Subject: Re: [PATCH v1 0/2] Use H_RPT_INVALIDATE for nested guest

From: Bharata B Rao <[email-masked]>
Date: Tue, 24 Nov 2020 15:14:11 +0530

Hi,

Any comments on this patchset? Anything specific to be addressed
before it could be considered for inclusion?

Regards,
Bharata.

On Mon, Oct 19, 2020 at 04:56:40PM +0530, Bharata B Rao wrote:
> 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.
> 
> Changes in v1:
> -------------
> - Removed the bits that added the FW_FEATURE_RPT_INVALIDATE feature
>   as they are already upstream.
> 
> v0: https://lore.kernel.org/linuxppc-dev/[email-masked]/T/#m1800c5f5b3d4f6a154ae58fc1c617c06f286358f
> 
> 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/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 -
>  include/uapi/linux/kvm.h                      |   1 +
>  9 files changed, 200 insertions(+), 11 deletions(-)
> 
> -- 
> 2.26.2