Add helpers to get the "Transitional PCI Device ID" and "class_id"
of the device specified by the "Virtio Device ID".
These helpers will be used to build the generic vDPA device later.
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
Message-Id: <20221215134944.2809-2-longpeng2@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Convert the TYPE_VIRTIO_PCI class to 3-phase reset. This is
necessary so that we can convert the subclass TYPE_VIRTIO_VGA_BASE
also to 3-phase reset.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20221125115240.3005559-2-peter.maydell@linaro.org
There were several different ways to deal with the situation where the
vector specified for a msix function is out of bound:
- early return a function and keep progresssing
- propagate the error to the caller
- mark msix unusable
- assert it is in bound
- just ignore
An out-of-bound vector should not be specified if the device
implementation is correct so let msix functions always assert that the
specified vector is in range.
An exceptional case is virtio-pci, which allows the guest to configure
vectors. For virtio-pci, it is more appropriate to introduce its own
checks because it is sometimes too late to check the vector range in
msix functions.
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20220829083524.143640-1-akihiko.odaki@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Signed-off-by: Akihiko Odaki <<a href="mailto:akihiko.odaki@daynix.com" target="_blank">akihiko.odaki@daynix.com</a>><br>
PCI devices support device specific vq enable.
Based on this function, the driver can re-enable the virtqueue after the
virtqueue is reset.
Signed-off-by: Kangjie Xu <kangjie.xu@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221017092558.111082-7-xuanzhuo@linux.alibaba.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
PCI devices support vq reset.
Based on this function, the driver can adjust the size of the ring, and
quickly recycle the buffer in the ring.
The migration of the virtio devices will not happen during a reset
operation. This is becuase the global iothread lock is held. Migration
thread also needs the lock. As a result, when migration of virtio
devices starts, the 'reset' status of VirtIOPCIQueue will always be 0.
Thus, we do not need to add it in vmstate_virtio_pci_modern_queue_state.
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Kangjie Xu <kangjie.xu@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221017092558.111082-6-xuanzhuo@linux.alibaba.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
While being at it add a #define for the magic 0x1040 number.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-Id: <20221004112100.301935-6-kraxel@redhat.com>
virtio level reset should not affect pci express
registers such as PM, error or link.
Fixes: 27ce0f3afc ("hw/virtio: fix Power Management Control Register for PCI Express virtio devices")
Fixes: d584f1b9ca ("hw/virtio: fix Link Control Register for PCI Express virtio devices")
Fixes: c2cabb3422 ("hw/virtio: fix error enabling flags in Device Control register")
Cc: "Marcel Apfelbaum" <marcel@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The assert() protecting against leakage is a little aggressive and
causes needless crashes if a device is shutdown without having been
configured. In this case no descriptors are lost because none have
been assigned.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220728135503.1060062-4-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
All calls to virtio_bus_reset are preceded by virtio_bus_stop_ioeventfd,
move the call in virtio_bus_reset: that makes sense and clarifies
that the vdc->reset function is called with ioeventfd already stopped.
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200925125147.26943-6-alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220321153037.3622127-3-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This allows other device classes that will be exposed via PCI to be
able to do so in the appropriate hw/ directory. I resisted the
temptation to re-order headers to be more aesthetically pleasing.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200925125147.26943-4-alex.bennee@linaro.org>
Message-Id: <20220321153037.3622127-2-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We invoke the kvm_irqchip_commit_routes() for each addition to MSI route
table, which is not efficient if we are adding lots of routes in some cases.
This patch lets callers invoke the kvm_irqchip_commit_routes(), so the
callers can decide how to optimize.
[1] https://lists.gnu.org/archive/html/qemu-devel/2021-11/msg00967.html
Signed-off-by: Longpeng <longpeng2@huawei.com>
Message-Id: <20220222141116.2091-3-longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The migration code will not look at a VMStateDescription's
minimum_version_id_old field unless that VMSD has set the
load_state_old field to something non-NULL. (The purpose of
minimum_version_id_old is to specify what migration version is needed
for the code in the function pointed to by load_state_old to be able
to handle it on incoming migration.)
We have exactly one VMSD which still has a load_state_old,
in the PPC CPU; every other VMSD which sets minimum_version_id_old
is doing so unnecessarily. Delete all the unnecessary ones.
Commit created with:
sed -i '/\.minimum_version_id_old/d' $(git grep -l '\.minimum_version_id_old')
with the one legitimate use then hand-edited back in.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
It missed vmstate_ppc_cpu.
This reverts commit 316011b8a7.
Fixes: 316011b8a7 ("virtio-pci: decouple the single vector from the interrupt process")
Cc: "Cindy Lu" <lulu@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This reverts commit d5d24d859c.
Fixes: d5d24d859c ("virtio-pci: add support for configure interrupt")
Cc: "Cindy Lu" <lulu@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Add support for configure interrupt, The process is used kvm_irqfd_assign
to set the gsi to kernel. When the configure notifier was signal by
host, qemu will inject a msix interrupt to guest
Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-11-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
To reuse the interrupt process in configure interrupt
Need to decouple the single vector from the interrupt process. Add new function
kvm_virtio_pci_vector_use_one and _release_one. These functions are use
for the single vector, the whole process will finish in a loop for the vq number.
Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-4-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
To reuse the notifier process in configure interrupt.
Use the virtio_pci_get_notifier function to get the notifier.
the INPUT of this function is the IDX, the OUTPUT is notifier and
the vector
Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-3-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Rename qbus_create_inplace() to qbus_init(); this is more in line
with our usual naming convention for functions that in-place
initialize objects.
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>
Message-id: 20210923121153.23754-5-peter.maydell@linaro.org
This patch implements the PCI transport version of iommu_enabled. This
is done by comparing the address space returned by
pci_device_iommu_address_space() against address_space_memory.
Note that an ideal approach is to use pci_device_iommu_address_space()
in get_dma_as(), but it might not work well since the IOMMU could be
initialized after the virtio-pci device is initialized.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20210804034803.1644-3-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
At some point, after unplugging virtio-pci the virtio device may be unrealised,
but the memory regions may be present in flatview. So, it's a possible situation
when memory region's callbacks are called for "unplugged" device.
Previous two patches made sure this case does not cause QEMU to crash.
This patch adds check for "notify" memory region. Now reads will return "-1" if a virtio
device is not present on a virtio bus.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1938042
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1743098
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Message-Id: <20210609095843.141378-4-andrew@daynix.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Now, if virtio device is not present on virtio-bus - pci config callbacks
will not lead to possible crush. The read will return "-1" which should be
interpreted by a driver that pci device may be unplugged.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Message-Id: <20210609095843.141378-3-andrew@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
During unplug the virtio device is unplugged from virtio-bus on pci. In some cases,
requests to virtio-pci mm may acquire during/after unplug. Added check that virtio
device is on the bus, for "common" memory region.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Message-Id: <20210609095843.141378-2-andrew@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio devices support separate iothreads waiting for
events from file descriptors. These are asynchronous
events that can't be recorded and replayed, therefore
this patch disables ioeventfd for all devices when
record or replay is enabled.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <162125678869.1252810.4317416444097392406.stgit@pasha-ThinkPad-X280>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Commit 4c70875372 ("pci: advertise a page aligned ATS") advertises
the page aligned via ATS capability (RO) to unbrek recent Linux IOMMU
drivers since 5.2. But it forgot the compat the capability which
breaks the migration from old machine type:
(qemu) qemu-kvm: get_pci_config_device: Bad config data: i=0x104 read:
0 device: 20 cmask: ff wmask: 0 w1cmask:0
This patch introduces a new parameter "x-ats-page-aligned" for
virtio-pci device and turns it on for machine type which is newer than
5.1.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: qemu-stable@nongnu.org
Fixes: 4c70875372 ("pci: advertise a page aligned ATS")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20210406040330.11306-1-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The value is assigned later in this procedure.
Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Message-Id: <20210315115937.14286-3-yuri.benditovich@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1743098
This commit completes the solution of segfault in hot unplug flow
(by commit ccec7e9603).
Added missing check for vdev in virtio_pci_isr_read.
Typical stack of crash:
virtio_pci_isr_read ../hw/virtio/virtio-pci.c:1365 with proxy-vdev = 0
memory_region_read_accessor at ../softmmu/memory.c:442
access_with_adjusted_size at ../softmmu/memory.c:552
memory_region_dispatch_read1 at ../softmmu/memory.c:1420
memory_region_dispatch_read at ../softmmu/memory.c:1449
flatview_read_continue at ../softmmu/physmem.c:2822
flatview_read at ../softmmu/physmem.c:2862
address_space_read_full at ../softmmu/physmem.c:2875
Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Message-Id: <20210315115937.14286-2-yuri.benditovich@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When viewing/debugging memory regions it is sometimes hard to figure
out which PCI device something belongs to. Make the names unique by
including the vdev name in the name string.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20210213130325.14781-2-alex.bennee@linaro.org>
Added AER capability for virtio-pci devices.
Also added property for devices, by default AER is disabled.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Message-Id: <20201203110713.204938-3-andrew@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Removed hardcoded offset for ats. Added cap offset counter
for future capabilities like AER.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Message-Id: <20201203110713.204938-2-andrew@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Commit 9b3a35ec82 ("virtio: verify that legacy support is not accidentally
on") added a check that returns an error if legacy support is on, but the
device does not support legacy.
Unfortunately some devices were wrongly declared legacy capable even if
they were not (e.g vhost-vsock).
To avoid migration issues, we add a virtio-device property
(x-disable-legacy-check) to skip the legacy error, printing a warning
instead, for machine types < 5.1.
Cc: qemu-stable@nongnu.org
Fixes: 9b3a35ec82 ("virtio: verify that legacy support is not accidentally on")
Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20200921122506.82515-2-sgarzare@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@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>
Both VirtioPCIBusClass and VirtioCcwBusClass are typedefs of
VirtioBusClass, but set .class_size in the TypeInfo anyway
to be safe if that changes in the future.
Reported-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Message-Id: <20200824122051.99432-1-cohuck@redhat.com>
Multi-queue devices achieve the best performance when each vCPU has a
dedicated queue. This ensures that virtqueue used notifications are
handled on the same vCPU that submitted virtqueue buffers. When another
vCPU handles the the notification an IPI will be necessary to wake the
submission vCPU and this incurs a performance overhead.
Provide a helper function that virtio-pci devices will use in later
patches to automatically select the optimal number of queues.
The function handles guests with large numbers of CPUs by limiting the
number of queues to fit within the following constraints:
1. The maximum number of MSI-X vectors.
2. The maximum number of virtqueues.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200818143348.310613-4-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We should use the index passed by the caller instead of the queue_sel
when checking the enablement of a specific virtqueue.
This is reported in https://bugzilla.redhat.com/show_bug.cgi?id=1702608
Fixes: f19bcdfedd ("virtio-pci: implement queue_enabled method")
Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
In legacy mode, virtio_pci_queue_enabled() falls back to
virtio_queue_enabled() to know if the queue is enabled.
But virtio_queue_enabled() calls again virtio_pci_queue_enabled()
if k->queue_enabled is set. This ends in a crash after a stack
overflow.
The problem can be reproduced with
"-device virtio-net-pci,disable-legacy=off,disable-modern=true
-net tap,vhost=on"
And a look to the backtrace is very explicit:
...
#4 0x000000010029a438 in virtio_queue_enabled ()
#5 0x0000000100497a9c in virtio_pci_queue_enabled ()
...
#130902 0x000000010029a460 in virtio_queue_enabled ()
#130903 0x0000000100497a9c in virtio_pci_queue_enabled ()
#130904 0x000000010029a460 in virtio_queue_enabled ()
#130905 0x0000000100454a20 in vhost_net_start ()
...
This patch fixes the problem by introducing a new function
for the legacy case and calls it from virtio_pci_queue_enabled().
It also calls it from virtio_queue_enabled() to avoid code duplication.
Fixes: f19bcdfedd ("virtio-pci: implement queue_enabled method")
Cc: Jason Wang <jasowang@redhat.com>
Cc: Cindy Lu <lulu@redhat.com>
CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20200727153319.43716-1-lvivier@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
There is an issue when callback may be called with invalid vdev.
It happens on unplug when vdev already deleted and VirtIOPciProxy is not.
So now, callbacks accept proxy device, and vdev retrieved from it.
Technically memio callbacks should be removed during the flatview update,
but memoryregions remain til PCI device(and it's address space) completely deleted.
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1716352
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Message-Id: <20200706112123.971087-1-andrew@daynix.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
If a virtio device does not have legacy support, make sure that
it is actually off, and bail out if not.
For virtio-pci, this means that any device without legacy support
that has been specified to modern-only (or that has been forced
to it) will work.
For virtio-ccw, this duplicates the check that is currently done
prior to realization for any device that explicitly specified no
support for legacy.
This catches devices that have not been fenced properly.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200707105446.677966-3-cohuck@redhat.com>
Cc: qemu-stable@nongnu.org
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
With version 1, we can detect whether a queue is enabled via
queue_enabled.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20200701145538.22333-5-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Spec said: The driver uses this to selectively prevent the device from
executing requests from this virtqueue. 1 - enabled; 0 - disabled.
Though write 0 to queue_enable is forbidden by the spec, we should not
assume that the value is 1.
Fix this by ignore the write value other than 1.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20200610054351.15811-1-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The modern io bar was never documented.
Signed-off-by: Anthoine Bourgeois <anthoine.bourgeois@gmail.com>
Message-Id: <20200422215455.10244-2-anthoine.bourgeois@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Currently the SLOF firmware for pseries guests will disable/re-enable
a PCI device multiple times via IO/MEM/MASTER bits of PCI_COMMAND
register after the initial probe/feature negotiation, as it tends to
work with a single device at a time at various stages like probing
and running block/network bootloaders without doing a full reset
in-between.
In QEMU, when PCI_COMMAND_MASTER is disabled we disable the
corresponding IOMMU memory region, so DMA accesses (including to vring
fields like idx/flags) will no longer undergo the necessary
translation. Normally we wouldn't expect this to happen since it would
be misbehavior on the driver side to continue driving DMA requests.
However, in the case of pseries, with iommu_platform=on, we trigger the
following sequence when tearing down the virtio-blk dataplane ioeventfd
in response to the guest unsetting PCI_COMMAND_MASTER:
#2 0x0000555555922651 in virtqueue_map_desc (vdev=vdev@entry=0x555556dbcfb0, p_num_sg=p_num_sg@entry=0x7fffe657e1a8, addr=addr@entry=0x7fffe657e240, iov=iov@entry=0x7fffe6580240, max_num_sg=max_num_sg@entry=1024, is_write=is_write@entry=false, pa=0, sz=0)
at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:757
#3 0x0000555555922a89 in virtqueue_pop (vq=vq@entry=0x555556dc8660, sz=sz@entry=184)
at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:950
#4 0x00005555558d3eca in virtio_blk_get_request (vq=0x555556dc8660, s=0x555556dbcfb0)
at /home/mdroth/w/qemu.git/hw/block/virtio-blk.c:255
#5 0x00005555558d3eca in virtio_blk_handle_vq (s=0x555556dbcfb0, vq=0x555556dc8660)
at /home/mdroth/w/qemu.git/hw/block/virtio-blk.c:776
#6 0x000055555591dd66 in virtio_queue_notify_aio_vq (vq=vq@entry=0x555556dc8660)
at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:1550
#7 0x000055555591ecef in virtio_queue_notify_aio_vq (vq=0x555556dc8660)
at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:1546
#8 0x000055555591ecef in virtio_queue_host_notifier_aio_poll (opaque=0x555556dc86c8)
at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:2527
#9 0x0000555555d02164 in run_poll_handlers_once (ctx=ctx@entry=0x55555688bfc0, timeout=timeout@entry=0x7fffe65844a8)
at /home/mdroth/w/qemu.git/util/aio-posix.c:520
#10 0x0000555555d02d1b in try_poll_mode (timeout=0x7fffe65844a8, ctx=0x55555688bfc0)
at /home/mdroth/w/qemu.git/util/aio-posix.c:607
#11 0x0000555555d02d1b in aio_poll (ctx=ctx@entry=0x55555688bfc0, blocking=blocking@entry=true)
at /home/mdroth/w/qemu.git/util/aio-posix.c:639
#12 0x0000555555d0004d in aio_wait_bh_oneshot (ctx=0x55555688bfc0, cb=cb@entry=0x5555558d5130 <virtio_blk_data_plane_stop_bh>, opaque=opaque@entry=0x555556de86f0)
at /home/mdroth/w/qemu.git/util/aio-wait.c:71
#13 0x00005555558d59bf in virtio_blk_data_plane_stop (vdev=<optimized out>)
at /home/mdroth/w/qemu.git/hw/block/dataplane/virtio-blk.c:288
#14 0x0000555555b906a1 in virtio_bus_stop_ioeventfd (bus=bus@entry=0x555556dbcf38)
at /home/mdroth/w/qemu.git/hw/virtio/virtio-bus.c:245
#15 0x0000555555b90dbb in virtio_bus_stop_ioeventfd (bus=bus@entry=0x555556dbcf38)
at /home/mdroth/w/qemu.git/hw/virtio/virtio-bus.c:237
#16 0x0000555555b92a8e in virtio_pci_stop_ioeventfd (proxy=0x555556db4e40)
at /home/mdroth/w/qemu.git/hw/virtio/virtio-pci.c:292
#17 0x0000555555b92a8e in virtio_write_config (pci_dev=0x555556db4e40, address=<optimized out>, val=1048832, len=<optimized out>)
at /home/mdroth/w/qemu.git/hw/virtio/virtio-pci.c:613
I.e. the calling code is only scheduling a one-shot BH for
virtio_blk_data_plane_stop_bh, but somehow we end up trying to process
an additional virtqueue entry before we get there. This is likely due
to the following check in virtio_queue_host_notifier_aio_poll:
static bool virtio_queue_host_notifier_aio_poll(void *opaque)
{
EventNotifier *n = opaque;
VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
bool progress;
if (!vq->vring.desc || virtio_queue_empty(vq)) {
return false;
}
progress = virtio_queue_notify_aio_vq(vq);
namely the call to virtio_queue_empty(). In this case, since no new
requests have actually been issued, shadow_avail_idx == last_avail_idx,
so we actually try to access the vring via vring_avail_idx() to get
the latest non-shadowed idx:
int virtio_queue_empty(VirtQueue *vq)
{
bool empty;
...
if (vq->shadow_avail_idx != vq->last_avail_idx) {
return 0;
}
rcu_read_lock();
empty = vring_avail_idx(vq) == vq->last_avail_idx;
rcu_read_unlock();
return empty;
but since the IOMMU region has been disabled we get a bogus value (0
usually), which causes virtio_queue_empty() to falsely report that
there are entries to be processed, which causes errors such as:
"virtio: zero sized buffers are not allowed"
or
"virtio-blk missing headers"
and puts the device in an error state.
This patch works around the issue by introducing virtio_set_disabled(),
which sets a 'disabled' flag to bypass checks like virtio_queue_empty()
when bus-mastering is disabled. Since we'd check this flag at all the
same sites as vdev->broken, we replace those checks with an inline
function which checks for either vdev->broken or vdev->disabled.
The 'disabled' flag is only migrated when set, which should be fairly
rare, but to maintain migration compatibility we disable it's use for
older machine types. Users requiring the use of the flag in conjunction
with older machine types can set it explicitly as a virtio-device
option.
NOTES:
- This leaves some other oddities in play, like the fact that
DRIVER_OK also gets unset in response to bus-mastering being
disabled, but not restored (however the device seems to continue
working)
- Similarly, we disable the host notifier via
virtio_bus_stop_ioeventfd(), which seems to move the handling out
of virtio-blk dataplane and back into the main IO thread, and it
ends up staying there till a reset (but otherwise continues working
normally)
Cc: David Gibson <david@gibson.dropbear.id.au>,
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Message-Id: <20191120005003.27035-1-mdroth@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Some guests read back queue size after writing it.
Update the size immediatly upon write otherwise
they get confused.
In particular this is the case for seabios.
Reported-by: Roman Kagan <rkagan@virtuozzo.com>
Suggested-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Using FLR becomes convenient in cases where resetting the bus is
impractical, for example, when debugging the behavior of individual
functions.
Signed-off-by: Julia Suvorova <jusual@redhat.com>
Message-Id: <20190820163005.1880-1-jusual@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Now that MemOp has been pushed down into the memory API, and
callers are encoding endianness, we can collapse byte swaps
along the I/O path into the accelerator and target independent
adjust_endianness.
Collapsing byte swaps along the I/O path enables additional endian
inversion logic, e.g. SPARC64 Invert Endian TTE bit, with redundant
byte swaps cancelling out.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Message-Id: <911ff31af11922a9afba9b7ce128af8b8b80f316.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
