Re: [PATCH for-4.5 v8 4/7] xen: Add vmware_port support

[Don Slutz <dslutz@verizon.com>]

On 01/28/15 17:47, Don Slutz wrote:
> On 01/28/15 03:19, Jan Beulich wrote:
>>>>> On 27.01.15 at 08:58, <JBeulich@suse.com> wrote:
>>>>>> On 26.01.15 at 21:19, <dslutz@verizon.com> wrote:
>>>> On 01/26/15 11:46, Jan Beulich wrote:



> The delay is not in coding up this, but is that QEMU master (and now
> xenbits's qemu staging) do not work with my changes and so far I am
> unable to link why this is the case.  I am adding a new hvm param
> as part of getting vmport requests to QEMU (HVM_PARAM_VMPORT_REGS_PFN)
> which changes QEMU to call xc_map_foreign_range() 1 more time.  However
> what is failing is hvmloader's pci setup and scan (~70 ioreqs work and
> the next one hangs because it is sent to the default QEMU which does not
> "exist" because of the patch in QEMU:
>


I have found the link.  The following will reproduce my issue:

1) xl create -p <config>
2) read one of HVM_PARAM_IOREQ_PFN, HVM_PARAM_BUFIOREQ_PFN, or
   HVM_PARAM_BUFIOREQ_EVTCHN
3) xl unpause new guest

The guest will hang in hvmloader.

More in thread:

Subject: [Qemu-devel] [PATCH v5 2/2] Xen: Use the ioreq-server API when
	available
Message-ID: <1417776605-36309-3-git-send-email-paul.durrant@citrix.com>
X-Mailer: git-send-email 1.7.10.4
In-Reply-To: <1417776605-36309-1-git-send-email-paul.durrant@citrix.com>


    -Don Slutz

P.S. Can post info to xen-devel also if needed.


> 
> commit 7665d6ba98e20fb05c420de947c1750fd47e5c07
> Author: Paul Durrant <paul.durrant@citrix.com>
> Date:   Tue Jan 20 11:06:19 2015 +0000
> 
>     Xen: Use the ioreq-server API when available
> 
>     The ioreq-server API added to Xen 4.5 offers better security than
>     the existing Xen/QEMU interface because the shared pages that are
>     used to pass emulation request/results back and forth are removed
>     from the guest's memory space before any requests are serviced.
>     This prevents the guest from mapping these pages (they are in a
>     well known location) and attempting to attack QEMU by synthesizing
>     its own request structures. Hence, this patch modifies configure
>     to detect whether the API is available, and adds the necessary
>     code to use the API if it is.
> 
>     upstream-commit-id: 3996e85c1822e05c50250f8d2d1e57b6bea1229d
> 
>     Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
>     Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
>     Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> 
> 
> 
> Since I had the code for handing off vmport requests to QEMU I was
> planning on adding those patches to this patch set.  Now that I have hit
> a road block, the best I can do is put out a next RFC version of
> these patches with the issue listed.
> 
> So I will switch to spending most of my time on reworking (like a new
> hvm_emulate_one_vmport() (or hvm_emulate_one_gp()).
> 
> 
>    -Don Slutz
> 
>> Jan
>>