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// 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_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_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_DoubleLock), feature_ids))
mdcr_set |= MDCR_EL2_TDOSA;
/* Trap SPE */
if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_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_TraceFilt), feature_ids))
mdcr_set |= MDCR_EL2_TTRF;
/* Trap Trace */
if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_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);
}
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