Curiously absent from the stable API/ABIs is an ability to query the number of
vcpus which a domain has. Emulators need to know this information in
particular to know how many stuct ioreq's live in the ioreq server mappings.
In practice, this forces all userspace to link against libxenctrl to use
xc_domain_getinfo(), which rather defeats the purpose of the stable libraries.
Introduce a DMOP to retrieve this information and surface it in
libxendevicemodel to help emulators shed their use of unstable interfaces.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Wei Liu <wl@xen.org>
CC: Paul Durrant <paul@xen.org>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Julien Grall <julien@xen.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Ian Jackson <iwj@xenproject.org>
For 4.15. This was a surprise discovery in the massive ABI untangling effort
I'm currently doing for XenServer's new build system.
This is one new read-only op to obtain information which isn't otherwise
available under a stable API/ABI. As such, its risk for 4.15 is very low,
with a very real quality-of-life improvement for downstreams.
I realise this is technically a new feature and we're long past feature
freeze, but I'm hoping that "really lets some emulators move off the unstable
libraries" is sufficiently convincing argument.
It's not sufficient to let Qemu move off unstable libraries yet - at a
minimum, the add_to_phymap hypercalls need stabilising to support PCI
Passthrough and BAR remapping.
I'd prefer not to duplicate the op handling between ARM and x86, and if this
weren't a release window, I'd submit a prereq patch to dedup the common dmop
handling. That can wait to 4.16 at this point. Also, this op ought to work
against x86 PV guests, but fixing that up will also need this rearrangement
into common code, so needs to wait.
This patch adds ability to the device emulator to notify otherend
(some entity running in the guest) using a SPI and implements Arm
specific bits for it. Proposed interface allows emulator to set
the logical level of a one of a domain's IRQ lines.
We can't reuse the existing DM op (xen_dm_op_set_isa_irq_level)
to inject an interrupt as the "isa_irq" field is only 8-bit and
able to cover IRQ 0 - 255, whereas we need a wider range (0 - 1020).
Please note, for egde-triggered interrupt (which is used for
the virtio-mmio emulation) we only trigger the interrupt on Arm
if the level is asserted (rising edge) and do nothing if the level
is deasserted (falling edge), so the call could be named "trigger_irq"
(without the level parameter). But, in order to model the line closely
(to be able to support level-triggered interrupt) we need to know whether
the line is low or high, so the proposed interface has been chosen.
However, it is worth mentioning that in case of the level-triggered
interrupt, we should keep injecting the interrupt to the guest until
the line is deasserted (this is not covered by current patch).
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[On Arm only]
Tested-by: Wei Chen <Wei.Chen@arm.com>
c/s 6902cb00e0 "tools/libxendevicemodel: extract functions and add a compat
layer" introduced calls to both xencall_open() and osdep_xendevicemodel_open()
but failed to fix up the error path.
c/s f68c7c618a "libs/devicemodel: free xencall handle in error path in
_open()" fixed up the xencall_open() aspect of the error path (missing the
osdep_xendevicemodel_open() aspect), but positioned the xencall_close()
incorrectly, creating the same pattern proved to be problematic by c/s
30a72f0287 "tools: fix error path of xenhypfs_open()".
Reposition xtl_logger_destroy(), and introduce the missing
osdep_xendevicemodel_close().
Fixes: 6902cb00e0 ("tools/libxendevicemodel: extract functions and add a compat layer")
Fixes: f68c7c618a ("libs/devicemodel: free xencall handle in error path in _open()")
Backport: 4.9+
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Release-acked-by: Paul Durrant <paul@xen.org>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Like %cr2 for pagefaults, %dr6 contains ancillary information for debug
exceptions, and needs similar handling.
For xendevicemodel_inject_event(), no ABI change is needed (although an API
one would be ideal). Switch from 'cr2' to 'extra' in variable names which
don't constitute an API change, and update the documentation to match.
For the monitor interface, vm_event_debug needs extending with a pending_dbg
field. This shall behave like the VT-x PENDING_DBG control. Extend
hvm_monitor_debug() and for now, always pass in 0 - this will be fixed
eventually, when other hypervisor bugfixes are complete.
While modifying hvm_monitor_debug(), take the opportunity to correct trap type
and instruction length from unsigned long to unsigned int, as they are both
tiny values.
Finally, adjust xen-access.c to the new expectations. Introspection tools
intercepting debug exceptions should mirror the new pending_dbg field into
xendevicemodel_inject_event() for %dr6 to be processed correctly for the
guest.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Petre Pircalabu <ppircalabu@bitdefender.com>
A subsequent patch will introduce a new scheme to allow an emulator to
map ioreq server pages directly from Xen rather than the guest P2M.
This patch lays the groundwork for that change by deferring mapping of
gfns until their values are requested by an emulator. To that end, the
pad field of the xen_dm_op_get_ioreq_server_info structure is re-purposed
to a flags field and new flag, XEN_DMOP_no_gfns, defined which modifies the
behaviour of XEN_DMOP_get_ioreq_server_info to allow the caller to avoid
requesting the gfn values.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Closing the fd before unhooking it from the list runs the risk that a
concurrent thread calls xentoolcore_restrict_all will operate on the
old fd value, which might refer to a new fd by then. So we need to do
it in the other order.
Sadly this weakens the guarantee provided by xentoolcore_restrict_all
slightly, but not (I think) in a problematic way. It would be
possible to implement the previous guarantee, but it would involve
replacing all of the close() calls in all of the individual osdep
parts of all of the individual libraries with calls to a new function
which does
dup2("/dev/null", thing->fd);
pthread_mutex_lock(&handles_lock);
thing->fd = -1;
pthread_mutex_unlock(&handles_lock);
close(fd);
which would be terribly tedious.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Release-acked-by: Julien Grall <julien.grall@linaro.org>
This necessitates adding $(CFLAGS_xeninclude) to all the depending
libraries (which can be done via Rules.mk), so that the definition of
domid_t (in xen.h) can be found.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The pad field needs to be zero as required by the hypervisor.
Instead of setting the pad separately, use C99 initialiser.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Since ioreq servers are only relevant to HVM guests and all the names in
question unequivocally refer to guest frame numbers, name them all .*gfn
to avoid any confusion.
This patch is purely cosmetic. No semantic or functional change.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
This new lib devicemodel call allows multiple extents of pages to be
marked as modified in a single call. This is something needed for a
usecase I'm working on.
The xen side of the modified_memory call has been modified to accept
an array of extents. The devicemodel library either provides an array
of length 1, to support the original library function, or a second
function allows an array to be provided.
Signed-off-by: Jennifer Herbert <Jennifer.Herbert@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Julien Grall <julien.grall@arm.com>
A new device model wrapper is added for the newly introduced
DMOP - XEN_DMOP_map_mem_type_to_ioreq_server.
Since currently this DMOP only supports the emulation of write
operations, attempts to trigger the DMOP with values other than
XEN_DMOP_IOREQ_MEM_ACCESS_WRITE or 0(to unmap the ioreq server)
shall fail. The wrapper shall be updated once read operations
are also to be emulated in the future.
Also note currently this DMOP only supports one memory type,
and can be extended in the future to map multiple memory types
to multiple ioreq servers, e.g. mapping HVMMEM_ioreq_serverX to
ioreq server X, This wrapper shall be updated when such change
is made.
Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
This patch extracts all functions resulting in a dm_op hypercall from
libxenctrl and moves them into libxendevicemodel. It also adds a compat
layer into libxenctrl, which can be selected by defining
XC_WANT_COMPAT_DEVICEMODEL_API to 1 before including xenctrl.h.
With this patch the core of libxendevicemodel still uses libxencall to
issue the dm_op hypercalls, but this is done by calling through code that
can be modified on a per-OS basis. A subsequent patch will add a Linux-
specific variant.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
The new xendevicemodel library is intended to be used by all Xen device
models such that the only hypercall that use will be the dm_op hypercall
added by commit 524a98c2.
This patch adds the boilerplate for the new library, with only open() and
close() entry points, and calls to those from libxenctrl in preparation
for the compat layer added by a subsequent patch.
[ Also: update MINIOS_UPSTREAM_REVISION and QEMU_TRADITIONAL_REVISION
to the commits with the corresponding changes to those other trees
- Ian Jackson ]
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Andrew Cooper
Oleksandr Tyshchenko
Paul Durrant
Ross Lagerwall
Ian Jackson
Wei Liu
Jennifer Herbert
Yu Zhang