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

[Juan Quintela <quintela@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> wrote:
> On 02/12/2015 11:30, Paolo Bonzini wrote:
>> 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 */
>> 
>> 
>
> Ok, I tested this by adding
>
> +     assert(HOST_PAGE_ALIGN(0x123456700ll) == 0x123457000ll);
> +     assert(REAL_HOST_PAGE_ALIGN(0x123456700ll) == 0x123457000ll);
>
> and doing a 32-bit x86_64-linux-user build.  Since Dave's patch does not
> compile for user-mode emulation (ram_addr_t is a softmmu concept), I'm
> queuing my patch for 2.5.
>
> Paolo

Reviewed-by: Juan Quintela <quintela@redhat.com>

Dave patch massively broke linux-user.  Going that route can make sense,
but not so late on the cycle.