[PATCH v3 06/11] KVM: arm: add trap handlers for 32-bit debug registers
Christoffer Dall
christoffer.dall at linaro.org
Mon Jun 29 14:16:41 PDT 2015
On Mon, Jun 22, 2015 at 06:41:29PM +0800, Zhichao Huang wrote:
> Add handlers for all the 32-bit debug registers.
>
> Signed-off-by: Zhichao Huang <zhichao.huang at linaro.org>
> ---
> arch/arm/include/asm/kvm_asm.h | 12 ++++
> arch/arm/include/asm/kvm_host.h | 3 +
> arch/arm/kernel/asm-offsets.c | 1 +
> arch/arm/kvm/coproc.c | 122 ++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 138 insertions(+)
>
> diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
> index 25410b2..ba65e05 100644
> --- a/arch/arm/include/asm/kvm_asm.h
> +++ b/arch/arm/include/asm/kvm_asm.h
> @@ -52,6 +52,18 @@
> #define c10_AMAIR1 30 /* Auxilary Memory Attribute Indirection Reg1 */
> #define NR_CP15_REGS 31 /* Number of regs (incl. invalid) */
>
> +/* 0 is reserved as an invalid value. */
> +#define cp14_DBGBVR0 1 /* Debug Breakpoint Control Registers (0-15) */
> +#define cp14_DBGBVR15 16
> +#define cp14_DBGBCR0 17 /* Debug Breakpoint Value Registers (0-15) */
> +#define cp14_DBGBCR15 32
> +#define cp14_DBGWVR0 33 /* Debug Watchpoint Control Registers (0-15) */
> +#define cp14_DBGWVR15 48
> +#define cp14_DBGWCR0 49 /* Debug Watchpoint Value Registers (0-15) */
> +#define cp14_DBGWCR15 64
> +#define cp14_DBGDSCRext 65 /* Debug Status and Control external */
> +#define NR_CP14_REGS 66 /* Number of regs (incl. invalid) */
> +
> #define ARM_EXCEPTION_RESET 0
> #define ARM_EXCEPTION_UNDEFINED 1
> #define ARM_EXCEPTION_SOFTWARE 2
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index d71607c..3d16820 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -124,6 +124,9 @@ struct kvm_vcpu_arch {
> struct vgic_cpu vgic_cpu;
> struct arch_timer_cpu timer_cpu;
>
> + /* System control coprocessor (cp14) */
> + u32 cp14[NR_CP14_REGS];
> +
> /*
> * Anything that is not used directly from assembly code goes
> * here.
> diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
> index 871b826..9158de0 100644
> --- a/arch/arm/kernel/asm-offsets.c
> +++ b/arch/arm/kernel/asm-offsets.c
> @@ -172,6 +172,7 @@ int main(void)
> #ifdef CONFIG_KVM_ARM_HOST
> DEFINE(VCPU_KVM, offsetof(struct kvm_vcpu, kvm));
> DEFINE(VCPU_MIDR, offsetof(struct kvm_vcpu, arch.midr));
> + DEFINE(VCPU_CP14, offsetof(struct kvm_vcpu, arch.cp14));
> DEFINE(VCPU_CP15, offsetof(struct kvm_vcpu, arch.cp15));
> DEFINE(VCPU_VFP_GUEST, offsetof(struct kvm_vcpu, arch.vfp_guest));
> DEFINE(VCPU_VFP_HOST, offsetof(struct kvm_vcpu, arch.host_cpu_context));
> diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
> index 16d5f69..59b65b7 100644
> --- a/arch/arm/kvm/coproc.c
> +++ b/arch/arm/kvm/coproc.c
> @@ -220,6 +220,47 @@ bool access_vm_reg(struct kvm_vcpu *vcpu,
> return true;
> }
>
> +static bool trap_debug32(struct kvm_vcpu *vcpu,
> + const struct coproc_params *p,
> + const struct coproc_reg *r)
> +{
> + if (p->is_write)
> + vcpu->arch.cp14[r->reg] = *vcpu_reg(vcpu, p->Rt1);
> + else
> + *vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp14[r->reg];
> +
> + return true;
> +}
> +
> +/* DBGIDR (RO) Debug ID */
> +static bool trap_dbgidr(struct kvm_vcpu *vcpu,
> + const struct coproc_params *p,
> + const struct coproc_reg *r)
> +{
> + u32 val;
> +
> + if (p->is_write)
> + return ignore_write(vcpu, p);
> +
> + ARM_DBG_READ(c0, c0, 0, val);
> + *vcpu_reg(vcpu, p->Rt1) = val;
> +
> + return true;
> +}
> +
> +/* DBGDSCRint (RO) Debug Status and Control Register */
> +static bool trap_dbgdscr(struct kvm_vcpu *vcpu,
> + const struct coproc_params *p,
> + const struct coproc_reg *r)
> +{
> + if (p->is_write)
> + return ignore_write(vcpu, p);
> +
> + *vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp14[r->reg];
> +
> + return true;
> +}
> +
> /*
> * We could trap ID_DFR0 and tell the guest we don't support performance
> * monitoring. Unfortunately the patch to make the kernel check ID_DFR0 was
> @@ -375,7 +416,88 @@ static const struct coproc_reg cp15_regs[] = {
> { CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
> };
>
> +#define DBG_BCR_BVR_WCR_WVR(n) \
> + /* DBGBVRn */ \
> + { CRn( 0), CRm((n)), Op1( 0), Op2( 4), is32, \
> + trap_debug32, reset_val, (cp14_DBGBVR0 + (n)), 0 }, \
> + /* DBGBCRn */ \
> + { CRn( 0), CRm((n)), Op1( 0), Op2( 5), is32, \
> + trap_debug32, reset_val, (cp14_DBGBCR0 + (n)), 0 }, \
> + /* DBGWVRn */ \
> + { CRn( 0), CRm((n)), Op1( 0), Op2( 6), is32, \
> + trap_debug32, reset_val, (cp14_DBGWVR0 + (n)), 0 }, \
> + /* DBGWCRn */ \
> + { CRn( 0), CRm((n)), Op1( 0), Op2( 7), is32, \
> + trap_debug32, reset_val, (cp14_DBGWCR0 + (n)), 0 }
> +
> +/* No OS DBGBXVR machanism implemented. */
> +#define DBGBXVR(n) \
> + { CRn( 1), CRm((n)), Op1( 0), Op2( 1), is32, trap_raz_wi }
> +
> +/*
> + * 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.
s/whould/should/
> + */
> static const struct coproc_reg cp14_regs[] = {
> + /* DBGIDR */
> + { CRn( 0), CRm( 0), Op1( 0), Op2( 0), is32, trap_dbgidr},
> + /* DBGDTRRXext */
> + { CRn( 0), CRm( 0), Op1( 0), Op2( 2), is32, trap_raz_wi },
> + DBG_BCR_BVR_WCR_WVR(0),
> + /* DBGDSCRint */
> + { CRn( 0), CRm( 1), Op1( 0), Op2( 0), is32, trap_dbgdscr,
> + NULL, cp14_DBGDSCRext },
> + DBG_BCR_BVR_WCR_WVR(1),
> + /* DBGDSCRext */
> + { CRn( 0), CRm( 2), Op1( 0), Op2( 2), is32, trap_debug32,
> + reset_val, cp14_DBGDSCRext, 0 },
> + DBG_BCR_BVR_WCR_WVR(2),
> + /* DBGDTRRXext */
> + { CRn( 0), CRm( 3), Op1( 0), Op2( 2), is32, trap_raz_wi },
isn't this the DBGDTRTXext register?
> + DBG_BCR_BVR_WCR_WVR(3),
> + DBG_BCR_BVR_WCR_WVR(4),
> + /* DBGDTR[RT]Xint */
> + { CRn( 0), CRm( 5), Op1( 0), Op2( 0), is32, trap_raz_wi },
> + DBG_BCR_BVR_WCR_WVR(5),
> + DBG_BCR_BVR_WCR_WVR(6),
> + /* DBGVCR */
> + { CRn( 0), CRm( 7), Op1( 0), Op2( 0), is32, 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),
> +
> + DBGBXVR(0),
> + /* DBGOSLAR */
> + { CRn( 1), CRm( 0), Op1( 0), Op2( 4), is32, trap_raz_wi },
> + DBGBXVR(1),
> + /* DBGOSLSR */
> + { CRn( 1), CRm( 1), Op1( 0), Op2( 4), is32, trap_raz_wi },
> + DBGBXVR(2),
> + DBGBXVR(3),
> + /* DBGOSDLRd */
> + { CRn( 1), CRm( 3), Op1( 0), Op2( 4), is32, trap_raz_wi },
> + DBGBXVR(4),
> + DBGBXVR(5),
> + /* DBGPRSRa */
> + { CRn( 1), CRm( 5), Op1( 0), Op2( 4), is32, trap_raz_wi },
> +
> + DBGBXVR(6),
> + DBGBXVR(7),
> + DBGBXVR(8),
> + DBGBXVR(9),
> + DBGBXVR(10),
> + DBGBXVR(11),
> + DBGBXVR(12),
> + DBGBXVR(13),
> + DBGBXVR(14),
> + DBGBXVR(15),
> };
>
> /* Target specific emulation tables */
> --
> 1.7.12.4
>
Otherwise this looks ok,
-Christoffer
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