WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] Re: [PATCH 4/5] xen: Fix the memory registration to reflect

To: Anthony PERARD <anthony.perard@xxxxxxxxxx>
Subject: [Xen-devel] Re: [PATCH 4/5] xen: Fix the memory registration to reflect of what is done by Xen.
From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Date: Fri, 15 Jul 2011 18:05:34 +0100
Cc: Xen Devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Stefano Stabellini <Stefano.Stabellini@xxxxxxxxxxxxx>, QEMU-devel <qemu-devel@xxxxxxxxxx>, Alexander Graf <agraf@xxxxxxx>
Delivery-date: Fri, 15 Jul 2011 10:07:02 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <1310740376-13323-5-git-send-email-anthony.perard@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <1310740376-13323-1-git-send-email-anthony.perard@xxxxxxxxxx> <1310740376-13323-5-git-send-email-anthony.perard@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Alpine 2.00 (DEB 1167 2008-08-23)
On Fri, 15 Jul 2011, Anthony PERARD wrote:
> A Xen guest memory is allocated by libxc. But this memory is not
> allocated continuously, instead, it leaves the VGA IO memory space not
> allocated, same for the MMIO space (at HVM_BELOW_4G_MMIO_START of size
> HVM_BELOW_4G_MMIO_LENGTH).
> 
> So to reflect that, we do not register the physical memory for this two
> holes. But we still keep only one RAMBlock for the all RAM as it is more
> easier than have two separate blocks (1 above 4G). Also this prevent QEMU
> from use the MMIO space for a ROM.
> 
> Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
> ---
>  xen-all.c |   21 ++++++++++++++-------
>  1 files changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/xen-all.c b/xen-all.c
> index 2c0a62d..76d5c5c 100644
> --- a/xen-all.c
> +++ b/xen-all.c
> @@ -144,6 +144,12 @@ static void xen_ram_init(ram_addr_t ram_size)
>      new_block->host = NULL;
>      new_block->offset = 0;
>      new_block->length = ram_size;
> +    if (ram_size >= HVM_BELOW_4G_RAM_END) {
> +        /* Xen does not allocate the memory continuously, and keep a hole at
> +         * HVM_BELOW_4G_MMIO_START of HVM_BELOW_4G_MMIO_LENGTH
> +         */
> +        new_block->length += HVM_BELOW_4G_MMIO_LENGTH;
> +    }
>  
>      QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
>  
> @@ -152,20 +158,21 @@ static void xen_ram_init(ram_addr_t ram_size)
>      memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
>             0xff, new_block->length >> TARGET_PAGE_BITS);
>  
> -    if (ram_size >= 0xe0000000 ) {
> -        above_4g_mem_size = ram_size - 0xe0000000;
> -        below_4g_mem_size = 0xe0000000;
> +    if (ram_size >= HVM_BELOW_4G_RAM_END) {
> +        above_4g_mem_size = ram_size - HVM_BELOW_4G_RAM_END;
> +        below_4g_mem_size = HVM_BELOW_4G_RAM_END;
>      } else {
>          below_4g_mem_size = ram_size;
>      }
>  
> -    cpu_register_physical_memory(0, below_4g_mem_size, new_block->offset);
> -#if TARGET_PHYS_ADDR_BITS > 32
> +    cpu_register_physical_memory(0, 0xa0000, 0);
> +    /* Skip of the VGA IO memory space */
> +    cpu_register_physical_memory(0xc0000, below_4g_mem_size - 0xc0000,
> +                                 0xc0000);
 
Shouldn't we avoid registering any memory for the whole video ram area?
I mean:
    
0xa0000 - 0x100000



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>