ISM devices are sensitive to manipulation of the IOMMU, so the ISM device
needs to be reset before the vfio-pci device is reset (triggering a full
UNMAP). In order to ensure this occurs, trigger ISM device resets from
subsystem_reset before triggering the PCI bus reset (which will also
trigger vfio-pci reset). This only needs to be done for ISM devices
which were enabled for use by the guest.
Further, ensure that AIF is disabled as part of the reset event.
Fixes: ef1535901a ("s390x: do a subsystem reset before the unprotect on reboot")
Fixes: 03451953c7 ("s390x/pci: reset ISM passthrough devices on shutdown and system reset")
Reported-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-ID: <20240118185151.265329-4-mjrosato@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Typically we refresh the host fh during CLP enable, however it's possible
that the device goes through multiple reset events before the guest
performs another CLP enable. Let's handle this for now by refreshing the
host handle from vfio before disabling aif.
Fixes: 03451953c7 ("s390x/pci: reset ISM passthrough devices on shutdown and system reset")
Reported-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-ID: <20240118185151.265329-3-mjrosato@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Use a flag to keep track of whether AIF is currently enabled. This can be
used to avoid enabling/disabling AIF multiple times as well as to determine
whether or not it should be disabled during reset processing.
Fixes: d0bc7091c2 ("s390x/pci: enable adapter event notification for interpreted devices")
Reported-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-ID: <20240118185151.265329-2-mjrosato@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The current code assumes that there is always a vfio group, but
that's no longer guaranteed with the iommufd backend when using
cdev. In this case, we don't need to track the vfio dma limit
anyway.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-ID: <20231110175108.465851-2-mjrosato@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
ISM device firmware stores unique state information that can
can cause a wholesale unmap of the associated IOMMU (e.g. when
we get a termination signal for QEMU) to trigger firmware errors
because firmware believes we are attempting to invalidate entries
that are still in-use by the guest OS (when in fact that guest is
in the process of being terminated or rebooted).
To alleviate this, register both a shutdown notifier (for unexpected
termination cases e.g. virsh destroy) as well as a reset callback
(for cases like guest OS reboot). For each of these scenarios, trigger
PCI device reset; this is enough to indicate to firmware that the IOMMU
is no longer in-use by the guest OS, making it safe to invalidate any
associated IOMMU entries.
Fixes: 15d0e7942d ("s390x/pci: don't fence interpreted devices without MSI-X")
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20221209195700.263824-1-mjrosato@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
[thuth: Adjusted the hunk in s390-pci-vfio.c due to different context]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Currently, s390x-pci performs accounting against the vfio DMA
limit and triggers the guest to clean up mappings when the limit
is reached. Let's go a step further and also limit the size of
the supported DMA aperture reported to the guest based upon the
initial vfio DMA limit reported for the container (if less than
than the size reported by the firmware/host zPCI layer). This
avoids processing sections of the guest DMA table during global
refresh that, for common use cases, will never be used anway, and
makes exhausting the vfio DMA limit due to mismatch between guest
aperture size and host limit far less likely and more indicitive
of an error.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20221028194758.204007-4-mjrosato@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
If we encounter a new mapping while the number of available DMA entries
in vfio is 0, we are currently skipping that mapping which is a problem
if we manage to free up DMA space after that within the same RPCIT --
we will return to the guest with CC0 and have not mapped everything
within the specified range. This issue was uncovered while testing
changes to the s390 linux kernel iommu/dma code, where a different
usage pattern was employed (new mappings start at the end of the
aperture and work back towards the front, making us far more likely
to encounter new mappings before invalidated mappings during a
global refresh).
Fix this by tracking whether any mappings were skipped due to vfio
DMA limit hitting 0; when this occurs, we still continue the range
and unmap/map anything we can - then we must re-run the range again
to pickup anything that was missed. This must occur in a loop until
all requests are satisfied (success) or we detect that we are still
unable to complete all mappings (return ZPCI_RPCIT_ST_INSUFF_RES).
Link: https://lore.kernel.org/linux-s390/20221019144435.369902-1-schnelle@linux.ibm.com/
Fixes: 37fa32de70 ("s390x/pci: Honor DMA limits set by vfio")
Reported-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20221028194758.204007-2-mjrosato@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The zpcii-disable machine property can be used to force-disable the use
of zPCI interpretation facilities for a VM. By default, this setting
will be off for machine 7.2 and newer.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20220902172737.170349-9-mjrosato@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
[thuth: Fix contextual conflict in ccw_machine_7_1_instance_options()]
Signed-off-by: Thomas Huth <thuth@redhat.com>
The maximum supported store block length might be different depending
on whether the instruction is interpretively executed (firmware-reported
maximum) or handled via userspace intercept (host kernel API maximum).
Choose the best available value during group creation.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20220902172737.170349-8-mjrosato@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Let's use the reserved pool of simulated PCI groups to allow intercept
devices to have separate groups from interpreted devices as some group
values may be different. If we run out of simulated PCI groups, subsequent
intercept devices just get the default group.
Furthermore, if we encounter any PCI groups from hostdevs that are marked
as simulated, let's just assign them to the default group to avoid
conflicts between host simulated groups and our own simulated groups.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20220902172737.170349-7-mjrosato@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Use the associated kvm ioctl operation to enable adapter event notification
and forwarding for devices when requested. This feature will be set up
with or without firmware assist based upon the 'forwarding_assist' setting.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20220902172737.170349-6-mjrosato@linux.ibm.com>
[thuth: Rename "forwarding_assist" property to "forwarding-assist"]
Signed-off-by: Thomas Huth <thuth@redhat.com>
If the ZPCI_OP ioctl reports that is is available and usable, then the
underlying KVM host will enable load/store intepretation for any guest
device without a SHM bit in the guest function handle. For a device that
will be using interpretation support, ensure the guest function handle
matches the host function handle; this value is re-checked every time the
guest issues a SET PCI FN to enable the guest device as it is the only
opportunity to reflect function handle changes.
By default, unless interpret=off is specified, interpretation support will
always be assumed and exploited if the necessary ioctl and features are
available on the host kernel. When these are unavailable, we will silently
revert to the interception model; this allows existing guest configurations
to work unmodified on hosts with and without zPCI interpretation support,
allowing QEMU to choose the best support model available.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20220902172737.170349-4-mjrosato@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
In order to interface with the underlying host zPCI device, we need
to know its function handle. Add a routine to grab this from the
vfio CLP capabilities chain.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20220902172737.170349-3-mjrosato@linux.ibm.com>
[thuth: Replace free(info) with g_free(info)]
Signed-off-by: Thomas Huth <thuth@redhat.com>
The current default PCI group being used can technically collide with a
real group ID passed from a hostdev. Let's instead use a group ID that
comes from a special pool (0xF0-0xFF) that is architected to be reserved
for simulated devices.
Fixes: 28dc86a072 ("s390x/pci: use a PCI Group structure")
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20211203142706.427279-2-mjrosato@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Some CLP response data was accidentally dropped when fixing endianness
issues with the Query PCI Function CLP response. All of these values are
sent as 0s to the guest for emulated devices, so the impact is only
observed on passthrough devices.
Fixes: a4e2fff1b1 ("s390x/pci: fix endianness issues")
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <1613681609-9349-1-git-send-email-mjrosato@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
In pcistb_service_handler, a call is made to validate that the memory
region can be accessed. However, the call is made using the entire length
of the pcistb operation, which can be larger than the allowed memory
access size (8). Since we already know that the provided buffer is a
multiple of 8, fix the call to memory_region_access_valid to iterate
over the memory region in the same way as the subsequent call to
memory_region_dispatch_write.
Fixes: 863f6f52b7 ("s390: implement pci instructions")
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <1608243397-29428-3-git-send-email-mjrosato@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Hot-unplugging a vfio-pci device on s390x causes a QEMU crash:
qemu-system-s390x: ../softmmu/memory.c:2772:
do_address_space_destroy: Assertion `QTAILQ_EMPTY(&as->listeners)' failed.
In s390, the IOMMU address space is freed during device unplug but the
associated vfio-pci device may not yet be finalized and therefore may
still have a listener registered to the IOMMU address space.
Commit a2166410ad ("spapr_pci: Unregister listeners before destroying
the IOMMU address space") previously resolved this issue for spapr_pci.
We are now seeing this in s390x; it would seem the possibility for this
issue was already present but based on a bisect commit 2d24a64661
("device-core: use RCU for list of children of a bus") has now changed
the timing such that it is now readily reproducible.
Add logic to ensure listeners are removed before destroying the address
space.
Reported-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1605562955-21152-1-git-send-email-mjrosato@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
We use the capability chains of the VFIO_DEVICE_GET_INFO ioctl to retrieve
the CLP information that the kernel exports.
To be compatible with previous kernel versions we fall back on previous
predefined values, same as the emulation values, when the ioctl is found
to not support capability chains. If individual CLP capabilities are not
found, we fall back on default values for only those capabilities missing
from the chain.
This patch is based on work previously done by Pierre Morel.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[aw: non-Linux build fixes]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Now that VFIO_DEVICE_GET_INFO supports capability chains, add a helper
function to find specific capabilities in the chain.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
When an s390 guest is using lazy unmapping, it can result in a very
large number of oustanding DMA requests, far beyond the default
limit configured for vfio. Let's track DMA usage similar to vfio
in the host, and trigger the guest to flush their DMA mappings
before vfio runs out.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[aw: non-Linux build fixes]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Create new files for separating out vfio-specific work for s390
pci. Add the first such routine, which issues VFIO_IOMMU_GET_INFO
ioctl to collect the current dma available count.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[aw: Fix non-Linux build with CONFIG_LINUX]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The underlying host may be limiting the number of outstanding DMA
requests for type 1 IOMMU. Add helper functions to check for the
DMA available capability and retrieve the current number of DMA
mappings allowed.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[aw: vfio_get_info_dma_avail moved inside CONFIG_LINUX]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
commit 3650b228f83adda7e5ee532e2b90429c03f7b9ec
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
[aw: drop pvrdma_ring.h changes to avoid revert of d73415a315 ("qemu/atomic.h: rename atomic_ to qatomic_")]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio_zdev.h is used by s390x zPCI support to pass device-specific
CLP information between host and userspace.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
