Rename the "allocate and return" qbus creation function to
qbus_new(), to bring it into line with our _init vs _new convention.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Corey Minyard <cminyard@mvista.com>
Message-id: 20210923121153.23754-6-peter.maydell@linaro.org
Having properties registered conditionally makes QOM type
introspection difficult. Instead of skipping registration of the
"instanceid" property, always register the property but validate
its value against the instance id required by the class.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <20201009200701.1830060-1-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Move the property types and property macros implemented in
qdev-properties-system.c to a new qdev-properties-system.h
header.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20201211220529.2290218-16-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:
$ CC=clang CXX=clang++ ./configure ... && make
../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)
Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.
This patch was generated using:
$ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
sort -u >/tmp/changed_identifiers
$ for identifier in $(</tmp/changed_identifiers); do
sed -i "s%\<$identifier\>%q$identifier%g" \
$(git grep -I -l "\<$identifier\>")
done
I manually fixed line-wrap issues and misaligned rST tables.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
Fix 32-bit build error for vmbus:
hw/hyperv/vmbus.c: In function ‘gpadl_iter_io’:
hw/hyperv/vmbus.c:383:13: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
383 | p = (void *)(((uintptr_t)iter->map & TARGET_PAGE_MASK) | off_in_page);
| ^
cc1: all warnings being treated as errors
Fixes: 0d71f7082d ("vmbus: vmbus implementation")
Signed-off-by: Jon Doron <arilou@gmail.com>
Tested-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Message-Id: <20200715084326.678715-3-arilou@gmail.com>
[lv: updated with commit description from <20200906050113.2783642-1-richard.henderson@linaro.org>]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Some trace points are attributed to the wrong source file. Happens
when we neglect to update trace-events for code motion, or add events
in the wrong place, or misspell the file name.
Clean up with help of scripts/cleanup-trace-events.pl. Funnies
requiring manual post-processing:
* accel/tcg/cputlb.c trace points are in trace-events.
* block.c and blockdev.c trace points are in block/trace-events.
* hw/block/nvme.c uses the preprocessor to hide its trace point use
from cleanup-trace-events.pl.
* hw/tpm/tpm_spapr.c uses pseudo trace point tpm_spapr_show_buffer to
guard debug code.
* include/hw/xen/xen_common.h trace points are in hw/xen/trace-events.
* linux-user/trace-events abbreviates a tedious list of filenames to
*/signal.c.
* net/colo-compare and net/filter-rewriter.c use pseudo trace points
colo_compare_miscompare and colo_filter_rewriter_debug to guard
debug code.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200806141334.3646302-5-armbru@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Some typedefs and macros are defined after the type check macros.
This makes it difficult to automatically replace their
definitions with OBJECT_DECLARE_TYPE.
Patch generated using:
$ ./scripts/codeconverter/converter.py -i \
--pattern=QOMStructTypedefSplit $(git grep -l '' -- '*.[ch]')
which will split "typdef struct { ... } TypedefName"
declarations.
Followed by:
$ ./scripts/codeconverter/converter.py -i --pattern=MoveSymbols \
$(git grep -l '' -- '*.[ch]')
which will:
- move the typedefs and #defines above the type check macros
- add missing #include "qom/object.h" lines if necessary
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-9-ehabkost@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-10-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-11-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Move all declarations related to TYPE_VMBUS to the same place in
vmbus.h.
This will make future conversion to OBJECT_DECLARE* easier.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Tested-By: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200825192110.3528606-35-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Meson doesn't enjoy the same flexibility we have with Make in choosing
the include path. In particular the tracing headers are using
$(build_root)/$(<D).
In order to keep the include directives unchanged,
the simplest solution is to generate headers with patterns like
"trace/trace-audio.h" and place forwarding headers in the source tree
such that for example "audio/trace.h" includes "trace/trace-audio.h".
This patch is too ugly to be applied to the Makefiles now. It's only
a way to separate the changes to the tracing header files from the
Meson rewrite of the tracing logic.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
It seems like Windows does not really require 2 IRQs to have a
functioning VMBus.
Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20200617160904.681845-2-arilou@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All remaining conversions to qdev_realize() are for bus-less devices.
Coccinelle script:
// only correct for bus-less @dev!
@@
expression errp;
expression dev;
@@
- qdev_init_nofail(dev);
+ qdev_realize(dev, NULL, &error_fatal);
@ depends on !(file in "hw/core/qdev.c") && !(file in "hw/core/bus.c")@
expression errp;
expression dev;
symbol true;
@@
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize(DEVICE(dev), NULL, errp);
@ depends on !(file in "hw/core/qdev.c") && !(file in "hw/core/bus.c")@
expression errp;
expression dev;
symbol true;
@@
- object_property_set_bool(dev, true, "realized", errp);
+ qdev_realize(DEVICE(dev), NULL, errp);
Note that Coccinelle chokes on ARMSSE typedef vs. macro in
hw/arm/armsse.c. Worked around by temporarily renaming the macro for
the spatch run.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-57-armbru@redhat.com>
This can be allow to include controller-specific data while
saving/loading in-flight scsi requests of the vmbus scsi controller.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20200424123444.3481728-7-arilou@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Guest OS uses ACPI to discover VMBus presence. Add a corresponding
entry to DSDT in case VMBus has been enabled.
Experimentally Windows guests were found to require this entry to
include two IRQ resources. They seem to never be used but they still
have to be there.
Make IRQ numbers user-configurable via corresponding properties; use 7
and 13 by default.
Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20200424123444.3481728-6-arilou@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add the VMBus infrastructure -- bus, devices, root bridge, vmbus state
machine, vmbus channel interactions, etc.
VMBus is a collection of technologies. At its lowest layer, it's a message
passing and signaling mechanism, allowing efficient passing of messages to and
from guest VMs. A layer higher, it's a mechanism for defining channels of
communication, where each channel is tagged with a type (which implies a
protocol) and a instance ID. A layer higher than that, it's a bus driver,
serving as the basis of device enumeration within a VM, where a channel can
optionally be exposed as a paravirtual device. When a server-side (paravirtual
back-end) component wishes to offer a channel to a guest VM, it does so by
specifying a channel type, a mode, and an instance ID. VMBus then exposes this
in the guest.
More information about VMBus can be found in the file
vmbuskernelmodeclientlibapi.h in Microsoft's WDK.
TODO:
- split into smaller palatable pieces
- more comments
- check and handle corner cases
Kudos to Evgeny Yakovlev (formerly eyakovlev@virtuozzo.com) and Andrey
Smetatin (formerly asmetanin@virtuozzo.com) for research and
prototyping.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20200424123444.3481728-4-arilou@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@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]
Provide a temporary device_legacy_reset function doing what
device_reset does to prepare for the transition with Resettable
API.
All occurrence of device_reset in the code tree are also replaced
by device_legacy_reset.
The new resettable API has different prototype and semantics
(resetting child buses as well as the specified device). Subsequent
commits will make the changeover for each call site individually; once
that is complete device_legacy_reset() will be removed.
Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-2-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Use RCU_READ_LOCK_GUARD and WITH_RCU_READ_LOCK_GUARD
to replace the manual rcu_read_(un)lock calls.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
remove default-configs/hyperv.mak and make dependencies
with Kconfig.
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190123065618.3520-41-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The Kconfig files were generated mostly with this script:
for i in `grep -ho CONFIG_[A-Z0-9_]* default-configs/* | sort -u`; do
set fnord `git grep -lw $i -- 'hw/*/Makefile.objs' `
shift
if test $# = 1; then
cat >> $(dirname $1)/Kconfig << EOF
config ${i#CONFIG_}
bool
EOF
git add $(dirname $1)/Kconfig
else
echo $i $*
fi
done
sed -i '$d' hw/*/Kconfig
for i in hw/*; do
if test -d $i && ! test -f $i/Kconfig; then
touch $i/Kconfig
git add $i/Kconfig
fi
done
Whenever a symbol is referenced from multiple subdirectories, the
script prints the list of directories that reference the symbol.
These symbols have to be added manually to the Kconfig files.
Kconfig.host and hw/Kconfig were created manually.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20190123065618.3520-27-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When started in compat configuration of SynIC, e.g.
qemu-system-x86_64 -machine pc-i440fx-2.10,accel=kvm \
-cpu host,-vmx,hv-relaxed,hv_spinlocks=0x1fff,hv-vpindex,hv-synic
or explicitly
qemu-system-x86_64 -enable-kvm -cpu host,hv-synic,x-hv-synic-kvm-only=on
QEMU crashes in hyperv_synic_reset() trying to access the non-present
qobject for SynIC.
Add the missing check for NULL.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reported-by: Igor Mammedov <imammedo@redhat.com>
Fixes: 9b4cf107b0
Fixes: 4a93722f9c
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20181126152836.25379-1-rkagan@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Add testmodes for SynIC messages and events. The message or event
connection setup / teardown is initiated by the guest via new control
codes written to the test device port. Then the test connections bounce
the respective operations back to the guest, i.e. the incoming messages
are posted or the incoming events are signaled on the configured vCPUs.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add handling of POST_MESSAGE hypercall. For that, add an interface to
regsiter a handler for the messages arrived from the guest on a
particular connection id (IOW set up a message connection in Hyper-V
speak).
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-10-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When setting up a notifier for Hyper-V event connection, try to use the
KVM-assisted one first, and fall back to userspace handling of the
hypercall if the kernel doesn't provide the requested feature.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-9-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add handling of SIGNAL_EVENT hypercall. For that, provide an interface
to associate an EventNotifier with an event connection number, so that
it's signaled when the SIGNAL_EVENT hypercall with the matching
connection ID is called by the guest.
Support for using KVM functionality for this will be added in a followup
patch.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-8-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add infrastructure to signal SynIC event flags by atomically setting the
corresponding bit in the event flags page and firing a SINT if
necessary.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-7-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add infrastructure to deliver SynIC messages to the SynIC message page.
Note that KVM may also want to deliver (SynIC timer) messages to the
same message slot.
The problem is that the access to a SynIC message slot is controlled by
the value of its .msg_type field which indicates if the slot is being
owned by the hypervisor (zero) or by the guest (non-zero).
This leaves no room for synchronizing multiple concurrent producers.
The simplest way to deal with this for both KVM and QEMU is to only
deliver messages in the vcpu thread. KVM already does this; this patch
makes it for QEMU, too.
Specifically,
- add a function for posting messages, which only copies the message
into the staging buffer if its free, and schedules a work on the
corresponding vcpu to actually deliver it to the guest slot;
- instead of a sint ack callback, set up the sint route with a message
status callback. This function is called in a bh whenever there are
updates to the message slot status: either the vcpu made definitive
progress delivering the message from the staging buffer (succeeded or
failed) or the guest issued EOM; the status is passed as an argument
to the callback.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-6-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Per Hyper-V spec, SynIC message and event flag pages are to be
implemented as so called overlay pages. That is, they are owned by the
hypervisor and, when mapped into the guest physical address space,
overlay the guest physical pages such that
1) the overlaid guest page becomes invisible to the guest CPUs until the
overlay page is turned off
2) the contents of the overlay page is preserved when it's turned off
and back on, even at a different address; it's only zeroed at vcpu
reset
This particular nature of SynIC message and event flag pages is ignored
in the current code, and guest physical pages are used directly instead.
This happens to (mostly) work because the actual guests seem not to
depend on the features listed above.
This patch implements those pages as the spec mandates.
Since the extra RAM regions, which introduce migration incompatibility,
are only added at SynIC object creation which only happens when
hyperv_synic_kvm_only == false, no extra compat logic is necessary.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-5-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make Hyper-V SynIC a device which is attached as a child to a CPU. For
now it only makes SynIC visibile in the qom hierarchy, and maintains its
internal fields in sync with the respecitve msrs of the parent cpu (the
fields will be used in followup patches).
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-3-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A significant part of hyperv.c is not actually tied to x86, and can
be moved to hw/.
This will allow to maintain most of Hyper-V and VMBus
target-independent, and to avoid conflicts with inclusion of
arch-specific headers down the road in VMBus implementation.
Also this stuff can now be opt-out with CONFIG_HYPERV.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082041.29380-4-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Peter Maydell
Eduardo Habkost
Stefan Hajnoczi
Jon Doron
Markus Armbruster
Marc-André Lureau
Paolo Bonzini
Simran Singhal
Damien Hedde
Dr. David Alan Gilbert
Yang Zhong
Roman Kagan