linux/arch/arm/kvm/guest.c
Christoffer Dall 1138245ccf KVM: ARM: User space API for getting/setting co-proc registers
The following three ioctls are implemented:
 -  KVM_GET_REG_LIST
 -  KVM_GET_ONE_REG
 -  KVM_SET_ONE_REG

Now we have a table for all the cp15 registers, we can drive a generic
API.

The register IDs carry the following encoding:

ARM registers are mapped using the lower 32 bits.  The upper 16 of that
is the register group type, or coprocessor number:

ARM 32-bit CP15 registers have the following id bit patterns:
  0x4002 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3>

ARM 64-bit CP15 registers have the following id bit patterns:
  0x4003 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3>

For futureproofing, we need to tell QEMU about the CP15 registers the
host lets the guest access.

It will need this information to restore a current guest on a future
CPU or perhaps a future KVM which allow some of these to be changed.

We use a separate table for these, as they're only for the userspace API.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23 13:29:14 -05:00

223 lines
5.6 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/uaccess.h>
#include <asm/kvm.h>
#include <asm/kvm_asm.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[] = {
{ 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.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.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;
}
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);
}
/**
* kvm_arm_copy_reg_indices - get indices of all registers.
*
* We do core registers right here, then we apppend 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;
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_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);
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);
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 kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
const struct kvm_vcpu_init *init)
{
unsigned int i;
/* We can only do a cortex A15 for now. */
if (init->target != kvm_target_cpu())
return -EINVAL;
vcpu->arch.target = init->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 (test_bit(i, (void *)init->features)) {
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;
}