Previously, PXB_CXL_DEVICE, PXB_PCIE_DEVICE and PXB_DEVICE all
have PCI_DEVICE as their direct parent but share a common state
struct PXBDev. convert_to_pxb() is used to get the PXBDev
instance from which ever of these types it is called on.
This patch switches to an explicit hierarchy based on shared
functionality. To allow use of OBJECT_DECLARE_SIMPLE_TYPE()
whilst minimizing code changes, all types are renamed to have
the postfix _DEV rather than _DEVICE. The new heirarchy
has PXB_CXL_DEV with parent PXB_PCIE_DEV which in turn
has parent PXB_DEV which continues to have parent PCI_DEVICE.
This allows simple use of PXB_DEV() etc rather than a custom function
+ removal of duplicated properties and moving the CXL specific
elements out of struct PXBDev.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230420142750.6950-3-Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The CXL r3.0 specification allows for there to be no HDM decoders on CXL
Host Bridges if they have only a single root port. Instead, all accesses
directed to the host bridge (as specified in CXL Fixed Memory Windows)
are assumed to be routed to the single root port.
Linux currently assumes this implementation choice. So to simplify testing,
make QEMU emulation also default to no HDM decoders under these particular
circumstances, but provide a hdm_for_passthrough boolean option to have
HDM decoders as previously.
Technically this is breaking backwards compatibility, but given the only
known software stack used with the QEMU emulation is the Linux kernel
and this configuration did not work before this change, there are
unlikely to be any complaints that it now works. The option is retained
to allow testing of software that does allow for these HDM decoders to exist,
once someone writes it.
Reported-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Tested-by: Fan Ni <fan.ni@samsung.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
--
v2: Pick up and fix typo in tag from Fan Ni
Message-Id: <20230227153128.8164-3-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
CXL uses PCI AER Internal errors to signal to the host that an error has
occurred. The host can then read more detailed status from the CXL RAS
capability.
For uncorrectable errors: support multiple injection in one operation
as this is needed to reliably test multiple header logging support in an
OS. The equivalent feature doesn't exist for correctable errors, so only
one error need be injected at a time.
Note:
- Header content needs to be manually specified in a fashion that
matches the specification for what can be in the header for each
error type.
Injection via QMP:
{ "execute": "qmp_capabilities" }
...
{ "execute": "cxl-inject-uncorrectable-errors",
"arguments": {
"path": "/machine/peripheral/cxl-pmem0",
"errors": [
{
"type": "cache-address-parity",
"header": [ 3, 4]
},
{
"type": "cache-data-parity",
"header": [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31]
},
{
"type": "internal",
"header": [ 1, 2, 4]
}
]
}}
...
{ "execute": "cxl-inject-correctable-error",
"arguments": {
"path": "/machine/peripheral/cxl-pmem0",
"type": "physical"
} }
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230302133709.30373-9-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
As these are about to be modified, fix the endian handle for
this set of registers rather than making it worse.
Note that CXL is currently only supported in QEMU on
x86 (arm64 patches out of tree) so we aren't going to yet hit
an problems with big endian. However it is good to avoid making
things worse for that support in the future.
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230302133709.30373-7-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
The cel_uuid was programatically generated previously because there was
no static initializer for network order UUIDs.
Use the new network order initializer for cel_uuid. Adjust
cxl_initialize_mailbox() because it can't fail now.
Update specification reference.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Gregory Price <gregory.price@memverge.com>
Tested-by: Gregory Price <gregory.price@memverge.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230206172816.8201-11-Jonathan.Cameron@huawei.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Remove usage of magic numbers when accessing capacity fields and replace
with CXL_CAPACITY_MULTIPLIER, matching the kernel definition.
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230206172816.8201-5-Jonathan.Cameron@huawei.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The Data Object Exchange implementation of CXL Coherent Device Attribute
Table (CDAT). This implementation is referring to "Coherent Device
Attribute Table Specification, Rev. 1.03, July. 2022" and "Compute
Express Link Specification, Rev. 3.0, July. 2022"
This patch adds core support that will be shared by both
end-points and switch port emulation.
Signed-off-by: Huai-Cheng Kuo <hchkuo@avery-design.com.tw>
Signed-off-by: Chris Browy <cbrowy@avery-design.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20221014151045.24781-4-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
A placeholder of ~0 is used to indicate variable payload size.
Whilst the checks for output payload correctly took this into
account, those for input payload did not.
This results in failure of the Set LSA command.
Fixes: 464e14ac43 ("hw/cxl/device: Implement basic mailbox (8.2.8.4)")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220817145759.32603-4-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
There is no checking on the availability of a write callback.
Hence QEMU crashes if a write does occur to one of these regions.
Discovered whilst chasing a Linux kernel bug that incorrectly
wrote into one of these regions.
Fixes: 6364adacdf ("hw/cxl/device: Implement the CAP array (8.2.8.1-2)")
Reported-by: Bobo WL <lmw.bobo@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220817145759.32603-2-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Two issues were present in this code:
1) Check on which register to look in was inverted.
2) Both branches use the _LO register.
Whilst here moved to extract32() rather than hand rolling
the field extraction as simpler and hopefully less error prone.
Fixes Coverity CID: 1488873
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220808122051.14822-3-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Use g_autofree to free the CXLFixedWindow structure if an
error occurs in configuration before we have added to
the list (via g_steal_pointer())
Fix Coverity CID: 1488872
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220808122051.14822-2-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Emulation of a simple CXL Switch downstream port.
The Device ID has been allocated for this use.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220616145126.8002-3-Jonathan.Cameron@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Without being able to write these registers, no interleaving is possible.
More refined checks of HDM register state on commit to follow.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Message-Id: <20220608130804.25795-1-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
As the CXLState will no long be accessible via MachineState
at time of PXB_CXL realization, come back later from the machine specific
code to fill in the missing memory region setup. Only at this stage
is it possible to check if cxl=on, so that check is moved to this
later point.
Note that for multiple host bridges, the allocation order of the
register spaces is changed. This will be reflected in ACPI CEDT.
Stubs are added to handle case of CONFIG_PXB=n for machines that
call these functions.
The bus walking logic is common to all machines so add a utility
function + stub to cxl-host*.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Message-Id: <20220608145440.26106-6-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Whilst here take the oportunity to shorten the function name.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Message-Id: <20220608145440.26106-4-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Paolo Bonzini requested this change to simplify the ongoing
effort to allow machine setup entirely via RPC.
Includes shortening the command line form cxl-fixed-memory-window
to cxl-fmw as the command lines are extremely long even with this
change.
The json change is needed to ensure that there is
a CXLFixedMemoryWindowOptionsList even though the actual
element in the json is never used. Similar to existing
SgxEpcProperties.
Update qemu-options.hx to reflect that this is now a -machine
parameter. The bulk of -M / -machine parameters are documented
under machine, so use that in preference to M.
Update cxl-test and bios-tables-test to reflect new parameters.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Message-Id: <20220608145440.26106-2-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Add a trivial handler for now to cover the root bridge
where we could do some error checking in future.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220429144110.25167-35-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
These memops perform interleave decoding, walking down the
CXL topology from CFMWS described host interleave
decoder via CXL host bridge HDM decoders, through the CXL
root ports and finally call CXL type 3 specific read and write
functions.
Note that, whilst functional the current implementation does
not support:
* switches
* multiple HDM decoders at a given level.
* unaligned accesses across the interleave boundaries
Signed-off-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Message-Id: <20220429144110.25167-34-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The concept of these is introduced in [1] in terms of the
description the CEDT ACPI table. The principal is more general.
Unlike once traffic hits the CXL root bridges, the host system
memory address routing is implementation defined and effectively
static once observable by standard / generic system software.
Each CXL Fixed Memory Windows (CFMW) is a region of PA space
which has fixed system dependent routing configured so that
accesses can be routed to the CXL devices below a set of target
root bridges. The accesses may be interleaved across multiple
root bridges.
For QEMU we could have fully specified these regions in terms
of a base PA + size, but as the absolute address does not matter
it is simpler to let individual platforms place the memory regions.
ExampleS:
-cxl-fixed-memory-window targets.0=cxl.0,size=128G
-cxl-fixed-memory-window targets.0=cxl.1,size=128G
-cxl-fixed-memory-window targets.0=cxl0,targets.1=cxl.1,size=256G,interleave-granularity=2k
Specifies
* 2x 128G regions not interleaved across root bridges, one for each of
the root bridges with ids cxl.0 and cxl.1
* 256G region interleaved across root bridges with ids cxl.0 and cxl.1
with a 2k interleave granularity.
When system software enumerates the devices below a given root bridge
it can then decide which CFMW to use. If non interleave is desired
(or possible) it can use the appropriate CFMW for the root bridge in
question. If there are suitable devices to interleave across the
two root bridges then it may use the 3rd CFMS.
A number of other designs were considered but the following constraints
made it hard to adapt existing QEMU approaches to this particular problem.
1) The size must be known before a specific architecture / board brings
up it's PA memory map. We need to set up an appropriate region.
2) Using links to the host bridges provides a clean command line interface
but these links cannot be established until command line devices have
been added.
Hence the two step process used here of first establishing the size,
interleave-ways and granularity + caching the ids of the host bridges
and then, once available finding the actual host bridges so they can
be used later to support interleave decoding.
[1] CXL 2.0 ECN: CEDT CFMWS & QTG DSM (computeexpresslink.org / specifications)
Signed-off-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Acked-by: Markus Armbruster <armbru@redhat.com> # QAPI Schema
Message-Id: <20220429144110.25167-28-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Both registers and the CFMWS entries in CDAT use simple encodings
for the number of interleave ways and the interleave granularity.
Introduce simple conversion functions to/from the unencoded
number / size. So far the iw decode has not been needed so is
it not implemented.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-27-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Implement get and set handlers for the Label Storage Area
used to hold data describing persistent memory configuration
so that it can be ensured it is seen in the same configuration
after reboot.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220429144110.25167-22-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This should introduce no change. Subsequent work will make use of this
new class member.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220429144110.25167-21-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
GET_FW_INFO and GET_PARTITION_INFO, for this emulation, is equivalent to
info already returned in the IDENTIFY command. To have a more robust
implementation, add those.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220429144110.25167-20-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
A CXL memory device (AKA Type 3) is a CXL component that contains some
combination of volatile and persistent memory. It also implements the
previously defined mailbox interface as well as the memory device
firmware interface.
Although the memory device is configured like a normal PCIe device, the
memory traffic is on an entirely separate bus conceptually (using the
same physical wires as PCIe, but different protocol).
Once the CXL topology is fully configure and address decoders committed,
the guest physical address for the memory device is part of a larger
window which is owned by the platform. The creation of these windows
is later in this series.
The following example will create a 256M device in a 512M window:
-object "memory-backend-file,id=cxl-mem1,share,mem-path=cxl-type3,size=512M"
-device "cxl-type3,bus=rp0,memdev=cxl-mem1,id=cxl-pmem0"
Note: Dropped PCDIMM info interfaces for now. They can be added if
appropriate at a later date.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220429144110.25167-18-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
CXL specification provides for the ability to obtain logs from the
device. Logs are either spec defined, like the "Command Effects Log"
(CEL), or vendor specific. UUIDs are defined for all log types.
The CEL is a mechanism to provide information to the host about which
commands are supported. It is useful both to determine which spec'd
optional commands are supported, as well as provide a list of vendor
specified commands that might be used. The CEL is already created as
part of mailbox initialization, but here it is now exported to hosts
that use these log commands.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-11-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Errata F4 to CXL 2.0 clarified the meaning of the timer as the
sum of the value set with the timestamp set command and the number
of nano seconds since it was last set.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-10-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Using the previously implemented stubbed helpers, it is now possible to
easily add the missing, required commands to the implementation.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-9-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Memory devices implement extra capabilities on top of CXL devices. This
adds support for that.
A large part of memory devices is the mailbox/command interface. All of
the mailbox handling is done in the mailbox-utils library. Longer term,
new CXL devices that are being emulated may want to handle commands
differently, and therefore would need a mechanism to opt in/out of the
specific generic handlers. As such, this is considered sufficient for
now, but may need more depth in the future.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-8-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This is the beginning of implementing mailbox support for CXL 2.0
devices. The implementation recognizes when the doorbell is rung,
handles the command/payload, clears the doorbell while returning error
codes and data.
Generally the mailbox mechanism is designed to permit communication
between the host OS and the firmware running on the device. For our
purposes, we emulate both the firmware, implemented primarily in
cxl-mailbox-utils.c, and the hardware.
No commands are implemented yet.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-7-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This implements all device MMIO up to the first capability. That
includes the CXL Device Capabilities Array Register, as well as all of
the CXL Device Capability Header Registers. The latter are filled in as
they are implemented in the following patches.
Endianness and alignment are managed by softmmu memory core.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-6-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
A CXL 2.0 component is any entity in the CXL topology. All components
have a analogous function in PCIe. Except for the CXL host bridge, all
have a PCIe config space that is accessible via the common PCIe
mechanisms. CXL components are enumerated via DVSEC fields in the
extended PCIe header space. CXL components will minimally implement some
subset of CXL.mem and CXL.cache registers defined in 8.2.5 of the CXL
2.0 specification. Two headers and a utility library are introduced to
support the minimum functionality needed to enumerate components.
The cxl_pci header manages bits associated with PCI, specifically the
DVSEC and related fields. The cxl_component.h variant has data
structures and APIs that are useful for drivers implementing any of the
CXL 2.0 components. The library takes care of making use of the DVSEC
bits and the CXL.[mem|cache] registers. Per spec, the registers are
little endian.
None of the mechanisms required to enumerate a CXL capable hostbridge
are introduced at this point.
Note that the CXL.mem and CXL.cache registers used are always 4B wide.
It's possible in the future that this constraint will not hold.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Adam Manzanares <a.manzanares@samsung.com>
Message-Id: <20220429144110.25167-3-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
