1 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
new file mode 100644
index 000000000000..e17455773b98
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <hyp/debug-sr.h>
+
+#include <linux/compiler.h>
+#include <linux/kvm_host.h>
+
+#include <asm/debug-monitors.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+
+static void __debug_save_spe(u64 *pmscr_el1)
+{
+	u64 reg;
+
+	/* Clear pmscr in case of early return */
+	*pmscr_el1 = 0;
+
+	/*
+	 * 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;
+
+	/* Yes; save the control register and disable data generation */
+	*pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
+	write_sysreg_s(0, SYS_PMSCR_EL1);
+	isb();
+
+	/* Now drain all buffered data to memory */
+	psb_csync();
+	dsb(nsh);
+}
+
+static void __debug_restore_spe(u64 pmscr_el1)
+{
+	if (!pmscr_el1)
+		return;
+
+	/* The host page table is installed, but not yet synchronised */
+	isb();
+
+	/* Re-enable data generation */
+	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 */
+	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
+		__debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
+	/* Disable and flush Self-Hosted Trace generation */
+	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
+		__debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1);
+}
+
+void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
+{
+	__debug_switch_to_guest_common(vcpu);
+}
+
+void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
+{
+	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
+		__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
+	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
+		__debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1);
+}
+
+void __debug_switch_to_host(struct kvm_vcpu *vcpu)
+{
+	__debug_switch_to_host_common(vcpu);
+}
+
+u64 __kvm_get_mdcr_el2(void)
+{
+	return read_sysreg(mdcr_el2);
+}