arch/arm64/kvm/hyp/nvhe/debug-sr.c

   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         /* SPE present on this CPU? */
  25         if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
  26                                                   ID_AA64DFR0_PMSVER_SHIFT))
  27                 return;
  28
  29         /* Yes; is it owned by EL3? */
  30         reg = read_sysreg_s(SYS_PMBIDR_EL1);
  31         if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
  32                 return;
  33
  34         /* No; is the host actually using the thing? */
  35         reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
  36         if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
  37                 return;
  38
  39         /* Yes; save the control register and disable data generation */
  40         *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
  41         write_sysreg_s(0, SYS_PMSCR_EL1);
  42         isb();
  43
  44         /* Now drain all buffered data to memory */
  45         psb_csync();
  46         dsb(nsh);
  47 }
  48
  49 static void __debug_restore_spe(u64 pmscr_el1)
  50 {
  51         if (!pmscr_el1)
  52                 return;
  53
  54         /* The host page table is installed, but not yet synchronised */
  55         isb();
  56
  57         /* Re-enable data generation */
  58         write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
  59 }
  60
  61 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
  62 {
  63         /* Disable and flush SPE data generation */
  64         __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
  65 }
  66
  67 void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
  68 {
  69         __debug_switch_to_guest_common(vcpu);
  70 }
  71
  72 void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
  73 {
  74         __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
  75 }
  76
  77 void __debug_switch_to_host(struct kvm_vcpu *vcpu)
  78 {
  79         __debug_switch_to_host_common(vcpu);
  80 }
  81
  82 u32 __kvm_get_mdcr_el2(void)
  83 {
  84         return read_sysreg(mdcr_el2);
  85 }