The ARM SMC instructions are already configured to trap to Xen by default. In
this patch we allow a user-space process in a privileged domain to receive
notification of when such event happens through the vm_event subsystem by
introducing the PRIVILEGED_CALL type.
The intended use-case for this feature is for a monitor application to be able
insert tap-points into the domU kernel-code. For this task only unconditional
SMC instruction should be used.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Extend the CPUID monitor event to include EAX and ECX values that were used
when CPUID was executed. This is useful in identifying which leaf was queried.
We also adjust the xen-access output format to more closely resemble the output
of the Linux cpuid tool's raw format.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Since in-guest debug exceptions are now unconditionally trapped to Xen, adding
a hook for vm_event subscribers to tap into this new always-on guest event. We
rename along the way hvm_event_breakpoint_type to hvm_event_type to better
match the various events that can be passed with it. We also introduce the
necessary monitor_op domctl's to enable subscribing to the events.
This patch also provides monitor subscribers to int3 events proper access
to the instruction length necessary for accurate event-reinjection. Without
this subscribers manually have to evaluate if the int3 instruction has any
prefix attached which would change the instruction length.
Signed-off-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Without specifying the altp2m flag on the response the view never got switched.
Also, add extra information printouts that can be useful during debugging.
Signed-off-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
libxenevtchn will provide a stable API and ABI for accessing the
evtchn device.
The functions are moved into the xenevtchn namespace to make a clean
break from libxc and avoid ambiguity regarding which interfaces are
stable.
All in-tree users are updated to use the new names.
Upon request (via #define XC_WANT_COMPAT_EVTCHN_API) libxenctrl will
provide a compat API for the old names. This is used by qemu-xen for
the time being. qemu-xen-traditional is updated in lockstep.
This leaves a few event channel related functions which go via privcmd
(EVTCHNOP) rather than ioctls on the /dev/xen/evtchn device in
libxenctrl. Specifically:
- xc_evtchn_alloc_unbound
- xc_evtchn_reset
- xc_evtchn_status
Note that xc_evtchn_alloc_unbound's functionality is also provided by
xenevtchn_bind_unbound_port() (née xc_evtchn_bind_unbound_port) and is
probably redundant.
These functions do not appear to be needed by qemu-dm, qemu-pv
(provision of device model to HVM guests and PV backends respectively)
or by libvchan suggesting they are not needed by non-toolstack uses of
event channels. QEMU does use these in hw/xenpv/xen_domainbuild.c but
that is a "toolstack use".
The new library uses a version script to ensure that only expected
symbols are exported and to version them such that ABI guarantees can
be kept in the future.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ ijc -- updated MINIOS_UPSTREAM_REVISION and QEMU_TRADITIONAL_REVISION ]
For all supported targets HAS_MEM_ACCESS is enabled so this drops the
conditional and always makes it enabled. The goal here is to remove the
setting in the top level config directory when kconfig changes land.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Otherwise when building with 32bit compiler, we get:
xen-access.c: In function 'xenaccess_init':
xen-access.c:263:5: error: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'xen_pfn_t' [-Werror=format]
cc1: all warnings being treated as errors
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
This patch adds support for memory-content hiding, by modifying the
value returned by emulated instructions that read certain memory
addresses that contain sensitive data. The patch only applies to
cases where VM_FLAG_ACCESS_EMULATE has been set to a vm_event
response.
Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Tamas K Lengyel <tlengyel@novetta.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
Switch to use maximum gpfn as the limit to setting permissions. Also,
move HAS_MEM_ACCESS definition into config.
Signed-off-by: Tamas K Lengyel <tklengyel@sec.in.tum.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- removed obsolete reference to test_and_set_bit from the
commit message ]
Thus far mem_access and mem_sharing memops had been able to signal
to Xen to start pulling responses off the corresponding rings. In this patch
we retire these memops and add them to the option to the vm_event_op domctl.
The vm_event_op domctl suboptions are the same for each ring thus we
consolidate them into XEN_VM_EVENT_ENABLE/DISABLE/RESUME.
As part of this patch in libxc we also rename the mem_access_enable/disable
functions to monitor_enable/disable and move them into xc_monitor.c.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
In preparation for allowing for introspecting ARM and PV domains the old
control interface via the hvm_op hypercall is retired. A new control mechanism
is introduced via the domctl hypercall: monitor_op.
This patch aims to establish a base API on which future applications can build
on.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Tim Deegan <tim@xen.org>
The spin-lock implementation in the xen-access test program is implemented
in a fashion that is actually incomplete. The x86 assembly that guarantees that
the lock is held by only one thread lacks the "lock;" instruction.
However, the spin-lock is not actually necessary in xen-access as it is not
multithreaded. The presence of the faulty implementation of the lock in a non-
multithreaded environment is unnecessarily complicated for developers who are
trying to follow this code as a guide in implementing their own applications.
Thus, removing it from the code improves the clarity on the behavior of the
system.
Also converting functions that always return 0 to return to void, and making
the teardown function actually return an error code on error.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
In this patch we mechanically rename mem_event to vm_event. This patch
introduces no logic changes to the code. Using the name vm_event better
describes the intended use of this subsystem, which is not limited to memory
events. It can be used for off-loading the decision making logic into helper
applications when encountering various events during a VM's execution.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The public mem_event structures used to communicate with helper applications via
shared rings have been used in different settings. However, the variable names
within this structure have not reflected this fact, resulting in the reuse of
variables to mean different things under different scenarios.
This patch remedies the issue by clearly defining the structure members based on
the actual context within which the structure is used.
Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
The original rule to target "distclean" in tools/Rules.mk was in effect
"make clean". It should be "make distclean".
However not all Makefiles in subdirectories have distclean target
defined. So this patch also adds a bunch of distclean targets to various
Makefiles. They only depend on clean target and don't have any actions
in most cases.
With the patch applied, following command outputs 0 results:
find tools -name 'Makefile*' -exec grep -L 'distclean' {} \+ \
| grep -v ocaml | grep -v libfsimage
Ocaml and libfsimage are known to have distclean defined in a dedicated
rules file.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
HVMOP_get_param and HVMOP_set_param take a uint32_t for the parameter
index and a uint64_t for the value. So add xc_hvm_param_get() and
xc_hvm_param_set() that take the same types.
The existing xc_get_hvm_param() and xc_set_hvm_param() are retained
for compatibility but are deprecated.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- dropped one hunk against xen-access.c which didn't apply due to
intervening changes ]
tools/libxc: Add helper function to setup ring for mem events
This patch adds a helper function that maps the ring, enables mem_event
and removes the ring from the guest physmap while the domain is paused.
This can be used by all mem_events but is only enabled for mem_access at
the moment.
tests/xen-access: Use helper API to setup ring and enable mem_access
Prior to this patch, xen-access was setting up the ring page in a way
that would give a malicous guest a window to write in to the shared ring
page. This patch fixes this by using the helper API that does it safely
on behalf of xen-access.
This is XSA-99.
Signed-off-by: Aravindh Puthiyaparambil <aravindp@cisco.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Modify the xen-access test program to use the new mem_access APIs.
Signed-off-by: Aravindh Puthiyaparambil <aravindp@cisco.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Patch generated by the following semantic patch
(http://coccinelle.lip6.fr/):
@@
expression *P;
@@
- if(P) free(P);
+ free(P);
...and then by filtering through the following command:
filterdiff -p1 -x 'stubdom/*' -x 'tools/firmware/*' -x 'tools/qemu-*' -x 'tools/blktap*'
Signed-off-by: Matthew Daley <mattjd@gmail.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The emacs variable to set the C style from a local variable block is
c-file-style, not c-set-style.
Signed-off-by: David Vrabel <david.vrabel@citrix.com
Check the return values of the libxc mem_access calls. Free allocated
structures (platform_info, domain_info) on errors during
initialization and exit. Unbind VIRQ, close event channel and
connection to Xen on errors during initialization
Signed-off-by: Aravindh Puthiyaparambil <aravindh@virtuata.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
This limits the ability of the guest to play around with its own rings, and DoS
itself.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Tim Deegan <tim@xen.org>
This solves a long-standing issue in which the pages backing these rings were
pages belonging to dom0 user-space processes. Thus, if the process would die
unexpectedly, Xen would keep posting events to a page now belonging to some
other process.
We update all API-consumers in tree (xenpaging and xen-access).
This is an API/ABI change, so please speak up if it breaks your accumptions.
The patch touches tools, hypervisor x86/hvm bits, and hypervisor x86/mm bits.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Tim Deegan <tim@xen.org>
Don't use the superfluous shared page, return the event channel directly as
part of the domctl struct, instead.
In-tree consumers (xenpaging, xen-access) updated. This is an ABI/API change,
so please voice any concerns.
Known pending issues:
- pager could die and its ring page could be used by some other process, yet
Xen retains the mapping to it.
- use a saner interface for the paging_load buffer.
This change also affects the x86/mm bits in the hypervisor that process the
mem_event setup domctl.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Tim Deegan <tim@xen.org>
Up to now a single ring buffer was used for mem_share, xenpaging and
xen-access. Each helper would have to cooperate and pull only its own
requests from the ring. Unfortunately this was not implemented. And
even if it was, it would make the whole concept fragile because a crash
or early exit of one helper would stall the others.
What happend up to now is that active xenpaging + memory_sharing would
push memsharing requests in the buffer. xenpaging is not prepared for
such requests.
This patch creates an independet ring buffer for mem_share, xenpaging
and xen-access and adds also new functions to enable xenpaging and
xen-access. The xc_mem_event_enable/xc_mem_event_disable functions will
be removed. The various XEN_DOMCTL_MEM_EVENT_* macros were cleaned up.
Due to the removal the API changed, so the SONAME will be changed too.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Tim Deegan <tim@xen.org>
Fix a couple of minor bugs in xen-access test program:
* Fix -m option handling.
* Fix a segfault that was occurring during program exit.
Signed-off-by: Aravindh Puthiyaparambil <aravindh@virtuata.com>
Several places include it in CFLAGS even though it is never defined. A
few others use it as nothing more than a gathering point for
CFLAGS. Get rid of it.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Otherwise make can search the path relative to certain standard paths
such as /usr/include (e.g., the line '-include $(XEN_ROOT)/.config' in
Config.mk suffers from this).
Signed-off-by: Keir Fraser <keir@xen.org>
Added a test tool to let the memory access APIs be tested. This tool
logs to stdout the memory accesses that the domain given is performing.
Signed-off-by: Joe Epstein <jepstein98@gmail.com>
Signed-off-by: Keir Fraser <keir@xen.org>
Tamas K Lengyel
Tamas K Lengyel
Tamas K Lengyel
Ian Campbell
Doug Goldstein
Wei Liu
Razvan Cojocaru
Tamas K Lengyel
David Vrabel
Aravindh Puthiyaparambil
Tim Deegan
Matthew Daley
Keir Fraser
Xudong Hao
Aravindh Puthiyaparambil
Andres Lagar-Cavilla
Olaf Hering
Joe Epstein