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Commit 8ed31300 authored by Rusty Russell's avatar Rusty Russell
Browse files

lguest: add infrastructure for userspace to deliver a trap to the guest. 



This is required for instruction emulation to move to userspace.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 69a09dc1

drivers/lguest/lguest_user.c

+19 −0
Original line number Diff line number Diff line
@@ -243,6 +243,23 @@ static int user_send_irq(struct lg_cpu *cpu, const unsigned long __user *input) 
	return 0;

}



/*L:053

 * Deliver a trap: this is used by the Launcher if it can't emulate

 * an instruction.

 */

static int trap(struct lg_cpu *cpu, const unsigned long __user *input)

{

	unsigned long trapnum;



	if (get_user(trapnum, input) != 0)

		return -EFAULT;



	if (!deliver_trap(cpu, trapnum))

		return -EINVAL;



	return 0;

}



/*L:040

 * Once our Guest is initialized, the Launcher makes it run by reading

 * from /dev/lguest.
@@ -487,6 +504,8 @@ static ssize_t write(struct file *file, const char __user *in, 
		return getreg_setup(cpu, input);

	case LHREQ_SETREG:

		return setreg(cpu, input);

	case LHREQ_TRAP:

		return trap(cpu, input);

	default:

		return -EINVAL;

	}

include/linux/lguest_launcher.h

+1 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ enum lguest_req 
	LHREQ_EVENTFD, /* + address, fd. */

	LHREQ_GETREG, /* + offset within struct pt_regs (then read value). */

	LHREQ_SETREG, /* + offset within struct pt_regs, value. */

	LHREQ_TRAP, /* + trap number to deliver to guest. */

};



/*