On 23 August 2013 21:10, Christoffer Dall christoffer.dall@linaro.org wrote:
Right now the arm gic emulation doesn't keep track of the source of an SGI (which apparently Linux guests don't use, or they're fine with assuming CPU 0 always).
Add the necessary matrix on the GICState structure and maintain the data when setting and clearing the pending state of an IRQ.
Note that we always choose to present the source as the lowest-numbered CPU in case multiple cores have signalled the same SGI number to a core on the system.
@@ -525,6 +538,11 @@ static void gic_dist_writel(void *opaque, hwaddr offset, break; } GIC_SET_PENDING(irq, mask);
target_cpu = (unsigned)ffs(mask) - 1;while (target_cpu < NCPU) {s->sgi_source[irq][target_cpu] |= (1 << cpu);target_cpu = (unsigned)ffs(mask) - 1;}
This is an infinite loop, because you don't do anything with mask inside the loop, so target_cpu is always the same each time round. gcc with optimization is smart enough to notice this:
=> 0x00005555556c1625 <+229>: jmp 0x5555556c1625 <gic_dist_writel+229>
:-)
Unsurprisingly, my test vexpress-a9 image hangs on startup.
--- a/hw/intc/arm_gic_common.c +++ b/hw/intc/arm_gic_common.c @@ -71,6 +71,7 @@ static const VMStateDescription vmstate_gic = { VMSTATE_UINT8_2DARRAY(priority1, GICState, GIC_INTERNAL, NCPU), VMSTATE_UINT8_ARRAY(priority2, GICState, GIC_MAXIRQ - GIC_INTERNAL), VMSTATE_UINT16_2DARRAY(last_active, GICState, GIC_MAXIRQ, NCPU),
VMSTATE_UINT8_2DARRAY(sgi_source, GICState, GIC_NR_SGIS, NCPU), VMSTATE_UINT16_ARRAY(priority_mask, GICState, NCPU), VMSTATE_UINT16_ARRAY(running_irq, GICState, NCPU), VMSTATE_UINT16_ARRAY(running_priority, GICState, NCPU),
You need to bump the version_id and minimum_version_id if you add a new field here.
-- PMM