Merge remote-tracking branch 'coresight/next-ETE-TRBE' into kvmarm-master/next

Signed-off-by: Marc Zyngier <maz@kernel.org>

5 files changed, 80 insertions, 15 deletions

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 7f06ba76698d..954752208509 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -416,10 +416,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 
 	if (vcpu_has_ptrauth(vcpu))
 		vcpu_ptrauth_disable(vcpu);
+	kvm_arch_vcpu_load_debug_state_flags(vcpu);
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 {
+	kvm_arch_vcpu_put_debug_state_flags(vcpu);
 	kvm_arch_vcpu_put_fp(vcpu);
 	if (has_vhe())
 		kvm_vcpu_put_sysregs_vhe(vcpu);
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index 7a7e425616b5..6f992c696911 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -89,6 +89,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
  *  - Debug ROM Address (MDCR_EL2_TDRA)
  *  - OS related registers (MDCR_EL2_TDOSA)
  *  - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB)
+ *  - Self-hosted Trace (MDCR_EL2_TTRF/MDCR_EL2_E2TB)
  *
  * Additionally, KVM only traps guest accesses to the debug registers if
  * the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
@@ -106,12 +107,13 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
 	trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug);
 
 	/*
-	 * This also clears MDCR_EL2_E2PB_MASK to disable guest access
-	 * to the profiling buffer.
+	 * This also clears MDCR_EL2_E2PB_MASK and MDCR_EL2_E2TB_MASK
+	 * to disable guest access to the profiling and trace buffers
 	 */
 	vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
 	vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM |
 				MDCR_EL2_TPMS |
+				MDCR_EL2_TTRF |
 				MDCR_EL2_TPMCR |
 				MDCR_EL2_TDRA |
 				MDCR_EL2_TDOSA);
@@ -229,3 +231,32 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu)
 		}
 	}
 }
+
+void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu)
+{
+	u64 dfr0;
+
+	/* For VHE, there is nothing to do */
+	if (has_vhe())
+		return;
+
+	dfr0 = read_sysreg(id_aa64dfr0_el1);
+	/*
+	 * If SPE is present on this CPU and is available at current EL,
+	 * we may need to check if the host state needs to be saved.
+	 */
+	if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_PMSVER_SHIFT) &&
+	    !(read_sysreg_s(SYS_PMBIDR_EL1) & BIT(SYS_PMBIDR_EL1_P_SHIFT)))
+		vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_SPE;
+
+	/* Check if we have TRBE implemented and available at the host */
+	if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_TRBE_SHIFT) &&
+	    !(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_PROG))
+		vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_TRBE;
+}
+
+void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.flags &= ~(KVM_ARM64_DEBUG_STATE_SAVE_SPE |
+			      KVM_ARM64_DEBUG_STATE_SAVE_TRBE);
+}
diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
index f401724f12ef..7d3f25868cae 100644
--- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -21,17 +21,11 @@ static void __debug_save_spe(u64 *pmscr_el1)
 	/* Clear pmscr in case of early return */
 	*pmscr_el1 = 0;
 
-	/* SPE present on this CPU? */
-	if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
-						  ID_AA64DFR0_PMSVER_SHIFT))
-		return;
-
-	/* Yes; is it owned by EL3? */
-	reg = read_sysreg_s(SYS_PMBIDR_EL1);
-	if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
-		return;
-
-	/* No; is the host actually using the thing? */
+	/*
+	 * At this point, we know that this CPU implements
+	 * SPE and is available to the host.
+	 * Check if the host is actually using it ?
+	 */
 	reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
 	if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
 		return;
@@ -58,10 +52,43 @@ static void __debug_restore_spe(u64 pmscr_el1)
 	write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
 }
 
+static void __debug_save_trace(u64 *trfcr_el1)
+{
+	*trfcr_el1 = 0;
+
+	/* Check if the TRBE is enabled */
+	if (!(read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_ENABLE))
+		return;
+	/*
+	 * Prohibit trace generation while we are in guest.
+	 * Since access to TRFCR_EL1 is trapped, the guest can't
+	 * modify the filtering set by the host.
+	 */
+	*trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1);
+	write_sysreg_s(0, SYS_TRFCR_EL1);
+	isb();
+	/* Drain the trace buffer to memory */
+	tsb_csync();
+	dsb(nsh);
+}
+
+static void __debug_restore_trace(u64 trfcr_el1)
+{
+	if (!trfcr_el1)
+		return;
+
+	/* Restore trace filter controls */
+	write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1);
+}
+
 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
 {
 	/* Disable and flush SPE data generation */
-	__debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
+	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE)
+		__debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
+	/* Disable and flush Self-Hosted Trace generation */
+	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE)
+		__debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1);
 }
 
 void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
@@ -71,7 +98,10 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
 
 void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
 {
-	__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
+	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE)
+		__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
+	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE)
+		__debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1);
 }
 
 void __debug_switch_to_host(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 68ab6b4d5141..736805232521 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -95,6 +95,7 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
 
 	mdcr_el2 &= MDCR_EL2_HPMN_MASK;
 	mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
+	mdcr_el2 |= MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT;
 
 	write_sysreg(mdcr_el2, mdcr_el2);
 	if (is_protected_kvm_enabled())
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 4f2f1e3145de..52fdb9a015a4 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1472,6 +1472,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_GCR_EL1), undef_access },
 
 	{ SYS_DESC(SYS_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = sve_visibility },
+	{ SYS_DESC(SYS_TRFCR_EL1), undef_access },
 	{ SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
 	{ SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 },
 	{ SYS_DESC(SYS_TCR_EL1), access_vm_reg, reset_val, TCR_EL1, 0 },