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From: Richard Henderson <richard.henderson@linaro.org>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: david.spickett@linaro.org, qemu-arm <qemu-arm@nongnu.org>,
	QEMU Developers <qemu-devel@nongnu.org>,
	Stephen Long <steplong@quicinc.com>
Subject: Re: [PATCH v8 38/45] target/arm: Complete TBI clearing for user-only for SVE
Date: Thu, 25 Jun 2020 09:54:55 -0700	[thread overview]
Message-ID: <9e80eb42-655f-9ffa-264a-f72627efdf42@linaro.org> (raw)
In-Reply-To: <CAFEAcA8xy_Q-6zXexBEHLR=WSYTXVvttL9V4HqiMPmtRm__TEw@mail.gmail.com>

On 6/25/20 5:52 AM, Peter Maydell wrote:
> On Tue, 23 Jun 2020 at 20:37, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> There are a number of paths by which the TBI is still intact
>> for user-only in the SVE helpers.
>>
>> Because we currently always set TBI for user-only, we do not
>> need to pass down the actual TBI setting from above, and we
>> can remove the top byte in the inner-most primitives, so that
>> none are forgotten.  Moreover, this keeps the "dirty" pointer
>> around at the higher levels, where we need it for any MTE checking.
>>
>> Since the normal case, especially for user-only, goes through
>> RAM, this clearing merely adds two insns per page lookup, which
>> will be completely in the noise.
> 
> Can we have an assert() somewhere suitable that TBI is set?
> That way if we ever do have an SVE-capable linux-user which
> doesn't set TBI for some reason we'll get a useful reminder
> that we need to fix something.

At what level would you like such an assert?
At present we have, in arm_cpu_reset,

      /*
       * Enable TBI0 and TBI1.  While the real kernel only enables TBI0,
       * turning on both here will produce smaller code and otherwise
       * make no difference to the user-level emulation.
       */
      env->cp15.tcr_el[1].raw_tcr = (3ULL << 37);


r~


  reply	other threads:[~2020-06-25 16:55 UTC|newest]

Thread overview: 77+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-23 19:36 [PATCH v8 00/45] target/arm: Implement ARMv8.5-MemTag, system mode Richard Henderson
2020-06-23 19:36 ` [PATCH v8 01/45] target/arm: Add isar tests for mte Richard Henderson
2020-06-23 19:36 ` [PATCH v8 02/45] target/arm: Improve masking of SCR RES0 bits Richard Henderson
2020-06-23 19:36 ` [PATCH v8 03/45] target/arm: Add support for MTE to SCTLR_ELx Richard Henderson
2020-06-23 19:36 ` [PATCH v8 04/45] target/arm: Add support for MTE to HCR_EL2 and SCR_EL3 Richard Henderson
2020-06-23 19:36 ` [PATCH v8 05/45] target/arm: Rename DISAS_UPDATE to DISAS_UPDATE_EXIT Richard Henderson
2020-06-23 19:36 ` [PATCH v8 06/45] target/arm: Add DISAS_UPDATE_NOCHAIN Richard Henderson
2020-06-23 19:36 ` [PATCH v8 07/45] target/arm: Add MTE system registers Richard Henderson
2020-06-23 19:36 ` [PATCH v8 08/45] target/arm: Add MTE bits to tb_flags Richard Henderson
2020-06-23 19:36 ` [PATCH v8 09/45] target/arm: Implement the IRG instruction Richard Henderson
2020-06-23 19:36 ` [PATCH v8 10/45] target/arm: Revise decoding for disas_add_sub_imm Richard Henderson
2020-06-25 10:16   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 11/45] target/arm: Implement the ADDG, SUBG instructions Richard Henderson
2020-06-25 10:39   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 12/45] target/arm: Implement the GMI instruction Richard Henderson
2020-06-23 19:36 ` [PATCH v8 13/45] target/arm: Implement the SUBP instruction Richard Henderson
2020-06-23 19:36 ` [PATCH v8 14/45] target/arm: Define arm_cpu_do_unaligned_access for user-only Richard Henderson
2020-06-25 10:45   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 15/45] target/arm: Implement LDG, STG, ST2G instructions Richard Henderson
2020-06-25 10:48   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 16/45] target/arm: Implement the STGP instruction Richard Henderson
2020-06-23 19:36 ` [PATCH v8 17/45] target/arm: Restrict the values of DCZID.BS under TCG Richard Henderson
2020-06-23 19:36 ` [PATCH v8 18/45] target/arm: Simplify DC_ZVA Richard Henderson
2020-06-23 19:36 ` [PATCH v8 19/45] target/arm: Implement the LDGM, STGM, STZGM instructions Richard Henderson
2020-06-23 19:36 ` [PATCH v8 20/45] target/arm: Implement the access tag cache flushes Richard Henderson
2020-06-23 19:36 ` [PATCH v8 21/45] target/arm: Move regime_el to internals.h Richard Henderson
2020-06-23 19:36 ` [PATCH v8 22/45] target/arm: Move regime_tcr " Richard Henderson
2020-06-23 19:36 ` [PATCH v8 23/45] target/arm: Add gen_mte_check1 Richard Henderson
2020-06-23 19:36 ` [PATCH v8 24/45] target/arm: Add gen_mte_checkN Richard Henderson
2020-06-23 19:36 ` [PATCH v8 25/45] target/arm: Implement helper_mte_check1 Richard Henderson
2020-06-25 10:55   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 26/45] target/arm: Implement helper_mte_checkN Richard Henderson
2020-06-23 19:36 ` [PATCH v8 27/45] target/arm: Add helper_mte_check_zva Richard Henderson
2020-06-23 19:36 ` [PATCH v8 28/45] target/arm: Use mte_checkN for sve unpredicated loads Richard Henderson
2020-06-25 11:06   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 29/45] target/arm: Use mte_checkN for sve unpredicated stores Richard Henderson
2020-06-25 11:07   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 30/45] target/arm: Use mte_check1 for sve LD1R Richard Henderson
2020-06-25 11:12   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 31/45] target/arm: Tidy trans_LD1R_zpri Richard Henderson
2020-06-25 11:12   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 32/45] target/arm: Add arm_tlb_bti_gp Richard Henderson
2020-06-25 12:29   ` Peter Maydell
2020-06-25 18:59     ` Richard Henderson
2020-06-23 19:36 ` [PATCH v8 33/45] target/arm: Add mte helpers for sve scalar + int loads Richard Henderson
2020-06-25 12:36   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 34/45] target/arm: Add mte helpers for sve scalar + int stores Richard Henderson
2020-06-25 12:37   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 35/45] target/arm: Add mte helpers for sve scalar + int ff/nf loads Richard Henderson
2020-06-25 12:38   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 36/45] target/arm: Handle TBI for sve scalar + int memory ops Richard Henderson
2020-06-25 12:40   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 37/45] target/arm: Add mte helpers for sve scatter/gather " Richard Henderson
2020-06-25 12:43   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 38/45] target/arm: Complete TBI clearing for user-only for SVE Richard Henderson
2020-06-25 12:52   ` Peter Maydell
2020-06-25 16:54     ` Richard Henderson [this message]
2020-06-25 17:07       ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 39/45] target/arm: Implement data cache set allocation tags Richard Henderson
2020-06-23 19:36 ` [PATCH v8 40/45] target/arm: Set PSTATE.TCO on exception entry Richard Henderson
2020-06-23 19:36 ` [PATCH v8 41/45] target/arm: Always pass cacheattr to get_phys_addr Richard Henderson
2020-06-25 12:56   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 42/45] target/arm: Cache the Tagged bit for a page in MemTxAttrs Richard Henderson
2020-06-25 12:59   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 43/45] target/arm: Create tagged ram when MTE is enabled Richard Henderson
2020-06-25 13:26   ` Peter Maydell
2020-06-23 19:36 ` [PATCH v8 44/45] target/arm: Add allocation tag storage for system mode Richard Henderson
2020-06-25 13:03   ` Peter Maydell
2020-06-25 17:02     ` Richard Henderson
2020-06-25 17:09       ` Peter Maydell
2020-06-25 22:16         ` Richard Henderson
2020-06-23 19:36 ` [PATCH v8 45/45] target/arm: Enable MTE Richard Henderson
2020-06-25 13:06   ` Peter Maydell
2020-06-23 19:55 ` [PATCH v8 00/45] target/arm: Implement ARMv8.5-MemTag, system mode Derrick McKee
2020-06-23 20:06   ` Richard Henderson
2020-06-23 20:30 ` no-reply
2020-06-25 13:28 ` Peter Maydell

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