James Harper
2009-Jun-20 12:25 UTC
[Xen-devel] how to tell if a DomU (HVM) touches a specific address
I need to know if my Windows DomU attempts to read or write (or even map) a certain physical address. Is there a way I could do this? Maybe via xentrace? Thanks James _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2009-Jun-21 08:06 UTC
Re: [Xen-devel] how to tell if a DomU (HVM) touches a specific address
Is the physical address RAM? If there is no physical page at that address then accesses in that range will trap to qemu and you could pick them up there. -- Keir On 20/06/2009 13:25, "James Harper" <james.harper@bendigoit.com.au> wrote:> I need to know if my Windows DomU attempts to read or write (or even > map) a certain physical address. Is there a way I could do this? Maybe > via xentrace? > > Thanks > > James > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
James Harper
2009-Jun-21 09:49 UTC
RE: [Xen-devel] how to tell if a DomU (HVM) touches a specific address
> > Is the physical address RAM? If there is no physical page at thataddress> then accesses in that range will trap to qemu and you could pick themup> there. >What''s the best place to do that? I''ve had a little look and can''t find where the trap would ''come in''. Thanks James _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2009-Jun-21 11:19 UTC
Re: [Xen-devel] how to tell if a DomU (HVM) touches a specific address
On 21/06/2009 10:49, "James Harper" <james.harper@bendigoit.com.au> wrote:>> Is the physical address RAM? If there is no physical page at that > address >> then accesses in that range will trap to qemu and you could pick them > up >> there. >> > > What''s the best place to do that? I''ve had a little look and can''t find > where the trap would ''come in''.cpu_physical_memory_rw() is qemu''s main interface to readign and writing physical memory regions. Everything (RAM accesses, MMIO accesses, and also accesses which go to nowhere) go through that, so hooking there would be sensible. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Gianluca Guida
2009-Jun-21 12:00 UTC
Re: [Xen-devel] how to tell if a DomU (HVM) touches a specific address
On Sat, Jun 20, 2009 at 2:25 PM, James Harper<james.harper@bendigoit.com.au> wrote:> I need to know if my Windows DomU attempts to read or write (or even > map) a certain physical address. Is there a way I could do this? Maybe > via xentrace?If you don''t want to modify the Shadow/HAP level, an idea would be, in case it''s physical RAM, to create a dummy MMIO device. This way it will trap at every access to the memory you''re interested and be able to look at it via xentrace/printk/etc. Thanks, Gianluca -- It was a type of people I did not know, I found them very strange and they did not inspire confidence at all. Later I learned that I had been introduced to electronic engineers. E. W. Dijkstra _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel