* controls and communicates with the Guest. For example, the first write will
* tell us the Guest's memory layout, pagetable, entry point and kernel address
* offset. A read will run the Guest until something happens, such as a signal
- * or the Guest doing a DMA out to the Launcher. Writes are also used to get a
- * DMA buffer registered by the Guest and to send the Guest an interrupt. :*/
+ * or the Guest doing a NOTIFY out to the Launcher. :*/
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
+#include <linux/sched.h>
#include "lg.h"
-/*L:310 To send DMA into the Guest, the Launcher needs to be able to ask for a
- * DMA buffer. This is done by writing LHREQ_GETDMA and the key to
- * /dev/lguest. */
-static long user_get_dma(struct lguest *lg, const unsigned long __user *input)
-{
- unsigned long key, udma, irq;
-
- /* Fetch the key they wrote to us. */
- if (get_user(key, input) != 0)
- return -EFAULT;
- /* Look for a free Guest DMA buffer bound to that key. */
- udma = get_dma_buffer(lg, key, &irq);
- if (!udma)
- return -ENOENT;
-
- /* We need to tell the Launcher what interrupt the Guest expects after
- * the buffer is filled. We stash it in udma->used_len. */
- lgwrite_u32(lg, udma + offsetof(struct lguest_dma, used_len), irq);
-
- /* The (guest-physical) address of the DMA buffer is returned from
- * the write(). */
- return udma;
-}
-
-/*L:315 To force the Guest to stop running and return to the Launcher, the
- * Waker sets writes LHREQ_BREAK and the value "1" to /dev/lguest. The
- * Launcher then writes LHREQ_BREAK and "0" to release the Waker. */
-static int break_guest_out(struct lguest *lg, const unsigned long __user *input)
+/*L:055 When something happens, the Waker process needs a way to stop the
+ * kernel running the Guest and return to the Launcher. So the Waker writes
+ * 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 lg_cpu *cpu, const unsigned long __user*input)
{
unsigned long on;
- /* Fetch whether they're turning break on or off.. */
+ /* Fetch whether they're turning break on or off. */
if (get_user(on, input) != 0)
return -EFAULT;
if (on) {
- lg->break_out = 1;
- /* Pop it out (may be running on different CPU) */
- wake_up_process(lg->tsk);
+ cpu->break_out = 1;
+ /* Pop it out of the Guest (may be running on different CPU) */
+ 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;
- /* If you're not the task which owns the guest, go away. */
- if (current != lg->tsk)
+ /* 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 != cpu->tsk)
return -EPERM;
/* If the guest is already dead, we indicate why */
return len;
}
- /* If we returned from read() last time because the Guest sent DMA,
+ /* If we returned from read() last time because the Guest notified,
* clear the flag. */
- if (lg->dma_is_pending)
- lg->dma_is_pending = 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)
* base: The start of the Guest-physical memory inside the Launcher memory.
*
* pfnlimit: The highest (Guest-physical) page number the Guest should be
- * allowed to access. The Launcher has to live in Guest memory, so it sets
- * this to ensure the Guest can't reach it.
+ * 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).
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
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 a 32 bit number: for the first write this must be
+ * 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 get DMA buffers and send interrupts. */
+ * writes of other values to send interrupts. */
static ssize_t write(struct file *file, const char __user *in,
size_t size, loff_t *off)
{
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)
- return -EINVAL;
+ 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_GETDMA:
- return user_get_dma(lg, 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 any DMA buffers the Guest had bound. */
- release_all_dma(lg);
+
/* 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));
* The Launcher is the Host userspace program which sets up, runs and services
* the Guest. In fact, many comments in the Drivers which refer to "the Host"
* doing things are inaccurate: the Launcher does all the device handling for
- * the Guest. The Guest can't tell what's done by the the Launcher and what by
- * the Host.
+ * the Guest, but the Guest can't know that.
*
* Just to confuse you: to the Host kernel, the Launcher *is* the Guest and we
* shall see more of that later.
projects / linux-2.6 / blobdiff