[v7,3/6] KVM: PPC: Book3S HV: Add support for H_RPT_INVALIDATE

H_RPT_INVALIDATE does two types of TLB invalidations:

1. Process-scoped invalidations for guests when LPCR[GTSE]=0.
   This is currently not used in KVM as GTSE is not usually
   disabled in KVM.
2. Partition-scoped invalidations that an L1 hypervisor does on
   behalf of an L2 guest. This is currently handled
   by H_TLB_INVALIDATE hcall and this new replaces the old that.

This commit enables process-scoped invalidations for L1 guests.
Support for process-scoped and partition-scoped invalidations
from/for nested guests will be added separately.

Process scoped tlbie invalidations from L1 and nested guests
need RS register for TLBIE instruction to contain both PID and
LPID.  This patch introduces primitives that execute tlbie
instruction with both PID and LPID set in prepartion for
H_RPT_INVALIDATE hcall.

A description of H_RPT_INVALIDATE follows:

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 id,        /* PID/LPID to invalidate */
      uint64 target,    /* Invalidation target */
      uint64 type,      /* Type of lookaside information */
      uint64 pg_sizes,  /* 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 caching of Process Table
			Entries if NESTED is clear */
PAT          0x0008  /* Invalidate caching of Partition Table
			Entries if NESTED is set */

A combination of the above can be specified.

Page size mask (pages)
----------------------
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.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 arch/powerpc/include/asm/mmu_context.h |  11 ++
 arch/powerpc/kvm/book3s_hv.c           |  46 ++++++++
 arch/powerpc/mm/book3s64/radix_tlb.c   | 148 +++++++++++++++++++++++++
 3 files changed, 205 insertions(+)

Excerpts from Bharata B Rao's message of May 6, 2021 1:46 am:
> H_RPT_INVALIDATE does two types of TLB invalidations:
> 
> 1. Process-scoped invalidations for guests when LPCR[GTSE]=0.
>    This is currently not used in KVM as GTSE is not usually
>    disabled in KVM.
> 2. Partition-scoped invalidations that an L1 hypervisor does on
>    behalf of an L2 guest. This is currently handled
>    by H_TLB_INVALIDATE hcall and this new replaces the old that.
> 
> This commit enables process-scoped invalidations for L1 guests.
> Support for process-scoped and partition-scoped invalidations
> from/for nested guests will be added separately.
> 
> Process scoped tlbie invalidations from L1 and nested guests
> need RS register for TLBIE instruction to contain both PID and
> LPID.  This patch introduces primitives that execute tlbie
> instruction with both PID and LPID set in prepartion for
> H_RPT_INVALIDATE hcall.
> 
> A description of H_RPT_INVALIDATE follows:
> 
> 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 id,        /* PID/LPID to invalidate */
>       uint64 target,    /* Invalidation target */
>       uint64 type,      /* Type of lookaside information */
>       uint64 pg_sizes,  /* 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 caching of Process Table
> 			Entries if NESTED is clear */
> PAT          0x0008  /* Invalidate caching of Partition Table
> 			Entries if NESTED is set */
> 
> A combination of the above can be specified.
> 
> Page size mask (pages)
> ----------------------
> 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.
> 
> Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  arch/powerpc/include/asm/mmu_context.h |  11 ++
>  arch/powerpc/kvm/book3s_hv.c           |  46 ++++++++
>  arch/powerpc/mm/book3s64/radix_tlb.c   | 148 +++++++++++++++++++++++++
>  3 files changed, 205 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
> index 4bc45d3ed8b0..128760eb598e 100644
> --- a/arch/powerpc/include/asm/mmu_context.h
> +++ b/arch/powerpc/include/asm/mmu_context.h
> @@ -124,8 +124,19 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
>  
>  #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
>  extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
> +void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
> +			     unsigned long type, unsigned long page_size,
> +			     unsigned long psize, unsigned long start,
> +			     unsigned long end);
>  #else
>  static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
> +static inline void do_h_rpt_invalidate_prt(unsigned long pid,
> +					   unsigned long lpid,
> +					   unsigned long type,
> +					   unsigned long page_size,
> +					   unsigned long psize,
> +					   unsigned long start,
> +					   unsigned long end) { }
>  #endif
>  
>  extern void switch_cop(struct mm_struct *next);
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 28a80d240b76..bcf34246bbe9 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -76,6 +76,7 @@
>  #include <asm/kvm_book3s_uvmem.h>
>  #include <asm/ultravisor.h>
>  #include <asm/dtl.h>
> +#include <asm/plpar_wrappers.h>
>  
>  #include "book3s.h"
>  
> @@ -924,6 +925,42 @@ static int kvmppc_get_yield_count(struct kvm_vcpu *vcpu)
>  	return yield_count;
>  }
>  
> +static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu,
> +				    unsigned long id, unsigned long target,
> +				    unsigned long type, unsigned long pg_sizes,
> +				    unsigned long start, unsigned long end)
> +{
> +	unsigned long psize;
> +	struct mmu_psize_def *def;
> +
> +	if (!kvm_is_radix(vcpu->kvm))
> +		return H_UNSUPPORTED;
> +
> +	if (end < start)
> +		return H_P5;
> +
> +	/*
> +	 * Partition-scoped invalidation for nested guests.
> +	 * Not yet supported
> +	 */
> +	if (type & H_RPTI_TYPE_NESTED)
> +		return H_P3;
> +
> +	/*
> +	 * Process-scoped invalidation for L1 guests.
> +	 */
> +	for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
> +		def = &mmu_psize_defs[psize];
> +		if (!(pg_sizes & def->h_rpt_pgsize))
> +			continue;

Not that it really matters but why did you go this approach rather than
use a bitmask iteration over h_rpt_pgsize?

I would actually prefer to put this loop into the TLB invalidation code
itself.

The reason is that not all flush types are based on page size. You only
need to do IS=1/2/3 flushes once and it takes out all page sizes.

You don't need to do all these optimisations right now, but it would
be good to make them possible to implement.

> +
> +		do_h_rpt_invalidate_prt(id, vcpu->kvm->arch.lpid,
> +					type, (1UL << def->shift),
> +					psize, start, end);
> +	}
> +	return H_SUCCESS;
> +}
> +
>  int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>  {
>  	unsigned long req = kvmppc_get_gpr(vcpu, 3);
> @@ -1132,6 +1169,14 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>  		 */
>  		ret = kvmppc_h_svm_init_abort(vcpu->kvm);
>  		break;
> +	case H_RPT_INVALIDATE:
> +		ret = kvmppc_h_rpt_invalidate(vcpu, kvmppc_get_gpr(vcpu, 4),
> +					      kvmppc_get_gpr(vcpu, 5),
> +					      kvmppc_get_gpr(vcpu, 6),
> +					      kvmppc_get_gpr(vcpu, 7),
> +					      kvmppc_get_gpr(vcpu, 8),
> +					      kvmppc_get_gpr(vcpu, 9));
> +		break;
>  
>  	default:
>  		return RESUME_HOST;
> @@ -1178,6 +1223,7 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd)
>  	case H_XIRR_X:
>  #endif
>  	case H_PAGE_INIT:
> +	case H_RPT_INVALIDATE:
>  		return 1;
>  	}
>  
> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
> index 409e61210789..65aad9ce3557 100644
> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
> @@ -130,6 +130,21 @@ static __always_inline void __tlbie_pid(unsigned long pid, unsigned long ric)
>  	trace_tlbie(0, 0, rb, rs, ric, prs, r);
>  }
>  
> +static __always_inline void __tlbie_pid_lpid(unsigned long pid,
> +					     unsigned long lpid,
> +					     unsigned long ric)
> +{
> +	unsigned long rb, rs, prs, r;
> +
> +	rb = PPC_BIT(53); /* IS = 1 */
> +	rs = (pid << PPC_BITLSHIFT(31)) | (lpid & ~(PPC_BITMASK(0, 31)));
> +	prs = 1; /* process scoped */
> +	r = 1;   /* radix format */
> +
> +	asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
> +		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
> +	trace_tlbie(0, 0, rb, rs, ric, prs, r);
> +}
>  static __always_inline void __tlbie_lpid(unsigned long lpid, unsigned long ric)
>  {
>  	unsigned long rb,rs,prs,r;
> @@ -190,6 +205,23 @@ static __always_inline void __tlbie_va(unsigned long va, unsigned long pid,
>  	trace_tlbie(0, 0, rb, rs, ric, prs, r);
>  }
>  
> +static __always_inline void __tlbie_va_lpid(unsigned long va, unsigned long pid,
> +					    unsigned long lpid,
> +					    unsigned long ap, unsigned long ric)
> +{
> +	unsigned long rb, rs, prs, r;
> +
> +	rb = va & ~(PPC_BITMASK(52, 63));
> +	rb |= ap << PPC_BITLSHIFT(58);
> +	rs = (pid << PPC_BITLSHIFT(31)) | (lpid & ~(PPC_BITMASK(0, 31)));
> +	prs = 1; /* process scoped */
> +	r = 1;   /* radix format */
> +
> +	asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
> +		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
> +	trace_tlbie(0, 0, rb, rs, ric, prs, r);
> +}
> +
>  static __always_inline void __tlbie_lpid_va(unsigned long va, unsigned long lpid,
>  					    unsigned long ap, unsigned long ric)
>  {
> @@ -235,6 +267,22 @@ static inline void fixup_tlbie_va_range(unsigned long va, unsigned long pid,
>  	}
>  }
>  
> +static inline void fixup_tlbie_va_range_lpid(unsigned long va,
> +					     unsigned long pid,
> +					     unsigned long lpid,
> +					     unsigned long ap)
> +{
> +	if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
> +		asm volatile("ptesync" : : : "memory");
> +		__tlbie_pid_lpid(0, lpid, RIC_FLUSH_TLB);
> +	}
> +
> +	if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
> +		asm volatile("ptesync" : : : "memory");
> +		__tlbie_va_lpid(va, pid, lpid, ap, RIC_FLUSH_TLB);
> +	}
> +}
> +
>  static inline void fixup_tlbie_pid(unsigned long pid)
>  {
>  	/*
> @@ -254,6 +302,25 @@ static inline void fixup_tlbie_pid(unsigned long pid)
>  	}
>  }
>  
> +static inline void fixup_tlbie_pid_lpid(unsigned long pid, unsigned long lpid)
> +{
> +	/*
> +	 * We can use any address for the invalidation, pick one which is
> +	 * probably unused as an optimisation.
> +	 */
> +	unsigned long va = ((1UL << 52) - 1);
> +
> +	if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
> +		asm volatile("ptesync" : : : "memory");
> +		__tlbie_pid_lpid(0, lpid, RIC_FLUSH_TLB);
> +	}
> +
> +	if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
> +		asm volatile("ptesync" : : : "memory");
> +		__tlbie_va_lpid(va, pid, lpid, mmu_get_ap(MMU_PAGE_64K),
> +				RIC_FLUSH_TLB);
> +	}
> +}
>  
>  static inline void fixup_tlbie_lpid_va(unsigned long va, unsigned long lpid,
>  				       unsigned long ap)
> @@ -344,6 +411,31 @@ static inline void _tlbie_pid(unsigned long pid, unsigned long ric)
>  	asm volatile("eieio; tlbsync; ptesync": : :"memory");
>  }
>  
> +static inline void _tlbie_pid_lpid(unsigned long pid, unsigned long lpid,
> +				   unsigned long ric)
> +{
> +	asm volatile("ptesync" : : : "memory");
> +
> +	/*
> +	 * Workaround the fact that the "ric" argument to __tlbie_pid
> +	 * must be a compile-time contraint to match the "i" constraint
> +	 * in the asm statement.
> +	 */
> +	switch (ric) {
> +	case RIC_FLUSH_TLB:
> +		__tlbie_pid_lpid(pid, lpid, RIC_FLUSH_TLB);
> +		fixup_tlbie_pid_lpid(pid, lpid);
> +		break;
> +	case RIC_FLUSH_PWC:
> +		__tlbie_pid_lpid(pid, lpid, RIC_FLUSH_PWC);
> +		break;
> +	case RIC_FLUSH_ALL:
> +	default:
> +		__tlbie_pid_lpid(pid, lpid, RIC_FLUSH_ALL);
> +		fixup_tlbie_pid_lpid(pid, lpid);
> +	}
> +	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
> +}
>  struct tlbiel_pid {
>  	unsigned long pid;
>  	unsigned long ric;
> @@ -469,6 +561,20 @@ static inline void __tlbie_va_range(unsigned long start, unsigned long end,
>  	fixup_tlbie_va_range(addr - page_size, pid, ap);
>  }
>  
> +static inline void __tlbie_va_range_lpid(unsigned long start, unsigned long end,
> +					 unsigned long pid, unsigned long lpid,
> +					 unsigned long page_size,
> +					 unsigned long psize)
> +{
> +	unsigned long addr;
> +	unsigned long ap = mmu_get_ap(psize);
> +
> +	for (addr = start; addr < end; addr += page_size)
> +		__tlbie_va_lpid(addr, pid, lpid, ap, RIC_FLUSH_TLB);
> +
> +	fixup_tlbie_va_range_lpid(addr - page_size, pid, lpid, ap);
> +}
> +
>  static __always_inline void _tlbie_va(unsigned long va, unsigned long pid,
>  				      unsigned long psize, unsigned long ric)
>  {
> @@ -549,6 +655,18 @@ static inline void _tlbie_va_range(unsigned long start, unsigned long end,
>  	asm volatile("eieio; tlbsync; ptesync": : :"memory");
>  }
>  
> +static inline void _tlbie_va_range_lpid(unsigned long start, unsigned long end,
> +					unsigned long pid, unsigned long lpid,
> +					unsigned long page_size,
> +					unsigned long psize, bool also_pwc)
> +{
> +	asm volatile("ptesync" : : : "memory");
> +	if (also_pwc)
> +		__tlbie_pid_lpid(pid, lpid, RIC_FLUSH_PWC);
> +	__tlbie_va_range_lpid(start, end, pid, lpid, page_size, psize);
> +	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
> +}
> +
>  static inline void _tlbiel_va_range_multicast(struct mm_struct *mm,
>  				unsigned long start, unsigned long end,
>  				unsigned long pid, unsigned long page_size,
> @@ -1381,4 +1499,34 @@ extern void radix_kvm_prefetch_workaround(struct mm_struct *mm)
>  	}
>  }
>  EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround);
> +
> +/*
> + * Performs process-scoped invalidations for a given LPID
> + * as part of H_RPT_INVALIDATE hcall.
> + */
> +void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
> +			     unsigned long type, unsigned long page_size,
> +			     unsigned long psize, unsigned long start,
> +			     unsigned long end)
> +{
> +	/*
> +	 * A H_RPTI_TYPE_ALL request implies RIC=3, hence
> +	 * do a single IS=1 based flush.
> +	 */
> +	if ((type & H_RPTI_TYPE_ALL) == H_RPTI_TYPE_ALL) {
> +		_tlbie_pid_lpid(pid, lpid, RIC_FLUSH_ALL);
> +		return;
> +	}
> +
> +	if (type & H_RPTI_TYPE_PWC)
> +		_tlbie_pid_lpid(pid, lpid, RIC_FLUSH_PWC);
> +
> +	if (start == 0 && end == -1) /* PID */
> +		_tlbie_pid_lpid(pid, lpid, RIC_FLUSH_TLB);
> +	else /* EA */
> +		_tlbie_va_range_lpid(start, end, pid, lpid, page_size,
> +				     psize, false);

At least one thing that is probably needed is to use the 
single_page_flush_ceiling to flip the va range flush over to a pid 
flush, so the guest can't cause problems in the hypervisor with an 
enormous range.

Thanks,
Nick

> +}
> +EXPORT_SYMBOL_GPL(do_h_rpt_invalidate_prt);
> +
>  #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
> -- 
> 2.26.2
> 
>

On Thu, May 06, 2021 at 03:45:21PM +1000, Nicholas Piggin wrote:
> Excerpts from Bharata B Rao's message of May 6, 2021 1:46 am:
> >  
> > +static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu,
> > +				    unsigned long id, unsigned long target,
> > +				    unsigned long type, unsigned long pg_sizes,
> > +				    unsigned long start, unsigned long end)
> > +{
> > +	unsigned long psize;
> > +	struct mmu_psize_def *def;
> > +
> > +	if (!kvm_is_radix(vcpu->kvm))
> > +		return H_UNSUPPORTED;
> > +
> > +	if (end < start)
> > +		return H_P5;
> > +
> > +	/*
> > +	 * Partition-scoped invalidation for nested guests.
> > +	 * Not yet supported
> > +	 */
> > +	if (type & H_RPTI_TYPE_NESTED)
> > +		return H_P3;
> > +
> > +	/*
> > +	 * Process-scoped invalidation for L1 guests.
> > +	 */
> > +	for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
> > +		def = &mmu_psize_defs[psize];
> > +		if (!(pg_sizes & def->h_rpt_pgsize))
> > +			continue;
> 
> Not that it really matters but why did you go this approach rather than
> use a bitmask iteration over h_rpt_pgsize?

If you are asking why I am not just looping over the hcall argument
@pg_sizes bitmask then, I was doing that in my earlier version. But
David suggested that it would be good to have page size encodings
of H_RPT_INVALIDATE within mmu_pgsize_defs[]. Based on this, I am
populating mmu_pgsize_defs[] during radix page size initialization
and using that here to check for those page sizes that have been set
in @pg_sizes.

> 
> I would actually prefer to put this loop into the TLB invalidation code
> itself.

Yes, I could easily move it there.

> 
> The reason is that not all flush types are based on page size. You only
> need to do IS=1/2/3 flushes once and it takes out all page sizes.

I see. So we have to do explicit flushing for different page sizes
only if we are doing range based invalidation (IS=0). For rest of
the cases (IS=1/2/3), that's not necessary.

> 
> You don't need to do all these optimisations right now, but it would
> be good to make them possible to implement.

Sure.

> > +void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
> > +			     unsigned long type, unsigned long page_size,
> > +			     unsigned long psize, unsigned long start,
> > +			     unsigned long end)
> > +{
> > +	/*
> > +	 * A H_RPTI_TYPE_ALL request implies RIC=3, hence
> > +	 * do a single IS=1 based flush.
> > +	 */
> > +	if ((type & H_RPTI_TYPE_ALL) == H_RPTI_TYPE_ALL) {
> > +		_tlbie_pid_lpid(pid, lpid, RIC_FLUSH_ALL);
> > +		return;
> > +	}
> > +
> > +	if (type & H_RPTI_TYPE_PWC)
> > +		_tlbie_pid_lpid(pid, lpid, RIC_FLUSH_PWC);
> > +
> > +	if (start == 0 && end == -1) /* PID */
> > +		_tlbie_pid_lpid(pid, lpid, RIC_FLUSH_TLB);
> > +	else /* EA */
> > +		_tlbie_va_range_lpid(start, end, pid, lpid, page_size,
> > +				     psize, false);
> 
> At least one thing that is probably needed is to use the 
> single_page_flush_ceiling to flip the va range flush over to a pid 
> flush, so the guest can't cause problems in the hypervisor with an 
> enormous range.

Yes, makes sense. I shall do this and the above as later optimizations.

Regards,
Bharata.