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lguest: allow any process to send interrupts 

We currently only allow the Launcher process to send interrupts, but it
as we already send interrupts from the hrtimer, it's a simple matter of
extracting that code into a common set_interrupt routine.

As we switch to a thread per virtqueue, this avoids a bottleneck through the
main Launcher process.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2009-06-12 22:27:08 -06:00
parent 92b4d8df84
commit 9f155a9b3d
3 changed files with 18 additions and 12 deletions
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19
drivers/lguest/interrupts_and_traps.c
View File

@ -213,6 +213,20 @@ void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more)
if (!more)
put_user(0, &cpu->lg->lguest_data->irq_pending);
}
/* And this is the routine when we want to set an interrupt for the Guest. */
void set_interrupt(struct lg_cpu *cpu, unsigned int irq)
{
/* Next time the Guest runs, the core code will see if it can deliver
* this interrupt. */
set_bit(irq, cpu->irqs_pending);
/* Make sure it sees it; it might be asleep (eg. halted), or
* running the Guest right now, in which case kick_process()
* will knock it out. */
if (!wake_up_process(cpu->tsk))
kick_process(cpu->tsk);
}
/*:*/
/* Linux uses trap 128 for system calls. Plan9 uses 64, and Ron Minnich sent
@ -528,10 +542,7 @@ static enum hrtimer_restart clockdev_fn(struct hrtimer *timer)
struct lg_cpu *cpu = container_of(timer, struct lg_cpu, hrt);
/* Remember the first interrupt is the timer interrupt. */
set_bit(0, cpu->irqs_pending);
/* Guest may be stopped or running on another CPU. */
if (!wake_up_process(cpu->tsk))
kick_process(cpu->tsk);
set_interrupt(cpu, 0);
return HRTIMER_NORESTART;
}

1
drivers/lguest/lg.h
View File

@ -143,6 +143,7 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
/* interrupts_and_traps.c: */
unsigned int interrupt_pending(struct lg_cpu *cpu, bool *more);
void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more);
void set_interrupt(struct lg_cpu *cpu, unsigned int irq);
bool 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);

10
drivers/lguest/lguest_user.c
View File

@ -45,9 +45,8 @@ static int user_send_irq(struct lg_cpu *cpu, const unsigned long __user *input)
return -EFAULT;
if (irq >= LGUEST_IRQS)
return -EINVAL;
/* Next time the Guest runs, the core code will see if it can deliver
* this interrupt. */
set_bit(irq, cpu->irqs_pending);
set_interrupt(cpu, irq);
return 0;
}
@ -252,11 +251,6 @@ static ssize_t write(struct file *file, const char __user *in,
/* 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) {