When restoring a VM, the restore codepath will take care of mapping the
MMIO regions based on the information from the snapshot, rather than
having the mapping being performed during device creation.
When the device is created, information such as which BARs contain the
MSI-X tables are missing, preventing to perform the mapping of the MMIO
regions.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the VfioCommon implementation, the VfioUserPciDevice now
implements the Migratable trait.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the VfioCommon implementation, the VfioPciDevice now implements
the Migratable trait.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Introduces the common code to handle one aspect of the migration
support. Particularly, the ability to store VMM internal states related
to such device. The internal state of the device will happen later in a
dedicated patchset that will implement the VFIO migration API.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
So that we can save and restore the whole structure through snapshot and
restore operations.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
We can return prematurely from 'map_mmio_regions()' (e.g. when a mmap call
failed for vfio or 'create_user_memory_region()' failed for vfio-user)
without updating the 'MmioRegion::user_memory_regions' with the
information of previous successful mmaps, which in turn would cause mmap
leaks particularly for the case of hotplug where the 'vmm' thread will
keep running. To fix the issue, let's keep 'MmioRegion::user_memory_regions'
updated right after successful mmap calls.
Fixes: #4068
Signed-off-by: Bo Chen <chen.bo@intel.com>
Reorganizing the code to leverage the same mechanics implemented for
vfio-user and aimed at supporting sparse memory mappings for a single
region.
Relying on the capabilities returned by the vfio-ioctls crate, we create
a list of sparse areas depending if we get SPARSE_MMAP or MSIX_MAPPABLE
capability, or a single sparse area in case we couldn't find any
capability.
The list of sparse areas is then used to create both the memory mappings
in the Cloud Hypervisor address space and the hypervisor user memory
regions.
This allowed for the simplification of the MmioRegion structure.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Instead of always creating a single large mmap for the MMIO region of a
BAR, we create multiple mmaps for the BARs that need multiple kvm user
memory regions. In this way, we can simplify 'unmap_mmio_regions()' (by
reusing information kept from 'MmioRegion::user_memory_region').
Signed-off-by: Bo Chen <chen.bo@intel.com>
Similar to what's being supported for vfio devices, vfio-user devices
may also have BARs that need multiple kvm user memory regions,
e.g. device regions with `VFIO_REGION_INFO_CAP_SPARSE_MMAP`.
Signed-off-by: Bo Chen <chen.bo@intel.com>
Extend VfioCommon to simplify the overall code, and also in preparation
for supporting the restore code path.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Extend VfioCommon structure to own the legacy interrupt manager. This
will be useful for implementing the restore code path.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Extend VfioCommon structure to own the MSI interrupt manager. This will
be useful for implementing the restore code path.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
We need to split the parsing functions into one function dedicated to
the actual parsing and a second function for initializing the interrupt
type. This will be useful on the restore path as the parsing won't be
needed.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Adding support for snapshot and restore to the MsiConfig structure, as
it will be needed part of VFIO migration.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In case a list of resources is provided to allocate_bars(), it directly
means we're restoring some existing BARs. That's why we shouldn't share
the codepath that creates BARs from scratch as we don't need to interact
with the device to retrieve the information.
Whenever resources are provided, we simply iterate over the list of
possible BAR indexes and create the BARs if the resource could be found.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Instead of defining some very generic resources as PioAddressRange or
MmioAddressRange for each PCI BAR, let's move to the new Resource type
PciBar in order to make things clearer. This allows the code for being
more readable, but also removes the need for hard assumptions about the
MMIO and PIO ranges. PioAddressRange and MmioAddressRange types can be
used to describe everything except PCI BARs. BARs are very special as
they can be relocated and have special information we want to carry
along with them.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to make the code more consistent and easier to read, we remove
the former tuple that was used to describe a BAR, replacing it with the
existing structure PciBarConfiguration.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The code was quite unclear regarding the type of index that was being
used regarding a BAR. This is improved by differenciating register
indexes and BAR indexes more clearly.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
By adding a new method id() to the PciDevice trait, we allow the caller
to retrieve a unique identifier. This is used in the context of BAR
relocation to identify the device being relocated, so that we can update
the DeviceTree resources for all PCI devices (and not only
VirtioPciDevice).
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Relying on the list of resources, VfioCommon is now able to allocate the
BARs at specific addresses. This will be useful for restoring VFIO and
vfio-user devices.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Updating the way of restoring BAR addresses for virtio-pci by providing
a more generic approach that will be reused for other PciDevice
implementations (i.e VfioPcidevice and VfioUserPciDevice).
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The calls to these functions are always preceded by a call to
InterruptSourceGroup::update(). By adding a masked boolean to that
function call it possible to remove 50% of the calls to the
KVM_SET_GSI_ROUTING ioctl as the the update will correctly handle the
masked or unmasked case.
This causes the ioctl to disappear from the perf report for a boot of
the VM.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Whenever a vfio-user device is dropped, the communication between the
VMM and the backend should be shutdown.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The same way we mask the writes coming from the guest to the message
control register related to MSI-X capability, let's do the same for MSI.
The point is to prevent the guest from writing to read-only bits.
The correct writable bits for MSI are only bits 0, 4, 5 and 6 of 2nd
16-bit word.
Those are:
* MSI Enable: 0
* Multiple Message Enable: 6-4
See "Table 7-39 Message Control Register for MSI" from
"NCB-PCI_Express_Base_5.0r1.0-2019-05-22.pdf".
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
I incorrectly used the MSI message control register values for the mask
not the the MSI-X control registers.
The correct writable fields for MSI-X are only bits 14 and 15 of 2nd
16-bit word.
Those are:
* Function Mask: 14
* MSI-X Enable: 15
See "Table 7-47 Message Control Register for MSI-X" from
"NCB-PCI_Express_Base_5.0r1.0-2019-05-22.pdf"
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The PCI spec specifies that only the following bits are writable:
16: MSI Enable
20,21,22: Multiple Message Enable
26: Extended Message Data Enable
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
By having the DeviceNode storing a PciBdf, we simplify the internal code
as well as allow for custom Serialize/Deserialize implementation for the
PciBdf structure. These custom implementations let us display the PCI
s/b/d/f in a human readable format.
Fixes#3711
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
AArch64 does not use IOBAR, and current code of panics the whole VMM if
we need to allocate the IOBAR.
This commit checks if IOBAR is enabled before the arch conditional code
of IOBAR allocation and if the IOBAR is not enabled, we can just skip
the IOBAR allocation and do nothing.
Fixes: https://github.com/cloud-hypervisor/cloud-hypervisor/issues/3479
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
The sendmsg() syscall is limited in the number of fds it can handle.
This number matches that used by the vfio-user library and is
conservative (since we've seen it work with 64 fds.)
Fixes: #3401
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Now that vfio-ioctls correctly exposes the list of capabilities related
to each region, Cloud Hypervisor can decide to mmap a region based on
the presence or absence of MSIX_MAPPABLE. Instead of blindly mmap'ing
the region, we check if the MSI-X table or PBA is present on the BAR,
and if that's the case, we look for MSIX_MAPPABLE.
If MSIX_MAPPABLE is present, we can go ahead and mmap the entire region.
If MSIX_MAPPABLE is not present, we simply ignore the mmap'ing of this
region as it wouldn't be supported.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In particular use the accessor for getting the device id from the bdf.
As a side effect the VIOT table is now segment aware.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This will allow making the code that handles bdf parsing simpler and
remove the need for manual shifting.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Since each segment must have a non-overlapping memory range associated
with it the device memory must be equally divided amongst all segments.
A new allocator is used for each segment to ensure that BARs are
allocated from the correct address ranges. This requires changes to
PciDevice::allocate/free_bars to take that allocator and when
reallocating BARs the correct allocator must be identified from the
ranges.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
In order to get proper performance out of hardware that might be passed
through the VM with VFIO, we decide to try mapping any region marked as
mappable, ignoring the failure and moving on to the next region. When
the mapping succeeds, we establish a list of user memory regions so that
we enable only subparts of the global mapping through the hypervisor.
This allows MSI-X table and PBA to keep trapping accesses from the guest
so that the VMM can properly emulate MSI-X.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Move the PCI related state from the DeviceManager struct to a PciSegment
struct inside the DeviceManager. This is in preparation for multiple
segment support. Currently this state is just the bus itself, the MMIO
and PIO config devices and hotplug related state.
The main change that this required is using the Arc<Mutex<PciBus>> in
the device addition logic in order to ensure that
the bus could be created earlier.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Implement the infrastructure that lets a virtio-mem device map the guest
memory into the device. This is necessary since with virtio-mem zones
memory can be added or removed and the vfio-user device must be
informed.
Fixes: #3025
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
By moving this from the VfioUserPciDevice to DeviceManager the client
can be reused for handling DMA mapping behind an IOMMU.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Looking up devices on the port I/O bus is time consuming during the
boot at there is an O(lg n) tree lookup and the overhead from taking a
lock on the bus contents.
Avoid this by adding a fast path uses the hardcoded port address and
size and directs PCI config requests directly to the device.
Command line:
target/release/cloud-hypervisor --kernel ~/src/linux/vmlinux --cmdline "root=/dev/vda1 console=ttyS0" --serial tty --console off --disk path=~/workloads/focal-server-cloudimg-amd64-custom-20210609-0.raw --api-socket /tmp/api
PIO exit: 17913
PCI fast path: 17871
Percentage on fast path: 99.8%
perf before:
marvin:~/src/cloud-hypervisor (main *)$ perf report -g | grep resolve
6.20% 6.20% vcpu0 cloud-hypervisor [.] vm_device:🚌:Bus::resolve
perf after:
marvin:~/src/cloud-hypervisor (2021-09-17-ioapic-fast-path *)$ perf report -g | grep resolve
0.08% 0.08% vcpu0 cloud-hypervisor [.] vm_device:🚌:Bus::resolve
The compromise required to implement this fast path is bringing the
creation of the PciConfigIo device into the DeviceManager::new() so that
it can be used in the VmmOps struct which is created before
DeviceManager::create_devices() is called.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This message only occurs sporadically and so it should be included at
info!() level. Enhance the output to also include the BAR number.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
