linux/arch/arm64/kvm/reset.c

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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>
kvm: arm64: Set a limit on the IPA size So far we have restricted the IPA size of the VM to the default value (40bits). Now that we can manage the IPA size per VM and support dynamic stage2 page tables, we can allow VMs to have larger IPA. This patch introduces a the maximum IPA size supported on the host. This is decided by the following factors : 1) Maximum PARange supported by the CPUs - This can be inferred from the system wide safe value. 2) Maximum PA size supported by the host kernel (48 vs 52) 3) Number of levels in the host page table (as we base our stage2 tables on the host table helpers). Since the stage2 page table code is dependent on the stage1 page table, we always ensure that : Number of Levels at Stage1 >= Number of Levels at Stage2 So we limit the IPA to make sure that the above condition is satisfied. This will affect the following combinations of VA_BITS and IPA for different page sizes. Host configuration | Unsupported IPA ranges 39bit VA, 4K | [44, 48] 36bit VA, 16K | [41, 48] 42bit VA, 64K | [47, 52] Supporting the above combinations need independent stage2 page table manipulation code, which would need substantial changes. We could purse the solution independently and switch the page table code once we have it ready. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <cdall@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-26 16:32:52 +00:00
/* 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
* VL_ARCH_MAX:
*/
if (WARN_ON(kvm_sve_max_vl > VL_ARCH_MAX))
kvm_sve_max_vl = 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;
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;
size_t reg_sz;
int ret;
vl = vcpu->arch.sve_max_vl;
/*
* Responsibility for these properties is shared between
* kvm_arm_init_sve(), 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 > VL_ARCH_MAX))
return -EIO;
reg_sz = vcpu_sve_state_size(vcpu);
buf = kzalloc(reg_sz, GFP_KERNEL_ACCOUNT);
if (!buf)
return -ENOMEM;
ret = kvm_share_hyp(buf, buf + reg_sz);
if (ret) {
kfree(buf);
return ret;
}
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)
{
void *sve_state = vcpu->arch.sve_state;
kvm_vcpu_unshare_task_fp(vcpu);
kvm_unshare_hyp(vcpu, vcpu + 1);
if (sve_state)
kvm_unshare_hyp(sve_state, sve_state + vcpu_sve_state_size(vcpu));
kfree(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;
}
static bool vcpu_allowed_register_width(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu *tmp;
bool is32bit;
unsigned long i;
is32bit = vcpu_has_feature(vcpu, KVM_ARM_VCPU_EL1_32BIT);
if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1) && is32bit)
return false;
/* MTE is incompatible with AArch32 */
if (kvm_has_mte(vcpu->kvm) && is32bit)
return false;
/* Check that the vcpus are either all 32bit or all 64bit */
kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
if (vcpu_has_feature(tmp, KVM_ARM_VCPU_EL1_32BIT) != is32bit)
return false;
}
return true;
}
/**
* kvm_reset_vcpu - sets core registers and sys_regs to reset value
* @vcpu: The VCPU pointer
*
* This function 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)
{
struct vcpu_reset_state reset_state;
int ret;
bool loaded;
u32 pstate;
mutex_lock(&vcpu->kvm->lock);
reset_state = vcpu->arch.reset_state;
WRITE_ONCE(vcpu->arch.reset_state.reset, false);
mutex_unlock(&vcpu->kvm->lock);
/* 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;
}
}
if (!vcpu_allowed_register_width(vcpu)) {
ret = -EINVAL;
goto out;
}
switch (vcpu->arch.target) {
default:
if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
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)));
memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
vcpu->arch.ctxt.spsr_abt = 0;
vcpu->arch.ctxt.spsr_und = 0;
vcpu->arch.ctxt.spsr_irq = 0;
vcpu->arch.ctxt.spsr_fiq = 0;
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 (reset_state.reset) {
unsigned long target_pc = 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 (reset_state.be)
kvm_vcpu_set_be(vcpu);
*vcpu_pc(vcpu) = target_pc;
vcpu_set_reg(vcpu, 0, reset_state.r0);
}
/* 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)
kvm: arm64: Set a limit on the IPA size So far we have restricted the IPA size of the VM to the default value (40bits). Now that we can manage the IPA size per VM and support dynamic stage2 page tables, we can allow VMs to have larger IPA. This patch introduces a the maximum IPA size supported on the host. This is decided by the following factors : 1) Maximum PARange supported by the CPUs - This can be inferred from the system wide safe value. 2) Maximum PA size supported by the host kernel (48 vs 52) 3) Number of levels in the host page table (as we base our stage2 tables on the host table helpers). Since the stage2 page table code is dependent on the stage1 page table, we always ensure that : Number of Levels at Stage1 >= Number of Levels at Stage2 So we limit the IPA to make sure that the above condition is satisfied. This will affect the following combinations of VA_BITS and IPA for different page sizes. Host configuration | Unsupported IPA ranges 39bit VA, 4K | [44, 48] 36bit VA, 16K | [41, 48] 42bit VA, 64K | [47, 52] Supporting the above combinations need independent stage2 page table manipulation code, which would need substantial changes. We could purse the solution independently and switch the page table code once we have it ready. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <cdall@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-26 16:32:52 +00:00
{
unsigned int parange;
u64 mmfr0;
kvm: arm64: Set a limit on the IPA size So far we have restricted the IPA size of the VM to the default value (40bits). Now that we can manage the IPA size per VM and support dynamic stage2 page tables, we can allow VMs to have larger IPA. This patch introduces a the maximum IPA size supported on the host. This is decided by the following factors : 1) Maximum PARange supported by the CPUs - This can be inferred from the system wide safe value. 2) Maximum PA size supported by the host kernel (48 vs 52) 3) Number of levels in the host page table (as we base our stage2 tables on the host table helpers). Since the stage2 page table code is dependent on the stage1 page table, we always ensure that : Number of Levels at Stage1 >= Number of Levels at Stage2 So we limit the IPA to make sure that the above condition is satisfied. This will affect the following combinations of VA_BITS and IPA for different page sizes. Host configuration | Unsupported IPA ranges 39bit VA, 4K | [44, 48] 36bit VA, 16K | [41, 48] 42bit VA, 64K | [47, 52] Supporting the above combinations need independent stage2 page table manipulation code, which would need substantial changes. We could purse the solution independently and switch the page table code once we have it ready. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <cdall@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-26 16:32:52 +00:00
mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
parange = cpuid_feature_extract_unsigned_field(mmfr0,
ID_AA64MMFR0_PARANGE_SHIFT);
/*
* IPA size beyond 48 bits could not be supported
* on either 4K or 16K page size. Hence let's cap
* it to 48 bits, in case it's reported as larger
* on the system.
*/
if (PAGE_SIZE != SZ_64K)
parange = min(parange, (unsigned int)ID_AA64MMFR0_PARANGE_48);
/*
* Check with ARMv8.5-GTG that our PAGE_SIZE is supported at
* Stage-2. If not, things will stop very quickly.
*/
switch (cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_TGRAN_2_SHIFT)) {
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);
2021-03-11 10:00:15 +00:00
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;
kvm: arm64: Set a limit on the IPA size So far we have restricted the IPA size of the VM to the default value (40bits). Now that we can manage the IPA size per VM and support dynamic stage2 page tables, we can allow VMs to have larger IPA. This patch introduces a the maximum IPA size supported on the host. This is decided by the following factors : 1) Maximum PARange supported by the CPUs - This can be inferred from the system wide safe value. 2) Maximum PA size supported by the host kernel (48 vs 52) 3) Number of levels in the host page table (as we base our stage2 tables on the host table helpers). Since the stage2 page table code is dependent on the stage1 page table, we always ensure that : Number of Levels at Stage1 >= Number of Levels at Stage2 So we limit the IPA to make sure that the above condition is satisfied. This will affect the following combinations of VA_BITS and IPA for different page sizes. Host configuration | Unsupported IPA ranges 39bit VA, 4K | [44, 48] 36bit VA, 16K | [41, 48] 42bit VA, 64K | [47, 52] Supporting the above combinations need independent stage2 page table manipulation code, which would need substantial changes. We could purse the solution independently and switch the page table code once we have it ready. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <cdall@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-26 16:32:52 +00:00
}
int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
{
u64 mmfr0, mmfr1;
u32 phys_shift;
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 < ARM64_MIN_PARANGE_BITS)
return -EINVAL;
} else {
phys_shift = KVM_PHYS_SHIFT;
2021-03-11 10:00:15 +00:00
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);
mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
kvm->arch.vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift);
return 0;
}