[PATCH] hw/intc: Handle software disabling of APIC correctly

[Jay Khandkar <jaykhandkar2002@gmail.com>]

When the local APIC is in a software disabled state, all local interrupt
sources must be masked and all attempts to unmask them should be
ignored. Currently, we don't do either. Fix this by handling it
correctly in apic_mem_write().

Signed-off-by: Jay Khandkar <jaykhandkar2002@gmail.com>
---
 hw/intc/apic.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/hw/intc/apic.c b/hw/intc/apic.c
index 3df11c34d6..493c70af62 100644
--- a/hw/intc/apic.c
+++ b/hw/intc/apic.c
@@ -792,9 +792,16 @@ static void apic_mem_write(void *opaque, hwaddr addr, uint64_t val,
         s->dest_mode = val >> 28;
         break;
     case 0x0f:
-        s->spurious_vec = val & 0x1ff;
-        apic_update_irq(s);
-        break;
+        {
+            s->spurious_vec = val & 0x1ff;
+            if (!(val & APIC_SPURIO_ENABLED)) {
+                for (int i = 0; i < APIC_LVT_NB; i++) {
+                    s->lvt[i] |= APIC_LVT_MASKED;
+                }
+            }
+            apic_update_irq(s);
+            break;
+        }
     case 0x10 ... 0x17:
     case 0x18 ... 0x1f:
     case 0x20 ... 0x27:
@@ -812,6 +819,9 @@ static void apic_mem_write(void *opaque, hwaddr addr, uint64_t val,
     case 0x32 ... 0x37:
         {
             int n = index - 0x32;
+            if (!(s->spurious_vec & APIC_SPURIO_ENABLED)) {
+                val |= APIC_LVT_MASKED;
+            }
             s->lvt[n] = val;
             if (n == APIC_LVT_TIMER) {
                 apic_timer_update(s, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
-- 
2.37.0