Re: [PATCH v3] target/arm: Add raw_writes ops for register whose write induce TLB maintenance

[Eric Auger]

Hi Peter,

On 2/28/23 10:36, Eric Auger wrote:
> Some registers whose 'cooked' writefns induce TLB maintenance do
> not have raw_writefn ops defined. If only the writefn ops is set
> (ie. no raw_writefn is provided), it is assumed the cooked also
> work as the raw one. For those registers it is not obvious the
> tlb_flush works on KVM mode so better/safer setting the raw write.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>

If I am not wrong this patch fell into the cracks. Is it in a decent
state now?

Thanks

Eric
>
> ---
>
> v2 -> v3:
> - remove modifs related to ARM_CP_NO_RAW regs [Peter]
> - do not add raw_writefn for hcr_writelow and hcr_writehigh
>
> v1 -> v2:
> - do not add raw_writefn if type is set to ARM_CP_NO_RAW [Peter]
> ---
>  target/arm/helper.c | 23 +++++++++++++----------
>  1 file changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 14af7ba095..42ada408cc 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -4184,14 +4184,14 @@ static const ARMCPRegInfo vmsa_cp_reginfo[] = {
>        .opc0 = 3, .opc1 = 0, .crn = 2, .crm = 0, .opc2 = 0,
>        .access = PL1_RW, .accessfn = access_tvm_trvm,
>        .fgt = FGT_TTBR0_EL1,
> -      .writefn = vmsa_ttbr_write, .resetvalue = 0,
> +      .writefn = vmsa_ttbr_write, .resetvalue = 0, .raw_writefn = raw_write,
>        .bank_fieldoffsets = { offsetof(CPUARMState, cp15.ttbr0_s),
>                               offsetof(CPUARMState, cp15.ttbr0_ns) } },
>      { .name = "TTBR1_EL1", .state = ARM_CP_STATE_BOTH,
>        .opc0 = 3, .opc1 = 0, .crn = 2, .crm = 0, .opc2 = 1,
>        .access = PL1_RW, .accessfn = access_tvm_trvm,
>        .fgt = FGT_TTBR1_EL1,
> -      .writefn = vmsa_ttbr_write, .resetvalue = 0,
> +      .writefn = vmsa_ttbr_write, .resetvalue = 0, .raw_writefn = raw_write,
>        .bank_fieldoffsets = { offsetof(CPUARMState, cp15.ttbr1_s),
>                               offsetof(CPUARMState, cp15.ttbr1_ns) } },
>      { .name = "TCR_EL1", .state = ARM_CP_STATE_AA64,
> @@ -4451,13 +4451,13 @@ static const ARMCPRegInfo lpae_cp_reginfo[] = {
>        .type = ARM_CP_64BIT | ARM_CP_ALIAS,
>        .bank_fieldoffsets = { offsetof(CPUARMState, cp15.ttbr0_s),
>                               offsetof(CPUARMState, cp15.ttbr0_ns) },
> -      .writefn = vmsa_ttbr_write, },
> +      .writefn = vmsa_ttbr_write, .raw_writefn = raw_write },
>      { .name = "TTBR1", .cp = 15, .crm = 2, .opc1 = 1,
>        .access = PL1_RW, .accessfn = access_tvm_trvm,
>        .type = ARM_CP_64BIT | ARM_CP_ALIAS,
>        .bank_fieldoffsets = { offsetof(CPUARMState, cp15.ttbr1_s),
>                               offsetof(CPUARMState, cp15.ttbr1_ns) },
> -      .writefn = vmsa_ttbr_write, },
> +      .writefn = vmsa_ttbr_write, .raw_writefn = raw_write },
>  };
>  
>  static uint64_t aa64_fpcr_read(CPUARMState *env, const ARMCPRegInfo *ri)
> @@ -5900,7 +5900,7 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
>        .type = ARM_CP_IO,
>        .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 1, .opc2 = 0,
>        .access = PL2_RW, .fieldoffset = offsetof(CPUARMState, cp15.hcr_el2),
> -      .writefn = hcr_write },
> +      .writefn = hcr_write, .raw_writefn = raw_write },
>      { .name = "HCR", .state = ARM_CP_STATE_AA32,
>        .type = ARM_CP_ALIAS | ARM_CP_IO,
>        .cp = 15, .opc1 = 4, .crn = 1, .crm = 1, .opc2 = 0,
> @@ -5972,6 +5972,7 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
>      { .name = "TCR_EL2", .state = ARM_CP_STATE_BOTH,
>        .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 0, .opc2 = 2,
>        .access = PL2_RW, .writefn = vmsa_tcr_el12_write,
> +      .raw_writefn = raw_write,
>        .fieldoffset = offsetof(CPUARMState, cp15.tcr_el[2]) },
>      { .name = "VTCR", .state = ARM_CP_STATE_AA32,
>        .cp = 15, .opc1 = 4, .crn = 2, .crm = 1, .opc2 = 2,
> @@ -5988,10 +5989,10 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
>        .type = ARM_CP_64BIT | ARM_CP_ALIAS,
>        .access = PL2_RW, .accessfn = access_el3_aa32ns,
>        .fieldoffset = offsetof(CPUARMState, cp15.vttbr_el2),
> -      .writefn = vttbr_write },
> +      .writefn = vttbr_write, .raw_writefn = raw_write },
>      { .name = "VTTBR_EL2", .state = ARM_CP_STATE_AA64,
>        .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 1, .opc2 = 0,
> -      .access = PL2_RW, .writefn = vttbr_write,
> +      .access = PL2_RW, .writefn = vttbr_write, .raw_writefn = raw_write,
>        .fieldoffset = offsetof(CPUARMState, cp15.vttbr_el2) },
>      { .name = "SCTLR_EL2", .state = ARM_CP_STATE_BOTH,
>        .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 0, .opc2 = 0,
> @@ -6003,7 +6004,8 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
>        .fieldoffset = offsetof(CPUARMState, cp15.tpidr_el[2]) },
>      { .name = "TTBR0_EL2", .state = ARM_CP_STATE_AA64,
>        .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 0, .opc2 = 0,
> -      .access = PL2_RW, .resetvalue = 0, .writefn = vmsa_tcr_ttbr_el2_write,
> +      .access = PL2_RW, .resetvalue = 0,
> +      .writefn = vmsa_tcr_ttbr_el2_write, .raw_writefn = raw_write,
>        .fieldoffset = offsetof(CPUARMState, cp15.ttbr0_el[2]) },
>      { .name = "HTTBR", .cp = 15, .opc1 = 4, .crm = 2,
>        .access = PL2_RW, .type = ARM_CP_64BIT | ARM_CP_ALIAS,
> @@ -6190,12 +6192,12 @@ static const ARMCPRegInfo el3_cp_reginfo[] = {
>      { .name = "SCR_EL3", .state = ARM_CP_STATE_AA64,
>        .opc0 = 3, .opc1 = 6, .crn = 1, .crm = 1, .opc2 = 0,
>        .access = PL3_RW, .fieldoffset = offsetof(CPUARMState, cp15.scr_el3),
> -      .resetfn = scr_reset, .writefn = scr_write },
> +      .resetfn = scr_reset, .writefn = scr_write, .raw_writefn = raw_write },
>      { .name = "SCR",  .type = ARM_CP_ALIAS | ARM_CP_NEWEL,
>        .cp = 15, .opc1 = 0, .crn = 1, .crm = 1, .opc2 = 0,
>        .access = PL1_RW, .accessfn = access_trap_aa32s_el1,
>        .fieldoffset = offsetoflow32(CPUARMState, cp15.scr_el3),
> -      .writefn = scr_write },
> +      .writefn = scr_write, .raw_writefn = raw_write },
>      { .name = "SDER32_EL3", .state = ARM_CP_STATE_AA64,
>        .opc0 = 3, .opc1 = 6, .crn = 1, .crm = 1, .opc2 = 1,
>        .access = PL3_RW, .resetvalue = 0,
> @@ -7839,6 +7841,7 @@ static const ARMCPRegInfo vhe_reginfo[] = {
>      { .name = "TTBR1_EL2", .state = ARM_CP_STATE_AA64,
>        .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 0, .opc2 = 1,
>        .access = PL2_RW, .writefn = vmsa_tcr_ttbr_el2_write,
> +      .raw_writefn = raw_write,
>        .fieldoffset = offsetof(CPUARMState, cp15.ttbr1_el[2]) },
>  #ifndef CONFIG_USER_ONLY
>      { .name = "CNTHV_CVAL_EL2", .state = ARM_CP_STATE_AA64,