[0/5] Multiple fixes to XENMEM_acquire_resource

Message

Andrew Cooper July 28, 2020, 11:37 a.m. UTC

I thought this was going to be a very simple small bugfix for Michał's
Processor Trace series.  Serves me right for expecting it not to be full of
bear traps...

The sole implementation of acquire_resource never asks for size, so its little
surprise that Xen is broken for compat callers, and returns incorrect
information for regular callers.

Patches 1-2 are cleanup with no net functional change.  Patches 3-5 are fixes
to the size side of this interface, and allow userspace to obtain the actual
size of resources.

I'm still working on fixing the batch mapping support, which has further sharp
corners, especially for compat callers.

This is sufficenet of a series so far to post for comments.  A branch can be
obtained from:

  https://xenbits.xen.org/gitweb/?p=people/andrewcoop/xen.git;a=shortlog;h=refs/heads/xen-acquire-size

Andrew Cooper (5):
  xen/memory: Introduce CONFIG_ARCH_ACQUIRE_RESOURCE
  xen/gnttab: Rework resource acquisition
  xen/memory: Fix compat XENMEM_acquire_resource for size requests
  xen/memory: Fix acquire_resource size semantics
  tools/foreignmem: Support querying the size of a resource

 tools/libs/foreignmemory/Makefile                  |   2 +-
 tools/libs/foreignmemory/core.c                    |  14 +++
 .../libs/foreignmemory/include/xenforeignmemory.h  |  15 +++
 tools/libs/foreignmemory/libxenforeignmemory.map   |   4 +
 tools/libs/foreignmemory/linux.c                   |  35 +++++++
 tools/libs/foreignmemory/private.h                 |  14 +++
 xen/arch/x86/Kconfig                               |   1 +
 xen/arch/x86/mm.c                                  |  20 ++++
 xen/common/Kconfig                                 |   3 +
 xen/common/compat/memory.c                         |   2 +-
 xen/common/grant_table.c                           | 112 ++++++++++++++++-----
 xen/common/memory.c                                |  85 +++++++---------
 xen/include/asm-arm/mm.h                           |   8 --
 xen/include/asm-x86/mm.h                           |   3 +
 xen/include/public/memory.h                        |  16 ++-
 xen/include/xen/grant_table.h                      |  21 ++--
 xen/include/xen/mm.h                               |  15 +++
 17 files changed, 273 insertions(+), 97 deletions(-)