1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2015 - ARM Ltd 4 * Author: Marc Zyngier <marc.zyngier@arm.com> 5 */ 6 7 #include <hyp/debug-sr.h> 8 9 #include <linux/compiler.h> 10 #include <linux/kvm_host.h> 11 12 #include <asm/debug-monitors.h> 13 #include <asm/kvm_asm.h> 14 #include <asm/kvm_hyp.h> 15 #include <asm/kvm_mmu.h> 16 17 static void __debug_save_spe(u64 *pmscr_el1) 18 { 19 u64 reg; 20 21 /* Clear pmscr in case of early return */ 22 *pmscr_el1 = 0; 23 24 /* 25 * At this point, we know that this CPU implements 26 * SPE and is available to the host. 27 * Check if the host is actually using it ? 28 */ 29 reg = read_sysreg_s(SYS_PMBLIMITR_EL1); 30 if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT))) 31 return; 32 33 /* Yes; save the control register and disable data generation */ 34 *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1); 35 write_sysreg_s(0, SYS_PMSCR_EL1); 36 isb(); 37 38 /* Now drain all buffered data to memory */ 39 psb_csync(); 40 dsb(nsh); 41 } 42 43 static void __debug_restore_spe(u64 pmscr_el1) 44 { 45 if (!pmscr_el1) 46 return; 47 48 /* The host page table is installed, but not yet synchronised */ 49 isb(); 50 51 /* Re-enable data generation */ 52 write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1); 53 } 54 55 static void __debug_save_trace(u64 *trfcr_el1) 56 { 57 *trfcr_el1 = 0; 58 59 /* Check if the TRBE is enabled */ 60 if (!(read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_ENABLE)) 61 return; 62 /* 63 * Prohibit trace generation while we are in guest. 64 * Since access to TRFCR_EL1 is trapped, the guest can't 65 * modify the filtering set by the host. 66 */ 67 *trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1); 68 write_sysreg_s(0, SYS_TRFCR_EL1); 69 isb(); 70 /* Drain the trace buffer to memory */ 71 tsb_csync(); 72 dsb(nsh); 73 } 74 75 static void __debug_restore_trace(u64 trfcr_el1) 76 { 77 if (!trfcr_el1) 78 return; 79 80 /* Restore trace filter controls */ 81 write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1); 82 } 83 84 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) 85 { 86 /* Disable and flush SPE data generation */ 87 if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE) 88 __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1); 89 /* Disable and flush Self-Hosted Trace generation */ 90 if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE) 91 __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1); 92 } 93 94 void __debug_switch_to_guest(struct kvm_vcpu *vcpu) 95 { 96 __debug_switch_to_guest_common(vcpu); 97 } 98 99 void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) 100 { 101 if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE) 102 __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1); 103 if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE) 104 __debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1); 105 } 106 107 void __debug_switch_to_host(struct kvm_vcpu *vcpu) 108 { 109 __debug_switch_to_host_common(vcpu); 110 } 111 112 u32 __kvm_get_mdcr_el2(void) 113 { 114 return read_sysreg(mdcr_el2); 115 } 116