1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2012-2015 - ARM Ltd 4 * Author: Marc Zyngier <marc.zyngier@arm.com> 5 */ 6 7 #include <hyp/sysreg-sr.h> 8 9 #include <linux/compiler.h> 10 #include <linux/kvm_host.h> 11 12 #include <asm/kprobes.h> 13 #include <asm/kvm_asm.h> 14 #include <asm/kvm_emulate.h> 15 #include <asm/kvm_hyp.h> 16 17 /* 18 * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and 19 * pstate, which are handled as part of the el2 return state) on every 20 * switch (sp_el0 is being dealt with in the assembly code). 21 * tpidr_el0 and tpidrro_el0 only need to be switched when going 22 * to host userspace or a different VCPU. EL1 registers only need to be 23 * switched when potentially going to run a different VCPU. The latter two 24 * classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put. 25 */ 26 27 void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt) 28 { 29 __sysreg_save_common_state(ctxt); 30 } 31 NOKPROBE_SYMBOL(sysreg_save_host_state_vhe); 32 33 void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt) 34 { 35 __sysreg_save_common_state(ctxt); 36 __sysreg_save_el2_return_state(ctxt); 37 } 38 NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe); 39 40 void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt) 41 { 42 __sysreg_restore_common_state(ctxt); 43 } 44 NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe); 45 46 void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt) 47 { 48 __sysreg_restore_common_state(ctxt); 49 __sysreg_restore_el2_return_state(ctxt); 50 } 51 NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe); 52 53 /** 54 * kvm_vcpu_load_sysregs_vhe - Load guest system registers to the physical CPU 55 * 56 * @vcpu: The VCPU pointer 57 * 58 * Load system registers that do not affect the host's execution, for 59 * example EL1 system registers on a VHE system where the host kernel 60 * runs at EL2. This function is called from KVM's vcpu_load() function 61 * and loading system register state early avoids having to load them on 62 * every entry to the VM. 63 */ 64 void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu) 65 { 66 struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; 67 struct kvm_cpu_context *host_ctxt; 68 69 host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; 70 __sysreg_save_user_state(host_ctxt); 71 72 /* 73 * Load guest EL1 and user state 74 * 75 * We must restore the 32-bit state before the sysregs, thanks 76 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). 77 */ 78 __sysreg32_restore_state(vcpu); 79 __sysreg_restore_user_state(guest_ctxt); 80 __sysreg_restore_el1_state(guest_ctxt); 81 82 vcpu->arch.sysregs_loaded_on_cpu = true; 83 84 activate_traps_vhe_load(vcpu); 85 } 86 87 /** 88 * kvm_vcpu_put_sysregs_vhe - Restore host system registers to the physical CPU 89 * 90 * @vcpu: The VCPU pointer 91 * 92 * Save guest system registers that do not affect the host's execution, for 93 * example EL1 system registers on a VHE system where the host kernel 94 * runs at EL2. This function is called from KVM's vcpu_put() function 95 * and deferring saving system register state until we're no longer running the 96 * VCPU avoids having to save them on every exit from the VM. 97 */ 98 void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu) 99 { 100 struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; 101 struct kvm_cpu_context *host_ctxt; 102 103 host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; 104 deactivate_traps_vhe_put(vcpu); 105 106 __sysreg_save_el1_state(guest_ctxt); 107 __sysreg_save_user_state(guest_ctxt); 108 __sysreg32_save_state(vcpu); 109 110 /* Restore host user state */ 111 __sysreg_restore_user_state(host_ctxt); 112 113 vcpu->arch.sysregs_loaded_on_cpu = false; 114 } 115