This is a follow-up of [0].
# Advantages
- This saves dozens of unneeded clone()s across the whole code base
- Makes it much easier to reason about how parameters are used
(often we passed owned Arc/Rc versions without actually needing
ownership)
# Exceptions
For certain code paths, the alternatives would require awkward or overly
complex code, and in some cases the functions are the logical owners of
the values they take. In those cases, I've added
#[allow(clippy::needless_pass_by_value)].
This does not mean that one should not improve this in the future.
[0] 6a86c157af
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
The Memory Space Enable (MSE) bit from the COMMAND register in the
PCI configuration space controls whether a PCI device responds to memory
space accesses, e.g. read and write cycles to the device MMIO regions
defined by its BARs. The MSE bit is used by the device drivers to ensure
the correctness of BAR reprogramming. A common workflow is, the driver
first clears the MSE bit, then writes new values to the BAR registers,
and finally set the MSE bit to finish the BAR reprogramming.
This patch changes how we handle BAR reprogramming for all PCI
devices (e.g. virtio-pci, vfio, vfio-user, etc.), so that we follow the
same convention, e.g. moving PCI BARs when its MSE bit is set.
Note that some device drivers (such as edk2) only clear and set MSE once
while reprogramming multiple BARs of a single device. To support such
behavior, this patch adds support for multiple pending BAR reprogramming.
See: https://github.com/cloud-hypervisor/cloud-hypervisor/issues/7027#issuecomment-2853642959
Signed-off-by: Bo Chen <bchen@crusoe.ai>
A BAR reprogramming of a PCI device will only happen when the (guest)
kernel write to its PCI config space, e.g. the detection of bar
reprogramming (`detect_bar_repgraomming()`) can be embedded to the PCI
config space write (`write_config_register()`). It simplifies APIs
exposed by the `struct PciConfiguration` and `trait PciDevice`. It also
prepares for easier handling of pending bar reprogramming when the MSE
bit of the COMMAND register is not enabled at the time of changing BAR
registers.
See: https://github.com/cloud-hypervisor/cloud-hypervisor/issues/7027#issuecomment-2853642959
Signed-off-by: Bo Chen <bchen@crusoe.ai>
While non-Intel CPU architectures don't have a special concept of IO
address space, support for PCI I/O regions is still needed to be able
to handle PCI devices that use them.
With this change, I'm able to pass through an e1000e device from QEMU
to a cloud-hypervisor VM on aarch64 and use it in the cloud-hypervisor
guest. Previously, it would hit the unimplemented!().
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Historically the Cloud Hypervisor coding style has been to ensure that
all imports are ordered and placed in a single group. Unfortunately
cargo fmt has no support for ensuring that all imports are in a single
group so if whitespace lines were added as part of the import statements
then they would only be odered correctly in the group.
By adopting "group_imports="StdExternalCrate" we can enforce a style
where imports are placed in at most three groups for std, external
crates and the crate itself. Choosing a style enforceable by the tooling
reduces the reviewer burden.
Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
Port I/O is only supported on x86_64 - use inverted conditional logic to
match the other architectures rather than calling them out specifically.
This will be relevant when RISC-V support is added.
Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
BusDevice trait functions currently holds a mutable reference to self,
and exclusive access is guaranteed by taking a Mutex when dispatched by
the Bus object. However, this prevents individual devices from serving
accesses that do not require an mutable reference or is better served
with different synchronization primitives. We switch Bus to dispatch via
BusDeviceSync, which holds a shared reference, and delegate locking to
the BusDeviceSync trait implementation for Mutex<BusDevice>.
Other changes are made to make use of the dyn BusDeviceSync
trait object.
Signed-off-by: Yuanchu Xie <yuanchu@google.com>
In accordance with reuse requirements:
- Place each license file in the LICENSES/ directory
- Add missing SPDX-License-Identifier to files.
- Add .reuse/dep5 to bulk-license files
Fixes: #5887
Signed-off-by: Ruslan Mstoi <ruslan.mstoi@intel.com>
The code for restoring a VirtioPciDevice has been updated, including the
dependencies VirtioPciCommonConfig, MsixConfig and PciConfiguration.
It's important to note that both PciConfiguration and MsixConfig still
have restore() implementations because Vfio and VfioUser devices still
rely on the old way for restore.
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>
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>
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>
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>
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::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::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>
warning: name `IORegion` contains a capitalized acronym
--> pci/src/configuration.rs:320:5
|
320 | IORegion = 0x01,
| ^^^^^^^^ help: consider making the acronym lowercase, except the initial letter (notice the capitalization): `IoRegion`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
We need to be able to return the barrier from the code that prepares to
activate the virtio device. This triggered by a write to the
configuration fields stored in the PCI BAR. Since bars can be accessed
by both memory mapping and through PCI config I/O several prototypes
must be changed.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This can be uses to indicate to the caller that it should wait on the
barrier before returning as there is some asynchronous activity
triggered by the write which requires the KVM exit to block until it's
completed.
This is useful for having vCPU thread wait for the VMM thread to proceed
to activate the virtio devices.
See #1863
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This removes the dependency of the pci crate on the devices crate which
now only contains the device implementations themselves.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
In order to let the PciBus user choose where a device should be placed
on the bus, a new function get_device_id() is introduced. This will be
helpful in the context of snapshot/restore as the caller will be able to
place the PCI devices on the same slot they were placed before the
snapshot was taken.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Add support for specifying the PCI revision in the PCI configuration and
populate this with the value of 1 for virtio-pci devices.
The virtio-pci specification is slightly ambiguous only saying that
transitional (i.e. devices that support legacy and virtio 1.0) should
set this to 0. In practice it seems that software expects the revision
to be set to 1 for modern only devices.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
By using a Vec to hold the list of devices on the PciBus, there's a
problem when we use unplug. Indeed, the vector of devices gets reduced
and if the unplugged device was not the last one from the list, every
other device after this one is shifted on the bus.
To solve this problem, a HashMap is used. This allows to keep track of
the exact place where each device stands on the bus.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Upon removal of a PCI device, make sure we don't hold onto the device ID
as it could be reused for another device later.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to handle the case where devices are very often plugged and
unplugged from a VM, we need to handle the PCI device ID allocation
better.
Any PCI device could be removed, which means we cannot simply rely on
the vector size to give the next available PCI device ID.
That's why this patch stores in memory the information about the 32
slots availability. Based on this information, whenever a new slot is
needed, the code can correctly provide an available ID, or simply return
an error because all slots are taken.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Simple function relying on the retain() method from std::Vec, allowing
to remove every occurence of the same device.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that the BusDevice devices are stored as Weak references by the IO
and MMIO buses, there's no need to use Weak references from the PciBus
anymore.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
We should not assume the offset produced by ECAM is identical to the
CONFIG_ADDRESS register of legacy PCI port io enumeration.
Signed-off-by: Qiu Wenbo <qiuwenbo@phytium.com.cn>
In order to anticipate the need to support more features related to the
access of a device's PCI config space, this commits changes the self
reference in the function read_config_register() to be mutable.
This also brings some more flexibility for any implementation of the
PciDevice trait.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The specific part of PCI BAR reprogramming that happens for a virtio PCI
device is the update of the ioeventfds addresses KVM should listen to.
This should not be triggered for every BAR reprogramming associated with
the virtio device since a virtio PCI device might have multiple BARs.
The update of the ioeventfds addresses should only happen when the BAR
related to those addresses is being moved.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The PciDevice trait is supposed to describe only functions related to
PCI. The specific method ioeventfds() has nothing to do with PCI, but
instead would be more specific to virtio transport devices.
This commit removes the ioeventfds() method from the PciDevice trait,
adding some convenient helper as_any() to retrieve the Any trait from
the structure behing the PciDevice trait. This is the only way to keep
calling into ioeventfds() function from VirtioPciDevice, so that we can
still properly reprogram the PCI BAR.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Storing a strong reference to the AddressManager behind the
DeviceRelocation trait results in a cyclic reference count.
Use a weak reference to break that dependency.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the value being written to the BAR, the implementation can
now detect if the BAR is being moved to another address. If that is the
case, it invokes move_bar() function from the DeviceRelocation trait.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to trigger the PCI BAR reprogramming from PciConfigIo and
PciConfigMmmio, we need the PciBus to have a hold onto the trait
implementation of DeviceRelocation.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit is the glue between the virtio-pci devices attached to the
vIOMMU, and the IORT ACPI table exposing them to the guest as sitting
behind this vIOMMU.
An important thing is the trait implementation provided to the virtio
vrings for each device attached to the vIOMMU, as they need to perform
proper address translation before they can access the buffers.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Refactor the PCI datastructures to move the device ownership to a PciBus
struct. This PciBus struct can then be used by both a PciConfigIo and
PciConfigMmio in order to expose the configuration space via both IO
port and also via MMIO for PCI MMCONFIG.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Latest clippy version complains about our existing code for the
following reasons:
- trait objects without an explicit `dyn` are deprecated
- `...` range patterns are deprecated
- lint `clippy::const_static_lifetime` has been renamed to
`clippy::redundant_static_lifetimes`
- unnecessary `unsafe` block
- unneeded return statement
All these issues have been fixed through this patch, and rustfmt has
been run to cleanup potential formatting errors due to those changes.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Every PCI device is exposed as a separate device, on a specific PCI
slot, and we explicitely don't support to expose a device as a multi
function device. For this reason, this patch makes sure the enumeration
of the PCI bus will not find some multi function device.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This patch adds the support for both IO and Memory BARs by expecting
the function allocate_bars() to identify the type of each BAR.
Based on the type, register_mapping() insert the address range on the
appropriate bus (PIO or MMIO).
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
