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[00/23] target/arm: Implement FEAT_FGT fine-grained traps

Message ID 20230127175507.2895013-1-peter.maydell@linaro.org
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Series target/arm: Implement FEAT_FGT fine-grained traps | expand

Message

Peter Maydell Jan. 27, 2023, 5:54 p.m. UTC 
This series implements the FEAT_FGT fine-grained traps architectural
feature. The bulk of this is new system registers HFGRTR_EL2, HFGWTR_EL2,
HFGITR_EL2, HDFGRTR_EL2, HDFGWTR_EL2, which have bits that enable
trapping of system register and system instruction accesses on a
fine-grained basis (typically one or a few sysregs at a time).

In theory we could implement this with our existing ARMCPRegInfo::accessfn
machinery, but we would end up with many many very nearly identical
access functions. Instead this series adds a new ARMCPRegInfo::fgt
field, which specifies which bit in which FGT register should be
checked; this is then tested by code in the access_check_cp_reg
helper function.

A few bits in HFGITR_EL2 allow trapping of instructions which aren't
handled by the ARMCPRegInfo mechanism: ERET and SVC. These we just
implement "by hand". FEAT_FGT also adds new MDCR_EL3.TDCC and
MDCR_EL2.TDCC bits for trapping the Debug Comms Channel registers;
these we implement with a standard accessfn.

The first seven patches are various cleanups and bugfixes that
I noticed while I was doing the FEAT_FGT work. In particular, we
weren't getting the priority of HSTR_EL2 traps right -- these should
take priority over UNDEF-at-EL traps but not over UNDEF-at-EL0 traps.
The rest of the series is FEAT_FGT itself.

thanks
-- PMM

Peter Maydell (23):
  target/arm: Name AT_S1E1RP and AT_S1E1WP cpregs correctly
  target/arm: Correct syndrome for ATS12NSO* at Secure EL1
  target/arm: Remove CP_ACCESS_TRAP_UNCATEGORIZED_{EL2,EL3}
  target/arm: Move do_coproc_insn() syndrome calculation earlier
  target/arm: All UNDEF-at-EL0 traps take priority over HSTR_EL2 traps
  target/arm: Make HSTR_EL2 traps take priority over UNDEF-at-EL1
  target/arm: Disable HSTR_EL2 traps if EL2 is not enabled
  target/arm: Define the FEAT_FGT registers
  target/arm: Implement FGT trapping infrastructure
  target/arm: Mark up sysregs for HFGRTR bits 0..11
  target/arm: Mark up sysregs for HFGRTR bits 12..23
  target/arm: Mark up sysregs for HFGRTR bits 24..35
  target/arm: Mark up sysregs for HFGRTR bits 36..63
  target/arm: Mark up sysregs for HDFGRTR bits 0..11
  target/arm: Mark up sysregs for HDFGRTR bits 12..63
  target/arm: Mark up sysregs for HFGITR bits 0..11
  target/arm: Mark up sysregs for HFGITR bits 12..17
  target/arm: Mark up sysregs for HFGITR bits 18..47
  target/arm: Mark up sysregs for HFGITR bits 48..63
  target/arm: Implement the HFGITR_EL2.ERET trap
  target/arm: Implement the HFGITR_EL2.SVC_EL0 and SVC_EL1 traps
  target/arm: Implement MDCR_EL2.TDCC and MDCR_EL3.TDCC traps
  target/arm: Enable FEAT_FGT on '-cpu max'

 docs/system/arm/emulation.rst |   1 +
 target/arm/cpregs.h           | 484 +++++++++++++++++++++++++++++++++-
 target/arm/cpu.h              |  18 ++
 target/arm/helper.h           |   1 +
 target/arm/internals.h        |  20 ++
 target/arm/syndrome.h         |  10 +
 target/arm/translate.h        |   6 +
 hw/intc/arm_gicv3_cpuif.c     |   2 +
 target/arm/cpu64.c            |   1 +
 target/arm/debug_helper.c     |  46 +++-
 target/arm/helper.c           | 245 ++++++++++++++++-
 target/arm/op_helper.c        |  65 ++++-
 target/arm/translate-a64.c    |  22 +-
 target/arm/translate.c        | 132 ++++++----
 14 files changed, 986 insertions(+), 67 deletions(-)

Comments

Peter Maydell Jan. 27, 2023, 6:43 p.m. UTC | #1 
On Fri, 27 Jan 2023 at 17:55, Peter Maydell <peter.maydell@linaro.org> wrote:
> The first seven patches are various cleanups and bugfixes that
> I noticed while I was doing the FEAT_FGT work. In particular, we
> weren't getting the priority of HSTR_EL2 traps right -- these should
> take priority over UNDEF-at-EL traps but not over UNDEF-at-EL0 traps.
> The rest of the series is FEAT_FGT itself.

Missing character here -- should be "take priority over UNDEF-at-EL1"...

-- PMM