[RFC PATCH v3 12/29] KVM: arm64: Make ID_DFR1_EL1 writable

Eric Auger eauger at redhat.com
Thu Nov 25 12:30:36 PST 2021


Hi Reiji,

On 11/17/21 7:43 AM, Reiji Watanabe wrote:
> This patch adds id_reg_info for ID_DFR1_EL1 to make it writable
> by userspace.
> 
> Signed-off-by: Reiji Watanabe <reijiw at google.com>
> ---
>  arch/arm64/kvm/sys_regs.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index fbd335ac5e6b..dda7001959f6 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -859,6 +859,11 @@ static struct id_reg_info id_dfr0_el1_info = {
>  	.get_reset_val = get_reset_id_dfr0_el1,
>  };
>  
> +static struct id_reg_info id_dfr1_el1_info = {
> +	.sys_reg = SYS_ID_DFR1_EL1,
> +	.ftr_check_types = S_FCT(ID_DFR1_MTPMU_SHIFT, FCT_LOWER_SAFE),
what about the 0xF value which indicates the MTPMU is not implemented?

Eric
> +};
> +
>  /*
>   * An ID register that needs special handling to control the value for the
>   * guest must have its own id_reg_info in id_reg_info_table.
> @@ -869,6 +874,7 @@ static struct id_reg_info id_dfr0_el1_info = {
>  #define	GET_ID_REG_INFO(id)	(id_reg_info_table[IDREG_IDX(id)])
>  static struct id_reg_info *id_reg_info_table[KVM_ARM_ID_REG_MAX_NUM] = {
>  	[IDREG_IDX(SYS_ID_DFR0_EL1)] = &id_dfr0_el1_info,
> +	[IDREG_IDX(SYS_ID_DFR1_EL1)] = &id_dfr1_el1_info,
>  	[IDREG_IDX(SYS_ID_AA64PFR0_EL1)] = &id_aa64pfr0_el1_info,
>  	[IDREG_IDX(SYS_ID_AA64PFR1_EL1)] = &id_aa64pfr1_el1_info,
>  	[IDREG_IDX(SYS_ID_AA64DFR0_EL1)] = &id_aa64dfr0_el1_info,
> 




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