linux-stable/arch/arm/kvm/guest.c
Christoffer Dall 99a1db7a2c KVM: arm/arm64: Allow setting the timer IRQ numbers from userspace
First we define an ABI using the vcpu devices that lets userspace set
the interrupt numbers for the various timers on both the 32-bit and
64-bit KVM/ARM implementations.

Second, we add the definitions for the groups and attributes introduced
by the above ABI.  (We add the PMU define on the 32-bit side as well for
symmetry and it may get used some day.)

Third, we set up the arch-specific vcpu device operation handlers to
call into the timer code for anything related to the
KVM_ARM_VCPU_TIMER_CTRL group.

Fourth, we implement support for getting and setting the timer interrupt
numbers using the above defined ABI in the arch timer code.

Fifth, we introduce error checking upon enabling the arch timer (which
is called when first running a VCPU) to check that all VCPUs are
configured to use the same PPI for the timer (as mandated by the
architecture) and that the virtual and physical timers are not
configured to use the same IRQ number.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08 16:59:57 +02:00

354 lines
8 KiB
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, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#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 <linux/uaccess.h>
#include <asm/kvm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_coproc.h>
#define VM_STAT(x) { #x, offsetof(struct kvm, stat.x), KVM_STAT_VM }
#define VCPU_STAT(x) { #x, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU }
struct kvm_stats_debugfs_item debugfs_entries[] = {
VCPU_STAT(hvc_exit_stat),
VCPU_STAT(wfe_exit_stat),
VCPU_STAT(wfi_exit_stat),
VCPU_STAT(mmio_exit_user),
VCPU_STAT(mmio_exit_kernel),
VCPU_STAT(exits),
{ NULL }
};
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
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)
{
u32 __user *uaddr = (u32 __user *)(long)reg->addr;
struct kvm_regs *regs = &vcpu->arch.ctxt.gp_regs;
u64 off;
if (KVM_REG_SIZE(reg->id) != 4)
return -ENOENT;
/* Our ID is an index into the kvm_regs struct. */
off = core_reg_offset_from_id(reg->id);
if (off >= sizeof(*regs) / KVM_REG_SIZE(reg->id))
return -ENOENT;
return put_user(((u32 *)regs)[off], uaddr);
}
static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
u32 __user *uaddr = (u32 __user *)(long)reg->addr;
struct kvm_regs *regs = &vcpu->arch.ctxt.gp_regs;
u64 off, val;
if (KVM_REG_SIZE(reg->id) != 4)
return -ENOENT;
/* Our ID is an index into the kvm_regs struct. */
off = core_reg_offset_from_id(reg->id);
if (off >= sizeof(*regs) / KVM_REG_SIZE(reg->id))
return -ENOENT;
if (get_user(val, uaddr) != 0)
return -EFAULT;
if (off == KVM_REG_ARM_CORE_REG(usr_regs.ARM_cpsr)) {
unsigned long mode = val & MODE_MASK;
switch (mode) {
case USR_MODE:
case FIQ_MODE:
case IRQ_MODE:
case SVC_MODE:
case ABT_MODE:
case UND_MODE:
break;
default:
return -EINVAL;
}
}
((u32 *)regs)[off] = val;
return 0;
}
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;
}
#define NUM_TIMER_REGS 3
static bool is_timer_reg(u64 index)
{
switch (index) {
case KVM_REG_ARM_TIMER_CTL:
case KVM_REG_ARM_TIMER_CNT:
case KVM_REG_ARM_TIMER_CVAL:
return true;
}
return false;
}
static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
{
if (put_user(KVM_REG_ARM_TIMER_CTL, uindices))
return -EFAULT;
uindices++;
if (put_user(KVM_REG_ARM_TIMER_CNT, uindices))
return -EFAULT;
uindices++;
if (put_user(KVM_REG_ARM_TIMER_CVAL, uindices))
return -EFAULT;
return 0;
}
static int set_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
void __user *uaddr = (void __user *)(long)reg->addr;
u64 val;
int ret;
ret = copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id));
if (ret != 0)
return -EFAULT;
return kvm_arm_timer_set_reg(vcpu, reg->id, val);
}
static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
void __user *uaddr = (void __user *)(long)reg->addr;
u64 val;
val = kvm_arm_timer_get_reg(vcpu, reg->id);
return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
}
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_coproc_regs(vcpu)
+ NUM_TIMER_REGS;
}
/**
* kvm_arm_copy_reg_indices - get indices of all registers.
*
* We do core registers right here, then we append coproc regs.
*/
int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
{
unsigned int i;
const u64 core_reg = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_CORE;
int ret;
for (i = 0; i < sizeof(struct kvm_regs)/sizeof(u32); i++) {
if (put_user(core_reg | i, uindices))
return -EFAULT;
uindices++;
}
ret = copy_timer_indices(vcpu, uindices);
if (ret)
return ret;
uindices += NUM_TIMER_REGS;
return kvm_arm_copy_coproc_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_ARM >> 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);
if (is_timer_reg(reg->id))
return get_timer_reg(vcpu, reg);
return kvm_arm_coproc_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_ARM >> 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);
if (is_timer_reg(reg->id))
return set_timer_reg(vcpu, reg);
return kvm_arm_coproc_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)
{
switch (read_cpuid_part()) {
case ARM_CPU_PART_CORTEX_A7:
return KVM_ARM_TARGET_CORTEX_A7;
case ARM_CPU_PART_CORTEX_A15:
return KVM_ARM_TARGET_CORTEX_A15;
default:
return -EINVAL;
}
}
int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
{
int target = kvm_target_cpu();
if (target < 0)
return -ENODEV;
memset(init, 0, sizeof(*init));
/*
* For now, we don't return any features.
* In future, we might use features to return target
* specific features available for the preferred
* target type.
*/
init->target = (__u32)target;
return 0;
}
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;
}
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
struct kvm_guest_debug *dbg)
{
return -EINVAL;
}
int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
int ret;
switch (attr->group) {
case KVM_ARM_VCPU_TIMER_CTRL:
ret = kvm_arm_timer_set_attr(vcpu, attr);
break;
default:
ret = -ENXIO;
break;
}
return ret;
}
int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
int ret;
switch (attr->group) {
case KVM_ARM_VCPU_TIMER_CTRL:
ret = kvm_arm_timer_get_attr(vcpu, attr);
break;
default:
ret = -ENXIO;
break;
}
return ret;
}
int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
int ret;
switch (attr->group) {
case KVM_ARM_VCPU_TIMER_CTRL:
ret = kvm_arm_timer_has_attr(vcpu, attr);
break;
default:
ret = -ENXIO;
break;
}
return ret;
}