Re: [PATCH v3 4/7] xen/arm: Add handler for ID registers on arm64

[Julien Grall <julien@xxxxxxx>]

On 09/12/2020 16:30, Bertrand Marquis wrote:
> Add vsysreg emulation for registers trapped when TID3 bit is activated
> in HSR.
> The emulation is returning the value stored in cpuinfo_guest structure
> for know registers and is handling reserved registers as RAZ.
>
> Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
> ---
> Changes in V2: Rebase
> Changes in V3:
>    Fix commit message
>    Fix code style for GENERATE_TID3_INFO declaration
>    Add handling of reserved registers as RAZ.
>
> ---
>   xen/arch/arm/arm64/vsysreg.c | 53 ++++++++++++++++++++++++++++++++++++
>   1 file changed, 53 insertions(+)
>
> diff --git a/xen/arch/arm/arm64/vsysreg.c b/xen/arch/arm/arm64/vsysreg.c
> index 8a85507d9d..ef7a11dbdd 100644
> --- a/xen/arch/arm/arm64/vsysreg.c
> +++ b/xen/arch/arm/arm64/vsysreg.c
> @@ -69,6 +69,14 @@ TVM_REG(CONTEXTIDR_EL1)
>           break;                                                          \
>       }
>   
> +/* Macro to generate easily case for ID co-processor emulation */
> +#define GENERATE_TID3_INFO(reg, field, offset)                          \
> +    case HSR_SYSREG_##reg:                                              \
> +    {                                                                   \
> +        return handle_ro_read_val(regs, regidx, hsr.sysreg.read, hsr,   \
> +                          1, guest_cpuinfo.field.bits[offset]);         \
The indentation looks wrong here. The "1" should be aligned with "regs".

> +    }
> +
>   void do_sysreg(struct cpu_user_regs *regs,
>                  const union hsr hsr)
>   {
> @@ -259,6 +267,51 @@ void do_sysreg(struct cpu_user_regs *regs,
>            */
>           return handle_raz_wi(regs, regidx, hsr.sysreg.read, hsr, 1);
>   
> +    /*
> +     * HCR_EL2.TID3
> +     *
> +     * This is trapping most Identification registers used by a guest
> +     * to identify the processor features
> +     */
> +    GENERATE_TID3_INFO(ID_PFR0_EL1, pfr32, 0)
> +    GENERATE_TID3_INFO(ID_PFR1_EL1, pfr32, 1)
> +    GENERATE_TID3_INFO(ID_PFR2_EL1, pfr32, 2)
> +    GENERATE_TID3_INFO(ID_DFR0_EL1, dbg32, 0)
> +    GENERATE_TID3_INFO(ID_DFR1_EL1, dbg32, 1)
> +    GENERATE_TID3_INFO(ID_AFR0_EL1, aux32, 0)
> +    GENERATE_TID3_INFO(ID_MMFR0_EL1, mm32, 0)
> +    GENERATE_TID3_INFO(ID_MMFR1_EL1, mm32, 1)
> +    GENERATE_TID3_INFO(ID_MMFR2_EL1, mm32, 2)
> +    GENERATE_TID3_INFO(ID_MMFR3_EL1, mm32, 3)
> +    GENERATE_TID3_INFO(ID_MMFR4_EL1, mm32, 4)
> +    GENERATE_TID3_INFO(ID_MMFR5_EL1, mm32, 5)
> +    GENERATE_TID3_INFO(ID_ISAR0_EL1, isa32, 0)
> +    GENERATE_TID3_INFO(ID_ISAR1_EL1, isa32, 1)
> +    GENERATE_TID3_INFO(ID_ISAR2_EL1, isa32, 2)
> +    GENERATE_TID3_INFO(ID_ISAR3_EL1, isa32, 3)
> +    GENERATE_TID3_INFO(ID_ISAR4_EL1, isa32, 4)
> +    GENERATE_TID3_INFO(ID_ISAR5_EL1, isa32, 5)
> +    GENERATE_TID3_INFO(ID_ISAR6_EL1, isa32, 6)
> +    GENERATE_TID3_INFO(MVFR0_EL1, mvfr, 0)
> +    GENERATE_TID3_INFO(MVFR1_EL1, mvfr, 1)
> +    GENERATE_TID3_INFO(MVFR2_EL1, mvfr, 2)
> +    GENERATE_TID3_INFO(ID_AA64PFR0_EL1, pfr64, 0)
> +    GENERATE_TID3_INFO(ID_AA64PFR1_EL1, pfr64, 1)
> +    GENERATE_TID3_INFO(ID_AA64DFR0_EL1, dbg64, 0)
> +    GENERATE_TID3_INFO(ID_AA64DFR1_EL1, dbg64, 1)
> +    GENERATE_TID3_INFO(ID_AA64ISAR0_EL1, isa64, 0)
> +    GENERATE_TID3_INFO(ID_AA64ISAR1_EL1, isa64, 1)
> +    GENERATE_TID3_INFO(ID_AA64MMFR0_EL1, mm64, 0)
> +    GENERATE_TID3_INFO(ID_AA64MMFR1_EL1, mm64, 1)
> +    GENERATE_TID3_INFO(ID_AA64MMFR2_EL1, mm64, 2)
> +    GENERATE_TID3_INFO(ID_AA64AFR0_EL1, aux64, 0)
> +    GENERATE_TID3_INFO(ID_AA64AFR1_EL1, aux64, 1)
> +    GENERATE_TID3_INFO(ID_AA64ZFR0_EL1, zfr64, 0)
> +
> +    HSR_SYSREG_TID3_RESERVED_CASE:
> +        /* Handle all reserved registers as RAZ */
> +        return handle_ro_raz(regs, regidx, hsr.sysreg.read, hsr, 1);
> +
>       /*
>        * HCR_EL2.TIDCP
>        *
--
Julien Grall