[RFC PATCH v0 0/2] Use H_RPT_INVALIDATE for nested guest

[Bharata B Rao]

This patchset adds support for the new hcall H_RPT_INVALIDATE
(currently handles nested case only) and replaces the nested tlb flush
calls with this new hcall if the support for the same exists.

This applies on top of "[PATCH v3 0/3] Off-load TLB invalidations to host
for !GTSE" patchset that was posted at:

https://lore.kernel.org/linuxppc-dev/20200703053608.12884-1-bharata@linux.ibm.com/T/#t

H_RPT_INVALIDATE
================
Syntax:
int64   /* H_Success: Return code on successful completion */
        /* H_Busy - repeat the call with the same */
        /* H_Parameter, H_P2, H_P3, H_P4, H_P5 : Invalid parameters */
        hcall(const uint64 H_RPT_INVALIDATE, /* Invalidate RPT translation lookaside information */
              uint64 pid,       /* PID/LPID to invalidate */
              uint64 target,    /* Invalidation target */
              uint64 type,      /* Type of lookaside information */
              uint64 pageSizes,     /* Page sizes */
              uint64 start,     /* Start of Effective Address (EA) range (inclusive) */
              uint64 end)       /* End of EA range (exclusive) */

Invalidation targets (target)
-----------------------------
Core MMU        0x01 /* All virtual processors in the partition */
Core local MMU  0x02 /* Current virtual processor */
Nest MMU        0x04 /* All nest/accelerator agents in use by the partition */

A combination of the above can be specified, except core and core local.

Type of translation to invalidate (type)
---------------------------------------
NESTED       0x0001  /* Invalidate nested guest partition-scope */
TLB          0x0002  /* Invalidate TLB */
PWC          0x0004  /* Invalidate Page Walk Cache */
PRT          0x0008  /* Invalidate Process Table Entries if NESTED is clear */
PAT          0x0008  /* Invalidate Partition Table Entries if NESTED is set */

A combination of the above can be specified.

Page size mask (pageSizes)
--------------------------
4K              0x01
64K             0x02
2M              0x04
1G              0x08
All sizes       (-1UL)

A combination of the above can be specified.
All page sizes can be selected with -1.

Semantics: Invalidate radix tree lookaside information
           matching the parameters given.
* Return H_P2, H_P3 or H_P4 if target, type, or pageSizes parameters are
  different from the defined values.
* Return H_PARAMETER if NESTED is set and pid is not a valid nested
  LPID allocated to this partition
* Return H_P5 if (start, end) doesn't form a valid range. Start and end
  should be a valid Quadrant address and  end > start.
* Return H_NotSupported if the partition is not in running in radix
  translation mode.
* May invalidate more translation information than requested.
* If start = 0 and end = -1, set the range to cover all valid addresses.
  Else start and end should be aligned to 4kB (lower 11 bits clear).
* If NESTED is clear, then invalidate process scoped lookaside information.
  Else pid specifies a nested LPID, and the invalidation is performed
  on nested guest partition table and nested guest partition scope real
  addresses.
* If pid = 0 and NESTED is clear, then valid addresses are quadrant 3 and
  quadrant 0 spaces, Else valid addresses are quadrant 0.
* Pages which are fully covered by the range are to be invalidated.
  Those which are partially covered are considered outside invalidation
  range, which allows a caller to optimally invalidate ranges that may
  contain mixed page sizes.
* Return H_SUCCESS on success.

Bharata B Rao (2):
  KVM: PPC: Book3S HV: Add support for H_RPT_INVALIDATE (nested case
    only)
  KVM: PPC: Book3S HV: Use H_RPT_INVALIDATE in nested KVM

 Documentation/virt/kvm/api.rst                |  17 +++
 .../include/asm/book3s/64/tlbflush-radix.h    |  18 +++
 arch/powerpc/include/asm/firmware.h           |   4 +-
 arch/powerpc/include/asm/kvm_book3s.h         |   3 +
 arch/powerpc/kvm/book3s_64_mmu_radix.c        |  26 ++++-
 arch/powerpc/kvm/book3s_hv.c                  |  32 ++++++
 arch/powerpc/kvm/book3s_hv_nested.c           | 107 +++++++++++++++++-
 arch/powerpc/kvm/powerpc.c                    |   3 +
 arch/powerpc/mm/book3s64/radix_tlb.c          |   4 -
 arch/powerpc/platforms/pseries/firmware.c     |   1 +
 include/uapi/linux/kvm.h                      |   1 +
 11 files changed, 204 insertions(+), 12 deletions(-)

-- 
2.21.3