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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Derived from arch/arm/kvm/reset.c
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Author: Christoffer Dall <c.dall@virtualopensystems.com>
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/hw_breakpoint.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>
#include <kvm/arm_arch_timer.h>
#include <asm/cpufeature.h>
#include <asm/cputype.h>
#include <asm/fpsimd.h>
#include <asm/ptrace.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_mmu.h>
#include <asm/virt.h>
/* Maximum phys_shift supported for any VM on this host */
static u32 kvm_ipa_limit;
/*
* ARMv8 Reset Values
*/
#define VCPU_RESET_PSTATE_EL1 (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT | \
PSR_F_BIT | PSR_D_BIT)
#define VCPU_RESET_PSTATE_SVC (PSR_AA32_MODE_SVC | PSR_AA32_A_BIT | \
PSR_AA32_I_BIT | PSR_AA32_F_BIT)
unsigned int kvm_sve_max_vl;
int kvm_arm_init_sve(void)
{
if (system_supports_sve()) {
kvm_sve_max_vl = sve_max_virtualisable_vl;
/*
* The get_sve_reg()/set_sve_reg() ioctl interface will need
* to be extended with multiple register slice support in
* order to support vector lengths greater than
* SVE_VL_ARCH_MAX:
*/
if (WARN_ON(kvm_sve_max_vl > SVE_VL_ARCH_MAX))
kvm_sve_max_vl = SVE_VL_ARCH_MAX;
/*
* Don't even try to make use of vector lengths that
* aren't available on all CPUs, for now:
*/
if (kvm_sve_max_vl < sve_max_vl)
pr_warn("KVM: SVE vector length for guests limited to %u bytes\n",
kvm_sve_max_vl);
}
return 0;
}
static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu)
{
if (!system_supports_sve())
return -EINVAL;
/* Verify that KVM startup enforced this when SVE was detected: */
if (WARN_ON(!has_vhe()))
return -EINVAL;
vcpu->arch.sve_max_vl = kvm_sve_max_vl;
/*
* Userspace can still customize the vector lengths by writing
* KVM_REG_ARM64_SVE_VLS. Allocation is deferred until
* kvm_arm_vcpu_finalize(), which freezes the configuration.
*/
vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_SVE;
return 0;
}
/*
* Finalize vcpu's maximum SVE vector length, allocating
* vcpu->arch.sve_state as necessary.
*/
static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
{
void *buf;
unsigned int vl;
vl = vcpu->arch.sve_max_vl;
/*
* Responsibility for these properties is shared between
* kvm_arm_init_arch_resources(), kvm_vcpu_enable_sve() and
* set_sve_vls(). Double-check here just to be sure:
*/
if (WARN_ON(!sve_vl_valid(vl) || vl > sve_max_virtualisable_vl ||
vl > SVE_VL_ARCH_MAX))
return -EIO;
buf = kzalloc(SVE_SIG_REGS_SIZE(sve_vq_from_vl(vl)), GFP_KERNEL);
if (!buf)
return -ENOMEM;
vcpu->arch.sve_state = buf;
vcpu->arch.flags |= KVM_ARM64_VCPU_SVE_FINALIZED;
return 0;
}
int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature)
{
switch (feature) {
case KVM_ARM_VCPU_SVE:
if (!vcpu_has_sve(vcpu))
return -EINVAL;
if (kvm_arm_vcpu_sve_finalized(vcpu))
return -EPERM;
return kvm_vcpu_finalize_sve(vcpu);
}
return -EINVAL;
}
bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu)
{
if (vcpu_has_sve(vcpu) && !kvm_arm_vcpu_sve_finalized(vcpu))
return false;
return true;
}
void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu)
{
kfree(vcpu->arch.sve_state);
}
static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu)
{
if (vcpu_has_sve(vcpu))
memset(vcpu->arch.sve_state, 0, vcpu_sve_state_size(vcpu));
}
static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
{
/*
* For now make sure that both address/generic pointer authentication
* features are requested by the userspace together and the system
* supports these capabilities.
*/
if (!test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) ||
!test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features) ||
!system_has_full_ptr_auth())
return -EINVAL;
vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_PTRAUTH;
return 0;
}
/**
* kvm_reset_vcpu - sets core registers and sys_regs to reset value
* @vcpu: The VCPU pointer
*
* This function finds the right table above and sets the registers on
* the virtual CPU struct to their architecturally defined reset
* values, except for registers whose reset is deferred until
* kvm_arm_vcpu_finalize().
*
* Note: This function can be called from two paths: The KVM_ARM_VCPU_INIT
* ioctl or as part of handling a request issued by another VCPU in the PSCI
* handling code. In the first case, the VCPU will not be loaded, and in the
* second case the VCPU will be loaded. Because this function operates purely
* on the memory-backed values of system registers, we want to do a full put if
* we were loaded (handling a request) and load the values back at the end of
* the function. Otherwise we leave the state alone. In both cases, we
* disable preemption around the vcpu reset as we would otherwise race with
* preempt notifiers which also call put/load.
*/
int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
{
int ret;
bool loaded;
u32 pstate;
/* Reset PMU outside of the non-preemptible section */
kvm_pmu_vcpu_reset(vcpu);
preempt_disable();
loaded = (vcpu->cpu != -1);
if (loaded)
kvm_arch_vcpu_put(vcpu);
if (!kvm_arm_vcpu_sve_finalized(vcpu)) {
if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) {
ret = kvm_vcpu_enable_sve(vcpu);
if (ret)
goto out;
}
} else {
kvm_vcpu_reset_sve(vcpu);
}
if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) ||
test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) {
if (kvm_vcpu_enable_ptrauth(vcpu)) {
ret = -EINVAL;
goto out;
}
}
switch (vcpu->arch.target) {
default:
if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) {
ret = -EINVAL;
goto out;
}
pstate = VCPU_RESET_PSTATE_SVC;
} else {
pstate = VCPU_RESET_PSTATE_EL1;
}
if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) {
ret = -EINVAL;
goto out;
}
break;
}
/* Reset core registers */
memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu)));
vcpu_gp_regs(vcpu)->pstate = pstate;
/* Reset system registers */
kvm_reset_sys_regs(vcpu);
/*
* Additional reset state handling that PSCI may have imposed on us.
* Must be done after all the sys_reg reset.
*/
if (vcpu->arch.reset_state.reset) {
unsigned long target_pc = vcpu->arch.reset_state.pc;
/* Gracefully handle Thumb2 entry point */
if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
target_pc &= ~1UL;
vcpu_set_thumb(vcpu);
}
/* Propagate caller endianness */
if (vcpu->arch.reset_state.be)
kvm_vcpu_set_be(vcpu);
*vcpu_pc(vcpu) = target_pc;
vcpu_set_reg(vcpu, 0, vcpu->arch.reset_state.r0);
vcpu->arch.reset_state.reset = false;
}
/* Reset timer */
ret = kvm_timer_vcpu_reset(vcpu);
out:
if (loaded)
kvm_arch_vcpu_load(vcpu, smp_processor_id());
preempt_enable();
return ret;
}
u32 get_kvm_ipa_limit(void)
{
return kvm_ipa_limit;
}
int kvm_set_ipa_limit(void)
{
unsigned int parange, tgran_2;
u64 mmfr0;
mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
parange = cpuid_feature_extract_unsigned_field(mmfr0,
ID_AA64MMFR0_PARANGE_SHIFT);
/*
* Check with ARMv8.5-GTG that our PAGE_SIZE is supported at
* Stage-2. If not, things will stop very quickly.
*/
switch (PAGE_SIZE) {
default:
case SZ_4K:
tgran_2 = ID_AA64MMFR0_TGRAN4_2_SHIFT;
break;
case SZ_16K:
tgran_2 = ID_AA64MMFR0_TGRAN16_2_SHIFT;
break;
case SZ_64K:
tgran_2 = ID_AA64MMFR0_TGRAN64_2_SHIFT;
break;
}
switch (cpuid_feature_extract_unsigned_field(mmfr0, tgran_2)) {
case ID_AA64MMFR0_TGRAN_2_SUPPORTED_NONE:
kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n");
return -EINVAL;
case ID_AA64MMFR0_TGRAN_2_SUPPORTED_DEFAULT:
kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n");
break;
case ID_AA64MMFR0_TGRAN_2_SUPPORTED_MIN ... ID_AA64MMFR0_TGRAN_2_SUPPORTED_MAX:
kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n");
break;
default:
kvm_err("Unsupported value for TGRAN_2, giving up\n");
return -EINVAL;
}
kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange);
kvm_info("IPA Size Limit: %d bits%s\n", kvm_ipa_limit,
((kvm_ipa_limit < KVM_PHYS_SHIFT) ?
" (Reduced IPA size, limited VM/VMM compatibility)" : ""));
return 0;
}
/*
* Configure the VTCR_EL2 for this VM. The VTCR value is common
* across all the physical CPUs on the system. We use system wide
* sanitised values to fill in different fields, except for Hardware
* Management of Access Flags. HA Flag is set unconditionally on
* all CPUs, as it is safe to run with or without the feature and
* the bit is RES0 on CPUs that don't support it.
*/
int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
{
u64 vtcr = VTCR_EL2_FLAGS, mmfr0;
u32 parange, phys_shift;
u8 lvls;
if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
return -EINVAL;
phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
if (phys_shift) {
if (phys_shift > kvm_ipa_limit ||
phys_shift < 32)
return -EINVAL;
} else {
phys_shift = KVM_PHYS_SHIFT;
if (phys_shift > kvm_ipa_limit) {
pr_warn_once("%s using unsupported default IPA limit, upgrade your VMM\n",
current->comm);
return -EINVAL;
}
}
mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
parange = cpuid_feature_extract_unsigned_field(mmfr0,
ID_AA64MMFR0_PARANGE_SHIFT);
if (parange > ID_AA64MMFR0_PARANGE_MAX)
parange = ID_AA64MMFR0_PARANGE_MAX;
vtcr |= parange << VTCR_EL2_PS_SHIFT;
vtcr |= VTCR_EL2_T0SZ(phys_shift);
/*
* Use a minimum 2 level page table to prevent splitting
* host PMD huge pages at stage2.
*/
lvls = stage2_pgtable_levels(phys_shift);
if (lvls < 2)
lvls = 2;
vtcr |= VTCR_EL2_LVLS_TO_SL0(lvls);
/*
* Enable the Hardware Access Flag management, unconditionally
* on all CPUs. The features is RES0 on CPUs without the support
* and must be ignored by the CPUs.
*/
vtcr |= VTCR_EL2_HA;
/* Set the vmid bits */
vtcr |= (kvm_get_vmid_bits() == 16) ?
VTCR_EL2_VS_16BIT :
VTCR_EL2_VS_8BIT;
kvm->arch.vtcr = vtcr;
return 0;
}