[v4,04/15] KVM: arm: common infrastructure for handling AArch32 CP14/CP15
diff mbox

Message ID 1439213167-8988-5-git-send-email-zhichao.huang@linaro.org
State New
Headers show

Commit Message

Zhichao Huang Aug. 10, 2015, 1:25 p.m. UTC
As we're about to trap a bunch of CP14 registers, let's rework
the CP15 handling so it can be generalized and work with multiple
tables.

We stop trapping access here, because we haven't finished our trap
handlers. We will enable trapping agian until everything is OK.

Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org>
---
 arch/arm/kvm/coproc.c          | 168 ++++++++++++++++++++++++++---------------
 arch/arm/kvm/interrupts_head.S |   2 +-
 2 files changed, 110 insertions(+), 60 deletions(-)

Comments

Christoffer Dall Sept. 2, 2015, 1:09 p.m. UTC | #1
On Mon, Aug 10, 2015 at 09:25:56PM +0800, Zhichao Huang wrote:
> As we're about to trap a bunch of CP14 registers, let's rework
> the CP15 handling so it can be generalized and work with multiple
> tables.
> 
> We stop trapping access here, because we haven't finished our trap
> handlers. We will enable trapping agian until everything is OK.
> 
> Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org>
> ---
>  arch/arm/kvm/coproc.c          | 168 ++++++++++++++++++++++++++---------------
>  arch/arm/kvm/interrupts_head.S |   2 +-
>  2 files changed, 110 insertions(+), 60 deletions(-)
> 
> diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
> index 4db571d..d23395b 100644
> --- a/arch/arm/kvm/coproc.c
> +++ b/arch/arm/kvm/coproc.c
> @@ -375,6 +375,9 @@ static const struct coproc_reg cp15_regs[] = {
>  	{ CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
>  };
>  
> +static const struct coproc_reg cp14_regs[] = {
> +};
> +
>  /* Target specific emulation tables */
>  static struct kvm_coproc_target_table *target_tables[KVM_ARM_NUM_TARGETS];
>  
> @@ -424,43 +427,75 @@ static const struct coproc_reg *find_reg(const struct coproc_params *params,
>  	return NULL;
>  }
>  
> -static int emulate_cp15(struct kvm_vcpu *vcpu,
> -			const struct coproc_params *params)
> +/*
> + * emulate_cp --  tries to match a cp14/cp15 access in a handling table,
> + *                and call the corresponding trap handler.
> + *
> + * @params: pointer to the descriptor of the access
> + * @table: array of trap descriptors
> + * @num: size of the trap descriptor array
> + *
> + * Return 0 if the access has been handled, and -1 if not.
> + */
> +static int emulate_cp(struct kvm_vcpu *vcpu,
> +			const struct coproc_params *params,
> +			const struct coproc_reg *table,
> +			size_t num)
>  {
> -	size_t num;
> -	const struct coproc_reg *table, *r;
> -
> -	trace_kvm_emulate_cp15_imp(params->Op1, params->Rt1, params->CRn,
> -				   params->CRm, params->Op2, params->is_write);
> +	const struct coproc_reg *r;
>  
> -	table = get_target_table(vcpu->arch.target, &num);
> +	if (!table)
> +		return -1;	/* Not handled */
>  
> -	/* Search target-specific then generic table. */
>  	r = find_reg(params, table, num);
> -	if (!r)
> -		r = find_reg(params, cp15_regs, ARRAY_SIZE(cp15_regs));
>  
> -	if (likely(r)) {
> +	if (r) {
>  		/* If we don't have an accessor, we should never get here! */
>  		BUG_ON(!r->access);
>  
>  		if (likely(r->access(vcpu, params, r))) {
>  			/* Skip instruction, since it was emulated */
>  			kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
> -			return 1;
>  		}
> -		/* If access function fails, it should complain. */
> -	} else {
> -		kvm_err("Unsupported guest CP15 access at: %08lx\n",
> -			*vcpu_pc(vcpu));
> -		print_cp_instr(params);
> +
> +		/* Handled */
> +		return 0;
>  	}
> +
> +	/* Not handled */
> +	return -1;
> +}
> +
> +static void unhandled_cp_access(struct kvm_vcpu *vcpu,
> +				const struct coproc_params *params)
> +{
> +	u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
> +	int cp;
> +
> +	switch (hsr_ec) {
> +	case HSR_EC_CP15_32:
> +	case HSR_EC_CP15_64:
> +		cp = 15;
> +		break;
> +	case HSR_EC_CP14_MR:
> +	case HSR_EC_CP14_64:
> +		cp = 14;
> +		break;
> +	default:
> +		WARN_ON((cp = -1));
> +	}
> +
> +	kvm_err("Unsupported guest CP%d access at: %08lx\n",
> +		cp, *vcpu_pc(vcpu));
> +	print_cp_instr(params);
>  	kvm_inject_undefined(vcpu);
> -	return 1;
>  }
>  
> -static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, struct kvm_run *run,
> -			    bool cp15)
> +int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
> +			const struct coproc_reg *global,
> +			size_t nr_global,
> +			const struct coproc_reg *target_specific,
> +			size_t nr_specific)
>  {
>  	struct coproc_params params;
>  
> @@ -474,37 +509,15 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, struct kvm_run *run,
>  	params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
>  	params.CRm = 0;
>  
> -	if (cp15)
> -		return emulate_cp15(vcpu, &params);
> +	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))
> +		return 1;
> +	if (!emulate_cp(vcpu, &params, global, nr_global))
> +		return 1;
>  
> -	/* raz_wi cp14 */
> -	(void)trap_raz_wi(vcpu, &params, NULL);
> -
> -	/* handled */
> -	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
> +	unhandled_cp_access(vcpu, &params);
>  	return 1;
>  }
>  
> -/**
> - * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access
> - * @vcpu: The VCPU pointer
> - * @run:  The kvm_run struct
> - */
> -int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> -{
> -	return kvm_handle_cp_64(vcpu, run, 1);
> -}
> -
> -/**
> - * kvm_handle_cp14_64 -- handles a mrrc/mcrr trap on a guest CP14 access
> - * @vcpu: The VCPU pointer
> - * @run:  The kvm_run struct
> - */
> -int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> -{
> -	return kvm_handle_cp_64(vcpu, run, 0);
> -}
> -
>  static void reset_coproc_regs(struct kvm_vcpu *vcpu,
>  			      const struct coproc_reg *table, size_t num)
>  {
> @@ -515,8 +528,11 @@ static void reset_coproc_regs(struct kvm_vcpu *vcpu,
>  			table[i].reset(vcpu, &table[i]);
>  }
>  
> -static int kvm_handle_cp_32(struct kvm_vcpu *vcpu, struct kvm_run *run,
> -			      bool cp15)
> +int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
> +			const struct coproc_reg *global,
> +			size_t nr_global,
> +			const struct coproc_reg *target_specific,
> +			size_t nr_specific)
>  {
>  	struct coproc_params params;
>  
> @@ -530,25 +546,57 @@ static int kvm_handle_cp_32(struct kvm_vcpu *vcpu, struct kvm_run *run,
>  	params.Op2 = (kvm_vcpu_get_hsr(vcpu) >> 17) & 0x7;
>  	params.Rt2 = 0;
>  
> -	if (cp15)
> -		return emulate_cp15(vcpu, &params);
> -
> -	/* raz_wi cp14 */
> -	(void)trap_raz_wi(vcpu, &params, NULL);
> +	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))
> +		return 1;
> +	if (!emulate_cp(vcpu, &params, global, nr_global))
> +		return 1;
>  
> -	/* handled */
> -	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
> +	unhandled_cp_access(vcpu, &params);
>  	return 1;
>  }
>  
>  /**
> + * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access
> + * @vcpu: The VCPU pointer
> + * @run:  The kvm_run struct
> + */
> +int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +{
> +	const struct coproc_reg *target_specific;
> +	size_t num;
> +
> +	target_specific = get_target_table(vcpu->arch.target, &num);
> +	return kvm_handle_cp_64(vcpu,
> +				cp15_regs, ARRAY_SIZE(cp15_regs),
> +				target_specific, num);
> +}
> +
> +/**
>   * kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access
>   * @vcpu: The VCPU pointer
>   * @run:  The kvm_run struct
>   */
>  int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  {
> -	return kvm_handle_cp_32(vcpu, run, 1);
> +	const struct coproc_reg *target_specific;
> +	size_t num;
> +
> +	target_specific = get_target_table(vcpu->arch.target, &num);
> +	return kvm_handle_cp_32(vcpu,
> +				cp15_regs, ARRAY_SIZE(cp15_regs),
> +				target_specific, num);
> +}
> +
> +/**
> + * kvm_handle_cp14_64 -- handles a mrrc/mcrr trap on a guest CP14 access
> + * @vcpu: The VCPU pointer
> + * @run:  The kvm_run struct
> + */
> +int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +{
> +	return kvm_handle_cp_64(vcpu,
> +				cp14_regs, ARRAY_SIZE(cp14_regs),
> +				NULL, 0);
>  }
>  
>  /**
> @@ -558,7 +606,9 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
>   */
>  int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  {
> -	return kvm_handle_cp_32(vcpu, run, 0);
> +	return kvm_handle_cp_32(vcpu,
> +				cp14_regs, ARRAY_SIZE(cp14_regs),
> +				NULL, 0);
>  }
>  
>  /******************************************************************************
> diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
> index 7c4075c..7ac5e51 100644
> --- a/arch/arm/kvm/interrupts_head.S
> +++ b/arch/arm/kvm/interrupts_head.S
> @@ -633,7 +633,7 @@ ARM_BE8(rev	r6, r6  )
>   * (hardware reset value is 0) */
>  .macro set_hdcr operation
>  	mrc	p15, 4, r2, c1, c1, 1
> -	ldr	r3, =(HDCR_TPM|HDCR_TPMCR|HDCR_TDRA|HDCR_TDOSA|HDCR_TDA)
> +	ldr	r3, =(HDCR_TPM|HDCR_TPMCR)

I know I said ok to this, but I don't like the ordering of this with
these patches.

I think we should only stop trapping debug accesses when we have proper
world-switching in place.

You should be able to put all the infrastructure needed in place first,
and then hook things up in the end.

Thanks,
-Christoffer

>  	.if \operation == vmentry
>  	orr	r2, r2, r3		@ Trap some perfmon accesses
>  	.else
> -- 
> 1.7.12.4
> 
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Patch
diff mbox

diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 4db571d..d23395b 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -375,6 +375,9 @@  static const struct coproc_reg cp15_regs[] = {
 	{ CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
 };
 
+static const struct coproc_reg cp14_regs[] = {
+};
+
 /* Target specific emulation tables */
 static struct kvm_coproc_target_table *target_tables[KVM_ARM_NUM_TARGETS];
 
@@ -424,43 +427,75 @@  static const struct coproc_reg *find_reg(const struct coproc_params *params,
 	return NULL;
 }
 
-static int emulate_cp15(struct kvm_vcpu *vcpu,
-			const struct coproc_params *params)
+/*
+ * emulate_cp --  tries to match a cp14/cp15 access in a handling table,
+ *                and call the corresponding trap handler.
+ *
+ * @params: pointer to the descriptor of the access
+ * @table: array of trap descriptors
+ * @num: size of the trap descriptor array
+ *
+ * Return 0 if the access has been handled, and -1 if not.
+ */
+static int emulate_cp(struct kvm_vcpu *vcpu,
+			const struct coproc_params *params,
+			const struct coproc_reg *table,
+			size_t num)
 {
-	size_t num;
-	const struct coproc_reg *table, *r;
-
-	trace_kvm_emulate_cp15_imp(params->Op1, params->Rt1, params->CRn,
-				   params->CRm, params->Op2, params->is_write);
+	const struct coproc_reg *r;
 
-	table = get_target_table(vcpu->arch.target, &num);
+	if (!table)
+		return -1;	/* Not handled */
 
-	/* Search target-specific then generic table. */
 	r = find_reg(params, table, num);
-	if (!r)
-		r = find_reg(params, cp15_regs, ARRAY_SIZE(cp15_regs));
 
-	if (likely(r)) {
+	if (r) {
 		/* If we don't have an accessor, we should never get here! */
 		BUG_ON(!r->access);
 
 		if (likely(r->access(vcpu, params, r))) {
 			/* Skip instruction, since it was emulated */
 			kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
-			return 1;
 		}
-		/* If access function fails, it should complain. */
-	} else {
-		kvm_err("Unsupported guest CP15 access at: %08lx\n",
-			*vcpu_pc(vcpu));
-		print_cp_instr(params);
+
+		/* Handled */
+		return 0;
 	}
+
+	/* Not handled */
+	return -1;
+}
+
+static void unhandled_cp_access(struct kvm_vcpu *vcpu,
+				const struct coproc_params *params)
+{
+	u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
+	int cp;
+
+	switch (hsr_ec) {
+	case HSR_EC_CP15_32:
+	case HSR_EC_CP15_64:
+		cp = 15;
+		break;
+	case HSR_EC_CP14_MR:
+	case HSR_EC_CP14_64:
+		cp = 14;
+		break;
+	default:
+		WARN_ON((cp = -1));
+	}
+
+	kvm_err("Unsupported guest CP%d access at: %08lx\n",
+		cp, *vcpu_pc(vcpu));
+	print_cp_instr(params);
 	kvm_inject_undefined(vcpu);
-	return 1;
 }
 
-static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, struct kvm_run *run,
-			    bool cp15)
+int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
+			const struct coproc_reg *global,
+			size_t nr_global,
+			const struct coproc_reg *target_specific,
+			size_t nr_specific)
 {
 	struct coproc_params params;
 
@@ -474,37 +509,15 @@  static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
 	params.CRm = 0;
 
-	if (cp15)
-		return emulate_cp15(vcpu, &params);
+	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))
+		return 1;
+	if (!emulate_cp(vcpu, &params, global, nr_global))
+		return 1;
 
-	/* raz_wi cp14 */
-	(void)trap_raz_wi(vcpu, &params, NULL);
-
-	/* handled */
-	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+	unhandled_cp_access(vcpu, &params);
 	return 1;
 }
 
-/**
- * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access
- * @vcpu: The VCPU pointer
- * @run:  The kvm_run struct
- */
-int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
-{
-	return kvm_handle_cp_64(vcpu, run, 1);
-}
-
-/**
- * kvm_handle_cp14_64 -- handles a mrrc/mcrr trap on a guest CP14 access
- * @vcpu: The VCPU pointer
- * @run:  The kvm_run struct
- */
-int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
-{
-	return kvm_handle_cp_64(vcpu, run, 0);
-}
-
 static void reset_coproc_regs(struct kvm_vcpu *vcpu,
 			      const struct coproc_reg *table, size_t num)
 {
@@ -515,8 +528,11 @@  static void reset_coproc_regs(struct kvm_vcpu *vcpu,
 			table[i].reset(vcpu, &table[i]);
 }
 
-static int kvm_handle_cp_32(struct kvm_vcpu *vcpu, struct kvm_run *run,
-			      bool cp15)
+int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
+			const struct coproc_reg *global,
+			size_t nr_global,
+			const struct coproc_reg *target_specific,
+			size_t nr_specific)
 {
 	struct coproc_params params;
 
@@ -530,25 +546,57 @@  static int kvm_handle_cp_32(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	params.Op2 = (kvm_vcpu_get_hsr(vcpu) >> 17) & 0x7;
 	params.Rt2 = 0;
 
-	if (cp15)
-		return emulate_cp15(vcpu, &params);
-
-	/* raz_wi cp14 */
-	(void)trap_raz_wi(vcpu, &params, NULL);
+	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))
+		return 1;
+	if (!emulate_cp(vcpu, &params, global, nr_global))
+		return 1;
 
-	/* handled */
-	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+	unhandled_cp_access(vcpu, &params);
 	return 1;
 }
 
 /**
+ * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access
+ * @vcpu: The VCPU pointer
+ * @run:  The kvm_run struct
+ */
+int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	const struct coproc_reg *target_specific;
+	size_t num;
+
+	target_specific = get_target_table(vcpu->arch.target, &num);
+	return kvm_handle_cp_64(vcpu,
+				cp15_regs, ARRAY_SIZE(cp15_regs),
+				target_specific, num);
+}
+
+/**
  * kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access
  * @vcpu: The VCPU pointer
  * @run:  The kvm_run struct
  */
 int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-	return kvm_handle_cp_32(vcpu, run, 1);
+	const struct coproc_reg *target_specific;
+	size_t num;
+
+	target_specific = get_target_table(vcpu->arch.target, &num);
+	return kvm_handle_cp_32(vcpu,
+				cp15_regs, ARRAY_SIZE(cp15_regs),
+				target_specific, num);
+}
+
+/**
+ * kvm_handle_cp14_64 -- handles a mrrc/mcrr trap on a guest CP14 access
+ * @vcpu: The VCPU pointer
+ * @run:  The kvm_run struct
+ */
+int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	return kvm_handle_cp_64(vcpu,
+				cp14_regs, ARRAY_SIZE(cp14_regs),
+				NULL, 0);
 }
 
 /**
@@ -558,7 +606,9 @@  int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
  */
 int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-	return kvm_handle_cp_32(vcpu, run, 0);
+	return kvm_handle_cp_32(vcpu,
+				cp14_regs, ARRAY_SIZE(cp14_regs),
+				NULL, 0);
 }
 
 /******************************************************************************
diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
index 7c4075c..7ac5e51 100644
--- a/arch/arm/kvm/interrupts_head.S
+++ b/arch/arm/kvm/interrupts_head.S
@@ -633,7 +633,7 @@  ARM_BE8(rev	r6, r6  )
  * (hardware reset value is 0) */
 .macro set_hdcr operation
 	mrc	p15, 4, r2, c1, c1, 1
-	ldr	r3, =(HDCR_TPM|HDCR_TPMCR|HDCR_TDRA|HDCR_TDOSA|HDCR_TDA)
+	ldr	r3, =(HDCR_TPM|HDCR_TPMCR)
 	.if \operation == vmentry
 	orr	r2, r2, r3		@ Trap some perfmon accesses
 	.else