diff options
author | David S. Miller <davem@davemloft.net> | 2009-06-15 03:02:23 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2009-06-15 03:02:23 -0700 |
commit | 9cbc1cb8cd46ce1f7645b9de249b2ce8460129bb (patch) | |
tree | 8d104ec2a459346b99413b0b77421ca7b9936c1a /drivers/lguest/interrupts_and_traps.c | |
parent | ca44d6e60f9de26281fda203f58b570e1748c015 (diff) | |
parent | 45e3e1935e2857c54783291107d33323b3ef33c8 (diff) |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
Documentation/feature-removal-schedule.txt
drivers/scsi/fcoe/fcoe.c
net/core/drop_monitor.c
net/core/net-traces.c
Diffstat (limited to 'drivers/lguest/interrupts_and_traps.c')
-rw-r--r-- | drivers/lguest/interrupts_and_traps.c | 57 |
1 files changed, 43 insertions, 14 deletions
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c index 6e99adbe194..0e9067b0d50 100644 --- a/drivers/lguest/interrupts_and_traps.c +++ b/drivers/lguest/interrupts_and_traps.c @@ -128,30 +128,39 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, /*H:205 * Virtual Interrupts. * - * maybe_do_interrupt() gets called before every entry to the Guest, to see if - * we should divert the Guest to running an interrupt handler. */ -void maybe_do_interrupt(struct lg_cpu *cpu) + * interrupt_pending() returns the first pending interrupt which isn't blocked + * by the Guest. It is called before every entry to the Guest, and just before + * we go to sleep when the Guest has halted itself. */ +unsigned int interrupt_pending(struct lg_cpu *cpu, bool *more) { unsigned int irq; DECLARE_BITMAP(blk, LGUEST_IRQS); - struct desc_struct *idt; /* If the Guest hasn't even initialized yet, we can do nothing. */ if (!cpu->lg->lguest_data) - return; + return LGUEST_IRQS; /* Take our "irqs_pending" array and remove any interrupts the Guest * wants blocked: the result ends up in "blk". */ if (copy_from_user(&blk, cpu->lg->lguest_data->blocked_interrupts, sizeof(blk))) - return; + return LGUEST_IRQS; bitmap_andnot(blk, cpu->irqs_pending, blk, LGUEST_IRQS); /* Find the first interrupt. */ irq = find_first_bit(blk, LGUEST_IRQS); - /* None? Nothing to do */ - if (irq >= LGUEST_IRQS) - return; + *more = find_next_bit(blk, LGUEST_IRQS, irq+1); + + return irq; +} + +/* This actually diverts the Guest to running an interrupt handler, once an + * interrupt has been identified by interrupt_pending(). */ +void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more) +{ + struct desc_struct *idt; + + BUG_ON(irq >= LGUEST_IRQS); /* They may be in the middle of an iret, where they asked us never to * deliver interrupts. */ @@ -170,8 +179,12 @@ void maybe_do_interrupt(struct lg_cpu *cpu) u32 irq_enabled; if (get_user(irq_enabled, &cpu->lg->lguest_data->irq_enabled)) irq_enabled = 0; - if (!irq_enabled) + if (!irq_enabled) { + /* Make sure they know an IRQ is pending. */ + put_user(X86_EFLAGS_IF, + &cpu->lg->lguest_data->irq_pending); return; + } } /* Look at the IDT entry the Guest gave us for this interrupt. The @@ -194,6 +207,25 @@ void maybe_do_interrupt(struct lg_cpu *cpu) * here is a compromise which means at least it gets updated every * timer interrupt. */ write_timestamp(cpu); + + /* If there are no other interrupts we want to deliver, clear + * the pending flag. */ + 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); } /*:*/ @@ -510,10 +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); - /* If the Guest is actually stopped, we need to wake it up. */ - if (cpu->halted) - wake_up_process(cpu->tsk); + set_interrupt(cpu, 0); return HRTIMER_NORESTART; } |