diff options
Diffstat (limited to 'drivers/lguest')
| -rw-r--r-- | drivers/lguest/core.c | 14 | ||||
| -rw-r--r-- | drivers/lguest/interrupts_and_traps.c | 26 | ||||
| -rw-r--r-- | drivers/lguest/lg.h | 3 |
3 files changed, 31 insertions, 12 deletions
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index 4845fb3cf74b..8ca1def5b142 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -188,6 +188,8 @@ 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; + /* First we run any hypercalls the Guest wants done. */ if (cpu->hcall) do_hypercalls(cpu); @@ -211,7 +213,9 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user) /* 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); + irq = interrupt_pending(cpu); + if (irq < LGUEST_IRQS) + try_deliver_interrupt(cpu, irq); /* All long-lived kernel loops need to check with this horrible * thing called the freezer. If the Host is trying to suspend, @@ -227,7 +231,13 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user) * clock timer or LHREQ_BREAK from the Waker will wake us. */ if (cpu->halted) { set_current_state(TASK_INTERRUPTIBLE); - schedule(); + /* Just before we sleep, make sure nothing snuck in + * which we should be doing. */ + if (interrupt_pending(cpu) < LGUEST_IRQS + || cpu->break_out) + set_current_state(TASK_RUNNING); + else + schedule(); continue; } diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c index 9ea26ad88c9d..a8c966fee1e4 100644 --- a/drivers/lguest/interrupts_and_traps.c +++ b/drivers/lguest/interrupts_and_traps.c @@ -128,30 +128,38 @@ 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) { 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; + + 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) +{ + 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. */ diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h index af92a176697f..6743cf147d97 100644 --- a/drivers/lguest/lg.h +++ b/drivers/lguest/lg.h @@ -139,7 +139,8 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user); #define pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT) /* interrupts_and_traps.c: */ -void maybe_do_interrupt(struct lg_cpu *cpu); +unsigned int interrupt_pending(struct lg_cpu *cpu); +void try_deliver_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); |