[PATCH 09/12] rust/hpet: change timer of num_timers to usize

[Paolo Bonzini <pbonzini@redhat.com>]

Remove the need to convert after every read of the BqlCell.  Because the
vmstate uses a u8 as the size of the VARRAY, this requires switching
the VARRAY to use num_timers_save; which in turn requires ensuring that
the num_timers_save is always there.  For simplicity do this by
removing support for version 1, which QEMU has not been producing for
~15 years.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 rust/hw/timer/hpet/src/hpet.rs | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/rust/hw/timer/hpet/src/hpet.rs b/rust/hw/timer/hpet/src/hpet.rs
index 55eef669a9d..b2922e6a843 100644
--- a/rust/hw/timer/hpet/src/hpet.rs
+++ b/rust/hw/timer/hpet/src/hpet.rs
@@ -12,7 +12,7 @@
 use qemu_api::{
     bindings::{
         address_space_memory, address_space_stl_le, qdev_prop_bit, qdev_prop_bool,
-        qdev_prop_uint32, qdev_prop_uint8,
+        qdev_prop_uint32, qdev_prop_usize,
     },
     cell::{BqlCell, BqlRefCell},
     irq::InterruptSource,
@@ -36,9 +36,9 @@
 const HPET_REG_SPACE_LEN: u64 = 0x400; // 1024 bytes
 
 /// Minimum recommended hardware implementation.
-const HPET_MIN_TIMERS: u8 = 3;
+const HPET_MIN_TIMERS: usize = 3;
 /// Maximum timers in each timer block.
-const HPET_MAX_TIMERS: u8 = 32;
+const HPET_MAX_TIMERS: usize = 32;
 
 /// Flags that HPETState.flags supports.
 const HPET_FLAG_MSI_SUPPORT_SHIFT: usize = 0;
@@ -561,8 +561,8 @@ pub struct HPETState {
 
     /// HPET timer array managed by this timer block.
     #[doc(alias = "timer")]
-    timers: [BqlRefCell<HPETTimer>; HPET_MAX_TIMERS as usize],
-    num_timers: BqlCell<u8>,
+    timers: [BqlRefCell<HPETTimer>; HPET_MAX_TIMERS],
+    num_timers: BqlCell<usize>,
     num_timers_save: BqlCell<u8>,
 
     /// Instance id (HPET timer block ID).
@@ -572,7 +572,7 @@ pub struct HPETState {
 impl HPETState {
     // Get num_timers with `usize` type, which is useful to play with array index.
     fn get_num_timers(&self) -> usize {
-        self.num_timers.get().into()
+        self.num_timers.get()
     }
 
     const fn has_msi_flag(&self) -> bool {
@@ -854,7 +854,7 @@ fn pre_save(&self) -> i32 {
          * also added to the migration stream.  Check that it matches the value
          * that was configured.
          */
-        self.num_timers_save.set(self.num_timers.get());
+        self.num_timers_save.set(self.num_timers.get() as u8);
         0
     }
 
@@ -884,7 +884,7 @@ fn is_offset_needed(&self) -> bool {
     }
 
     fn validate_num_timers(&self, _version_id: u8) -> bool {
-        self.num_timers.get() == self.num_timers_save.get()
+        self.num_timers.get() == self.num_timers_save.get().into()
     }
 }
 
@@ -911,7 +911,7 @@ impl ObjectImpl for HPETState {
         c"timers",
         HPETState,
         num_timers,
-        unsafe { &qdev_prop_uint8 },
+        unsafe { &qdev_prop_usize },
         u8,
         default = HPET_MIN_TIMERS
     ),
@@ -1016,16 +1016,16 @@ impl ObjectImpl for HPETState {
 static VMSTATE_HPET: VMStateDescription = VMStateDescription {
     name: c"hpet".as_ptr(),
     version_id: 2,
-    minimum_version_id: 1,
+    minimum_version_id: 2,
     pre_save: Some(hpet_pre_save),
     post_load: Some(hpet_post_load),
     fields: vmstate_fields! {
         vmstate_of!(HPETState, config),
         vmstate_of!(HPETState, int_status),
         vmstate_of!(HPETState, counter),
-        vmstate_of!(HPETState, num_timers_save).with_version_id(2),
+        vmstate_of!(HPETState, num_timers_save),
         vmstate_validate!(HPETState, VALIDATE_TIMERS_NAME, HPETState::validate_num_timers),
-        vmstate_struct!(HPETState, timers[0 .. num_timers], &VMSTATE_HPET_TIMER, BqlRefCell<HPETTimer>, HPETState::validate_num_timers).with_version_id(0),
+        vmstate_struct!(HPETState, timers[0 .. num_timers_save], &VMSTATE_HPET_TIMER, BqlRefCell<HPETTimer>, HPETState::validate_num_timers).with_version_id(0),
     },
     subsections: vmstate_subsections! {
         VMSTATE_HPET_RTC_IRQ_LEVEL,
-- 
2.49.0