[PATCH v3 04/11] KVM: arm: common infrastructure for handling AArch32 CP14/CP15

[Zhichao Huang <zhichao.huang@linaro.org>]

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.

Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org>
---
 arch/arm/kvm/coproc.c          | 176 ++++++++++++++++++++++++++---------------
 arch/arm/kvm/interrupts_head.S |   2 +-
 2 files changed, 112 insertions(+), 66 deletions(-)

diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 9d283d9..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];
 
@@ -424,47 +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;
 }
 
-/**
- * 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)
+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;
 
@@ -478,7 +509,13 @@ int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
 	params.CRm = 0;
 
-	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;
+
+	unhandled_cp_access(vcpu, &params);
+	return 1;
 }
 
 static void reset_coproc_regs(struct kvm_vcpu *vcpu,
@@ -491,12 +528,11 @@ static void reset_coproc_regs(struct kvm_vcpu *vcpu,
 			table[i].reset(vcpu, &table[i]);
 }
 
-/**
- * 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)
+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;
 
@@ -510,33 +546,57 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	params.Op2 = (kvm_vcpu_get_hsr(vcpu) >> 17) & 0x7;
 	params.Rt2 = 0;
 
-	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;
+
+	unhandled_cp_access(vcpu, &params);
+	return 1;
 }
 
 /**
- * kvm_handle_cp14_64 -- handles a mrrc/mcrr trap on a guest CP14 access
+ * 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_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
+int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-	struct coproc_params params;
+	const struct coproc_reg *target_specific;
+	size_t num;
 
-	params.CRn = (kvm_vcpu_get_hsr(vcpu) >> 1) & 0xf;
-	params.Rt1 = (kvm_vcpu_get_hsr(vcpu) >> 5) & 0xf;
-	params.is_write = ((kvm_vcpu_get_hsr(vcpu) & 1) == 0);
-	params.is_64bit = true;
+	target_specific = get_target_table(vcpu->arch.target, &num);
+	return kvm_handle_cp_64(vcpu,
+				cp15_regs, ARRAY_SIZE(cp15_regs),
+				target_specific, num);
+}
 
-	params.Op1 = (kvm_vcpu_get_hsr(vcpu) >> 16) & 0xf;
-	params.Op2 = 0;
-	params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
-	params.CRm = 0;
+/**
+ * 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)
+{
+	const struct coproc_reg *target_specific;
+	size_t num;
 
-	(void)trap_raz_wi(vcpu, &params, NULL);
+	target_specific = get_target_table(vcpu->arch.target, &num);
+	return kvm_handle_cp_32(vcpu,
+				cp15_regs, ARRAY_SIZE(cp15_regs),
+				target_specific, num);
+}
 
-	/* handled */
-	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
-	return 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,
+				cp14_regs, ARRAY_SIZE(cp14_regs),
+				NULL, 0);
 }
 
 /**
@@ -546,23 +606,9 @@ int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
  */
 int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-	struct coproc_params params;
-
-	params.CRm = (kvm_vcpu_get_hsr(vcpu) >> 1) & 0xf;
-	params.Rt1 = (kvm_vcpu_get_hsr(vcpu) >> 5) & 0xf;
-	params.is_write = ((kvm_vcpu_get_hsr(vcpu) & 1) == 0);
-	params.is_64bit = false;
-
-	params.CRn = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
-	params.Op1 = (kvm_vcpu_get_hsr(vcpu) >> 14) & 0x7;
-	params.Op2 = (kvm_vcpu_get_hsr(vcpu) >> 17) & 0x7;
-	params.Rt2 = 0;
-
-	(void)trap_raz_wi(vcpu, &params, NULL);
-
-	/* handled */
-	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
-	return 1;
+	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 f85c447..a20b9ad 100644
--- a/arch/arm/kvm/interrupts_head.S
+++ b/arch/arm/kvm/interrupts_head.S
@@ -618,7 +618,7 @@ 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
-- 
1.7.12.4

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