[Xen-devel] [RFC PATCH 00/84] Remove direct map from Xen

[<hongyax@xxxxxxxxxx>]

From: Hongyan Xia <hongyax@xxxxxxxxxx>

Previously, Wei Liu has created the patch series to switch to
alloc/map/unmap/free APIs for Xen page tables so that Xen page tables
are mapped with map_domain_page(). This is the first step towards
removing the direct map. I implemented patches on top of Wei's to remove
the direct map completely.

In addition to Wei's, my patches:
- (Wei) implement a proper PMAP infrastructure for bootstrapping
- remove direct map code in map_domain_page() and use mapcache, use PMAP
 when mapcache not ready
- map/unmap xenheap allocations to the direct map region so that va<->pa
 macros still work
- install dummy mappings (no permissions, INVALID_MFN) instead of actual
 1:1 mappings during boot, so the direct map no longer exists
- fix many places where code incorrectly assumes a direct map

I have moderately tested the patches. I am able to boot into dom0,
create/destroy PV/HVM guests and run XTF tests. Personally, I find it
difficult to discover all places where it incorrectly assumes a direct
map, so reviews and further testing are more than welcome.

Hongyan Xia (24):
  x86/mm: fix leaks in map_xen_pagetable.
  x86/pmap: break the loop in pmap APIs.
  x86/domain_page: use PMAP when d/vcache is not ready.
  x86/domain_page: mapcache is no longer tied to pv.
  mapcache: initialise the mapcache even for the idle domain.
  x86: fix some wrong assumptions on direct map. Increase PMAP slots to
    8.
  x86/domain_page: remove direct map code and initialise idle mapcache.
  page_alloc: actually do the mapping and unmapping on xenheap.
  page_alloc: comments on (un)mapping pages in xenheap allocations.
  x86/smpboot: use xenheap pages for rpts in smpboot.
  x86/setup: start tearing down the direct map.
  acpi: don't assume an always-mapped direct map in acpi allocations.
  x86/mm: Move vmap_to_mfn() to mm.c and rename to virt_to_mfn_walk().
  x86/pv: refactor how building dom0 in PV handles domheap mappings.
  x86/mm: handle PSE early termination cases in virt_to_mfn_walk().
  x86/setup: also clear the permission bits in the dummy 1:1 mapping.
  x86: properly (un)map pages in restore_all_guests.
  Revert "x86/smpboot: use xenheap pages for rpts in smpboot."
  Don't assume bootmem_region_list is mapped. Also fix a double unmap
    bug.
  x86/setup: Install dummy 1:1 mappings for all mem passed to
    allocators.
  x86/mm: optimise and properly unmap pages in virt_to_mfn_walk().
  x86: deduplicate code a bit and fix an unmapping bug.
  x86/pmap: rewrite logic for locking.
  x86/pv: fix a couple of direct map assumptions in dom0 building.

Wei Liu (60):
  x86/mm: defer clearing page in virt_to_xen_lXe
  x86: move some xen mm function declarations
  x86: introduce a new set of APIs to manage Xen page tables
  x86/mm: introduce l{1,2}t local variables to map_pages_to_xen
  x86/mm: introduce l{1,2}t local variables to modify_xen_mappings
  x86/mm: map_pages_to_xen should have one exit path
  x86/mm: add an end_of_loop label in map_pages_to_xen
  x86/mm: make sure there is one exit path for modify_xen_mappings
  x86/mm: add an end_of_loop label in modify_xen_mappings
  x86/mm: change pl2e to l2t in virt_to_xen_l2e
  x86/mm: change pl1e to l1t in virt_to_xen_l1e
  x86/mm: change pl3e to l3t in virt_to_xen_l3e
  x86/mm: rewrite virt_to_xen_l3e
  x86/mm: rewrite xen_to_virt_l2e
  x86/mm: rewrite virt_to_xen_l1e
  x86/mm: switch to new APIs in map_pages_to_xen
  xxx fixup: avoid shadowing mfn
  x86/mm: drop lXe_to_lYe invocations in map_pages_to_xen
  x86/mm: switch to new APIs in modify_xen_mappings
  x86/mm: drop lXe_to_lYe invocations from modify_xen_mappings
  x86/mm: switch to new APIs in arch_init_memory
  x86_64/mm: introduce pl2e in paging_init
  x86_64/mm: switch to new APIs in paging_init
  x86_64/mm: drop l4e_to_l3e invocation from paging_init
  x86_64/mm.c: remove code that serves no purpose in setup_m2p_table
  x86_64/mm: introduce pl2e in setup_m2p_table
  x86_64/mm: switch to new APIs in setup_m2p_table
  x86_64/mm: drop lXe_to_lYe invocations from setup_m2p_table
  efi: use new page table APIs in copy_mapping
  efi: avoid using global variable in copy_mapping
  efi: use new page table APIs in efi_init_memory
  efi: add emacs block to boot.c
  efi: switch EFI L4 table to use new APIs
  x86/smpboot: add emacs block
  x86/smpboot: clone_mapping should have one exit path
  x86/smpboot: switch pl3e to use new APIs in clone_mapping
  x86/smpboot: switch pl2e to use new APIs in clone_mapping
  x86/smpboot: switch pl1e to use new APIs in clone_mapping
  x86/smpboot: drop lXe_to_lYe invocations from cleanup_cpu_root_pgt
  x86: switch root_pgt to mfn_t and use new APIs
  x86/shim: map and unmap page tables in replace_va_mapping
  x86_64/mm: map and unmap page tables in m2p_mapped
  x86_64/mm: map and unmap page tables in share_hotadd_m2p_table
  x86_64/mm: map and unmap page tables in destroy_compat_m2p_mapping
  x86_64/mm: map and unmap page tables in destroy_m2p_mapping
  x86_64/mm: map and unmap page tables in setup_compat_m2p_table
  x86_64/mm: map and unmap page tables in cleanup_frame_table
  x86_64/mm: map and unmap page tables in subarch_init_memory
  x86_64/mm: map and unmap page tables in subarch_memory_op
  x86/smpboot: remove lXe_to_lYe in cleanup_cpu_root_pgt
  x86/pv: properly map and unmap page tables in mark_pv_pt_pages_rdonly
  x86/pv: properly map and unmap page table in dom0_construct_pv
  x86: remove lXe_to_lYe in __start_xen
  x86/mm: drop old page table APIs
  x86: switch to use domheap page for page tables
  x86/mm: drop _new suffix for page table APIs
  x86: add Persistent Map (PMAP) infrastructure
  x86: lift domain mapcache to arch_domain
  x86: lift vcpu mapcache to arch_vcpu
  x86/pv: domheap pages should be mapped while relocating initrd

 xen/arch/x86/Makefile           |   1 +
 xen/arch/x86/domain.c           |  19 +-
 xen/arch/x86/domain_page.c      |  71 ++---
 xen/arch/x86/efi/runtime.h      |  12 +-
 xen/arch/x86/mm.c               | 549 ++++++++++++++++++++++++--------
 xen/arch/x86/pmap.c             | 121 +++++++
 xen/arch/x86/pv/dom0_build.c    | 107 +++++--
 xen/arch/x86/pv/domain.c        |   2 +-
 xen/arch/x86/pv/shim.c          |  20 +-
 xen/arch/x86/setup.c            |  28 +-
 xen/arch/x86/smpboot.c          | 171 +++++++---
 xen/arch/x86/x86_64/entry.S     |  32 +-
 xen/arch/x86/x86_64/mm.c        | 268 +++++++++++-----
 xen/common/efi/boot.c           |  84 +++--
 xen/common/efi/efi.h            |   3 +-
 xen/common/efi/runtime.c        |   8 +-
 xen/common/page_alloc.c         |  37 ++-
 xen/common/schedule.c           |   1 +
 xen/common/vmap.c               |   2 +-
 xen/drivers/acpi/osl.c          |  41 ++-
 xen/include/asm-arm/mm.h        |   2 -
 xen/include/asm-x86/domain.h    |  12 +-
 xen/include/asm-x86/fixmap.h    |   3 +
 xen/include/asm-x86/mm.h        |  20 ++
 xen/include/asm-x86/page.h      |  12 -
 xen/include/asm-x86/pmap.h      |  10 +
 xen/include/asm-x86/processor.h |   2 -
 27 files changed, 1211 insertions(+), 427 deletions(-)
 create mode 100644 xen/arch/x86/pmap.c
 create mode 100644 xen/include/asm-x86/pmap.h

-- 
2.17.1


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