+static void fixup_gdt_table(struct lg_cpu *cpu, unsigned start, unsigned end)
 {
 	unsigned int i;
 
@@ -71,14 +71,14 @@ static void fixup_gdt_table(struct lguest *lg, unsigned start, unsigned end)
 		/* Segment descriptors contain a privilege level: the Guest is
 		 * sometimes careless and leaves this as 0, even though it's
 		 * running at privilege level 1.  If so, we fix it here. */
-		if ((lg->arch.gdt[i].b & 0x00006000) == 0)
-			lg->arch.gdt[i].b |= (GUEST_PL << 13);
+		if ((cpu->arch.gdt[i].b & 0x00006000) == 0)
+			cpu->arch.gdt[i].b |= (GUEST_PL << 13);
 
 		/* Each descriptor has an "accessed" bit.  If we don't set it
 		 * now, the CPU will try to set it when the Guest first loads
 		 * that entry into a segment register.  But the GDT isn't
 		 * writable by the Guest, so bad things can happen. */
-		lg->arch.gdt[i].b |= 0x00000100;
+		cpu->arch.gdt[i].b |= 0x00000100;
 	}
 }
 
@@ -109,31 +109,31 @@ void setup_default_gdt_entries(struct lguest_ro_state *state)
 
 /* This routine sets up the initial Guest GDT for booting.  All entries start
  * as 0 (unusable). */
-void setup_guest_gdt(struct lguest *lg)
+void setup_guest_gdt(struct lg_cpu *cpu)
 {
 	/* Start with full 0-4G segments... */
-	lg->arch.gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
-	lg->arch.gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
+	cpu->arch.gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
+	cpu->arch.gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
 	/* ...except the Guest is allowed to use them, so set the privilege
 	 * level appropriately in the flags. */
-	lg->arch.gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
-	lg->arch.gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
+	cpu->arch.gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
+	cpu->arch.gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
 }
 
 /*H:650 An optimization of copy_gdt(), for just the three "thead-local storage"
  * entries. */
-void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt)
+void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt)
 {
 	unsigned int i;
 
 	for (i = GDT_ENTRY_TLS_MIN; i <= GDT_ENTRY_TLS_MAX; i++)
-		gdt[i] = lg->arch.gdt[i];
+		gdt[i] = cpu->arch.gdt[i];
 }
 
 /*H:640 When the Guest is run on a different CPU, or the GDT entries have
  * changed, copy_gdt() is called to copy the Guest's GDT entries across to this
  * CPU's GDT. */
-void copy_gdt(const struct lguest *lg, struct desc_struct *gdt)
+void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt)
 {
 	unsigned int i;
 
@@ -141,38 +141,38 @@ void copy_gdt(const struct lguest *lg, struct desc_struct *gdt)
 	 * replaced.  See ignored_gdt() above. */
 	for (i = 0; i < GDT_ENTRIES; i++)
 		if (!ignored_gdt(i))
-			gdt[i] = lg->arch.gdt[i];
+			gdt[i] = cpu->arch.gdt[i];
 }
 
 /*H:620 This is where the Guest asks us to load a new GDT (LHCALL_LOAD_GDT).
  * We copy it from the Guest and tweak the entries. */
-void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num)
+void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
 {
 	/* We assume the Guest has the same number of GDT entries as the
 	 * Host, otherwise we'd have to dynamically allocate the Guest GDT. */
-	if (num > ARRAY_SIZE(lg->arch.gdt))
-		kill_guest(lg, "too many gdt entries %i", num);
+	if (num > ARRAY_SIZE(cpu->arch.gdt))
+		kill_guest(cpu, "too many gdt entries %i", num);
 
 	/* We read the whole thing in, then fix it up. */
-	__lgread(lg, lg->arch.gdt, table, num * sizeof(lg->arch.gdt[0]));
-	fixup_gdt_table(lg, 0, ARRAY_SIZE(lg->arch.gdt));
+	__lgread(cpu, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
+	fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt));
 	/* Mark that the GDT changed so the core knows it has to copy it again,
 	 * even if the Guest is run on the same CPU. */
-	lg->changed |= CHANGED_GDT;
+	cpu->changed |= CHANGED_GDT;
 }
 
 /* This is the fast-track version for just changing the three TLS entries.
  * Remember that this happens on every context switch, so it's worth
  * optimizing.  But wouldn't it be neater to have a single hypercall to cover
  * both cases? */
-void guest_load_tls(struct lguest *lg, unsigned long gtls)
+void guest_load_tls(struct lg_cpu *cpu, unsigned long gtls)
 {
-	struct desc_struct *tls = &lg->arch.gdt[GDT_ENTRY_TLS_MIN];
+	struct desc_struct *tls = &cpu->arch.gdt[GDT_ENTRY_TLS_MIN];
 
-	__lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
-	fixup_gdt_table(lg, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
+	__lgread(cpu, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
+	fixup_gdt_table(cpu, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
 	/* Note that just the TLS entries have changed. */
-	lg->changed |= CHANGED_GDT_TLS;
+	cpu->changed |= CHANGED_GDT_TLS;
 }
 /*:*/
 

include/asm-x86/lguest.h

@@ -56,7 +56,7 @@ struct lguest_ro_state
 	struct desc_struct guest_gdt[GDT_ENTRIES];
 };
 
-struct lguest_arch
+struct lg_cpu_arch
 {
 	/* The GDT entries copied into lguest_ro_state when running. */
 	struct desc_struct gdt[GDT_ENTRIES];

include/asm-x86/lguest_hcall.h

@@ -4,7 +4,7 @@
 
 #define LHCALL_FLUSH_ASYNC	0
 #define LHCALL_LGUEST_INIT	1
-#define LHCALL_CRASH		2
+#define LHCALL_SHUTDOWN		2
 #define LHCALL_LOAD_GDT		3
 #define LHCALL_NEW_PGTABLE	4
 #define LHCALL_FLUSH_TLB	5
@@ -20,6 +20,10 @@
 
 #define LGUEST_TRAP_ENTRY 0x1F
 
+/* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */
+#define LGUEST_SHUTDOWN_POWEROFF	1
+#define LGUEST_SHUTDOWN_RESTART		2
+
 #ifndef __ASSEMBLY__
 #include <asm/hw_irq.h>