[0/2] hw/mem: CXL Type-3 Volatile Memory Support

Message

Jonathan Cameron Jan. 31, 2023, 4:38 p.m. UTC

Now we have some kernel code to test this against (and it looks good)
I'd like to propose this series for upstream following 3 other series
already proposed for inclusion:

a) https://lore.kernel.org/linux-cxl/[e-mail]/
   [PATCH v3 00/10] hw/cxl: CXL emulation cleanups and minor fixes for upstream
b) https://lore.kernel.org/linux-cxl/[e-mail]/
   [PATCH v3 0/8] hw/cxl: RAS error emulation and injection
c) https://lore.kernel.org/linux-cxl/[e-mail]/
   [PATCH 0/2] hw/cxl: Passthrough HDM decoder emulation

Changes since RFC V4 called out in individual patches.
 - Some minor fixes.
 - Refactors to simplify patch / resulting code as relevant.
 - Update the bios-tables-test for CXL to use non deprecated interfaces.

Whilst the more significant changes have been discussed on list
Gregory, please take a look at these and check your are happy with
my tweaks.

Kernel support used to test this:
https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git/log/?h=for-6.3/cxl-ram-region

Previous cover letter updated to reflect pulling one patch out
as a precursor cleanup in set (a) above.

This patches provides 2 features to the CXL Type-3 Device:
    1) Volatile Memory Region Support
    2) Multi-Region support (1 Volatile, 1 Persistent)

Summary of Changes per-commit:
1) Whitespace updates to docs and tests
2) Refactor CDAT DSMAS Initialization for multi-region initialization
   Multi-Region and Volatile Memory support for CXL Type-3 Devices
   Test and Documentation updates

The final patch in this series makes 6 major changes to the type-3
device in order to implement multi-region and volatile region support
    1) The HostMemoryBackend [hostmem] has been replaced by two
       [hostvmem] and [hostpmem] to store volatile and persistent memory
       respectively
    2) The single AddressSpace has been replaced by two AddressSpaces
       [hostvmem_as] and [hostpmem_as] to map respective memdevs.
    3) Each memory region size and total region are stored separately
    4) The CDAT and DVSEC memory map entries have been updated:
       a) if vmem is present, vmem is mapped at DPA(0)
       b) if pmem is present
          i)  and vmem is present, pmem is mapped at DPA(vmem->size)
          ii) else, pmem is mapped at DPA(0)
       c) partitioning of pmem is not supported in this patch set but
          has been discussed and this design should suffice.
    5) Read/Write functions have been updated to access AddressSpaces
       according to the mapping described in #4.  Access to the
       persistent address space is calculated by (dpa-vmem_len)
    6) cxl-mailbox has been updated to report the respective size of
       volatile and persistent memory regions

Gregory Price (2):
  tests/qtest/cxl-test: whitespace, line ending cleanup
  hw/cxl: Multi-Region CXL Type-3 Devices (Volatile and Persistent)

 docs/system/devices/cxl.rst    |  49 ++++--
 hw/cxl/cxl-mailbox-utils.c     |  26 +--
 hw/mem/cxl_type3.c             | 300 +++++++++++++++++++++++++--------
 include/hw/cxl/cxl_device.h    |  11 +-
 tests/qtest/bios-tables-test.c |   8 +-
 tests/qtest/cxl-test.c         | 146 +++++++++++-----
 6 files changed, 398 insertions(+), 142 deletions(-)