linux/arch/arm64/kvm/vgic/vgic-kvm-device.c
Marc Zyngier 619064afa9 KVM: arm64: vgic: Tidy-up calls to vgic_{get,set}_common_attr()
The userspace accessors have an early call to vgic_{get,set}_common_attr()
that makes the code hard to follow. Move it to the default: clause of
the decoding switch statement, which results in a nice cleanup.

This requires us to move the handling of the pending table into the
common handling, even if it is strictly a GICv3 feature (it has the
benefit of keeping the whole control group handling in the same
function).

Also cleanup vgic_v3_{get,set}_attr() while we're at it, deduplicating
the calls to vgic_v3_attr_regs_access().

Suggested-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-17 11:55:33 +01:00

696 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* VGIC: KVM DEVICE API
*
* Copyright (C) 2015 ARM Ltd.
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <linux/kvm_host.h>
#include <kvm/arm_vgic.h>
#include <linux/uaccess.h>
#include <asm/kvm_mmu.h>
#include <asm/cputype.h>
#include "vgic.h"
/* common helpers */
int vgic_check_iorange(struct kvm *kvm, phys_addr_t ioaddr,
phys_addr_t addr, phys_addr_t alignment,
phys_addr_t size)
{
if (!IS_VGIC_ADDR_UNDEF(ioaddr))
return -EEXIST;
if (!IS_ALIGNED(addr, alignment) || !IS_ALIGNED(size, alignment))
return -EINVAL;
if (addr + size < addr)
return -EINVAL;
if (addr & ~kvm_phys_mask(kvm) || addr + size > kvm_phys_size(kvm))
return -E2BIG;
return 0;
}
static int vgic_check_type(struct kvm *kvm, int type_needed)
{
if (kvm->arch.vgic.vgic_model != type_needed)
return -ENODEV;
else
return 0;
}
int kvm_set_legacy_vgic_v2_addr(struct kvm *kvm, struct kvm_arm_device_addr *dev_addr)
{
struct vgic_dist *vgic = &kvm->arch.vgic;
int r;
mutex_lock(&kvm->lock);
switch (FIELD_GET(KVM_ARM_DEVICE_TYPE_MASK, dev_addr->id)) {
case KVM_VGIC_V2_ADDR_TYPE_DIST:
r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
if (!r)
r = vgic_check_iorange(kvm, vgic->vgic_dist_base, dev_addr->addr,
SZ_4K, KVM_VGIC_V2_DIST_SIZE);
if (!r)
vgic->vgic_dist_base = dev_addr->addr;
break;
case KVM_VGIC_V2_ADDR_TYPE_CPU:
r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
if (!r)
r = vgic_check_iorange(kvm, vgic->vgic_cpu_base, dev_addr->addr,
SZ_4K, KVM_VGIC_V2_CPU_SIZE);
if (!r)
vgic->vgic_cpu_base = dev_addr->addr;
break;
default:
r = -ENODEV;
}
mutex_unlock(&kvm->lock);
return r;
}
/**
* kvm_vgic_addr - set or get vgic VM base addresses
* @kvm: pointer to the vm struct
* @attr: pointer to the attribute being retrieved/updated
* @write: if true set the address in the VM address space, if false read the
* address
*
* Set or get the vgic base addresses for the distributor and the virtual CPU
* interface in the VM physical address space. These addresses are properties
* of the emulated core/SoC and therefore user space initially knows this
* information.
* Check them for sanity (alignment, double assignment). We can't check for
* overlapping regions in case of a virtual GICv3 here, since we don't know
* the number of VCPUs yet, so we defer this check to map_resources().
*/
static int kvm_vgic_addr(struct kvm *kvm, struct kvm_device_attr *attr, bool write)
{
u64 __user *uaddr = (u64 __user *)attr->addr;
struct vgic_dist *vgic = &kvm->arch.vgic;
phys_addr_t *addr_ptr, alignment, size;
u64 undef_value = VGIC_ADDR_UNDEF;
u64 addr;
int r;
/* Reading a redistributor region addr implies getting the index */
if (write || attr->attr == KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION)
if (get_user(addr, uaddr))
return -EFAULT;
mutex_lock(&kvm->lock);
switch (attr->attr) {
case KVM_VGIC_V2_ADDR_TYPE_DIST:
r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
addr_ptr = &vgic->vgic_dist_base;
alignment = SZ_4K;
size = KVM_VGIC_V2_DIST_SIZE;
break;
case KVM_VGIC_V2_ADDR_TYPE_CPU:
r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
addr_ptr = &vgic->vgic_cpu_base;
alignment = SZ_4K;
size = KVM_VGIC_V2_CPU_SIZE;
break;
case KVM_VGIC_V3_ADDR_TYPE_DIST:
r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V3);
addr_ptr = &vgic->vgic_dist_base;
alignment = SZ_64K;
size = KVM_VGIC_V3_DIST_SIZE;
break;
case KVM_VGIC_V3_ADDR_TYPE_REDIST: {
struct vgic_redist_region *rdreg;
r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V3);
if (r)
break;
if (write) {
r = vgic_v3_set_redist_base(kvm, 0, addr, 0);
goto out;
}
rdreg = list_first_entry_or_null(&vgic->rd_regions,
struct vgic_redist_region, list);
if (!rdreg)
addr_ptr = &undef_value;
else
addr_ptr = &rdreg->base;
break;
}
case KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION:
{
struct vgic_redist_region *rdreg;
u8 index;
r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V3);
if (r)
break;
index = addr & KVM_VGIC_V3_RDIST_INDEX_MASK;
if (write) {
gpa_t base = addr & KVM_VGIC_V3_RDIST_BASE_MASK;
u32 count = FIELD_GET(KVM_VGIC_V3_RDIST_COUNT_MASK, addr);
u8 flags = FIELD_GET(KVM_VGIC_V3_RDIST_FLAGS_MASK, addr);
if (!count || flags)
r = -EINVAL;
else
r = vgic_v3_set_redist_base(kvm, index,
base, count);
goto out;
}
rdreg = vgic_v3_rdist_region_from_index(kvm, index);
if (!rdreg) {
r = -ENOENT;
goto out;
}
addr = index;
addr |= rdreg->base;
addr |= (u64)rdreg->count << KVM_VGIC_V3_RDIST_COUNT_SHIFT;
goto out;
}
default:
r = -ENODEV;
}
if (r)
goto out;
if (write) {
r = vgic_check_iorange(kvm, *addr_ptr, addr, alignment, size);
if (!r)
*addr_ptr = addr;
} else {
addr = *addr_ptr;
}
out:
mutex_unlock(&kvm->lock);
if (!r && !write)
r = put_user(addr, uaddr);
return r;
}
static int vgic_set_common_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
int r;
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_ADDR:
r = kvm_vgic_addr(dev->kvm, attr, true);
return (r == -ENODEV) ? -ENXIO : r;
case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
u32 __user *uaddr = (u32 __user *)(long)attr->addr;
u32 val;
int ret = 0;
if (get_user(val, uaddr))
return -EFAULT;
/*
* We require:
* - at least 32 SPIs on top of the 16 SGIs and 16 PPIs
* - at most 1024 interrupts
* - a multiple of 32 interrupts
*/
if (val < (VGIC_NR_PRIVATE_IRQS + 32) ||
val > VGIC_MAX_RESERVED ||
(val & 31))
return -EINVAL;
mutex_lock(&dev->kvm->lock);
if (vgic_ready(dev->kvm) || dev->kvm->arch.vgic.nr_spis)
ret = -EBUSY;
else
dev->kvm->arch.vgic.nr_spis =
val - VGIC_NR_PRIVATE_IRQS;
mutex_unlock(&dev->kvm->lock);
return ret;
}
case KVM_DEV_ARM_VGIC_GRP_CTRL: {
switch (attr->attr) {
case KVM_DEV_ARM_VGIC_CTRL_INIT:
mutex_lock(&dev->kvm->lock);
r = vgic_init(dev->kvm);
mutex_unlock(&dev->kvm->lock);
return r;
case KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES:
/*
* OK, this one isn't common at all, but we
* want to handle all control group attributes
* in a single place.
*/
if (vgic_check_type(dev->kvm, KVM_DEV_TYPE_ARM_VGIC_V3))
return -ENXIO;
mutex_lock(&dev->kvm->lock);
if (!lock_all_vcpus(dev->kvm)) {
mutex_unlock(&dev->kvm->lock);
return -EBUSY;
}
r = vgic_v3_save_pending_tables(dev->kvm);
unlock_all_vcpus(dev->kvm);
mutex_unlock(&dev->kvm->lock);
return r;
}
break;
}
}
return -ENXIO;
}
static int vgic_get_common_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
int r = -ENXIO;
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_ADDR:
r = kvm_vgic_addr(dev->kvm, attr, false);
return (r == -ENODEV) ? -ENXIO : r;
case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
u32 __user *uaddr = (u32 __user *)(long)attr->addr;
r = put_user(dev->kvm->arch.vgic.nr_spis +
VGIC_NR_PRIVATE_IRQS, uaddr);
break;
}
}
return r;
}
static int vgic_create(struct kvm_device *dev, u32 type)
{
return kvm_vgic_create(dev->kvm, type);
}
static void vgic_destroy(struct kvm_device *dev)
{
kfree(dev);
}
int kvm_register_vgic_device(unsigned long type)
{
int ret = -ENODEV;
switch (type) {
case KVM_DEV_TYPE_ARM_VGIC_V2:
ret = kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
KVM_DEV_TYPE_ARM_VGIC_V2);
break;
case KVM_DEV_TYPE_ARM_VGIC_V3:
ret = kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
KVM_DEV_TYPE_ARM_VGIC_V3);
if (ret)
break;
ret = kvm_vgic_register_its_device();
break;
}
return ret;
}
int vgic_v2_parse_attr(struct kvm_device *dev, struct kvm_device_attr *attr,
struct vgic_reg_attr *reg_attr)
{
int cpuid;
cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
KVM_DEV_ARM_VGIC_CPUID_SHIFT;
if (cpuid >= atomic_read(&dev->kvm->online_vcpus))
return -EINVAL;
reg_attr->vcpu = kvm_get_vcpu(dev->kvm, cpuid);
reg_attr->addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
return 0;
}
/* unlocks vcpus from @vcpu_lock_idx and smaller */
static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
{
struct kvm_vcpu *tmp_vcpu;
for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
mutex_unlock(&tmp_vcpu->mutex);
}
}
void unlock_all_vcpus(struct kvm *kvm)
{
unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
}
/* Returns true if all vcpus were locked, false otherwise */
bool lock_all_vcpus(struct kvm *kvm)
{
struct kvm_vcpu *tmp_vcpu;
unsigned long c;
/*
* Any time a vcpu is run, vcpu_load is called which tries to grab the
* vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
* that no other VCPUs are run and fiddle with the vgic state while we
* access it.
*/
kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
if (!mutex_trylock(&tmp_vcpu->mutex)) {
unlock_vcpus(kvm, c - 1);
return false;
}
}
return true;
}
/**
* vgic_v2_attr_regs_access - allows user space to access VGIC v2 state
*
* @dev: kvm device handle
* @attr: kvm device attribute
* @is_write: true if userspace is writing a register
*/
static int vgic_v2_attr_regs_access(struct kvm_device *dev,
struct kvm_device_attr *attr,
bool is_write)
{
u32 __user *uaddr = (u32 __user *)(unsigned long)attr->addr;
struct vgic_reg_attr reg_attr;
gpa_t addr;
struct kvm_vcpu *vcpu;
int ret;
u32 val;
ret = vgic_v2_parse_attr(dev, attr, &reg_attr);
if (ret)
return ret;
vcpu = reg_attr.vcpu;
addr = reg_attr.addr;
if (is_write)
if (get_user(val, uaddr))
return -EFAULT;
mutex_lock(&dev->kvm->lock);
ret = vgic_init(dev->kvm);
if (ret)
goto out;
if (!lock_all_vcpus(dev->kvm)) {
ret = -EBUSY;
goto out;
}
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, &val);
break;
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, &val);
break;
default:
ret = -EINVAL;
break;
}
unlock_all_vcpus(dev->kvm);
out:
mutex_unlock(&dev->kvm->lock);
if (!ret && !is_write)
ret = put_user(val, uaddr);
return ret;
}
static int vgic_v2_set_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
return vgic_v2_attr_regs_access(dev, attr, true);
default:
return vgic_set_common_attr(dev, attr);
}
}
static int vgic_v2_get_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
return vgic_v2_attr_regs_access(dev, attr, false);
default:
return vgic_get_common_attr(dev, attr);
}
}
static int vgic_v2_has_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_ADDR:
switch (attr->attr) {
case KVM_VGIC_V2_ADDR_TYPE_DIST:
case KVM_VGIC_V2_ADDR_TYPE_CPU:
return 0;
}
break;
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
return vgic_v2_has_attr_regs(dev, attr);
case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
return 0;
case KVM_DEV_ARM_VGIC_GRP_CTRL:
switch (attr->attr) {
case KVM_DEV_ARM_VGIC_CTRL_INIT:
return 0;
}
}
return -ENXIO;
}
struct kvm_device_ops kvm_arm_vgic_v2_ops = {
.name = "kvm-arm-vgic-v2",
.create = vgic_create,
.destroy = vgic_destroy,
.set_attr = vgic_v2_set_attr,
.get_attr = vgic_v2_get_attr,
.has_attr = vgic_v2_has_attr,
};
int vgic_v3_parse_attr(struct kvm_device *dev, struct kvm_device_attr *attr,
struct vgic_reg_attr *reg_attr)
{
unsigned long vgic_mpidr, mpidr_reg;
/*
* For KVM_DEV_ARM_VGIC_GRP_DIST_REGS group,
* attr might not hold MPIDR. Hence assume vcpu0.
*/
if (attr->group != KVM_DEV_ARM_VGIC_GRP_DIST_REGS) {
vgic_mpidr = (attr->attr & KVM_DEV_ARM_VGIC_V3_MPIDR_MASK) >>
KVM_DEV_ARM_VGIC_V3_MPIDR_SHIFT;
mpidr_reg = VGIC_TO_MPIDR(vgic_mpidr);
reg_attr->vcpu = kvm_mpidr_to_vcpu(dev->kvm, mpidr_reg);
} else {
reg_attr->vcpu = kvm_get_vcpu(dev->kvm, 0);
}
if (!reg_attr->vcpu)
return -EINVAL;
reg_attr->addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
return 0;
}
/*
* vgic_v3_attr_regs_access - allows user space to access VGIC v3 state
*
* @dev: kvm device handle
* @attr: kvm device attribute
* @is_write: true if userspace is writing a register
*/
static int vgic_v3_attr_regs_access(struct kvm_device *dev,
struct kvm_device_attr *attr,
bool is_write)
{
struct vgic_reg_attr reg_attr;
gpa_t addr;
struct kvm_vcpu *vcpu;
bool uaccess;
u32 val;
int ret;
ret = vgic_v3_parse_attr(dev, attr, &reg_attr);
if (ret)
return ret;
vcpu = reg_attr.vcpu;
addr = reg_attr.addr;
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
/* Sysregs uaccess is performed by the sysreg handling code */
uaccess = false;
break;
default:
uaccess = true;
}
if (uaccess && is_write) {
u32 __user *uaddr = (u32 __user *)(unsigned long)attr->addr;
if (get_user(val, uaddr))
return -EFAULT;
}
mutex_lock(&dev->kvm->lock);
if (unlikely(!vgic_initialized(dev->kvm))) {
ret = -EBUSY;
goto out;
}
if (!lock_all_vcpus(dev->kvm)) {
ret = -EBUSY;
goto out;
}
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
ret = vgic_v3_dist_uaccess(vcpu, is_write, addr, &val);
break;
case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
ret = vgic_v3_redist_uaccess(vcpu, is_write, addr, &val);
break;
case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
ret = vgic_v3_cpu_sysregs_uaccess(vcpu, attr, is_write);
break;
case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO: {
unsigned int info, intid;
info = (attr->attr & KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_MASK) >>
KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT;
if (info == VGIC_LEVEL_INFO_LINE_LEVEL) {
intid = attr->attr &
KVM_DEV_ARM_VGIC_LINE_LEVEL_INTID_MASK;
ret = vgic_v3_line_level_info_uaccess(vcpu, is_write,
intid, &val);
} else {
ret = -EINVAL;
}
break;
}
default:
ret = -EINVAL;
break;
}
unlock_all_vcpus(dev->kvm);
out:
mutex_unlock(&dev->kvm->lock);
if (!ret && uaccess && !is_write) {
u32 __user *uaddr = (u32 __user *)(unsigned long)attr->addr;
ret = put_user(val, uaddr);
}
return ret;
}
static int vgic_v3_set_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO:
return vgic_v3_attr_regs_access(dev, attr, true);
default:
return vgic_set_common_attr(dev, attr);
}
}
static int vgic_v3_get_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO:
return vgic_v3_attr_regs_access(dev, attr, false);
default:
return vgic_get_common_attr(dev, attr);
}
}
static int vgic_v3_has_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_ADDR:
switch (attr->attr) {
case KVM_VGIC_V3_ADDR_TYPE_DIST:
case KVM_VGIC_V3_ADDR_TYPE_REDIST:
case KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION:
return 0;
}
break;
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
return vgic_v3_has_attr_regs(dev, attr);
case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
return 0;
case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO: {
if (((attr->attr & KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_MASK) >>
KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT) ==
VGIC_LEVEL_INFO_LINE_LEVEL)
return 0;
break;
}
case KVM_DEV_ARM_VGIC_GRP_CTRL:
switch (attr->attr) {
case KVM_DEV_ARM_VGIC_CTRL_INIT:
return 0;
case KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES:
return 0;
}
}
return -ENXIO;
}
struct kvm_device_ops kvm_arm_vgic_v3_ops = {
.name = "kvm-arm-vgic-v3",
.create = vgic_create,
.destroy = vgic_destroy,
.set_attr = vgic_v3_set_attr,
.get_attr = vgic_v3_get_attr,
.has_attr = vgic_v3_has_attr,
};