[Qemu-devel] [PATCH v3 00/40] ivshmem: Fixes, cleanups, device model split

[Markus Armbruster]

Based on Paolo's "[PULL 0/8] Memory, icount, chardev, KVM changes for
2016-03-15".

Major issues addressed by this series:

* The specification document is incomplete and vague.  Rewritten.

* When a peer goes away, and its ID gets reused for another one,
  interrupts don't work.

* When configured for interrupts, we receive shared memory from the
  server some time after realize().  This creates a (usually
  short-lived) "no shared memory, yet" state.  If the guest wins the
  race, it is exposed to this state (known issue, if you count burying
  in docs/specs/ as "known").  If migration wins the race, it fails or
  corrupts memory.

* Interrupts are unreliable in a (usually small) time window after the
  destination peer connects.  I believe fixing this will require
  changing the client/server protocol, so just document it for now.

* The device isn't capable to tell guest software whether it is
  configured for interrupts.  Fix that in a new, backwards-compatible
  revision of the guest ABI, and bump the PCI revision.  Deprecate the
  old revision.

* The device properties are a confusing mess and badly checked.
  Clean that up.

* Migration with interrupts relies on server behavior not guaranteed
  by the specification.  Tighten the specification.

Paolo, I'd like your opinion on PATCH 1 and 3.  I'm getting competent
review for my other patches elsewhere, but you're of course welcome to
review them, too.

v3:
* PATCH 01+02 picked up by Paolo, dropped from this series
* PATCH 01: Tidy up whitespace [Marc-André]
* PATCH 02: Refine help text and comments, R-by retained
* PATCH 03: Tidy up whitespace [checkpatch], refine help text and
  comments, steal an idea from Marc-André to simplify the code a bit
* PATCH 19: Drop the other redundant guard instead [Marc-André]
* PATCH 20: Fix a comment [Marc-André]
* PATCH 23+31+32: Rebase for commit 8e41fb6 "memory: Drop
  MemoryRegion.ram_addr", R-bys retained
* PATCH 26: Explain the "shmem is mapped" assertion [Marc-André]
* PATCH 31: Mention permission change and portability issues in commit
  message [Marc-André]
* PATCH 37: Minor fallout from PATCH 19, R-by retained

v2:
* PATCH 01: Rewritten [Paolo]
* PATCH 02-05: New
* PATCH 12: Typo [Eric]
* PATCH 22: Commit message improved [Paolo]
* PATCH 25: Variables renamed [Marc-André]
* PATCH 26: Reject disconnect message for own ID [Marc-André]
* PATCH 27+28: Move an assertion from PATCH 27 to PATCH 28
  [Marc-André]
* PATCH 31: Fix missing return on error [Marc-André]
* PATCH 33: Rewritten [Paolo]
* PATCH 34: Commit message improved, memory leak plugged by avoiding
  dynamic allocation [Paolo]
* PATCH 37: Botched conditionals fixed [Marc-André]
* PATCH 40: Bury dead code [Marc-André]

Markus Armbruster (40):
  target-ppc: Document TOCTTOU in hugepage support
  ivshmem-server: Fix and clean up command line help
  ivshmem-server: Don't overload POSIX shmem and file name
  qemu-doc: Fix ivshmem huge page example
  event_notifier: Make event_notifier_init_fd() #ifdef CONFIG_EVENTFD
  tests/libqos/pci-pc: Fix qpci_pc_iomap() to map BARs aligned
  ivshmem-test: Improve test case /ivshmem/single
  ivshmem-test: Clean up wait for devices to become operational
  ivshmem-test: Improve test cases /ivshmem/server-*
  ivshmem: Rewrite specification document
  ivshmem: Add missing newlines to debug printfs
  ivshmem: Compile debug prints unconditionally to prevent bit-rot
  ivshmem: Clean up after commit 9940c32
  ivshmem: Drop ivshmem_event() stub
  ivshmem: Don't destroy the chardev on version mismatch
  ivshmem: Fix harmless misuse of Error
  ivshmem: Failed realize() can leave migration blocker behind
  ivshmem: Clean up register callbacks
  ivshmem: Clean up MSI-X conditions
  ivshmem: Leave INTx alone when using MSI-X
  ivshmem: Assert interrupts are set up once
  ivshmem: Simplify rejection of invalid peer ID from server
  ivshmem: Disentangle ivshmem_read()
  ivshmem: Plug leaks on unplug, fix peer disconnect
  ivshmem: Receive shared memory synchronously in realize()
  ivshmem: Propagate errors through ivshmem_recv_setup()
  ivshmem: Rely on server sending the ID right after the version
  ivshmem: Drop the hackish test for UNIX domain chardev
  ivshmem: Simplify how we cope with short reads from server
  ivshmem: Tighten check of property "size"
  ivshmem: Implement shm=... with a memory backend
  ivshmem: Simplify memory regions for BAR 2 (shared memory)
  ivshmem: Inline check_shm_size() into its only caller
  qdev: New DEFINE_PROP_ON_OFF_AUTO
  ivshmem: Replace int role_val by OnOffAuto master
  ivshmem: Split ivshmem-plain, ivshmem-doorbell off ivshmem
  ivshmem: Clean up after the previous commit
  ivshmem: Drop ivshmem property x-memdev
  ivshmem: Require master to have ID zero
  contrib/ivshmem-server: Print "not for production" warning

 contrib/ivshmem-server/ivshmem-server.c |   56 +-
 contrib/ivshmem-server/ivshmem-server.h |    4 +-
 contrib/ivshmem-server/main.c           |   98 +--
 default-configs/pci.mak                 |    2 +-
 docs/specs/ivshmem-spec.txt             |  254 +++++++
 docs/specs/ivshmem_device_spec.txt      |  161 -----
 hw/core/qdev-properties.c               |   10 +
 hw/misc/ivshmem.c                       | 1091 +++++++++++++++++--------------
 include/hw/qdev-properties.h            |    3 +
 qemu-doc.texi                           |   47 +-
 target-ppc/kvm.c                        |    6 +
 tests/ivshmem-test.c                    |   99 +--
 tests/libqos/pci-pc.c                   |    8 +-
 util/event_notifier-posix.c             |    6 +
 14 files changed, 1017 insertions(+), 828 deletions(-)
 create mode 100644 docs/specs/ivshmem-spec.txt
 delete mode 100644 docs/specs/ivshmem_device_spec.txt

-- 
2.4.3