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[PATCH 00/16] target/arm: sve load/store improvements

From: Richard Henderson
Subject: [PATCH 00/16] target/arm: sve load/store improvements
Date: Tue, 10 Mar 2020 23:44:04 -0700

The goal here is to support MTE, but there's some cleanup to do.

Technically, we have sufficient interfaces in cputlb.c now, but it
requires multiple tlb lookups on different interfaces to do so.

Adding probe_access_flags() allows probing the tlb and getting out
some of the flags buried in the tlb comparator, such as TLB_MMIO
and TLB_WATCHPOINT.  In addition, we get no-fault semantics,
which we don't have via probe_acccess().

Adding cpu_probe_watchpoint() allows to *not* stop a first-fault
or no-fault load when the page contains a watchpoint, but the actual
access does not hit.

Having these available means that we can handle all of the watchpoints
for a given set of loads/stores all at once, before we begin doing any
actual memory operations.  Further, the actual memory operation on a
page of ram that has a watchpoint can still use the fast path.

Looking forward to MTE, we can examine the Tagged bit on a per-page
basis and avoid dozens of mte_check calls that must be Unchecked.
That comes later, in a new version of the MTE patch set, but I do
add comments for where the checks should be added.


Richard Henderson (16):
  accel/tcg: Add block comment for probe_access
  accel/tcg: Add probe_access_flags
  exec: Add cpu_probe_watchpoint
  target/arm: Use cpu_*_data_ra for sve_ldst_tlb_fn
  target/arm: Drop manual handling of set/clear_helper_retaddr
  target/arm: Add sve infrastructure for page lookup
  target/arm: Adjust interface of sve_ld1_host_fn
  target/arm: Use SVEContLdSt in sve_ld1_r
  target/arm: Handle watchpoints in sve_ld1_r
  target/arm: Use SVEContLdSt for multi-register contiguous loads
  target/arm: Update contiguous first-fault and no-fault loads
  target/arm: Use SVEContLdSt for contiguous stores
  target/arm: Reuse sve_probe_page for gather first-fault loads
  target/arm: Reuse sve_probe_page for scatter stores
  target/arm: Reuse sve_probe_page for gather loads
  target/arm: Remove sve_memopidx

 include/exec/cpu-all.h     |   13 +-
 include/exec/exec-all.h    |   39 +
 include/hw/core/cpu.h      |    7 +
 target/arm/internals.h     |    5 -
 accel/tcg/cputlb.c         |  178 +--
 accel/tcg/user-exec.c      |   36 +-
 exec.c                     |   19 +
 target/arm/sve_helper.c    | 2238 +++++++++++++++++++-----------------
 target/arm/translate-sve.c |   17 +-
 9 files changed, 1404 insertions(+), 1148 deletions(-)


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