If a vfio assigned device makes use of a physical IOMMU, then memory
ballooning is necessarily inhibited due to the page pinning, lack of
page level granularity at the IOMMU, and sufficient notifiers to both
remove the page on balloon inflation and add it back on deflation.
However, not all devices are backed by a physical IOMMU. In the case
of mediated devices, if a vendor driver is well synchronized with the
guest driver, such that only pages actively used by the guest driver
are pinned by the host mdev vendor driver, then there should be no
overlap between pages available for the balloon driver and pages
actively in use by the device. Under these conditions, ballooning
should be safe.
vfio-ccw devices are always mediated devices and always operate under
the constraints above. Therefore we can consider all vfio-ccw devices
as balloon compatible.
The situation is far from straightforward with vfio-pci. These
devices can be physical devices with physical IOMMU backing or
mediated devices where it is unknown whether a physical IOMMU is in
use or whether the vendor driver is well synchronized to the working
set of the guest driver. The safest approach is therefore to assume
all vfio-pci devices are incompatible with ballooning, but allow user
opt-in should they have further insight into mediated devices.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
There is at least one guest (OS) such that although it does not rely on
the guarantees provided by ORB 1 word 9 bit (aka unlimited prefetch, aka
P bit) not being set, it fails to tell this to the machine.
Usually this ain't a big deal, as the original purpose of the P bit is to
allow for performance optimizations. vfio-ccw however can not provide the
guarantees required if the bit is not set.
It is not possible to implement support for the P bit not set without
transitioning to lower level protocols for vfio-ccw. So let's give the
user the opportunity to force setting the P bit, if the user knows this
is safe. For self modifying channel programs forcing the P bit is not
safe. If the P bit is forced for a self modifying channel program things
are expected to break in strange ways.
Let's also avoid warning multiple about P bit not set in the ORB in case
P bit is not told to be forced, and designate the affected vfio-ccw
device.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Suggested-by: Dong Jia Shi <bjsdjshi@linux.ibm.com>
Acked-by: Jason J. Herne <jjherne@linux.ibm.com>
Tested-by: Jason J. Herne <jjherne@linux.ibm.com>
Message-Id: <20180524175828.3143-2-pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
No declaration of "hw/vfio/vfio-common.h" directly requires to include
the "exec/address-spaces.h" header. To simplify dependencies and
ease the upcoming cleanup of "exec/address-spaces.h", directly include
it in the source file where the declaration are used.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20180528232719.4721-2-f4bug@amsat.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A recent patch fixed leaks of the dynamically allocated vcdev->vdev.name
field in vfio_ccw_realize(), but we now have three freeing sites for it.
This is unfortunate and seems to indicate something is wrong with its
life cycle.
The root issue is that vcdev->vdev.name is set before vfio_get_device()
is called, which theoretically prevents to call vfio_put_device() to
do the freeing. Well actually, we could call it anyway because
vfio_put_base_device() is a nop if the device isn't attached, but this
would be confusing.
This patch hence moves all the logic of attaching the device, including
the "already attached" check, to a separate vfio_ccw_get_device() function,
counterpart of vfio_put_device(). While here, vfio_put_device() is renamed
to vfio_ccw_put_device() for consistency.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <152326891065.266543.9487977590811413472.stgit@bahia.lan>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
If the subchannel is already attached or if vfio_get_device() fails, the
code jumps to the 'out_device_err' label and doesn't free the string it
has just allocated.
The code should be reworked so that vcdev->vdev.name only gets set when
the device has been attached, and freed when it is about to be detached.
This could be achieved with the addition of a vfio_ccw_get_device()
function that would be the counterpart of vfio_put_device(). But this is
a more elaborate cleanup that should be done in a follow-up. For now,
let's just add calls to g_free() on the buggy error paths.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <152311222681.203086.8874800175539040298.stgit@bahia>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
The license text currently specifies "any version" of the GPL. It
is unlikely that GPL v1 was ever intended; change this to the
standard "or any later version" text.
Cc: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Cc: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
Cc: Pierre Morel <pmorel@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
applied using ./scripts/clean-includes
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Simplify the error handling of the SSCH and RSCH handler avoiding
arbitrary and cryptic error codes being used to tell how the instruction
is supposed to end. Let the code detecting the condition tell how it's
to be handled in a less ambiguous way. It's best to handle SSCH and RSCH
in one go as the emulation of the two shares a lot of code.
For passthrough this change isn't pure refactoring, but changes the way
kernel reported EFAULT is handled. After clarifying the kernel interface
we decided that EFAULT shall be mapped to unit exception. Same goes for
unexpected error codes and absence of required ORB flags.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Message-Id: <20171017140453.51099-4-pasic@linux.vnet.ibm.com>
Tested-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
[CH: cosmetic changes]
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Commit 7da624e2 ("vfio: Test realized when using VFIOGroup.device_list
iterator") introduced a pointer to the Object DeviceState in the VFIO
common base-device and skipped non-realized devices as we iterate
VFIOGroup.device_list. While it missed to initialize the pointer for
the vfio-ccw case. Let's fix it.
Fixes: 7da624e2 ("vfio: Test realized when using VFIOGroup.device_list
iterator")
Cc: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Message-Id: <20170718014926.44781-3-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
When allocating memory for the vfio_irq_info parameter of the
VFIO_DEVICE_GET_IRQ_INFO ioctl, we used the wrong size. Let's
fix it by using the right size.
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Jing Zhang <bjzhjing@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170718014926.44781-2-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Concurrent-sense data is currently not delivered. This patch stores
the concurrent-sense data to the subchannel if a unit check is pending
and the concurrent-sense bit is enabled. Then a TSCH can retreive the
right IRB data back to the guest.
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-13-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Introduce a new callback on subchannel to handle ccw-request.
Realize the callback in vfio-ccw device. Besides, resort to
the event notifier handler to handling the ccw-request results.
1. Pread the I/O results via MMIO region.
2. Update the scsw info to guest.
3. Inject an I/O interrupt to notify guest the I/O result.
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-11-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
vfio-ccw resorts to the eventfd mechanism to communicate with userspace.
We fetch the irqs info via the ioctl VFIO_DEVICE_GET_IRQ_INFO,
register a event notifier to get the eventfd fd which is sent
to kernel via the ioctl VFIO_DEVICE_SET_IRQS, then we can implement
read operation once kernel sends the signal.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-10-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
vfio-ccw provides an MMIO region for I/O operations. We fetch its
information via ioctls here, then we can use it performing I/O
instructions and retrieving I/O results later on.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-9-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
We use the IOMMU_TYPE1 of VFIO to realize the subchannels
passthrough, implement a vfio based subchannels passthrough
driver called "vfio-ccw".
Support qemu parameters in the style of:
"-device vfio-ccw,sysfsdev=$mdev_file_path,devno=xx.x.xxxx'
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-8-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>