As mentioned in the PCI specification, the Function Mask from the
Message Control Register can be set to prevent a device from injecting
MSI-X messages. This supersedes the vector masking as it interacts at
the device level.
Here quoted from the specification:
For MSI and MSI-X, while a vector is masked, the function is prohibited
from sending the associated message, and the function must set the
associated Pending bit whenever the function would otherwise send the
message. When software unmasks a vector whose associated Pending bit is
set, the function must schedule sending the associated message, and
clear the Pending bit as soon as the message has been sent. Note that
clearing the MSI-X Function Mask bit may result in many messages
needing to be sent.
This commit implements the behavior described above by reorganizing
the way the PCI configuration space is being written. It is indeed
important to be able to catch a change in the Message Control
Register without having to implement it for every PciDevice
implementation. Instead, the PciConfiguration has been modified to
take care of handling any update made to this register.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The current MSI-X implementation completely ignores the values found
in the Vector Control register related to a specific vector, and never
updates the Pending Bit Array.
According to the PCI specification, MSI-X vectors can be masked
through the Vector Control register on bit 0. If this bit is set,
the device should not inject any MSI message. When the device
runs into such situation, it must not inject the interrupt, but
instead it must update the bit corresponding to the vector number
in the Pending Bit Array.
Later on, if/when the Vector Control register is updated, and if
the bit 0 is flipped from 0 to 1, the device must look into the PBA
to find out if there was a pending interrupt for this specific
vector. If that's the case, an MSI message is injected and the
bit from the PBA is cleared.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
As mentioned in the PCI specification, MSI-X table supports both
DWORD and QWORD accesses:
For all accesses to MSI-X Table and MSI-X PBA fields, software must
use aligned full DWORD or aligned full QWORD transactions; otherwise,
the result is undefined.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to factorize the complexity brought by closures, this commit
merges IrqClosure and MsixClosure into a generic InterruptDelivery one.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to allow virtio-pci devices to use MSI-X messages instead
of legacy pin based interrupts, this patch implements the MSI-X
support for cloud-hypervisor. The VMM code and virtio-pci bits have
been modified based on the "msix" module previously added to the pci
crate.
Fixes#12
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to support MSI-X, this commit adds to the pci crate a new
module called "msix". This module brings all the necessary pieces
to let any PCI device implement MSI-X support.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Because we cannot always assume the irq fd will be the way to send
an IRQ to the guest, this means we cannot make the assumption that
every virtio device implementation should expect an EventFd to
trigger an IRQ.
This commit organizes the code related to virtio devices so that it
now expects a Rust closure instead of a known EventFd. This lets the
caller decide what should be done whenever a device needs to trigger
an interrupt to the guest.
The closure will allow for other type of interrupt mechanism such as
MSI to be implemented. From the device perspective, it could be a
pin based interrupt or an MSI, it does not matter since the device
will simply call into the provided callback, passing the appropriate
Queue as a reference. This design keeps the device model generic.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Add the BSD and Apache license.
Make all crosvm references point to the BSD license.
Add the right copyrights and identifier to our VMM code.
Add Intel copyright to the vm-virtio and pci crates.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
After the virtio-blk device support has been introduced in the
previous commit, the vmm need to rely on this new device to boot
from disk images instead of initrd built into the kernel.
In order to achieve the proper support of virtio-blk, this commit
had to handle a few things:
- Register an ioevent fd for each virtqueue. This important to be
notified from the virtio driver that something has been written
on the queue.
- Fix the retrieval of 64bits BAR address. This is needed to provide
the right address which need to be registered as the notification
address from the virtio driver.
- Fix the write_bar and read_bar functions. They were both assuming
to be provided with an address, from which they were trying to
find the associated offset. But the reality is that the offset is
directly provided by the Bus layer.
- Register a new virtio-blk device as a virtio-pci device from the
vm.rs code. When the VM is started, it expects a block device to
be created, using this block device as the VM rootfs.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This crate is based on the crosvm devices/src/pci implementation from 107edb3e
We introduced a few changes:
- This one is a standalone crate. The device crate does not carry any
PCI specific bits.
- Simplified PCI root configuration. We only carry a pointer to a
PciConfiguration, not a wrapper around it.
- Simplified BAR allocation API. All BARs from the PciDevice instance
must be generated at once through the PciDevice.allocate_bars()
method.
- The PCI BARs are added to the MMIO bus from the PciRoot add_device()
method.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
