If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
&error_fatal, this means that we don't break error_abort
(we'll abort on error_set, not on error_propagate)
If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call). No such cases are being fixed here.
This commit is generated by command
sed -n '/^X86 Xen CPUs$/,/^$/{s/^F: //p}' MAINTAINERS | \
xargs git ls-files | grep '\.[hc]$' | \
xargs spatch \
--sp-file scripts/coccinelle/errp-guard.cocci \
--macro-file scripts/cocci-macro-file.h \
--in-place --no-show-diff --max-width 80
Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-9-armbru@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci. Commit message
tweaked again.]
Replace
error_setg(&err, ...);
error_propagate(errp, err);
by
error_setg(errp, ...);
Related pattern:
if (...) {
error_setg(&err, ...);
goto out;
}
...
out:
error_propagate(errp, err);
return;
When all paths to label out are that way, replace by
if (...) {
error_setg(errp, ...);
return;
}
and delete the label along with the error_propagate().
When we have at most one other path that actually needs to propagate,
and maybe one at the end that where propagation is unnecessary, e.g.
foo(..., &err);
if (err) {
goto out;
}
...
bar(..., &err);
out:
error_propagate(errp, err);
return;
move the error_propagate() to where it's needed, like
if (...) {
foo(..., &err);
error_propagate(errp, err);
return;
}
...
bar(..., errp);
return;
and transform the error_setg() as above.
In some places, the transformation results in obviously unnecessary
error_propagate(). The next few commits will eliminate them.
Bonus: the elimination of gotos will make later patches in this series
easier to review.
Candidates for conversion tracked down with this Coccinelle script:
@@
identifier err, errp;
expression list args;
@@
- error_setg(&err, args);
+ error_setg(errp, args);
... when != err
error_propagate(errp, err);
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-34-armbru@redhat.com>
All callers pass &error_abort. Drop the parameter.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200630090351.1247703-14-armbru@redhat.com>
In addition to the qdev_create() patterns converted so far, we have a
qdev_set_parent_bus() pattern. Mostly when we embed a device in a
parent device rather than allocating it on the heap.
This pattern also puts devices in the dangerous "no QOM parent, but
plugged into bus" state I explained in recent commit "qdev: New
qdev_new(), qdev_realize(), etc."
Apply same solution: convert to qdev_realize(). Coccinelle script:
@@
expression dev, bus, errp;
symbol true;
@@
- qdev_set_parent_bus(DEVICE(dev), bus);
...
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize(DEVICE(dev), bus, errp);
@ depends on !(file in "qdev-monitor.c") && !(file in "hw/core/qdev.c")@
expression dev, bus, errp;
symbol true;
@@
- qdev_set_parent_bus(dev, bus);
...
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize(dev, bus, errp);
@@
expression dev, bus;
symbol true;
@@
- qdev_set_parent_bus(DEVICE(dev), bus);
...
- qdev_init_nofail(DEVICE(dev));
+ qdev_realize(DEVICE(dev), bus, &error_fatal);
Unconverted uses of qdev_set_parent_bus() remain. They'll be
converted later in this series.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-12-armbru@redhat.com>
[Also convert new hw/virtio/vhost-user-vsock-pci.c]
This is the transformation explained in the commit before previous.
Takes care of just one pattern that needs conversion. More to come in
this series.
Coccinelle script:
@ depends on !(file in "hw/arm/highbank.c")@
expression bus, type_name, dev, expr;
@@
- dev = qdev_create(bus, type_name);
+ dev = qdev_new(type_name);
... when != dev = expr
- qdev_init_nofail(dev);
+ qdev_realize_and_unref(dev, bus, &error_fatal);
@@
expression bus, type_name, dev, expr;
identifier DOWN;
@@
- dev = DOWN(qdev_create(bus, type_name));
+ dev = DOWN(qdev_new(type_name));
... when != dev = expr
- qdev_init_nofail(DEVICE(dev));
+ qdev_realize_and_unref(DEVICE(dev), bus, &error_fatal);
@@
expression bus, type_name, expr;
identifier dev;
@@
- DeviceState *dev = qdev_create(bus, type_name);
+ DeviceState *dev = qdev_new(type_name);
... when != dev = expr
- qdev_init_nofail(dev);
+ qdev_realize_and_unref(dev, bus, &error_fatal);
@@
expression bus, type_name, dev, expr, errp;
symbol true;
@@
- dev = qdev_create(bus, type_name);
+ dev = qdev_new(type_name);
... when != dev = expr
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize_and_unref(dev, bus, errp);
@@
expression bus, type_name, expr, errp;
identifier dev;
symbol true;
@@
- DeviceState *dev = qdev_create(bus, type_name);
+ DeviceState *dev = qdev_new(type_name);
... when != dev = expr
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize_and_unref(dev, bus, errp);
The first rule exempts hw/arm/highbank.c, because it matches along two
control flow paths there, with different @type_name. Covered by the
next commit's manual conversions.
Missing #include "qapi/error.h" added manually.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-10-armbru@redhat.com>
[Conflicts in hw/misc/empty_slot.c and hw/sparc/leon3.c resolved]
Xen PCI passthrough support may not be available and thus the global
variable "has_igd_gfx_passthru" might be compiled out. Common code
should not access it in that case.
Unfortunately, we can't use CONFIG_XEN_PCI_PASSTHROUGH directly in
xen-common.c so this patch instead move access to the
has_igd_gfx_passthru variable via function and those functions are
also implemented as stubs. The stubs will be used when QEMU is built
without passthrough support.
Now, when one will want to enable igd-passthru via the -machine
property, they will get an error message if QEMU is built without
passthrough support.
Fixes: 46472d8232 ('xen: convert "-machine igd-passthru" to an accelerator property')
Reported-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20200603160442.3151170-1-anthony.perard@citrix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This code is not related to hardware emulation.
Move it under accel/ with the other hypervisors.
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200508100222.7112-1-philmd@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The DEVICE() macro is defined as:
#define DEVICE(obj) OBJECT_CHECK(DeviceState, (obj), TYPE_DEVICE)
which expands to:
((DeviceState *)object_dynamic_cast_assert((Object *)(obj), (name),
__FILE__, __LINE__,
__func__))
This assertion can only fail when @obj points to something other
than its stated type, i.e. when we're in undefined behavior country.
Remove the unnecessary DEVICE() casts when we already know the
pointer is of DeviceState type.
Patch created mechanically using spatch with this script:
@@
typedef DeviceState;
DeviceState *s;
@@
- DEVICE(s)
+ s
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Paul Durrant <paul@xen.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: John Snow <jsnow@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200512070020.22782-4-f4bug@amsat.org>
Devices may have component devices and buses.
Device realization may fail. Realization is recursive: a device's
realize() method realizes its components, and device_set_realized()
realizes its buses (which should in turn realize the devices on that
bus, except bus_set_realized() doesn't implement that, yet).
When realization of a component or bus fails, we need to roll back:
unrealize everything we realized so far. If any of these unrealizes
failed, the device would be left in an inconsistent state. Must not
happen.
device_set_realized() lets it happen: it ignores errors in the roll
back code starting at label child_realize_fail.
Since realization is recursive, unrealization must be recursive, too.
But how could a partly failed unrealize be rolled back? We'd have to
re-realize, which can fail. This design is fundamentally broken.
device_set_realized() does not roll back at all. Instead, it keeps
unrealizing, ignoring further errors.
It can screw up even for a device with no buses: if the lone
dc->unrealize() fails, it still unregisters vmstate, and calls
listeners' unrealize() callback.
bus_set_realized() does not roll back either. Instead, it stops
unrealizing.
Fortunately, no unrealize method can fail, as we'll see below.
To fix the design error, drop parameter @errp from all the unrealize
methods.
Any unrealize method that uses @errp now needs an update. This leads
us to unrealize() methods that can fail. Merely passing it to another
unrealize method cannot cause failure, though. Here are the ones that
do other things with @errp:
* virtio_serial_device_unrealize()
Fails when qbus_set_hotplug_handler() fails, but still does all the
other work. On failure, the device would stay realized with its
resources completely gone. Oops. Can't happen, because
qbus_set_hotplug_handler() can't actually fail here. Pass
&error_abort to qbus_set_hotplug_handler() instead.
* hw/ppc/spapr_drc.c's unrealize()
Fails when object_property_del() fails, but all the other work is
already done. On failure, the device would stay realized with its
vmstate registration gone. Oops. Can't happen, because
object_property_del() can't actually fail here. Pass &error_abort
to object_property_del() instead.
* spapr_phb_unrealize()
Fails and bails out when remove_drcs() fails, but other work is
already done. On failure, the device would stay realized with some
of its resources gone. Oops. remove_drcs() fails only when
chassis_from_bus()'s object_property_get_uint() fails, and it can't
here. Pass &error_abort to remove_drcs() instead.
Therefore, no unrealize method can fail before this patch.
device_set_realized()'s recursive unrealization via bus uses
object_property_set_bool(). Can't drop @errp there, so pass
&error_abort.
We similarly unrealize with object_property_set_bool() elsewhere,
always ignoring errors. Pass &error_abort instead.
Several unrealize methods no longer handle errors from other unrealize
methods: virtio_9p_device_unrealize(),
virtio_input_device_unrealize(), scsi_qdev_unrealize(), ...
Much of the deleted error handling looks wrong anyway.
One unrealize methods no longer ignore such errors:
usb_ehci_pci_exit().
Several realize methods no longer ignore errors when rolling back:
v9fs_device_realize_common(), pci_qdev_unrealize(),
spapr_phb_realize(), usb_qdev_realize(), vfio_ccw_realize(),
virtio_device_realize().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-17-armbru@redhat.com>
The only way object_property_add() can fail is when a property with
the same name already exists. Since our property names are all
hardcoded, failure is a programming error, and the appropriate way to
handle it is passing &error_abort.
Same for its variants, except for object_property_add_child(), which
additionally fails when the child already has a parent. Parentage is
also under program control, so this is a programming error, too.
We have a bit over 500 callers. Almost half of them pass
&error_abort, slightly fewer ignore errors, one test case handles
errors, and the remaining few callers pass them to their own callers.
The previous few commits demonstrated once again that ignoring
programming errors is a bad idea.
Of the few ones that pass on errors, several violate the Error API.
The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL. Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call. ich9_pm_add_properties(), sparc32_ledma_realize(),
sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize()
are wrong that way.
When the one appropriate choice of argument is &error_abort, letting
users pick the argument is a bad idea.
Drop parameter @errp and assert the preconditions instead.
There's one exception to "duplicate property name is a programming
error": the way object_property_add() implements the magic (and
undocumented) "automatic arrayification". Don't drop @errp there.
Instead, rename object_property_add() to object_property_try_add(),
and add the obvious wrapper object_property_add().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-15-armbru@redhat.com>
[Two semantic rebase conflicts resolved]
object_property_set_description() and
object_class_property_set_description() fail only when property @name
is not found.
There are 85 calls of object_property_set_description() and
object_class_property_set_description(). None of them can fail:
* 84 immediately follow the creation of the property.
* The one in spapr_rng_instance_init() refers to a property created in
spapr_rng_class_init(), from spapr_rng_properties[].
Every one of them still gets to decide what to pass for @errp.
51 calls pass &error_abort, 32 calls pass NULL, one receives the error
and propagates it to &error_abort, and one propagates it to
&error_fatal. I'm actually surprised none of them violates the Error
API.
What are we gaining by letting callers handle the "property not found"
error? Use when the property is not known to exist is simpler: you
don't have to guard the call with a check. We haven't found such a
use in 5+ years. Until we do, let's make life a bit simpler and drop
the @errp parameter.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-8-armbru@redhat.com>
[One semantic rebase conflict resolved]
The conversion of xen_pt_initfn() to xen_pt_realize() blindly replaced
XEN_PT_ERR() by error_setg(). Several error conditions that did not
fail xen_pt_initfn() now fail xen_pt_realize(). Unsurprisingly, the
cleanup on these errors looks highly suspicious.
Revert the inappropriate replacements.
Fixes: 5a11d0f754
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Paul Durrant <paul@xen.org>
Cc: xen-devel@lists.xenproject.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Message-Id: <20200422130719.28225-10-armbru@redhat.com>
Since bd457782b3 ("x86/pc: use memdev for RAM") Xen
machine fails to start with:
qemu-system-i386: xen: failed to populate ram at 0
The reason is that xen_ram_alloc() which is called by
memory_region_init_ram(), compares memory region with
statically allocated 'global' ram_memory memory region
that it uses for RAM, and does nothing in case it matches.
While it's possible feed machine->ram to xen_ram_alloc()
in the same manner to keep that hack working, I'd prefer
not to keep that circular dependency and try to untangle that.
However it doesn't look trivial to fix, so as temporary
fixup opt out Xen machine from memdev based RAM allocation,
and let xen_ram_alloc() do its trick for now.
Reported-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20200402145418.5139-1-imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Description copied from Linux kernel commit from Gustavo A. R. Silva
(see [3]):
--v-- description start --v--
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to
declare variable-length types such as these ones is a flexible
array member [1], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler
warning in case the flexible array does not occur last in the
structure, which will help us prevent some kind of undefined
behavior bugs from being unadvertenly introduced [2] to the
Linux codebase from now on.
--^-- description end --^--
Do the similar housekeeping in the QEMU codebase (which uses
C99 since commit 7be41675f7).
All these instances of code were found with the help of the
following Coccinelle script:
@@
identifier s, m, a;
type t, T;
@@
struct s {
...
t m;
- T a[0];
+ T a[];
};
@@
identifier s, m, a;
type t, T;
@@
struct s {
...
t m;
- T a[0];
+ T a[];
} QEMU_PACKED;
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76497732932f
[3] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=17642a2fbd2c1
Inspired-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It is not safe to close an event channel from the QEMU main thread when
that channel's poller is running in IOThread context.
This patch adds a new xen_device_set_event_channel_context() function
to explicitly assign the channel AioContext, and modifies
xen_device_bind_event_channel() to initially assign the channel's poller
to the QEMU main thread context. The code in xen-block's dataplane is
then modified to assign the channel to IOThread context during
xen_block_dataplane_start() and de-assign it during in
xen_block_dataplane_stop(), such that the channel is always assigned
back to main thread context before it is closed. aio_set_fd_handler()
already deals with all the necessary synchronization when moving an fd
between AioContext-s so no extra code is needed to manage this.
Reported-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20191216143451.19024-1-pdurrant@amazon.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
xen_pt_load_rom.c does not use any of these includes, remove them.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Message-Id: <20191014142246.4538-9-philmd@redhat.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This commit was produced with the included Coccinelle script
scripts/coccinelle/exec_rw_const.
Inspired-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Use an explicit boolean type.
This commit was produced with the included Coccinelle script
scripts/coccinelle/exec_rw_const.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
The first machine property to fall is Xen's Intel integrated graphics
passthrough. The "-machine igd-passthru" option does not set anymore
a property on the machine object, but desugars to a GlobalProperty on
accelerator objects.
The setter is very simple, since the value ends up in a
global variable, so this patch also provides an example before the more
complicated cases that follow it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some toolstack implementations will set the frontend xenstore
keys to Initialising which will then trigger the in guest PV
drivers to begin initialising and some implementations will
then set their state to Closing. If this has occurred then
device realize must not overwrite the frontend keys as then
the handshake will stall.
Signed-off-by: Mark Syms <mark.syms@citrix.com>
Also avoid creating the frontend area if it already exists.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190918115745.39006-1-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Cleaning up offline XenDevice objects directly in
xen_device_backend_changed() is dangerous as xen_device_unrealize() will
modify the watch list that is being walked. Even the QLIST_FOREACH_SAFE()
used in notifier_list_notify() is insufficient as *two* notifiers (for
the frontend and backend watches) are removed, thus potentially rendering
the 'next' pointer unsafe.
The solution is to use the XenBus backend_watch handler to do the clean-up
instead, as it is invoked whilst walking a separate watch list.
This patch therefore adds a new 'inactive_devices' list to XenBus, to which
offline devices are added by xen_device_backend_changed(). The XenBus
backend_watch registration is also changed to not only invoke
xen_bus_enumerate() but also a new xen_bus_cleanup() function, which will
walk 'inactive_devices' and perform the necessary actions.
For safety an extra 'online' check is also added to xen_bus_type_enumerate()
to make sure that no attempt is made to create a new XenDevice object for a
backend that is offline.
NOTE: This patch also includes some cosmetic changes:
- substitute the local variable name 'backend_state'
in xen_bus_type_enumerate() with 'state', since there
is no ambiguity with any other state in that context.
- change xen_device_state_is_active() to
xen_device_frontend_is_active() (and pass a XenDevice directly)
since the state tests contained therein only apply to a frontend.
- use 'state' rather then 'xendev->backend_state' in
xen_device_backend_changed() to shorten the code.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190913082159.31338-4-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This patch uses the XenWatchList abstraction to add a separate watch list
for each device. This is more scalable than walking a single notifier
list for all watches and is also necessary to implement a bug-fix in a
subsequent patch.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Message-Id: <20190913082159.31338-3-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Xenstore watch call-backs are already abstracted away from XenBus using
the XenWatch data structure but the associated NotifierList manipulation
and file handle registration is still open coded in various xen_bus_...()
functions.
This patch creates a new XenWatchList data structure to allow these
interactions to be abstracted away from XenBus as well. This is in
preparation for a subsequent patch which will introduce separate watch lists
for XenBus and XenDevice objects.
NOTE: This patch also introduces a new notifier_list_empty() helper function
for the purposes of adding an assertion that a XenWatchList is not
freed whilst its associated NotifierList is still occupied.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Message-Id: <20190913082159.31338-2-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
...not the backend
Commit cb323146 "xen-bus: Fix backend state transition on device reset"
contained a subtle mistake. The hunk
@@ -539,11 +556,11 @@ static void xen_device_backend_changed(void *opaque)
/*
* If the toolstack (or unplug request callback) has set the backend
- * state to Closing, but there is no active frontend (i.e. the
- * state is not Connected) then set the backend state to Closed.
+ * state to Closing, but there is no active frontend then set the
+ * backend state to Closed.
*/
if (xendev->backend_state == XenbusStateClosing &&
- xendev->frontend_state != XenbusStateConnected) {
+ !xen_device_state_is_active(state)) {
xen_device_backend_set_state(xendev, XenbusStateClosed);
}
mistakenly replaced the check of 'xendev->frontend_state' with a check
(now in a helper function) of 'state', which actually equates to
'xendev->backend_state'.
This patch fixes the mistake.
Fixes: cb32314607
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190910171753.3775-1-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
When QEMU receives a xenstore watch event suggesting that the "state"
of the frontend changed, it records this in its own state but it also
re-write the value back into xenstore even so there were no change.
This triggers an unnecessary xenstore watch event which QEMU will
process again (and maybe the frontend as well). Also QEMU could
potentially write an already old value.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Message-Id: <20190823101534.465-3-anthony.perard@citrix.com>
When a frontend wants to reset its state and the backend one, it
starts with setting "Closing", then waits for the backend (QEMU) to do
the same.
But when QEMU is setting "Closing" to its state, it triggers an event
(xenstore watch) that re-execute xen_device_backend_changed() and set
the backend state to "Closed". QEMU should wait for the frontend to
set "Closed" before doing the same.
Before setting "Closed" to the backend_state, we are also going to
check if there is a frontend. If that the case, when the backend state
is set to "Closing" the frontend should react and sets its state to
"Closing" then "Closed". The backend should wait for that to happen.
Fixes: b6af8926fb
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Message-Id: <20190823101534.465-2-anthony.perard@citrix.com>
sysemu/sysemu.h is a rather unfocused dumping ground for stuff related
to the system-emulator. Evidence:
* It's included widely: in my "build everything" tree, changing
sysemu/sysemu.h still triggers a recompile of some 1100 out of 6600
objects (not counting tests and objects that don't depend on
qemu/osdep.h, down from 5400 due to the previous two commits).
* It pulls in more than a dozen additional headers.
Split stuff related to run state management into its own header
sysemu/runstate.h.
Touching sysemu/sysemu.h now recompiles some 850 objects. qemu/uuid.h
also drops from 1100 to 850, and qapi/qapi-types-run-state.h from 4400
to 4200. Touching new sysemu/runstate.h recompiles some 500 objects.
Since I'm touching MAINTAINERS to add sysemu/runstate.h anyway, also
add qemu/main-loop.h.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-30-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[Unbreak OS-X build]
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
hw/qdev-core.h includes sysemu/sysemu.h since recent commit e965ffa70a
"qdev: add qdev_add_vm_change_state_handler()". This is a bad idea:
hw/qdev-core.h is widely included.
Move the declaration of qdev_add_vm_change_state_handler() to
sysemu/sysemu.h, and drop the problematic include from hw/qdev-core.h.
Touching sysemu/sysemu.h now recompiles some 1800 objects.
qemu/uuid.h also drops from 5400 to 1800. A few more headers show
smaller improvement: qemu/notify.h drops from 5600 to 5200,
qemu/timer.h from 5600 to 4500, and qapi/qapi-types-run-state.h from
5500 to 5000.
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190812052359.30071-28-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Almost a third of its inclusions are actually superfluous. Delete
them. Downgrade two more to qapi/qapi-types-run-state.h, and move one
from char/serial.h to char/serial.c.
hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and
stubs/semihost.c define variables declared in sysemu/sysemu.h without
including it. The compiler is cool with that, but include it anyway.
This doesn't reduce actual use much, as it's still included into
widely included headers. The next commit will tackle that.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-27-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
In my "build everything" tree, changing hw/qdev-properties.h triggers
a recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Many places including hw/qdev-properties.h (directly or via hw/qdev.h)
actually need only hw/qdev-core.h. Include hw/qdev-core.h there
instead.
hw/qdev.h is actually pointless: all it does is include hw/qdev-core.h
and hw/qdev-properties.h, which in turn includes hw/qdev-core.h.
Replace the remaining uses of hw/qdev.h by hw/qdev-properties.h.
While there, delete a few superfluous inclusions of hw/qdev-core.h.
Touching hw/qdev-properties.h now recompiles some 1200 objects.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190812052359.30071-22-armbru@redhat.com>
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h). It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.
Include qemu/main-loop.h only where it's needed. Touching it now
recompiles only some 1700 objects. For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the
others, they shrink only slightly.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
In my "build everything" tree, changing hw/hw.h triggers a recompile
of some 2600 out of 6600 objects (not counting tests and objects that
don't depend on qemu/osdep.h).
The previous commits have left only the declaration of hw_error() in
hw/hw.h. This permits dropping most of its inclusions. Touching it
now recompiles less than 200 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
A Xen public header have been imported into QEMU (by
f65eadb639 "xen: import ring.h from xen"), but there are other header
that depends on ring.h which come from the system when building QEMU.
This patch resolves the issue of having headers from the system
importing a different copie of ring.h.
This patch is prompt by the build issue described in the previous
patch: 'Revert xen/io/ring.h of "Clean up a few header guard symbols"'
ring.h and the new imported headers are moved to
"include/hw/xen/interface" as those describe interfaces with a guest.
The imported headers are cleaned up a bit while importing them: some
part of the file that QEMU doesn't use are removed (description
of how to make hypercall in grant_table.h have been removed).
Other cleanup:
- xen-mapcache.c and xen-legacy-backend.c don't need grant_table.h.
- xenfb.c doesn't need event_channel.h.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Message-Id: <20190621105441.3025-3-anthony.perard@citrix.com>
This patch introduces a poll callback for event channel fd-s and uses
this to invoke the channel callback function.
To properly support polling, it is necessary for the event channel callback
function to return a boolean saying whether it has done any useful work or
not. Thus xen_block_dataplane_event() is modified to directly invoke
xen_block_handle_requests() and the latter only returns true if it actually
processes any requests. This also means that the call to qemu_bh_schedule()
is moved into xen_block_complete_aio(), which is more intuitive since the
only reason for doing a deferred poll of the shared ring should be because
there were previously insufficient resources to fully complete a previous
poll.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190408151617.13025-4-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This patch adds an AioContext parameter to xen_device_bind_event_channel()
and then uses aio_set_fd_handler() to set the callback rather than
qemu_set_fd_handler().
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190408151617.13025-3-paul.durrant@citrix.com>
[Call aio_set_fd_handler() with is_external=true]
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
To better support use of IOThread-s it will be necessary to be able to set
the AioContext for each XenEventChannel and hence it is necessary to open a
separate handle to libxenevtchan for each channel.
This patch stops using NotifierList for event channel callbacks, replacing
that construct by a list of complete XenEventChannel structures. Each of
these now has a xenevtchn_handle pointer in place of the single pointer
previously held in the XenDevice structure. The individual handles are
opened/closed in xen_device_bind/unbind_event_channel(), replacing the
single open/close in xen_device_realize/unrealize().
NOTE: This patch does not add an AioContext parameter to
xen_device_bind_event_channel(). That will be done in a subsequent
patch.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190408151617.13025-2-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
We spell out sub/dir/ in sub/dir/trace-events' comments pointing to
source files. That's because when trace-events got split up, the
comments were moved verbatim.
Delete the sub/dir/ part from these comments. Gets rid of several
misspellings.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190314180929.27722-3-armbru@redhat.com
Message-Id: <20190314180929.27722-3-armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
There is a flaw in the xen-bus state model. To allow a frontend to re-
connect the backend state of an online XenDevice is transitioned from
Closed to InitWait, but this is currently done unilaterally which is
incorrect. The backend state should remain Closed until the frontend state
transitions to Initialising.
This patch removes the automatic backend state transition from
xen_device_backend_state_changed() and, instead, adds an extra check in
xen_device_frontend_state_changed() to determine whether a frontend is
trying to re-connect to a previously Closed XenDevice. Only if this is
found to be the case is the backend state transitioned from Closed to
InitWait. Note that this transition will be common amongst all XenDevice
classes and hence xen_device_frontend_state_changed() returns immediately
afterwards without calling into the XenDeviceClass frontend_changed()
method.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This patch adds create and destroy function for XenBlockDevice-s so that
they can be created automatically when the Xen toolstack instantiates a new
PV backend via xenstore. When the XenBlockDevice is created this way it is
also necessary to create a 'drive' which matches the configuration that the
Xen toolstack has written into xenstore. This is done by formulating the
parameters necessary for each 'blockdev' layer of the drive and then using
qmp_blockdev_add() to create the layers. Also, for compatibility with the
legacy 'xen_disk' implementation, an iothread is automatically created for
the new XenBlockDevice. This, like the driver layers, will be destroyed
after the XenBlockDevice is unrealized.
The legacy backend scan for 'qdisk' is removed by this patch, which makes
the 'xen_disk' code is redundant. The code will be removed by a subsequent
patch.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
...that maintains compatibility with existing Xen toolstacks.
Xen toolstacks instantiate PV backends by simply writing information into
xenstore and expecting a backend implementation to be watching for this.
This patch adds a new 'xen-backend' module to allow individual XenDevice
implementations to register create and destroy functions. The creator
will be called when a tool-stack instantiates a new backend in this way,
and the destructor will then be called after the resulting XenDevice
object is unrealized.
To support this it is also necessary to add new watchers into the XenBus
implementation to handle enumeration of new backends and also destruction
of XenDevice-s when the toolstack sets the backend 'online' key to 0.
NOTE: This patch only adds the framework. A subsequent patch will add a
creator function for xen-block devices.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
...and wire in the dataplane.
This patch adds the remaining code to make the xen-block XenDevice
functional. The parameters that a block frontend expects to find are
populated in the backend xenstore area, and the 'ring-ref' and
'event-channel' values specified in the frontend xenstore area are
mapped/bound and used to set up the dataplane.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
The legacy PV backend infrastructure provides functions to bind, unbind
and send notifications to event channnels. Similar functionality will be
required by XenDevice implementations so this patch adds the necessary
support.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Patch squashed with:
Patch "xen: add event channel interface for XenDevice-s" makes use of
the type xenevtchn_port_or_error_t, but this isn't avaiable before Xen
4.7. Also the function xen_device_bind_event_channel assign the return
value of xenevtchn_bind_interdomain to channel->local_port but check the
result for error with xendev->local_port.
Fix by:
- removing local_port from struct XenDevice as it isn't use anywere.
- adding a compatibility typedef for xenevtchn_port_or_error_t for Xen
4.6 and earlier.
As extra, replace the type of XenEventChannel->local_port by
evtchn_port_t.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
The legacy PV backend infrastructure provides functions to map, unmap and
copy pages granted by frontends. Similar functionality will be required
by XenDevice implementations so this patch adds the necessary support.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
A Xen PV frontend communicates its state to the PV backend by writing to
the 'state' key in the frontend area in xenstore. It is therefore
necessary for a XenDevice implementation to be notified whenever the
value of this key changes.
This patch adds code to do this as follows:
- an 'fd handler' is registered on the libxenstore handle which will be
triggered whenever a 'watch' event occurs
- primitives are added to xen-bus-helper to add or remove watch events
- a list of Notifier objects is added to XenBus to provide a mechanism
to call the appropriate 'watch handler' when its associated event
occurs
The xen-block implementation is extended with a 'frontend_changed' method,
which calls as-yet stub 'connect' and 'disconnect' functions when the
relevant frontend state transitions occur. A subsequent patch will supply
a full implementation for these functions.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This patch adds a new source module, xen-bus-helper.c, which builds on
basic libxenstore primitives to provide functions to create (setting
permissions appropriately) and destroy xenstore areas, and functions to
'printf' and 'scanf' nodes therein. The main xen-bus code then uses
these primitives [1] to initialize and destroy the frontend and backend
areas for a XenDevice during realize and unrealize respectively.
The 'xen-block' implementation is extended with a 'get_name' method that
returns the VBD number. This number is required to 'name' the xenstore
areas.
NOTE: An exit handler is also added to make sure the xenstore areas are
cleaned up if QEMU terminates without devices being unrealized.
[1] The 'scanf' functions are actually not yet needed, but they will be
needed by code delivered in subsequent patches.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
