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-rw-r--r--arch/arm64/kvm/hyp/nvhe/pkvm.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
new file mode 100644
index 000000000..85d3b7ae7
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Google LLC
+ * Author: Fuad Tabba <tabba@google.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/mm.h>
+#include <nvhe/fixed_config.h>
+#include <nvhe/trap_handler.h>
+
+/*
+ * Set trap register values based on features in ID_AA64PFR0.
+ */
+static void pvm_init_traps_aa64pfr0(struct kvm_vcpu *vcpu)
+{
+ const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64PFR0_EL1);
+ u64 hcr_set = HCR_RW;
+ u64 hcr_clear = 0;
+ u64 cptr_set = 0;
+
+ /* Protected KVM does not support AArch32 guests. */
+ BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL0),
+ PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) != ID_AA64PFR0_EL1_ELx_64BIT_ONLY);
+ BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL1),
+ PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) != ID_AA64PFR0_EL1_ELx_64BIT_ONLY);
+
+ /*
+ * Linux guests assume support for floating-point and Advanced SIMD. Do
+ * not change the trapping behavior for these from the KVM default.
+ */
+ BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_FP),
+ PVM_ID_AA64PFR0_ALLOW));
+ BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AdvSIMD),
+ PVM_ID_AA64PFR0_ALLOW));
+
+ /* Trap RAS unless all current versions are supported */
+ if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_RAS), feature_ids) <
+ ID_AA64PFR0_EL1_RAS_V1P1) {
+ hcr_set |= HCR_TERR | HCR_TEA;
+ hcr_clear |= HCR_FIEN;
+ }
+
+ /* Trap AMU */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AMU), feature_ids)) {
+ hcr_clear |= HCR_AMVOFFEN;
+ cptr_set |= CPTR_EL2_TAM;
+ }
+
+ /* Trap SVE */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_SVE), feature_ids))
+ cptr_set |= CPTR_EL2_TZ;
+
+ vcpu->arch.hcr_el2 |= hcr_set;
+ vcpu->arch.hcr_el2 &= ~hcr_clear;
+ vcpu->arch.cptr_el2 |= cptr_set;
+}
+
+/*
+ * Set trap register values based on features in ID_AA64PFR1.
+ */
+static void pvm_init_traps_aa64pfr1(struct kvm_vcpu *vcpu)
+{
+ const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64PFR1_EL1);
+ u64 hcr_set = 0;
+ u64 hcr_clear = 0;
+
+ /* Memory Tagging: Trap and Treat as Untagged if not supported. */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE), feature_ids)) {
+ hcr_set |= HCR_TID5;
+ hcr_clear |= HCR_DCT | HCR_ATA;
+ }
+
+ vcpu->arch.hcr_el2 |= hcr_set;
+ vcpu->arch.hcr_el2 &= ~hcr_clear;
+}
+
+/*
+ * Set trap register values based on features in ID_AA64DFR0.
+ */
+static void pvm_init_traps_aa64dfr0(struct kvm_vcpu *vcpu)
+{
+ const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64DFR0_EL1);
+ u64 mdcr_set = 0;
+ u64 mdcr_clear = 0;
+ u64 cptr_set = 0;
+
+ /* Trap/constrain PMU */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), feature_ids)) {
+ mdcr_set |= MDCR_EL2_TPM | MDCR_EL2_TPMCR;
+ mdcr_clear |= MDCR_EL2_HPME | MDCR_EL2_MTPME |
+ MDCR_EL2_HPMN_MASK;
+ }
+
+ /* Trap Debug */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DebugVer), feature_ids))
+ mdcr_set |= MDCR_EL2_TDRA | MDCR_EL2_TDA | MDCR_EL2_TDE;
+
+ /* Trap OS Double Lock */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DoubleLock), feature_ids))
+ mdcr_set |= MDCR_EL2_TDOSA;
+
+ /* Trap SPE */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMSVer), feature_ids)) {
+ mdcr_set |= MDCR_EL2_TPMS;
+ mdcr_clear |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
+ }
+
+ /* Trap Trace Filter */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_TraceFilt), feature_ids))
+ mdcr_set |= MDCR_EL2_TTRF;
+
+ /* Trap Trace */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_TraceVer), feature_ids))
+ cptr_set |= CPTR_EL2_TTA;
+
+ vcpu->arch.mdcr_el2 |= mdcr_set;
+ vcpu->arch.mdcr_el2 &= ~mdcr_clear;
+ vcpu->arch.cptr_el2 |= cptr_set;
+}
+
+/*
+ * Set trap register values based on features in ID_AA64MMFR0.
+ */
+static void pvm_init_traps_aa64mmfr0(struct kvm_vcpu *vcpu)
+{
+ const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64MMFR0_EL1);
+ u64 mdcr_set = 0;
+
+ /* Trap Debug Communications Channel registers */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_FGT), feature_ids))
+ mdcr_set |= MDCR_EL2_TDCC;
+
+ vcpu->arch.mdcr_el2 |= mdcr_set;
+}
+
+/*
+ * Set trap register values based on features in ID_AA64MMFR1.
+ */
+static void pvm_init_traps_aa64mmfr1(struct kvm_vcpu *vcpu)
+{
+ const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64MMFR1_EL1);
+ u64 hcr_set = 0;
+
+ /* Trap LOR */
+ if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR1_EL1_LO), feature_ids))
+ hcr_set |= HCR_TLOR;
+
+ vcpu->arch.hcr_el2 |= hcr_set;
+}
+
+/*
+ * Set baseline trap register values.
+ */
+static void pvm_init_trap_regs(struct kvm_vcpu *vcpu)
+{
+ const u64 hcr_trap_feat_regs = HCR_TID3;
+ const u64 hcr_trap_impdef = HCR_TACR | HCR_TIDCP | HCR_TID1;
+
+ /*
+ * Always trap:
+ * - Feature id registers: to control features exposed to guests
+ * - Implementation-defined features
+ */
+ vcpu->arch.hcr_el2 |= hcr_trap_feat_regs | hcr_trap_impdef;
+
+ /* Clear res0 and set res1 bits to trap potential new features. */
+ vcpu->arch.hcr_el2 &= ~(HCR_RES0);
+ vcpu->arch.mdcr_el2 &= ~(MDCR_EL2_RES0);
+ vcpu->arch.cptr_el2 |= CPTR_NVHE_EL2_RES1;
+ vcpu->arch.cptr_el2 &= ~(CPTR_NVHE_EL2_RES0);
+}
+
+/*
+ * Initialize trap register values for protected VMs.
+ */
+void __pkvm_vcpu_init_traps(struct kvm_vcpu *vcpu)
+{
+ pvm_init_trap_regs(vcpu);
+ pvm_init_traps_aa64pfr0(vcpu);
+ pvm_init_traps_aa64pfr1(vcpu);
+ pvm_init_traps_aa64dfr0(vcpu);
+ pvm_init_traps_aa64mmfr0(vcpu);
+ pvm_init_traps_aa64mmfr1(vcpu);
+}