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 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.

Hmm yes OK; my alternate was just making ram_addr_t being always defined.
I'm not sure we have any other type that's more suitable than ram_addr_t
but I guess the intptr_t will work for the mask.

Dave

> 
> Paolo
--
Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK

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