Commit 2f4a07c5 authored by Marc Zyngier's avatar Marc Zyngier

arm64: KVM: guest one-reg interface

Let userspace play with the guest registers.
Reviewed-by: default avatarChristopher Covington <cov@codeaurora.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent d7246bf3
/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Derived from arch/arm/kvm/guest.c:
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Author: Christoffer Dall <c.dall@virtualopensystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <asm/cputype.h>
#include <asm/uaccess.h>
#include <asm/kvm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_coproc.h>
struct kvm_stats_debugfs_item debugfs_entries[] = {
{ NULL }
};
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
return 0;
}
static u64 core_reg_offset_from_id(u64 id)
{
return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
}
static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
/*
* Because the kvm_regs structure is a mix of 32, 64 and
* 128bit fields, we index it as if it was a 32bit
* array. Hence below, nr_regs is the number of entries, and
* off the index in the "array".
*/
__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
struct kvm_regs *regs = vcpu_gp_regs(vcpu);
int nr_regs = sizeof(*regs) / sizeof(__u32);
u32 off;
/* Our ID is an index into the kvm_regs struct. */
off = core_reg_offset_from_id(reg->id);
if (off >= nr_regs ||
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
return -EFAULT;
return 0;
}
static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
struct kvm_regs *regs = vcpu_gp_regs(vcpu);
int nr_regs = sizeof(*regs) / sizeof(__u32);
__uint128_t tmp;
void *valp = &tmp;
u64 off;
int err = 0;
/* Our ID is an index into the kvm_regs struct. */
off = core_reg_offset_from_id(reg->id);
if (off >= nr_regs ||
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
return -EINVAL;
if (copy_from_user(valp, uaddr, KVM_REG_SIZE(reg->id))) {
err = -EFAULT;
goto out;
}
if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
u32 mode = (*(u32 *)valp) & COMPAT_PSR_MODE_MASK;
switch (mode) {
case PSR_MODE_EL0t:
case PSR_MODE_EL1t:
case PSR_MODE_EL1h:
break;
default:
err = -EINVAL;
goto out;
}
}
memcpy((u32 *)regs + off, valp, KVM_REG_SIZE(reg->id));
out:
return err;
}
int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
return -EINVAL;
}
int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
return -EINVAL;
}
static unsigned long num_core_regs(void)
{
return sizeof(struct kvm_regs) / sizeof(__u32);
}
/**
* kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
*
* This is for all registers.
*/
unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
{
return num_core_regs() + kvm_arm_num_sys_reg_descs(vcpu);
}
/**
* kvm_arm_copy_reg_indices - get indices of all registers.
*
* We do core registers right here, then we apppend system regs.
*/
int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
{
unsigned int i;
const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | KVM_REG_ARM_CORE;
for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) {
if (put_user(core_reg | i, uindices))
return -EFAULT;
uindices++;
}
return kvm_arm_copy_sys_reg_indices(vcpu, uindices);
}
int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
/* We currently use nothing arch-specific in upper 32 bits */
if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
return -EINVAL;
/* Register group 16 means we want a core register. */
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
return get_core_reg(vcpu, reg);
return kvm_arm_sys_reg_get_reg(vcpu, reg);
}
int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
/* We currently use nothing arch-specific in upper 32 bits */
if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
return -EINVAL;
/* Register group 16 means we set a core register. */
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
return set_core_reg(vcpu, reg);
return kvm_arm_sys_reg_set_reg(vcpu, reg);
}
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
return -EINVAL;
}
int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
return -EINVAL;
}
int __attribute_const__ kvm_target_cpu(void)
{
unsigned long implementor = read_cpuid_implementor();
unsigned long part_number = read_cpuid_part_number();
if (implementor != ARM_CPU_IMP_ARM)
return -EINVAL;
switch (part_number) {
case ARM_CPU_PART_AEM_V8:
return KVM_ARM_TARGET_AEM_V8;
case ARM_CPU_PART_FOUNDATION:
return KVM_ARM_TARGET_FOUNDATION_V8;
case ARM_CPU_PART_CORTEX_A57:
/* Currently handled by the generic backend */
return KVM_ARM_TARGET_CORTEX_A57;
default:
return -EINVAL;
}
}
int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
const struct kvm_vcpu_init *init)
{
unsigned int i;
int phys_target = kvm_target_cpu();
if (init->target != phys_target)
return -EINVAL;
vcpu->arch.target = phys_target;
bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
/* -ENOENT for unknown features, -EINVAL for invalid combinations. */
for (i = 0; i < sizeof(init->features) * 8; i++) {
if (init->features[i / 32] & (1 << (i % 32))) {
if (i >= KVM_VCPU_MAX_FEATURES)
return -ENOENT;
set_bit(i, vcpu->arch.features);
}
}
/* Now we know what it is, we can reset it. */
return kvm_reset_vcpu(vcpu);
}
int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
return -EINVAL;
}
int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
return -EINVAL;
}
int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
struct kvm_translation *tr)
{
return -EINVAL;
}
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