[PATCH v2 02/13] KVM: arm64: MDCR_EL2 is a 64-bit register

[Will Deacon]

On Tue, Jun 15, 2021 at 02:39:39PM +0100, Fuad Tabba wrote:
> Fix the places in KVM that treat MDCR_EL2 as a 32-bit register.
> More recent features (e.g., FEAT_SPEv1p2) use bits above 31.
> 
> No functional change intended.
> 
> Signed-off-by: Fuad Tabba <tabba at google.com>
> ---
>  arch/arm64/include/asm/kvm_arm.h   | 20 ++++++++++----------
>  arch/arm64/include/asm/kvm_asm.h   |  2 +-
>  arch/arm64/include/asm/kvm_host.h  |  2 +-
>  arch/arm64/kvm/debug.c             |  5 +++--
>  arch/arm64/kvm/hyp/nvhe/debug-sr.c |  2 +-
>  arch/arm64/kvm/hyp/vhe/debug-sr.c  |  2 +-
>  6 files changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
> index 692c9049befa..25d8a61888e4 100644
> --- a/arch/arm64/include/asm/kvm_arm.h
> +++ b/arch/arm64/include/asm/kvm_arm.h
> @@ -280,18 +280,18 @@
>  /* Hyp Debug Configuration Register bits */
>  #define MDCR_EL2_E2TB_MASK	(UL(0x3))
>  #define MDCR_EL2_E2TB_SHIFT	(UL(24))
> -#define MDCR_EL2_TTRF		(1 << 19)
> -#define MDCR_EL2_TPMS		(1 << 14)
> +#define MDCR_EL2_TTRF		(UL(1) << 19)
> +#define MDCR_EL2_TPMS		(UL(1) << 14)
>  #define MDCR_EL2_E2PB_MASK	(UL(0x3))
>  #define MDCR_EL2_E2PB_SHIFT	(UL(12))
> -#define MDCR_EL2_TDRA		(1 << 11)
> -#define MDCR_EL2_TDOSA		(1 << 10)
> -#define MDCR_EL2_TDA		(1 << 9)
> -#define MDCR_EL2_TDE		(1 << 8)
> -#define MDCR_EL2_HPME		(1 << 7)
> -#define MDCR_EL2_TPM		(1 << 6)
> -#define MDCR_EL2_TPMCR		(1 << 5)
> -#define MDCR_EL2_HPMN_MASK	(0x1F)
> +#define MDCR_EL2_TDRA		(UL(1) << 11)
> +#define MDCR_EL2_TDOSA		(UL(1) << 10)
> +#define MDCR_EL2_TDA		(UL(1) << 9)
> +#define MDCR_EL2_TDE		(UL(1) << 8)
> +#define MDCR_EL2_HPME		(UL(1) << 7)
> +#define MDCR_EL2_TPM		(UL(1) << 6)
> +#define MDCR_EL2_TPMCR		(UL(1) << 5)
> +#define MDCR_EL2_HPMN_MASK	(UL(0x1F))

Personally, I prefer to use the BIT() macro for these things, but what
you've got here is consistent with the rest of the file and I think that's
more important.

>  /* For compatibility with fault code shared with 32-bit */
>  #define FSC_FAULT	ESR_ELx_FSC_FAULT
> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
> index 5e9b33cbac51..d88a5550552c 100644
> --- a/arch/arm64/include/asm/kvm_asm.h
> +++ b/arch/arm64/include/asm/kvm_asm.h
> @@ -209,7 +209,7 @@ extern u64 __vgic_v3_read_vmcr(void);
>  extern void __vgic_v3_write_vmcr(u32 vmcr);
>  extern void __vgic_v3_init_lrs(void);
>  
> -extern u32 __kvm_get_mdcr_el2(void);
> +extern u64 __kvm_get_mdcr_el2(void);
>  
>  #define __KVM_EXTABLE(from, to)						\
>  	"	.pushsection	__kvm_ex_table, \"a\"\n"		\
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 5645af2a1431..45fdd0b7063f 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -286,7 +286,7 @@ struct kvm_vcpu_arch {
>  
>  	/* HYP configuration */
>  	u64 hcr_el2;
> -	u32 mdcr_el2;
> +	u64 mdcr_el2;
>  
>  	/* Exception Information */
>  	struct kvm_vcpu_fault_info fault;
> diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
> index d5e79d7ee6e9..f7385bfbc9e4 100644
> --- a/arch/arm64/kvm/debug.c
> +++ b/arch/arm64/kvm/debug.c
> @@ -21,7 +21,7 @@
>  				DBG_MDSCR_KDE | \
>  				DBG_MDSCR_MDE)
>  
> -static DEFINE_PER_CPU(u32, mdcr_el2);
> +static DEFINE_PER_CPU(u64, mdcr_el2);
>  
>  /**
>   * save/restore_guest_debug_regs
> @@ -154,7 +154,8 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
>  
>  void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
>  {
> -	unsigned long mdscr, orig_mdcr_el2 = vcpu->arch.mdcr_el2;
> +	unsigned long mdscr;
> +	u64 orig_mdcr_el2 = vcpu->arch.mdcr_el2;

This is arm64 code, so 'unsigned long' is fine here and you can leave the
existing code as-is.

With that:

Acked-by: Will Deacon <will at kernel.org>

Will