pass info about hpets to seabios.]

Currently HPET ACPI table is created regardless of whether qemu actually
created hpet device. This may confuse some guests that don't check that
hpet is functional before using it. Solve this by passing info about
hpets in qemu to seabios via fw config interface. Additional benefit is
that seabios no longer uses hard coded hpet configuration. Proposed
interface supports up to 8 hpets. This is the number defined by hpet
spec.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/hw/hpet.c b/hw/hpet.c
index e9b585c69b..0c80ee5da7 100644
--- a/hw/hpet.c
+++ b/hw/hpet.c
@@ -71,8 +71,11 @@ typedef struct HPETState {
     uint64_t config;            /* configuration */
     uint64_t isr;               /* interrupt status reg */
     uint64_t hpet_counter;      /* main counter */
+    uint8_t  hpet_id;           /* instance id */
 } HPETState;
 
+struct hpet_fw_config hpet_cfg = {.count = ~0};
+
 static uint32_t hpet_in_legacy_mode(HPETState *s)
 {
     return s->config & HPET_CFG_LEGACY;
@@ -228,6 +231,7 @@ static int hpet_post_load(void *opaque, int version_id)
     /* Push number of timers into capability returned via HPET_ID */
     s->capability &= ~HPET_ID_NUM_TIM_MASK;
     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
+    hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
 
     /* Derive HPET_MSI_SUPPORT from the capability of the first timer. */
     s->flags &= ~(1 << HPET_MSI_SUPPORT);
@@ -657,6 +661,8 @@ static void hpet_reset(DeviceState *d)
          */
         hpet_pit_enable();
     }
+    hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
+    hpet_cfg.hpet[s->hpet_id].address = sysbus_from_qdev(d)->mmio[0].addr;
     count = 1;
 }
 
@@ -676,6 +682,16 @@ static int hpet_init(SysBusDevice *dev)
     int i, iomemtype;
     HPETTimer *timer;
 
+    if (hpet_cfg.count == ~0) /* first instance */
+        hpet_cfg.count = 0;
+
+    if (hpet_cfg.count == 8) {
+        fprintf(stderr, "Only 8 instances of HPET is allowed\n");
+        return -1;
+    }
+
+    s->hpet_id = hpet_cfg.count++;
+
     for (i = 0; i < HPET_NUM_IRQ_ROUTES; i++) {
         sysbus_init_irq(dev, &s->irqs[i]);
     }