#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
* 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;
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;
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;
}
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 */
+ /* If the Guest is already dead, we indicate why */
if (lg->dead) {
size_t len;
return len;
}
- /* If we returned from read() last time because the Guest notified,
+ /* If we returned from read() last time because the Guest sent I/O,
* 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);
+}
+
+/*L:025 This actually initializes a CPU. For the moment, a Guest is only
+ * uniprocessor, so "id" is always 0. */
+static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip)
+{
+ /* We have a limited number the number of CPUs in the lguest struct. */
+ if (id >= ARRAY_SIZE(cpu->lg->cpus))
+ return -EINVAL;
+
+ /* Set up this CPU's id, and pointer back to the lguest struct. */
+ cpu->id = id;
+ cpu->lg = container_of((cpu - id), struct lguest, cpus[0]);
+ cpu->lg->nr_cpus++;
+
+ /* Each CPU has a timer it can set. */
+ 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 (eg. console input). */
+ 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;
+
+ /* No error == success. */
+ return 0;
}
-/*L:020 The initialization write supplies 4 pointer sized (32 or 64 bit)
+/*L:020 The initialization write supplies 3 pointer sized (32 or 64 bit)
* values (in addition to the LHREQ_INITIALIZE value). These are:
*
* base: The start of the Guest-physical memory inside the Launcher memory.
* allowed to access. The Guest memory lives inside the Launcher, so it sets
* this to ensure the Guest can only reach its own memory.
*
- * pgdir: The (Guest-physical) address of the top of the initial Guest
- * pagetables (which are set up by the Launcher).
- *
* start: The first instruction to execute ("eip" in x86-speak).
*/
static int initialize(struct file *file, const unsigned long __user *input)
* Guest. */
struct lguest *lg;
int err;
- unsigned long args[4];
+ unsigned long args[3];
/* We grab the Big Lguest lock, which protects against multiple
* simultaneous initializations. */
}
/* Populate the easy fields of our "struct lguest" */
- lg->mem_base = (void __user *)(long)args[0];
+ lg->mem_base = (void __user *)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 (cpu 0) and it will start booting at args[2] */
+ err = lg_cpu_start(&lg->cpus[0], 0, args[2]);
+ 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
- * fail. */
- err = init_guest_pagetable(lg, args[2]);
+ * address the Launcher gave us. This allocates memory, so can fail. */
+ err = init_guest_pagetable(lg);
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;
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:
- memset(lg, 0, sizeof(*lg));
+ kfree(lg);
unlock:
mutex_unlock(&lguest_lock);
return err;
/*L:010 The first operation the Launcher does must be a write. All writes
* start with an unsigned long number: for the first write this must be
* LHREQ_INITIALIZE to set up the Guest. After that the Launcher can use
- * writes of other values to send interrupts. */
+ * writes of other values to send interrupts.
+ *
+ * Note that we overload the "offset" in the /dev/lguest file to indicate what
+ * CPU number we're dealing with. Currently this is always 0, since we only
+ * support uniprocessor Guests, but you can see the beginnings of SMP support
+ * here. */
static ssize_t write(struct file *file, const char __user *in,
size_t size, loff_t *off)
{
- /* Once the guest is initialized, we hold the "struct lguest" in the
+ /* Once the Guest is initialized, we hold the "struct lguest" in the
* file private data. */
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;
+ /* The first value tells us what this request is. */
if (get_user(req, input) != 0)
return -EFAULT;
input++;
/* If you haven't initialized, you must do that first. */
- if (req != LHREQ_INITIALIZE && !lg)
- 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)
- return -EPERM;
+ if (req != LHREQ_INITIALIZE) {
+ if (!lg || (cpu_id >= lg->nr_cpus))
+ return -EINVAL;
+ cpu = &lg->cpus[cpu_id];
+
+ /* Once the Guest is dead, you can only read() why it died. */
+ if (lg->dead)
+ return -ENOENT;
+
+ /* If you're not the task which owns the Guest, all you can do
+ * is break the Launcher out of running the Guest. */
+ if (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;
}
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)
/* 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));
+ /* Free the memory allocated to the lguest_struct */
+ kfree(lg);
/* Release lock and exit. */
mutex_unlock(&lguest_lock);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff