When running a TDX guest, we need the virtio drivers to use the DMA API
to share specific memory pages with the VMM on the host. The point is to
let the VMM get access to the pages related to the buffers pointed by
the virtqueues.
The way to force the virtio drivers to use the DMA API is by exposing
the virtio devices with the feature VIRTIO_F_IOMMU_PLATFORM. This is a
feature indicating the device will require some address translation, as
it will not deal directly with physical addresses.
Cloud Hypervisor takes care of this requirement by adding a generic
parameter called "force_iommu". This parameter value is decided based on
the "tdx" feature gate, and then passed to the DeviceManager. It's up to
the DeviceManager to use this parameter on every virtio device creation,
which will imply setting the VIRTIO_F_IOMMU_PLATFORM feature.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Previously the same function was used to both create and remove regions.
This worked on KVM because it uses size 0 to indicate removal.
MSHV has two calls -- one for creation and one for removal. It also
requires having the size field available because it is not slot based.
Split set_user_memory_region to {create/remove}_user_memory_region. For
KVM they still use set_user_memory_region underneath, but for MSHV they
map to different functions.
This fixes user memory region removal on MSHV.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
We have been building Cloud Hypervisor with command like:
`cargo build --no-default-features --features ...`.
After implementing ACPI, we donot have to use specify all features
explicitly. Default build command `cargo build` can work.
This commit fixed some build warnings with default build option and
changed github workflow correspondingly.
Signed-off-by: Michael Zhao <michael.zhao@arm.com>
Issue from beta verion of clippy:
Error: --> vm-virtio/src/queue.rs:700:59
|
700 | if let Some(used_event) = self.get_used_event(&mem) {
| ^^^^ help: change this to: `mem`
|
= note: `-D clippy::needless-borrow` implied by `-D warnings`
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow
Signed-off-by: Bo Chen <chen.bo@intel.com>
The Linux kernel expects that any PCI devices that advertise I/O bars
have use an address that is within the range advertised by the bus
itself. Unfortunately we were not advertising any I/O ports associated
with the PCI bus in the ACPI tables.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Make sure the unique PCI bus is tied to the default NUMA node 0, and
update the documentation to let the users know about this special case.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Sometimes we need balloon deflate automatically to give memory
back to guest, especially for some low priority guest processes
under memory pressure. Enable deflate_on_oom to support this.
Usage: --balloon "size=0,deflate_on_oom=on" \
Signed-off-by: Fei Li <lifei.shirley@bytedance.com>
Since using the VIRTIO configuration to expose the virtual IOMMU
topology has been deprecated, the virtio-iommu implementation must be
updated.
In order to follow the latest patchset that is about to be merged in the
upstream Linux kernel, it must rely on ACPI, and in particular the newly
introduced VIOT table to expose the information about the list of PCI
devices attached to the virtual IOMMU.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
_DSM (Device Specific Method) is a control method that enables devices
to provide device specific control functions. Linux kernel will evaluate
this device then initialize preserve_config in acpi pci initialization.
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
As the first step to complete live-migration with tracking dirty-pages
written by the VMM, this commit patches the dependent vm-memory crate to
the upstream version with the dirty-page-tracking capability. Most
changes are due to the updated `GuestMemoryMmap`, `GuestRegionMmap`, and
`MmapRegion` structs which are taking an additional generic type
parameter to specify what 'bitmap backend' is used.
The above changes should be transparent to the rest of the code base,
e.g. all unit/integration tests should pass without additional changes.
Signed-off-by: Bo Chen <chen.bo@intel.com>
After adding "get_interrupt_controller()" function in DeviceManager,
"enable_interrupt_controller()" became redundant, because the latter
one is the a simple wrapper on the interrupt controller.
Signed-off-by: Michael Zhao <michael.zhao@arm.com>
The function used to calculate "gicr-typer" value has nothing with
DeviceManager. Now it is moved to AArch64 specific files.
Signed-off-by: Michael Zhao <michael.zhao@arm.com>
We thought we could move the control queue to the backend as it was
making some good sense. Unfortunately, doing so was a wrong design
decision as it broke the compatibility with OVS-DPDK backend.
This is why this commit moves the control queue back to the VMM side,
meaning an additional thread is being run for handling the communication
with the guest.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that the control queue is correctly handled by the backend, there's
no need to handle it as well from the VMM.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
These messages are predominantly during the boot process but will also
occur during events such as hotplug.
These cover all the significant steps of the boot and can be helpful for
diagnosing performance and functionality issues during the boot.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Adding the support for an OVS vhost-user backend to connect as the
vhost-user client. This means we introduce with this patch a new
option to our `--net` parameter. This option is called 'server' in order
to ask the VMM to run as the server for the vhost-user socket.
Fixes#1745
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Windows guests read this field upon PCI device ejection. Let's make sure
we don't return an error as this is valid. We simply return an empty u32
since the ejection is done right away upon write access, which means
there's no pending ejection that might be reported to the guest.
Here is the error that was shown during PCI device removal:
ERROR:vmm/src/device_manager.rs:3960 -- Accessing unknown location at
base 0x7ffffee000, offset 0x8
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Fixes the current codebase so that every cargo clippy can be run with
the beta toolchain without any error.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
error: name `GPIOInterruptDisabled` contains a capitalized acronym
Error: --> devices/src/legacy/gpio_pl061.rs:46:5
|
46 | GPIOInterruptDisabled,
| ^^^^^^^^^^^^^^^^^^^^^ help: consider making the acronym lowercase, except the initial letter: `GpioInterruptDisabled`
|
= note: `-D clippy::upper-case-acronyms` implied by `-D warnings`
= 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>
warning: name `AcpiPMTimerDevice` contains a capitalized acronym
--> devices/src/acpi.rs:175:12
|
175 | pub struct AcpiPMTimerDevice {
| ^^^^^^^^^^^^^^^^^ help: consider making the acronym lowercase, except the initial letter: `AcpiPmTimerDevice`
|
= note: `#[warn(clippy::upper_case_acronyms)]` on by default
= 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>
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>
warning: name `LocalAPIC` contains a capitalized acronym
--> vmm/src/cpu.rs:197:8
|
197 | struct LocalAPIC {
| ^^^^^^^^^ help: consider making the acronym lowercase, except the initial letter: `LocalApic`
|
= 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>
error: name `TYPE_UNKNOWN` contains a capitalized acronym
--> vm-virtio/src/lib.rs:48:5
|
48 | TYPE_UNKNOWN = 0xFF,
| ^^^^^^^^^^^^ help: consider making the acronym lowercase, except the initial letter: `Type_Unknown`
|
= 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>
error: name `SDT` contains a capitalized acronym
--> acpi_tables/src/sdt.rs:27:12
|
27 | pub struct SDT {
| ^^^ help: consider making the acronym lowercase, except the initial letter: `Sdt`
|
= 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>
There's no need to have the code creating the passthrough_device being
duplicated since we can factorize it in a function used in both cases
(both cold plugged and hot plugged devices VFIO devices).
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Extend and use the existing DeviceTree to retrieve useful information
related to PCI devices. This removes the duplication with pci_devices
field which was internal to the DeviceManager.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Make the code a bit clearer by changing the naming of the structure
holding the list of IRQs reserved for PCI devices. It is also modified
into an array of 32 entries since we know this is the amount of PCI
slots that is supported.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
We define a new enum in order to classify PCI device under virtio or
VFIO. This is a cleaner approach than using the Any trait, and
downcasting it to find the object back.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Introduces a tuple holding both information needed by pci_id_list and
pci_devices.
Changes pci_devices to be a BTreeMap of this new tuple.
Now that pci_devices holds the information needed from pci_id_list,
pci_id_list is no longer needed.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In anticipation for further factorization, the pci_id_list is now a
hashmap of PCI b/d/f leading to each device name.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Instead of relying on a PCI specific device list, we use the DeviceTree
as a reference to determine if a device name is already in use or not.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit switches the default serial device from 16550 to the
Arm dedicated UART controller PL011. The `ttyAMA0` can be enabled.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Relies on the preliminary work allowing virtio devices to be updated
with a single memory at a time instead of updating the entire memory at
once.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
When a vm is created with a pty device, on reboot the pty fd (sub
only) will only be associated with the vmm through the epoll event
loop. The fd being polled will have been closed due to the vm itself
dropping the pty files (and potentially reopening the fd index to a
different item making things quite confusing) and new pty fds will be
opened but not polled on for input.
This change creates a structure to encapsulate the information about
the pty fd (main File, sub File and the path to the sub File). On
reboot, a copy of the console and serial pty structs is then passed
down to the new Vm instance which will be used instead of creating a
new pty device.
This resolves the underlying issue from #2316.
Signed-off-by: William Douglas <william.r.douglas@gmail.com>
Now that virtio-mem devices can update VFIO mappings through dedicated
handlers, let's provide them from the DeviceManager.
Important to note these handlers should either be provided to virtio-mem
devices or to the unique virtio-iommu device. This must be mutually
exclusive.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Instead of letting the VfioPciDevice take the decision on how/when to
perform the DMA mapping/unmapping, we move this to the DeviceManager
instead.
The point is to let the DeviceManager choose which guest memory regions
should be mapped or not. In particular, we don't want the virtio-mem
region to be mapped/unmapped as it will be virtio-mem device
responsibility to do so.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit moves both pci and vmm code from the internal vfio-ioctls
crate to the upstream one from the rust-vmm project.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that ExternalDmaMapping is defined in vm-device, let's use it from
there.
This commit also defines the function get_host_address_range() to move
away from the vfio-ioctls dependency.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
If the function can never return an error this is now a clippy failure:
error: this function's return value is unnecessarily wrapped by `Result`
--> virtio-devices/src/watchdog.rs:215:5
|
215 | / fn set_state(&mut self, state: &WatchdogState) -> io::Result<()> {
216 | | self.common.avail_features = state.avail_features;
217 | | self.common.acked_features = state.acked_features;
218 | | // When restoring enable the watchdog if it was previously enabled. We reset the timer
... |
223 | | Ok(())
224 | | }
| |_____^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_wraps
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
With all the preliminary work done in the previous commits, we can
update the VFIO implementation to support INTx along with MSI and MSI-X.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Here we are adding the PCI routing table, commonly called _PRT, to the
ACPI DSDT. For simplification reasons, we chose not to implement PCI
links as this involves dynamic decision from the guest OS, which result
in lots of complexity both from an AML perspective and from a device
manager perspective.
That's why the _PRT creates a static list of 32 entries, each assigned
with the IRQ number previously reserved by the device manager.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to support INTx for PCI devices, each PCI device must be
assigned an IRQ. This is preliminary work to reserve 8 IRQs which will
be shared across the 32 PCI devices.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In anticipation for accessing the legacy interrupt manager from the
function creating a VFIO PCI device, we store it as part of the
DeviceManager, to make it available for all methods.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The DeviceManager already has a hold onto the MSI interrupt manager,
therefore there's no need to pass it through every function. Instead,
let's simplify the code by using the attribute from DeviceManager's
instance.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Add the ability for cloud-hypervisor to create, manage and monitor a
pty for serial and/or console I/O from a user. The reasoning for
having cloud-hypervisor create the ptys is so that clients, libvirt
for example, could exit and later re-open the pty without causing I/O
issues. If the clients were responsible for creating the pty, when
they exit the main pty fd would close and cause cloud-hypervisor to
get I/O errors on writes.
Ideally the main and subordinate pty fds would be kept in the main
vmm's Vm structure. However, because the device manager owns parsing
the configuration for the serial and console devices, the information
is instead stored in new fields under the DeviceManager structure
directly.
From there hooking up the main fd is intended to look as close to
handling stdin and stdout on the tty as possible (there is some future
work ahead for perhaps moving support for the pty into the
vmm_sys_utils crate).
The main fd is used for reading user input and writing to output of
the Vm device. The subordinate fd is used to setup raw mode and it is
kept open in order to avoid I/O errors when clients open and close the
pty device.
The ability to handle multiple inputs as part of this change is
intentional. The current code allows serial and console ptys to be
created and both be used as input. There was an implementation gap
though with the queue_input_bytes needing to be modified so the pty
handlers for serial and console could access the methods on the serial
and console structures directly. Without this change only a single
input source could be processed as the console would switch based on
its input type (this is still valid for tty and isn't otherwise
modified).
Signed-off-by: William Douglas <william.r.douglas@gmail.com>
This commit introduces a new information to the VirtioMemZone structure
in order to know if the memory zone is backed by hugepages.
Based on this new information, the virtio-mem device is now able to
determine if madvise(MADV_DONTNEED) should be performed or not. The
madvise documentation specifies that MADV_DONTNEED advice will fail if
the memory range has been allocated with some hugepages.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: Hui Zhu <teawater@antfin.com>
By introducing a ResizeSender object, we avoid having a Resize clone
with a different content than the original Resize object.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Relying on the simplified version of the synchronous support for RAW
disk files, the new fixed_vhd_sync module in the block_util crate
introduces the synchronous support for fixed VHD disk files.
With this patch, the fixed VHD support is complete as it is implemented
in both synchronous and asynchronous versions.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Using directly preadv and pwritev, we can simply use a RawFd instead of
a file, and we don't need to use the more complex implementation from
the qcow crate.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit adds the asynchronous support for fixed VHD disk files.
It introduces FixedVhd as a new ImageType, moving the image type
detection to the block_util crate (instead of qcow crate).
It creates a new vhd module in the block_util crate in order to handle
VHD footer, following the VHD specification.
It creates a new fixed_vhd_async module in the block_util crate to
implement the asynchronous version of fixed VHD disk file. It relies on
io_uring.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This patch enables multi-queue support for creating virtio-net devices by
accepting multiple TAP fds, e.g. '--net fds=3:7'.
Fixes: #2164
Signed-off-by: Bo Chen <chen.bo@intel.com>
Building with 1.51 nightly produces the following warning:
warning: unnecessary trailing semicolon
--> vmm/src/device_manager.rs:396:6
|
396 | };
| ^ help: remove this semicolon
|
= note: `#[warn(redundant_semicolons)]` on by default
warning: 1 warning emitted
Signed-off-by: Wei Liu <liuwe@microsoft.com>
This skeleton commit brings in the support for compiling aarch64 with
the "acpi" feature ready to the ACPI enabling. It builds on the work to
move the ACPI hotplug devices from I/O ports to MMIO and conditionalises
any code that is x86_64 only (i.e. because it uses an I/O port.)
Filling in the aarch64 specific details in tables such as the MADT it
out of the scope.
See: #2178
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
It might be useful debugging information for the user to know what kind
of disk file implementation is in use.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that BlockIoUring is the only implementation of virtio-block,
handling both synchronous and asynchronous backends based on the
AsyncIo trait, we can rename it to Block.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the synchronous QCOW file implementation present in the qcow
crate, we created a new qcow_sync module in block_util that ports this
synchronous implementation to the AsyncIo trait.
The point is to reuse virtio-blk asynchronous implementation for both
synchronous and asynchronous backends.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the synchronous RAW file implementation present in the qcow
crate, we created a new raw_sync module in block_util that ports this
synchronous implementation to the AsyncIo trait.
The point is to reuse virtio-blk asynchronous implementation for both
synchronous and asynchronous backends.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the new DiskFile and AsyncIo traits, the implementation of
asynchronous block support does not have to be tied to io_uring anymore.
Instead, the only thing the virtio-blk implementation knows is that it
is using an asynchronous implementation of the underlying disk file.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Currently the GED control is in a fixed I/O port address but instead use
an MMIO address that has been chosen by the allocator.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Use the ACPI GED device to trigger a notitifcation of type
POWER_BUTTON_CHANGED which will ultimately lead to the guest being
notified.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Renamed this bitfield as it will also be used for non-hotplug purposes
such as synthesising a power button.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
When a device is ready to be activated signal to the VMM thread via an
EventFd that there is a device to be activated. When the VMM receives a
notification on the EventFd that there is a device to be activated
notify the device manager to attempt to activate any devices that have
not been activated.
As a side effect the VMM thread will create the virtio device threads.
Fixes: #1863
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>
There are some code base and function which are purely KVM specific for
now and we don't have those supports in mshv at the moment but we have plan
for the future. We are doing a feature guard with KVM. For example, KVM has
mp_state, cpu clock support, which we don't have for mshv. In order to build
those code we are making the code base for KVM specific compilation.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
The DeviceNode cannot be fully represented as it embeds a Rust style
enum (i.e. with data) which is instead represented by a simple
associative array.
Fixes: #1167
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Add config parameter to --disk called "_disable_io_uring" (the
underscore prefix indicating it is not for public consumpion.) Use this
option to disable io_uring if it would otherwise be used.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
In order to do this we must extend the MemoryManager API to add the
ability to specify the tracking of the dirty pages when creating the
userspace mappings and also keep track of the userspace mappings that
have been created for RAM regions.
Currently the dirty pages are collected into ranges based on a block
level of 64 pages. The algorithm could be tweaked to create smaller
ranges but for now if any page in the block of 64 is dirty the whole
block is added to the range.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This also removes the need to lookup up the "exe" symlink for finding
the VMM executable path.
Fixes: #1925
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Now that we have a new dedicated way of asking for a balloon through the
CLI and the REST API, we can move all the balloon code to the device
manager. This allows us to simplify the memory manager, which is already
quite complex.
It also simplifies the behavior of the balloon resizing command. Instead
of providing the expected size for the RAM, which is complex when memory
zones are involved, it now expects the balloon size. This is a much more
straightforward behavior as it really resizes the balloon to the desired
size. Additionally to the simplication, the benefit of this approach is
that it does not need to be tied to the memory manager at all.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The watchdog device is created through the "--watchdog" parameter. At
most a single watchdog can be created per VM.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
When shutting down a VM using VFIO, the following error has been
detected:
vfio-ioctls/src/vfio_device.rs:312 -- Could not delete VFIO group:
KvmSetDeviceAttr(Error(9))
After some investigation, it appears the KVM device file descriptor used
for removing a VFIO group was already closed. This is coming from the
Rust sequence of Drop, from the DeviceManager all the way down to
VfioDevice.
Because the DeviceManager owns passthrough_device, which is effectively
a KVM device file descriptor, when the DeviceManager is dropped, the
passthrough_device follows, with the effect of closing the KVM device
file descriptor. Problem is, VfioDevice has not been dropped yet and it
still needs a valid KVM device file descriptor.
That's why the simple way to fix this issue coming from Rust dropping
all resources is to make Linux accountable for it by duplicating the
file descriptor. This way, even when the passthrough_device is dropped,
the KVM file descriptor is closed, but a duplicated instance is still
valid and owned by the VfioContainer.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Small patch creating a dedicated `block_io_uring_is_supported()`
function for the non-io_uring case, so that we can simplify the
code in the DeviceManager.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Because of the PCI refactoring that happened in the previous commit
d793cc4da3, the ability to fully remove a
PCI device was altered.
The refactoring was correct, but the usage of a generic function to pass
the same reference for both BusDevice, PciDevice and Any + Send + Sync
causes the Arc::ptr_eq() function to behave differently than expected,
as it does not match the references later in the code. That means we
were not able to remove the device reference from the MMIO and/or PIO
buses, which was leading to some bus range overlapping error once we
were trying to add a device again to the previous range that should have
been removed.
Fixes#1802
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The PMEM support has an option called "discard_writes" which when true
will prevent changes to the device from hitting the backing file. This
is trying to be the equivalent of "readonly" support of the block
device.
Previously the memory of the device was marked as KVM_READONLY. This
resulted in a trap when the guest attempted to write to it resulting a
VM exit (and recently a warning). This has a very detrimental effect on
the performance so instead make "discard_writes" truly CoW by mapping
the memory as `PROT_READ | PROT_WRITE` and using `MAP_PRIVATE` to
establish the CoW mapping.
Fixes: #1795
Signed-off-by: Rob Bradford <robert.bradford@intel.com>