/*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 lg_cpu *cpu, unsigned long __user *user)
{
/* We stop running once the Guest is dead. */
while (!cpu->lg->dead) {
/* First we run any hypercalls the Guest wants done. */
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 (cpu->pending_notify) {
if (put_user(cpu->pending_notify, user))
return -EFAULT;
return sizeof(cpu->pending_notify);
}
/* Check for signals */
if (signal_pending(current))
return -ERESTARTSYS;
/* If Waker set break_out, return to Launcher. */
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(cpu);
/* All long-lived kernel loops need to check with this horrible
* thing called the freezer. If the Host is trying to suspend,
* it stops us. */
try_to_freeze();
/* Just make absolutely sure the Guest is still alive. One of
* those hypercalls could have been fatal, for example. */
if (cpu->lg->dead)
break;
/* If the Guest asked to be stopped, we sleep. The Guest's
* clock timer or LHREQ_BREAK from the Waker will wake us. */
if (cpu->halted) {
set_current_state(TASK_INTERRUPTIBLE);
schedule();
continue;
}
/* OK, now we're ready to jump into the Guest. First we put up
* the "Do Not Disturb" sign: */
local_irq_disable();
/* Actually run the Guest until something happens. */
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(cpu);
}
/* Special case: Guest is 'dead' but wants a reboot. */
if (cpu->lg->dead == ERR_PTR(-ERESTART))
return -ERESTART;
/* The Guest is dead => "No such file or directory" */
return -ENOENT;
}
/*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 lg_cpu *cpu, unsigned long __user *user)
{
/* We stop running once the Guest is dead. */
while (!cpu->lg->dead) {
unsigned int irq;
bool more;
/* First we run any hypercalls the Guest wants done. */
if (cpu->hcall)
do_hypercalls(cpu);
/*
* It's possible the Guest did a NOTIFY hypercall to the
* Launcher.
*/
if (cpu->pending_notify) {
/*
* Does it just needs to write to a registered
* eventfd (ie. the appropriate virtqueue thread)?
*/
if (!send_notify_to_eventfd(cpu)) {
/* OK, we tell the main Laucher. */
if (put_user(cpu->pending_notify, user))
return -EFAULT;
return sizeof(cpu->pending_notify);
}
}
/* Check for signals */
if (signal_pending(current))
return -ERESTARTSYS;
/*
* 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.
*/
irq = interrupt_pending(cpu, &more);
if (irq < LGUEST_IRQS)
try_deliver_interrupt(cpu, irq, more);
/*
* All long-lived kernel loops need to check with this horrible
* thing called the freezer. If the Host is trying to suspend,
* it stops us.
*/
try_to_freeze();
/*
* Just make absolutely sure the Guest is still alive. One of
* those hypercalls could have been fatal, for example.
*/
if (cpu->lg->dead)
break;
/*
* If the Guest asked to be stopped, we sleep. The Guest's
* clock timer will wake us.
*/
if (cpu->halted) {
set_current_state(TASK_INTERRUPTIBLE);
/*
* Just before we sleep, make sure no interrupt snuck in
* which we should be doing.
*/
if (interrupt_pending(cpu, &more) < LGUEST_IRQS)
set_current_state(TASK_RUNNING);
else
schedule();
continue;
}
/*
* OK, now we're ready to jump into the Guest. First we put up
* the "Do Not Disturb" sign:
*/
local_irq_disable();
/* Actually run the Guest until something happens. */
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(cpu);
}
/* Special case: Guest is 'dead' but wants a reboot. */
if (cpu->lg->dead == ERR_PTR(-ERESTART))
return -ERESTART;
/* The Guest is dead => "No such file or directory" */
return -ENOENT;
}
int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
{
while (!cpu->lg->dead) {
unsigned int irq;
bool more;
if (cpu->hcall)
do_hypercalls(cpu);
if (cpu->pending_notify) {
if (!send_notify_to_eventfd(cpu)) {
if (put_user(cpu->pending_notify, user))
return -EFAULT;
return sizeof(cpu->pending_notify);
}
}
if (signal_pending(current))
return -ERESTARTSYS;
irq = interrupt_pending(cpu, &more);
if (irq < LGUEST_IRQS)
try_deliver_interrupt(cpu, irq, more);
try_to_freeze();
if (cpu->lg->dead)
break;
if (cpu->halted) {
set_current_state(TASK_INTERRUPTIBLE);
if (interrupt_pending(cpu, &more) < LGUEST_IRQS)
set_current_state(TASK_RUNNING);
else
schedule();
continue;
}
local_irq_disable();
lguest_arch_run_guest(cpu);
local_irq_enable();
lguest_arch_handle_trap(cpu);
}
if (cpu->lg->dead == ERR_PTR(-ERESTART))
return -ERESTART;
return -ENOENT;
}