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Commit 9f155a9b authored by Rusty Russell's avatar Rusty Russell
Browse files

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: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 92b4d8df

drivers/lguest/interrupts_and_traps.c

+15 −4
Original line number Diff line number Diff line
@@ -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;

}

drivers/lguest/lg.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

drivers/lguest/lguest_user.c

+2 −8
Original line number Diff line number Diff line
@@ -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) {