[Qemu-devel] [PATCH] hpet config mask fix

[Qemu-devel] [PATCH] hpet config mask fix

[Beth Kon]

[-- Attachment #1: Type: text/plain, Size: 174 bytes --]

I discovered a bug in the hpet code that caused Windows to boot without 
hpet. The config mask I was using was preventing the guest from placing 
the hpet into 32 bit mode.


[-- Attachment #2: hpet_mask_fix.patch --]
[-- Type: text/x-diff, Size: 1944 bytes --]

diff --git a/qemu/hw/hpet.c b/qemu/hw/hpet.c
index 5c1aca2..7df2d05 100644
--- a/qemu/hw/hpet.c
+++ b/qemu/hw/hpet.c
@@ -388,7 +388,8 @@ 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, 0x3e4e);
+                timer->config = hpet_fixup_reg(new_val, old_val, 
+                                               HPET_TN_CFG_WRITE_MASK);
                 if (new_val & HPET_TN_32BIT) {
                     timer->cmp = (uint32_t)timer->cmp;
                     timer->period = (uint32_t)timer->period;
@@ -456,7 +457,8 @@ 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, 0x3);
+                s->config = hpet_fixup_reg(new_val, old_val, 
+                                           HPET_CFG_WRITE_MASK);
                 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)
diff --git a/qemu/hw/hpet_emul.h b/qemu/hw/hpet_emul.h
index fbe7a44..60893b6 100644
--- a/qemu/hw/hpet_emul.h
+++ b/qemu/hw/hpet_emul.h
@@ -36,6 +36,7 @@
 #define HPET_TN_CFG     0x000
 #define HPET_TN_CMP     0x008
 #define HPET_TN_ROUTE   0x010
+#define HPET_CFG_WRITE_MASK  0x3
 
 
 #define HPET_TN_ENABLE           0x004
@@ -45,6 +46,7 @@
 #define HPET_TN_SETVAL           0x040
 #define HPET_TN_32BIT            0x100
 #define HPET_TN_INT_ROUTE_MASK  0x3e00
+#define HPET_TN_CFG_WRITE_MASK  0x3f4e
 #define HPET_TN_INT_ROUTE_SHIFT      9
 #define HPET_TN_INT_ROUTE_CAP_SHIFT 32
 #define HPET_TN_CFG_BITS_READONLY_OR_RESERVED 0xffff80b1U

Re: [Qemu-devel] [PATCH] hpet config mask fix

[Aurelien Jarno]

On Wed, Jan 14, 2009 at 09:45:36AM -0500, Beth Kon wrote:
> I discovered a bug in the hpet code that caused Windows to boot without  
> hpet. The config mask I was using was preventing the guest from placing  
> the hpet into 32 bit mode.
>

Thanks, applied.

> diff --git a/qemu/hw/hpet.c b/qemu/hw/hpet.c
> index 5c1aca2..7df2d05 100644
> --- a/qemu/hw/hpet.c
> +++ b/qemu/hw/hpet.c
> @@ -388,7 +388,8 @@ 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, 0x3e4e);
> +                timer->config = hpet_fixup_reg(new_val, old_val, 
> +                                               HPET_TN_CFG_WRITE_MASK);
>                  if (new_val & HPET_TN_32BIT) {
>                      timer->cmp = (uint32_t)timer->cmp;
>                      timer->period = (uint32_t)timer->period;
> @@ -456,7 +457,8 @@ 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, 0x3);
> +                s->config = hpet_fixup_reg(new_val, old_val, 
> +                                           HPET_CFG_WRITE_MASK);
>                  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)
> diff --git a/qemu/hw/hpet_emul.h b/qemu/hw/hpet_emul.h
> index fbe7a44..60893b6 100644
> --- a/qemu/hw/hpet_emul.h
> +++ b/qemu/hw/hpet_emul.h
> @@ -36,6 +36,7 @@
>  #define HPET_TN_CFG     0x000
>  #define HPET_TN_CMP     0x008
>  #define HPET_TN_ROUTE   0x010
> +#define HPET_CFG_WRITE_MASK  0x3
>  
>  
>  #define HPET_TN_ENABLE           0x004
> @@ -45,6 +46,7 @@
>  #define HPET_TN_SETVAL           0x040
>  #define HPET_TN_32BIT            0x100
>  #define HPET_TN_INT_ROUTE_MASK  0x3e00
> +#define HPET_TN_CFG_WRITE_MASK  0x3f4e
>  #define HPET_TN_INT_ROUTE_SHIFT      9
>  #define HPET_TN_INT_ROUTE_CAP_SHIFT 32
>  #define HPET_TN_CFG_BITS_READONLY_OR_RESERVED 0xffff80b1U


-- 
  .''`.  Aurelien Jarno	            | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   aurel32@debian.org         | aurelien@aurel32.net
   `-    people.debian.org/~aurel32 | www.aurel32.net