arch/arm64/kvm/hyp/tlb.c

   1 /*
   2  * Copyright (C) 2015 - ARM Ltd
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <asm/kvm_hyp.h>
  19 #include <asm/tlbflush.h>
  20
  21 static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm)
  22 {
  23         u64 val;
  24
  25         /*
  26          * With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and
  27          * most TLB operations target EL2/EL0. In order to affect the
  28          * guest TLBs (EL1/EL0), we need to change one of these two
  29          * bits. Changing E2H is impossible (goodbye TTBR1_EL2), so
  30          * let's flip TGE before executing the TLB operation.
  31          */
  32         write_sysreg(kvm->arch.vttbr, vttbr_el2);
  33         val = read_sysreg(hcr_el2);
  34         val &= ~HCR_TGE;
  35         write_sysreg(val, hcr_el2);
  36         isb();
  37 }
  38
  39 static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm)
  40 {
  41         write_sysreg(kvm->arch.vttbr, vttbr_el2);
  42         isb();
  43 }
  44
  45 static hyp_alternate_select(__tlb_switch_to_guest,
  46                             __tlb_switch_to_guest_nvhe,
  47                             __tlb_switch_to_guest_vhe,
  48                             ARM64_HAS_VIRT_HOST_EXTN);
  49
  50 static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm)
  51 {
  52         /*
  53          * We're done with the TLB operation, let's restore the host's
  54          * view of HCR_EL2.
  55          */
  56         write_sysreg(0, vttbr_el2);
  57         write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
  58 }
  59
  60 static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm)
  61 {
  62         write_sysreg(0, vttbr_el2);
  63 }
  64
  65 static hyp_alternate_select(__tlb_switch_to_host,
  66                             __tlb_switch_to_host_nvhe,
  67                             __tlb_switch_to_host_vhe,
  68                             ARM64_HAS_VIRT_HOST_EXTN);
  69
  70 void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
  71 {
  72         dsb(ishst);
  73
  74         /* Switch to requested VMID */
  75         kvm = kern_hyp_va(kvm);
  76         __tlb_switch_to_guest()(kvm);
  77
  78         /*
  79          * We could do so much better if we had the VA as well.
  80          * Instead, we invalidate Stage-2 for this IPA, and the
  81          * whole of Stage-1. Weep...
  82          */
  83         ipa >>= 12;
  84         __tlbi(ipas2e1is, ipa);
  85
  86         /*
  87          * We have to ensure completion of the invalidation at Stage-2,
  88          * since a table walk on another CPU could refill a TLB with a
  89          * complete (S1 + S2) walk based on the old Stage-2 mapping if
  90          * the Stage-1 invalidation happened first.
  91          */
  92         dsb(ish);
  93         __tlbi(vmalle1is);
  94         dsb(ish);
  95         isb();
  96
  97         __tlb_switch_to_host()(kvm);
  98 }
  99
 100 void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)
 101 {
 102         dsb(ishst);
 103
 104         /* Switch to requested VMID */
 105         kvm = kern_hyp_va(kvm);
 106         __tlb_switch_to_guest()(kvm);
 107
 108         __tlbi(vmalls12e1is);
 109         dsb(ish);
 110         isb();
 111
 112         __tlb_switch_to_host()(kvm);
 113 }
 114
 115 void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
 116 {
 117         struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm);
 118
 119         /* Switch to requested VMID */
 120         __tlb_switch_to_guest()(kvm);
 121
 122         __tlbi(vmalle1);
 123         dsb(nsh);
 124         isb();
 125
 126         __tlb_switch_to_host()(kvm);
 127 }
 128
 129 void __hyp_text __kvm_flush_vm_context(void)
 130 {
 131         dsb(ishst);
 132         __tlbi(alle1is);
 133         asm volatile("ic ialluis" : : );
 134         dsb(ish);
 135 }