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Diffstat (limited to 'arch/arm64/kvm/debug.c')
-rw-r--r--arch/arm64/kvm/debug.c88
1 files changed, 60 insertions, 28 deletions
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index dbc890511631..2484b2cca74b 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -69,6 +69,64 @@ void kvm_arm_init_debug(void)
}
/**
+ * kvm_arm_setup_mdcr_el2 - configure vcpu mdcr_el2 value
+ *
+ * @vcpu: the vcpu pointer
+ *
+ * This ensures we will trap access to:
+ * - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR)
+ * - 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)
+ */
+static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu)
+{
+ /*
+ * This also clears MDCR_EL2_E2PB_MASK to disable guest access
+ * to the profiling buffer.
+ */
+ 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);
+
+ /* Is the VM being debugged by userspace? */
+ if (vcpu->guest_debug)
+ /* Route all software debug exceptions to EL2 */
+ vcpu->arch.mdcr_el2 |= MDCR_EL2_TDE;
+
+ /*
+ * Trap debug register access when one of the following is true:
+ * - Userspace is using the hardware to debug the guest
+ * (KVM_GUESTDBG_USE_HW is set).
+ * - The guest is not using debug (KVM_ARM64_DEBUG_DIRTY is clear).
+ */
+ if ((vcpu->guest_debug & KVM_GUESTDBG_USE_HW) ||
+ !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
+ vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA;
+
+ trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2);
+}
+
+/**
+ * kvm_arm_vcpu_init_debug - setup vcpu debug traps
+ *
+ * @vcpu: the vcpu pointer
+ *
+ * Set vcpu initial mdcr_el2 value.
+ */
+void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu)
+{
+ preempt_disable();
+ kvm_arm_setup_mdcr_el2(vcpu);
+ preempt_enable();
+}
+
+/**
* kvm_arm_reset_debug_ptr - reset the debug ptr to point to the vcpu state
*/
@@ -83,13 +141,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
* @vcpu: the vcpu pointer
*
* This is called before each entry into the hypervisor to setup any
- * debug related registers. Currently this just ensures we will trap
- * access to:
- * - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR)
- * - 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)
+ * debug related registers.
*
* Additionally, KVM only traps guest accesses to the debug registers if
* the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
@@ -101,28 +153,14 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
{
- bool trap_debug = !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY);
unsigned long mdscr, orig_mdcr_el2 = vcpu->arch.mdcr_el2;
trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug);
- /*
- * This also clears MDCR_EL2_E2PB_MASK to disable guest access
- * to the profiling buffer.
- */
- 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);
+ kvm_arm_setup_mdcr_el2(vcpu);
/* Is Guest debugging in effect? */
if (vcpu->guest_debug) {
- /* Route all software debug exceptions to EL2 */
- vcpu->arch.mdcr_el2 |= MDCR_EL2_TDE;
-
/* Save guest debug state */
save_guest_debug_regs(vcpu);
@@ -176,7 +214,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state;
vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
- trap_debug = true;
trace_kvm_arm_set_regset("BKPTS", get_num_brps(),
&vcpu->arch.debug_ptr->dbg_bcr[0],
@@ -191,10 +228,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
BUG_ON(!vcpu->guest_debug &&
vcpu->arch.debug_ptr != &vcpu->arch.vcpu_debug_state);
- /* Trap debug register access */
- if (trap_debug)
- vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA;
-
/* If KDE or MDE are set, perform a full save/restore cycle. */
if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE | DBG_MDSCR_MDE))
vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
@@ -203,7 +236,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
if (has_vhe() && orig_mdcr_el2 != vcpu->arch.mdcr_el2)
write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
- trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2);
trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1));
}