[Qemu-devel] [PATCH] HPET fixes for reg writes

[Beth Kon <eak@us.ibm.com>]

This patch addresses the problems found by Andriy Gapon: 

- The code was incorrectly overwriting the high order 32 
  bits of the timer and hpet config registers. This didn't show up
  in testing because linux and windows use hpet in legacy mode,
  where the high order 32 bits (advertising available interrupts)
  of the timer config register are ignored, and the high order 32
  bits of the hpet config register are reserved and unused.


- The mask for level-triggered interrupts was off by a bit. (hpet
  doesn't currently support level-triggered interrupts).

In addition, I removed some unused #defines, and corrected the ioapic
interrupt values advertised. I'd set this up early in hpet development
and never went back to correct it, and no bugs resulted since linux and
windows use hpet in legacy mode where available interrupts are ignored.




Signed-off-by: Beth Kon <eak@us.ibm.com>
---

diff --git a/hw/hpet.c b/hw/hpet.c
index 24aee6a..01b10aa 100644
--- a/hw/hpet.c
+++ b/hw/hpet.c
@@ -371,7 +371,7 @@ static void hpet_ram_writel(void *opaque, target_phys_addr_t addr,
 {
     int i;
     HPETState *s = (HPETState *)opaque;
-    uint64_t old_val, new_val, index;
+    uint64_t old_val, new_val, val, index;
 
     dprintf("qemu: Enter hpet_ram_writel at %" PRIx64 " = %#x\n", addr, value);
     index = addr;
@@ -387,8 +387,8 @@ static void hpet_ram_writel(void *opaque, target_phys_addr_t addr,
         switch ((addr - 0x100) % 0x20) {
             case HPET_TN_CFG:
                 dprintf("qemu: hpet_ram_writel HPET_TN_CFG\n");
-                timer->config = hpet_fixup_reg(new_val, old_val, 
-                                               HPET_TN_CFG_WRITE_MASK);
+                val = hpet_fixup_reg(new_val, old_val, HPET_TN_CFG_WRITE_MASK);
+                timer->config = (timer->config & 0xffffffff00000000ULL) | val;
                 if (new_val & HPET_TN_32BIT) {
                     timer->cmp = (uint32_t)timer->cmp;
                     timer->period = (uint32_t)timer->period;
@@ -456,8 +456,8 @@ static void hpet_ram_writel(void *opaque, target_phys_addr_t addr,
             case HPET_ID:
                 return;
             case HPET_CFG:
-                s->config = hpet_fixup_reg(new_val, old_val, 
-                                           HPET_CFG_WRITE_MASK);
+                val = hpet_fixup_reg(new_val, old_val, HPET_CFG_WRITE_MASK);
+                s->config = (s->config & 0xffffffff00000000ULL) | val;
                 if (activating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
                     /* Enable main counter and interrupt generation. */
                     s->hpet_offset = ticks_to_ns(s->hpet_counter)
@@ -541,8 +541,8 @@ static void hpet_reset(void *opaque) {
         timer->tn = i;
         timer->cmp = ~0ULL;
         timer->config =  HPET_TN_PERIODIC_CAP | HPET_TN_SIZE_CAP;
-        /* advertise availability of irqs 5,10,11 */
-        timer->config |=  0x00000c20ULL << 32;
+        /* advertise availability of ioapic inti2 */
+        timer->config |=  0x00000004ULL << 32;
         timer->state = s;
         timer->period = 0ULL;
         timer->wrap_flag = 0;
diff --git a/hw/hpet_emul.h b/hw/hpet_emul.h
index 60893b6..3258d8b 100644
--- a/hw/hpet_emul.h
+++ b/hw/hpet_emul.h
@@ -18,12 +18,7 @@
 
 #define FS_PER_NS 1000000
 #define HPET_NUM_TIMERS 3
-#define HPET_TIMER_TYPE_LEVEL 1
-#define HPET_TIMER_TYPE_EDGE 0
-#define HPET_TIMER_DELIVERY_APIC 0
-#define HPET_TIMER_DELIVERY_FSB 1
-#define HPET_TIMER_CAP_FSB_INT_DEL (1 << 15)
-#define HPET_TIMER_CAP_PER_INT (1 << 4)
+#define HPET_TIMER_TYPE_LEVEL 0x002
 
 #define HPET_CFG_ENABLE 0x001
 #define HPET_CFG_LEGACY 0x002