[Qemu-devel] [PATCH 2/2] ioapic: Implement polarity

[Jan Kiszka <jan.kiszka@web.de>]

From: Jan Kiszka <jan.kiszka@siemens.com>

If the polarity bit is set in a redirection table entry, the input level
simply has to inverted as it is low active in this case.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/ioapic.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/hw/ioapic.c b/hw/ioapic.c
index 5916387..61991d7 100644
--- a/hw/ioapic.c
+++ b/hw/ioapic.c
@@ -148,6 +148,9 @@ static void ioapic_set_irq(void *opaque, int vector, int level)
         uint32_t mask = 1 << vector;
         uint64_t entry = s->ioredtbl[vector];
 
+        if (entry & (1 << IOAPIC_LVT_POLARITY_SHIFT)) {
+            level = !level;
+        }
         if (((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1) ==
             IOAPIC_TRIGGER_LEVEL) {
             /* level triggered */