[Xen-devel] RE: [PATCH] txt: 1/6 - "fix" xen_phys_start for 32b builds

["Wang, Shane" <shane.wang@xxxxxxxxx>]

We are using xen_phys_start ~ xenheap_phys_end to check its integrity (for the 
purpose of memory integrity protection) before and after Sx by MACing this 
range.
It looks like xen heap is not continuous any more.

Shane
________________________________

From: Keir Fraser [mailto:keir.fraser@xxxxxxxxxxxxx] 
Sent: 2009年1月20日 17:00
To: Cihula, Joseph; xen-devel@xxxxxxxxxxxxxxxxxxx; 
xense-devel@xxxxxxxxxxxxxxxxxxx
Cc: Wang, Shane
Subject: Re: [PATCH] txt: 1/6 - "fix" xen_phys_start for 32b builds


Xen_phys/xenheap_phys has changed a bit since removing Xen heap for x86/64. It 
sounds like you’ll be re-sending these patches later once fixed up for 
xen-unstable tip. Perhaps this won’t be needed any more. I’m not sure what 
you’re using xen_phys_start for, but it does sound dubious.

 -- Keir

On 20/01/2009 05:48, "Cihula, Joseph" <joseph.cihula@xxxxxxxxx> wrote:



        On IA32 (32b/32b PAE) builds, set xen_phys_start (and by extension 
xenheap_phys_start) to be the start of hypervisor code (instead of 0).  This 
reflects the actual trust/protection boundary of the hypervisor.
        
        Signed-off-by: Joseph Cihula <joseph.cihula@xxxxxxxxx>
        
        diff -r 8df3c145923f -r f96073a97f5c xen/arch/x86/setup.c
        --- a/xen/arch/x86/setup.c      Mon Jan 19 17:40:28 2009 +0000
        +++ b/xen/arch/x86/setup.c      Mon Jan 19 20:22:24 2009 -0800
        @@ -843,7 +843,7 @@ void __init __start_xen(unsigned long mb
             /* Initialise the Xen heap. */
             init_xenheap_pages(xenheap_phys_start, xenheap_phys_end);
             nr_pages = (xenheap_phys_end - xenheap_phys_start) >> PAGE_SHIFT;
        -    xenheap_phys_start = xen_phys_start;
        +    xenheap_phys_start = xen_phys_start = __pa(&_start);
             printk("Xen heap: %luMB (%lukB)\n",
                    nr_pages >> (20 - PAGE_SHIFT),
                    nr_pages << (PAGE_SHIFT - 10));
        
        

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