[PATCH v3 7/9] arm64: KVM: add trap handlers for AArch32 debug registers

Christoffer Dall christoffer.dall at linaro.org
Wed Jul 9 02:43:26 PDT 2014


On Fri, Jun 20, 2014 at 02:00:05PM +0100, Marc Zyngier wrote:
> Add handlers for all the AArch32 debug registers that are accessible
> from EL0 or EL1. The code follow the same strategy as the AArch64
> counterpart with regards to tracking the dirty state of the debug
> registers.
> 
> Reviewed-by: Anup Patel <anup.patel at linaro.org>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
>  arch/arm64/include/asm/kvm_asm.h |   9 +++
>  arch/arm64/kvm/sys_regs.c        | 144 ++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 151 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
> index 12f9dd7..993a7db 100644
> --- a/arch/arm64/include/asm/kvm_asm.h
> +++ b/arch/arm64/include/asm/kvm_asm.h
> @@ -93,6 +93,15 @@
>  #define c10_AMAIR0	(AMAIR_EL1 * 2)	/* Aux Memory Attr Indirection Reg */
>  #define c10_AMAIR1	(c10_AMAIR0 + 1)/* Aux Memory Attr Indirection Reg */
>  #define c14_CNTKCTL	(CNTKCTL_EL1 * 2) /* Timer Control Register (PL1) */
> +
> +#define cp14_DBGDSCRext	(MDSCR_EL1 * 2)
> +#define cp14_DBGBCR0	(DBGBCR0_EL1 * 2)
> +#define cp14_DBGBVR0	(DBGBVR0_EL1 * 2)
> +#define cp14_DBGBXVR0	(cp14_DBGBVR0 + 1)
> +#define cp14_DBGWCR0	(DBGWCR0_EL1 * 2)
> +#define cp14_DBGWVR0	(DBGWVR0_EL1 * 2)
> +#define cp14_DBGDCCINT	(MDCCINT_EL1 * 2)
> +
>  #define NR_COPRO_REGS	(NR_SYS_REGS * 2)
>  
>  #define ARM_EXCEPTION_IRQ	  0
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 9147b0c..daa635e 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -483,12 +483,153 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>  	  NULL, reset_val, FPEXC32_EL2, 0x70 },
>  };
>  
> -/* Trapped cp14 registers */
> +static bool trap_dbgidr(struct kvm_vcpu *vcpu,
> +			const struct sys_reg_params *p,
> +			const struct sys_reg_desc *r)
> +{
> +	if (p->is_write) {
> +		return ignore_write(vcpu, p);
> +	} else {
> +		u64 dfr = read_cpuid(ID_AA64DFR0_EL1);
> +		u64 pfr = read_cpuid(ID_AA64PFR0_EL1);
> +		u32 el3 = !!((pfr >> 12) & 0xf);
> +
> +		*vcpu_reg(vcpu, p->Rt) = ((((dfr >> 20) & 0xf) << 28) |
> +					  (((dfr >> 12) & 0xf) << 24) |
> +					  (((dfr >> 28) & 0xf) << 20) |
> +					  (6 << 16) | (el3 << 14) | (el3 << 12));
> +		return true;
> +	}
> +}
> +
> +static bool trap_debug32(struct kvm_vcpu *vcpu,
> +			 const struct sys_reg_params *p,
> +			 const struct sys_reg_desc *r)
> +{
> +	if (p->is_write) {
> +		vcpu_cp14(vcpu, r->reg) = *vcpu_reg(vcpu, p->Rt);
> +		vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
> +	} else {
> +		*vcpu_reg(vcpu, p->Rt) = vcpu_cp14(vcpu, r->reg);
> +	}
> +
> +	return true;
> +}
> +
> +#define DBG_BCR_BVR_WCR_WVR(n)					\
> +	/* DBGBVRn */						\
> +	{ Op1( 0), CRn( 0), CRm((n)), Op2( 4), trap_debug32,	\
> +	  NULL, (cp14_DBGBVR0 + (n) * 2) },			\
> +	/* DBGBCRn */						\
> +	{ Op1( 0), CRn( 0), CRm((n)), Op2( 5), trap_debug32,	\
> +	  NULL, (cp14_DBGBCR0 + (n) * 2) },			\
> +	/* DBGWVRn */						\
> +	{ Op1( 0), CRn( 0), CRm((n)), Op2( 6), trap_debug32,	\
> +	  NULL, (cp14_DBGWVR0 + (n) * 2) },			\
> +	/* DBGWCRn */						\
> +	{ Op1( 0), CRn( 0), CRm((n)), Op2( 7), trap_debug32,	\
> +	  NULL, (cp14_DBGWCR0 + (n) * 2) }
> +
> +#define DBGBXVR(n)						\
> +	{ Op1( 0), CRn( 1), CRm((n)), Op2( 1), trap_debug32,	\
> +	  NULL, cp14_DBGBXVR0 + n * 2 }
> +
> +/*
> + * Trapped cp14 registers. We generally ignore most of the external
> + * debug, on the principle that they don't really make sense to a
> + * guest. Revisit this one day, whould this principle change.
> + */
>  static const struct sys_reg_desc cp14_regs[] = {
> +	/* DBGIDR */
> +	{ Op1( 0), CRn( 0), CRm( 0), Op2( 0), trap_dbgidr },
> +	/* DBGDTRRXext */
> +	{ Op1( 0), CRn( 0), CRm( 0), Op2( 2), trap_raz_wi },
> +
> +	DBG_BCR_BVR_WCR_WVR(0),
> +	/* DBGDSCRint */
> +	{ Op1( 0), CRn( 0), CRm( 1), Op2( 0), trap_raz_wi },
> +	DBG_BCR_BVR_WCR_WVR(1),
> +	/* DBGDCCINT */
> +	{ Op1( 0), CRn( 0), CRm( 2), Op2( 0), trap_debug32 },
> +	/* DBGDSCRext */
> +	{ Op1( 0), CRn( 0), CRm( 2), Op2( 2), trap_debug32 },
> +	DBG_BCR_BVR_WCR_WVR(2),
> +	/* DBGDTR[RT]Xint */
> +	{ Op1( 0), CRn( 0), CRm( 3), Op2( 0), trap_raz_wi },
> +	/* DBGDTR[RT]Xext */
> +	{ Op1( 0), CRn( 0), CRm( 3), Op2( 2), trap_raz_wi },
> +	DBG_BCR_BVR_WCR_WVR(3),
> +	DBG_BCR_BVR_WCR_WVR(4),
> +	DBG_BCR_BVR_WCR_WVR(5),
> +	/* DBGWFAR */
> +	{ Op1( 0), CRn( 0), CRm( 6), Op2( 0), trap_raz_wi },
> +	/* DBGOSECCR */
> +	{ Op1( 0), CRn( 0), CRm( 6), Op2( 2), trap_raz_wi },
> +	DBG_BCR_BVR_WCR_WVR(6),
> +	/* DBGVCR */
> +	{ Op1( 0), CRn( 0), CRm( 7), Op2( 0), trap_debug32 },
> +	DBG_BCR_BVR_WCR_WVR(7),
> +	DBG_BCR_BVR_WCR_WVR(8),
> +	DBG_BCR_BVR_WCR_WVR(9),
> +	DBG_BCR_BVR_WCR_WVR(10),
> +	DBG_BCR_BVR_WCR_WVR(11),
> +	DBG_BCR_BVR_WCR_WVR(12),
> +	DBG_BCR_BVR_WCR_WVR(13),
> +	DBG_BCR_BVR_WCR_WVR(14),
> +	DBG_BCR_BVR_WCR_WVR(15),
> +
> +	/* DBGDRAR (32bit) */
> +	{ Op1( 0), CRn( 1), CRm( 0), Op2( 0), trap_raz_wi },
> +
> +	DBGBXVR(0),
> +	/* DBGOSLAR */
> +	{ Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi },
> +	DBGBXVR(1),
> +	/* DBGOSLSR */
> +	{ Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 },
> +	DBGBXVR(2),
> +	DBGBXVR(3),
> +	/* DBGOSDLR */
> +	{ Op1( 0), CRn( 1), CRm( 3), Op2( 4), trap_raz_wi },
> +	DBGBXVR(4),
> +	/* DBGPRCR */
> +	{ Op1( 0), CRn( 1), CRm( 4), Op2( 4), trap_raz_wi },
> +	DBGBXVR(5),
> +	DBGBXVR(6),
> +	DBGBXVR(7),
> +	DBGBXVR(8),
> +	DBGBXVR(9),
> +	DBGBXVR(10),
> +	DBGBXVR(11),
> +	DBGBXVR(12),
> +	DBGBXVR(13),
> +	DBGBXVR(14),
> +	DBGBXVR(15),
> +
> +	/* DBGDSAR (32bit) */
> +	{ Op1( 0), CRn( 2), CRm( 0), Op2( 0), trap_raz_wi },
> +
> +	/* DBGDEVID2 */
> +	{ Op1( 0), CRn( 7), CRm( 0), Op2( 7), trap_raz_wi },
> +	/* DBGDEVID1 */
> +	{ Op1( 0), CRn( 7), CRm( 1), Op2( 7), trap_raz_wi },
> +	/* DBGDEVID */
> +	{ Op1( 0), CRn( 7), CRm( 2), Op2( 7), trap_raz_wi },
> +	/* DBGCLAIMSET */
> +	{ Op1( 0), CRn( 7), CRm( 8), Op2( 6), trap_raz_wi },
> +	/* DBGCLAIMCLR */
> +	{ Op1( 0), CRn( 7), CRm( 9), Op2( 6), trap_raz_wi },
> +	/* DBGAUTHSTATUS */
> +	{ Op1( 0), CRn( 7), CRm(14), Op2( 6), trap_dbgauthstatus_el1 },
>  };
>  
>  /* Trapped cp14 64bit registers */
>  static const struct sys_reg_desc cp14_64_regs[] = {
> +	/* DBGDRAR (64bit) */
> +	{ Op1( 0), CRm( 1), .access = trap_raz_wi },
> +
> +	/* DBGDSAR (64bit) */
> +	{ Op1( 0), CRm( 2), .access = trap_raz_wi },
>  };
>  
>  /*
> @@ -536,7 +677,6 @@ static const struct sys_reg_desc cp15_regs[] = {
>  	{ Op1( 0), CRn(10), CRm( 3), Op2( 0), access_vm_reg, NULL, c10_AMAIR0 },
>  	{ Op1( 0), CRn(10), CRm( 3), Op2( 1), access_vm_reg, NULL, c10_AMAIR1 },
>  	{ Op1( 0), CRn(13), CRm( 0), Op2( 1), access_vm_reg, NULL, c13_CID },
> -
>  };
>  
>  static const struct sys_reg_desc cp15_64_regs[] = {
> -- 
> 1.8.3.4
> 

Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>



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