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(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 } 41 42 static void __debug_restore_spe(u64 pmscr_el1) 43 { 44 if (!pmscr_el1) 45 return; 46 47 /* The host page table is installed, but not yet synchronised */ 48 isb(); 49 50 /* Re-enable data generation */ 51 write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1); 52 } 53 54 static void __debug_save_trace(u64 *trfcr_el1) 55 { 56 *trfcr_el1 = 0; 57 58 /* Check if the TRBE is enabled */ 59 if (!(read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_ENABLE)) 60 return; 61 /* 62 * Prohibit trace generation while we are in guest. 63 * Since access to TRFCR_EL1 is trapped, the guest can't 64 * modify the filtering set by the host. 65 */ 66 *trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1); 67 write_sysreg_s(0, SYS_TRFCR_EL1); 68 isb(); 69 /* Drain the trace buffer to memory */ 70 tsb_csync(); 71 } 72 73 static void __debug_restore_trace(u64 trfcr_el1) 74 { 75 if (!trfcr_el1) 76 return; 77 78 /* Restore trace filter controls */ 79 write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1); 80 } 81 82 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) 83 { 84 /* Disable and flush SPE data generation */ 85 if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) 86 __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1); 87 /* Disable and flush Self-Hosted Trace generation */ 88 if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) 89 __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1); 90 } 91 92 void __debug_switch_to_guest(struct kvm_vcpu *vcpu) 93 { 94 __debug_switch_to_guest_common(vcpu); 95 } 96 97 void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) 98 { 99 if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) 100 __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1); 101 if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) 102 __debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1); 103 } 104 105 void __debug_switch_to_host(struct kvm_vcpu *vcpu) 106 { 107 __debug_switch_to_host_common(vcpu); 108 } 109 110 u64 __kvm_get_mdcr_el2(void) 111 { 112 return read_sysreg(mdcr_el2); 113 } 114