Re: [Xen-devel] Regression: Xen guest with 5G of RAM on 32bit fail to boot

["Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>]

* Paolo Bonzini (pbonzini@xxxxxxxxxx) wrote:
> 
> 
> On 01/12/2015 18:53, Anthony PERARD wrote:
> > The problem is in qemu_ram_alloc_internal() where 'size' and 'maxsize' are
> > now been truncate to 32bit, due to 'qemu_host_page_size' been an uintptr_t
> > in the HOST_PAGE_ALIGN macro.
> 
> Isn't it qemu_host_page_mask that causes the problem?
> 
> This should also work, as it causes qemu_host_page_mask to sign-extend:

I've just posted a set that just flips them to ram_addr_t (and removes the 10 
year
old warning that questions whether the type is right - which it obviously 
wasn't);
see '[For 2.5?? PATCH 1/1] qemu_{real_}host_page_[size|mask] change types to
 ram_addr_t'

Anthony: I'd appreciate if you could give it a Xen test.

Dave

> diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
> index f9998b9..87a4145 100644
> --- a/include/exec/cpu-all.h
> +++ b/include/exec/cpu-all.h
> @@ -174,11 +174,10 @@ extern unsigned long reserved_va;
>  #define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1)
>  #define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & 
> TARGET_PAGE_MASK)
>  
> -/* ??? These should be the larger of uintptr_t and target_ulong.  */
>  extern uintptr_t qemu_real_host_page_size;
> -extern uintptr_t qemu_real_host_page_mask;
> +extern intptr_t qemu_real_host_page_mask;
>  extern uintptr_t qemu_host_page_size;
> -extern uintptr_t qemu_host_page_mask;
> +extern intptr_t qemu_host_page_mask;
>  
>  #define HOST_PAGE_ALIGN(addr) (((addr) + qemu_host_page_size - 1) & 
> qemu_host_page_mask)
>  #define REAL_HOST_PAGE_ALIGN(addr) (((addr) + qemu_real_host_page_size - 1) 
> & \
> diff --git a/translate-all.c b/translate-all.c
> index a940bd2..7a15109 100644
> --- a/translate-all.c
> +++ b/translate-all.c
> @@ -118,7 +118,7 @@ typedef struct PageDesc {
>  #define V_L1_SHIFT (L1_MAP_ADDR_SPACE_BITS - TARGET_PAGE_BITS - V_L1_BITS)
>  
>  uintptr_t qemu_host_page_size;
> -uintptr_t qemu_host_page_mask;
> +intptr_t qemu_host_page_mask;
>  
>  /* The bottom level has pointers to PageDesc */
>  static void *l1_map[V_L1_SIZE];
> @@ -326,14 +326,14 @@ void page_size_init(void)
>      /* NOTE: we can always suppose that qemu_host_page_size >=
>         TARGET_PAGE_SIZE */
>      qemu_real_host_page_size = getpagesize();
> -    qemu_real_host_page_mask = ~(qemu_real_host_page_size - 1);
> +    qemu_real_host_page_mask = -(intptr_t)qemu_real_host_page_size;
>      if (qemu_host_page_size == 0) {
>          qemu_host_page_size = qemu_real_host_page_size;
>      }
>      if (qemu_host_page_size < TARGET_PAGE_SIZE) {
>          qemu_host_page_size = TARGET_PAGE_SIZE;
>      }
> -    qemu_host_page_mask = ~(qemu_host_page_size - 1);
> +    qemu_host_page_mask = -(intptr_t)qemu_host_page_size;
>  }
>  
>  static void page_init(void)
> diff --git a/translate-common.c b/translate-common.c
> index 619feb4..171222d 100644
> --- a/translate-common.c
> +++ b/translate-common.c
> @@ -21,7 +21,7 @@
>  #include "qom/cpu.h"
>  
>  uintptr_t qemu_real_host_page_size;
> -uintptr_t qemu_real_host_page_mask;
> +intptr_t qemu_real_host_page_mask;
>  
>  #ifndef CONFIG_USER_ONLY
>  /* mask must never be zero, except for A20 change call */
--
Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK

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