Re: [Xen-devel] [PATCH V2] qemu-xen-traditionnal, Fix dirty logging during migration.

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Mon, 23 Jul 2012, Anthony PERARD wrote:
> This moves the xen_modified_memory call from cpu_physical_memory_map to
> cpu_physical_memory_unmap because the memory could be migrated before the
> device model have written to it.
> 
> But because we need to know the guest address and to avoid rewriting a new
> function, the call is moved to qemu_invalidate_entry. So this later has to new
> parameters, the length of the mapping and if it was a write.
> 
> Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>


Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


> Change since first version:
>   - No more extra function to get the guest address from a pointer.
>   > The xc_hvm_modied_memory is moved to qemu_invalidate_entry
> 
>  hw/xen_machine_fv.c |   16 ++++++++++++++--
>  i386-dm/exec-dm.c   |    6 +-----
>  qemu-xen.h          |    2 +-
>  3 files changed, 16 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/xen_machine_fv.c b/hw/xen_machine_fv.c
> index fdad42a..2bb44e0 100644
> --- a/hw/xen_machine_fv.c
> +++ b/hw/xen_machine_fv.c
> @@ -174,7 +174,8 @@ uint8_t *qemu_map_cache(target_phys_addr_t phys_addr, 
> uint8_t lock)
>      return last_address_vaddr + address_offset;
>  }
>  
> -void qemu_invalidate_entry(uint8_t *buffer)
> +void qemu_invalidate_entry(uint8_t *buffer, target_phys_addr_t access_len,
> +                           int was_written)
>  {
>      struct map_cache *entry = NULL, *pentry = NULL;
>      struct map_cache_rev *reventry;
> @@ -210,6 +211,17 @@ void qemu_invalidate_entry(uint8_t *buffer)
>          fprintf(logfile, "Trying to unmap address %p that is not in the 
> mapcache!\n", buffer);
>          return;
>      }
> +    if (xen_logdirty_enable && was_written) {
> +        unsigned long addr = (paddr_index << MCACHE_BUCKET_SHIFT)
> +            + ((unsigned long)buffer) - ((unsigned long)entry->vaddr_base);
> +        if (access_len == 0)
> +            access_len = TARGET_PAGE_SIZE;
> +        xc_hvm_modified_memory(xc_handle, domid,
> +            addr >> TARGET_PAGE_BITS,
> +            ((addr + access_len + TARGET_PAGE_SIZE - 1) >> TARGET_PAGE_BITS)
> +            - (addr >> TARGET_PAGE_BITS));
> +    }
> +
>      entry->lock--;
>      if (entry->lock > 0 || pentry == NULL)
>          return;
> @@ -265,7 +277,7 @@ uint8_t *qemu_map_cache(target_phys_addr_t phys_addr, 
> uint8_t lock)
>  
>  void qemu_invalidate_map_cache(void) {};
>  
> -void qemu_invalidate_entry(uint8_t *buffer) {};
> +void qemu_invalidate_entry(uint8_t *buffer, target_phys_addr_t len, int w) 
> {};
>  
>  #endif /* defined(MAPCACHE) */
>  
> diff --git a/i386-dm/exec-dm.c b/i386-dm/exec-dm.c
> index 96274d9..493146b 100644
> --- a/i386-dm/exec-dm.c
> +++ b/i386-dm/exec-dm.c
> @@ -820,10 +820,6 @@ void *cpu_physical_memory_map(target_phys_addr_t addr,
>      if ((*plen) > l)
>          *plen = l;
>  #endif
> -    if (xen_logdirty_enable)
> -        xc_hvm_modified_memory(xc_handle, domid, addr >> TARGET_PAGE_BITS,
> -                ((addr + l + TARGET_PAGE_SIZE - 1) >> TARGET_PAGE_BITS)
> -                    - (addr >> TARGET_PAGE_BITS));
>  
>      return qemu_map_cache(addr, 1);
>  }
> @@ -835,6 +831,6 @@ void *cpu_physical_memory_map(target_phys_addr_t addr,
>  void cpu_physical_memory_unmap(void *buffer, target_phys_addr_t len,
>                                 int is_write, target_phys_addr_t access_len)
>  {
> -    qemu_invalidate_entry(buffer);
> +    qemu_invalidate_entry(buffer, access_len, is_write);
>      cpu_notify_map_clients();
>  }
> diff --git a/qemu-xen.h b/qemu-xen.h
> index d50c89f..54159bf 100644
> --- a/qemu-xen.h
> +++ b/qemu-xen.h
> @@ -28,7 +28,7 @@ extern int vga_ram_size;
>  #endif
>  
>  uint8_t *qemu_map_cache(target_phys_addr_t phys_addr, uint8_t lock);
> -void     qemu_invalidate_entry(uint8_t *buffer);
> +void     qemu_invalidate_entry(uint8_t *buffer, target_phys_addr_t len, int 
> w);
>  void     qemu_invalidate_map_cache(void);
>  
>  #define mapcache_lock()   ((void)0)
> -- 
> Anthony PERARD
> 

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