Re: [Xen-devel] [Xen-users] xc_hvm_inject_trap() failing for int3 traps under Xen 4.2.2

[AP <apxeng@xxxxxxxxx>]

(Adding xen-devel)

On Tue, Jun 4, 2013 at 2:34 PM, Antony Saba <Antony.Saba@xxxxxxxxxxxx> wrote:
>
> Hello,
>
> Can anyone verify if reinjecting int3 mem_events work for them under Xen
> 4.2.2?
>
> I'm trying to move some systems which are making use of int3 mem_events
> from Xen 4.1.x to Xen 4.2.2, but seem to having an issue with
> xc_hvm_inject_trap().

Can you try with the following patch?

--- a/tools/tests/xen-access/xen-access.c
+++ b/tools/tests/xen-access/xen-access.c
@@ -664,7 +664,7 @@ int main(int argc, char *argv[])
                 /* Reinject */
                 rc = xc_hvm_inject_trap(
                     xch, domain_id, req.vcpu_id, 3,
-                    HVMOP_TRAP_sw_exc, -1, 0, 0);
+                    HVMOP_TRAP_sw_exc, -1, 1, 0);
                 if (rc < 0)
                 {
                     ERROR("Error %d injecting int3\n", rc);

BTW, I don't think you need to specify the instruction length for int3
as the IP should have been moved forward. But it might give us a clue
as to what is going on.

> I've got a simple program that doesn't do anything but "_asm int 3" in
> it's main.  Using the example in "tools/text/xen-access/", this is what
> the output of "xen-access 14 int3" looks like.  The domain is frozen
> after xen-access exits.
>   xenaccess init
>   max_pages = 40100
>   starting int3 14
>   Got event from Xen
>   Got event from Xen
>   INT3: rip=0000000000401000, gfn=1418f (vcpu 0)
>   xc: error: Error -1 injecting int3: Internal error
>   xenaccess shutting down on signal -1
>   xenaccess shut down on signal -1
>   xenaccess exit code -1

If you set access required, then this is the expected behavior
otherwise the domain should continue running.

> This shows up in xl dmesg (nothing else shows up with debug=y):
> (XEN) d14v0: bogus time -341046118 (offsets -3367129229295/0)
>
> The same behavior occurs with both 32-bit and 64-bit HVM guests.
>
> I'm using Xen 4.2.2 built from the dist tarball.
>
> dom0 is Ubuntu 12.04.2 using kernel 3.2.0-45-generic #70-Ubuntu SMP Wed
> May 29 20:12:06 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
>
> My CPU is an Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz
>
> I've also tried on 2nd machine with the same Ubuntu/kernel versions, but
> with the following CPU: Intel(R) Core(TM) i7-2720QM CPU @ 2.20GHz
>
> On 4.1.2, the result of xc_hvm_inject_trap() is always non-zero and
> errno is set to ENOENT, but the int3 is reinjected anyway and works as
> expected.
>
> -Tony
>
> --
> Antony Saba, antony.saba@xxxxxxxxxxxx
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxx
> http://lists.xen.org/xen-users

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