Once a read or write reaches a CXL type 3 device, the HDM decoders
on the device are used to establish the Device Physical Address
which should be accessed. These functions peform the required maths
and then use a device specific address space to access the
hostmem->mr to fullfil the actual operation. Note that failed writes
are silent, but failed reads return poison. Note this is based
loosely on:
https://lore.kernel.org/qemu-devel/20200817161853.593247-6-f4bug@amsat.org/
[RFC PATCH 0/9] hw/misc: Add support for interleaved memory accesses
Only lightly tested so far. More complex test cases yet to be written.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20220429144110.25167-33-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>
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>
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>
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 device is a type of CXL component. Conceptually, a CXL device
would be a leaf node in a CXL topology. From an emulation perspective,
CXL devices are the most complex and so the actual implementation is
reserved for discrete commits.
This new device type is specifically catered towards the eventual
implementation of a Type3 CXL.mem device, 8.2.8.5 in the CXL 2.0
specification.
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: <20220429144110.25167-5-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Jonathan Cameron
Ben Widawsky