FIXED: Re: [Qemu-devel] possible regression in qemu-kvm 0.13.0 (memtest)

Commit Message

Peter Lieven Dec. 26, 2010, 9:21 p.m. UTC

None

Patch

--- qemu-0.13.0/hw/pckbd.c	2010-10-15 22:56:09.000000000 +0200
+++ qemu-0.13.0-fix/hw/pckbd.c	2010-12-26 19:38:35.835114033 +0100
@@ -212,13 +212,16 @@ 
static void ioport92_write(void *opaque, uint32_t addr, uint32_t val)
{
    KBDState *s = opaque;
-
-    DPRINTF("kbd: write outport=0x%02x\n", val);
-    s->outport = val;
-    if (s->a20_out) {
-        qemu_set_irq(*s->a20_out, (val >> 1) & 1);
+    if (val & 0x02) { // bit 1: enable/disable A20
+       if (s->a20_out) qemu_irq_raise(*s->a20_out);
+       s->outport |= KBD_OUT_A20;
+    }
+    else
+    {
+       if (s->a20_out) qemu_irq_lower(*s->a20_out);
+       s->outport &= ~KBD_OUT_A20;
    }
-    if (!(val & 1)) {
+    if ((val & 1)) { // bit 0: raised -> fast reset
        qemu_system_reset_request();
    }
}
@@ -226,11 +229,8 @@ 
static uint32_t ioport92_read(void *opaque, uint32_t addr)
{
    KBDState *s = opaque;
-    uint32_t ret;
-
-    ret = s->outport;
-    DPRINTF("kbd: read outport=0x%02x\n", ret);
-    return ret;
+    return (s->outport & 0x02); // only bit 1 (KBD_OUT_A20) of port 0x92 is identical to s->outport
+    /* XXX: bit 0 is fast reset, bits 6-7 hdd activity */
}

static void kbd_write_command(void *opaque, uint32_t addr, uint32_t val)
@@ -340,7 +340,9 @@ 
        kbd_queue(s, val, 1);
        break;
    case KBD_CCMD_WRITE_OUTPORT:
-        ioport92_write(s, 0, val);
+        ioport92_write(s, 0, (ioport92_read(s,0) & 0xfc) // copy bits 2-7 of 0x92 
+                             | (val & 0x02) // bit 1 (enable a20)
+                             | (~val & 0x01)); // bit 0 (fast reset) of port 0x92 has inverse logic
        break;
    case KBD_CCMD_WRITE_MOUSE:
        ps2_write_mouse(s->mouse, val);