diff --git a/arch/arm64/include/asm/el2_setup.h
b/arch/arm64/include/asm/el2_setup.h
index d77d358f9395..bda918948471 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -65,6 +65,19 @@
// use EL1&0 translation.
.Lskip_spe_\@:
+ /* Trace buffer */
+ ubfx x0, x1, #ID_AA64DFR0_TRBE_SHIFT, #4
+ cbz x0, .Lskip_trace_\@ // Skip if TraceBuffer is not
present
+
+ mrs_s x0, SYS_TRBIDR_EL1
+ and x0, x0, TRBIDR_PROG
+ cbnz x0, .Lskip_trace_\@ // If TRBE is available at EL2
+
+ mov x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT)
+ orr x2, x2, x0 // allow the EL1&0 translation
+ // to own it.
+
+.Lskip_trace_\@:
msr mdcr_el2, x2 // Configure debug traps
.endm
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 94d4025acc0b..692c9049befa 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -278,6 +278,8 @@
#define CPTR_EL2_DEFAULT CPTR_EL2_RES1
/* Hyp Debug Configuration Register bits */
+#define MDCR_EL2_E2TB_MASK (UL(0x3))
+#define MDCR_EL2_E2TB_SHIFT (UL(24))
#define MDCR_EL2_TTRF (1 << 19)
#define MDCR_EL2_TPMS (1 << 14)
#define MDCR_EL2_E2PB_MASK (UL(0x3))
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 3d10e6527f7d..80d0a1a82a4c 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -315,6 +315,8 @@ struct kvm_vcpu_arch {
struct kvm_guest_debug_arch regs;
/* Statistical profiling extension */
u64 pmscr_el1;
+ /* Self-hosted trace */
+ u64 trfcr_el1;
} host_debug_state;
/* VGIC state */
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index 5eccbd62fec8..05d25e645b46 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -115,9 +115,10 @@ SYM_CODE_START_LOCAL(mutate_to_vhe)
mrs_s x0, SYS_VBAR_EL12
msr vbar_el1, x0
- // Use EL2 translations for SPE and disable access from EL1
+ // Use EL2 translations for SPE & TRBE and disable access from EL1
mrs x0, mdcr_el2
bic x0, x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
+ bic x0, x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT)
msr mdcr_el2, x0
// Transfer the MM state from EL1 to EL2
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index dbc890511631..7b16f42d39f4 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -89,7 +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 Filter controls (MDCR_EL2_TTRF)
+ * - 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
@@ -107,8 +107,8 @@ 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 |
diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
index f401724f12ef..9499e18dd28f 100644
--- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -58,10 +58,51 @@ 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 we have TRBE */
+ if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
+ ID_AA64DFR0_TRBE_SHIFT))
+ return;
+
+ /* Check we can access the TRBE */
+ if ((read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_PROG))
+ return;
+
+ /* 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);
+ /* Disable and flush Self-Hosted Trace generation */
+ __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1);
}
void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
@@ -72,6 +113,7 @@ 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);
+ __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())
--
2.24.1
