[PATCH v3 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix

[Lucas Amaral <lucaaamaral@gmail.com>]

Fix a bug in the MAP_FIXED blob mapping path (introduced by 4eb0aace)
where non-host-page-aligned offsets cause mmap(MAP_FIXED) to fail with
EINVAL.  This affects any host where the page size exceeds the guest's
(ARM64 with 16KB/64KB pages, macOS ARM64).

This series introduces:

1. MAP_FIXED alignment validation in virtio-gpu: check that both
   offset and blob size are aligned to the host page size before
   calling virgl_renderer_resource_map_fixed().  When not aligned,
   fall through to the subregion method (which works at any
   alignment).

2. A map granule abstraction (hvf_set/get_map_granule) replacing
   hardcoded qemu_real_host_page_size() calls in HVF memory mapping.
   Non-aligned regions return early instead of proceeding with
   add=false (which attempted an unnecessary unmap).
   An 'ipa-granule' property (auto, 4k, 16k) on the HVF accelerator
   object allows opt-in configuration:

     -accel hvf,ipa-granule=4k

   The property follows the kvm_arch_accel_class_init() pattern:
   ARM registers the property in hvf_arch_accel_class_init(), x86
   provides an empty stub.

3. macOS 26 IPA granule support via hv_vm_config_set_ipa_granule(),
   reading the ipa-granule property to select HV_IPA_GRANULE_4KB or
   HV_IPA_GRANULE_16KB.  Falls back with a warning on macOS < 26.

Dependencies: none.

Changes v2 → v3:
  - Rebased on current master
  - Add MAP_FIXED alignment validation (new patch 1)
  - Move #ifdef __aarch64__ property code into hvf_arch_accel_class_init
    following kvm_arch_accel_class_init() pattern (x86 empty stub)
  - Use MAC_OS_VERSION_26_0 named constant
  - Remove Venus blob mapping warning

Changes v1 → v2 (Mohamed Mosaad review):
  - Replace hardcoded 4KB with configurable ipa-granule property
    (auto, 4k, 16k) on the HVF accelerator object.
  - 'auto' defaults to host page size; explicit values opt in.
  - Add fallback warning when macOS < 26 can't honor the request.
  - Add Venus blob mapping safety warning.
  - Use KiB constants instead of magic numbers.

Lucas Amaral (3):
  virtio-gpu: validate host page alignment for MAP_FIXED blobs
  accel/hvf: introduce map granule abstraction and IPA property
  target/arm/hvf: configure IPA granule on macOS 26

 accel/hvf/hvf-all.c           | 30 +++++++++++++--
 hw/display/virtio-gpu-virgl.c | 45 +++++++++++++---------
 include/system/hvf.h          | 15 ++++++++
 include/system/hvf_int.h      |  2 +
 target/arm/hvf/hvf.c          | 72 +++++++++++++++++++++++++++++++++++
 target/i386/hvf/hvf.c         |  4 ++
 6 files changed, 147 insertions(+), 21 deletions(-)

--
2.52.0