qemu/target-arm/kvm64.c
Mian M. Hamayun 26861c7ce0 target-arm: Add minimal KVM AArch64 support
Add the bare minimum set of functions needed for control of an
AArch64 KVM vcpu:
 * CPU initialization
 * minimal get/put register functions which only handle the
   basic state of the CPU

Signed-off-by: Mian M. Hamayun <m.hamayun@virtualopensystems.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1385645602-18662-4-git-send-email-peter.maydell@linaro.org
[PMM: significantly overhauled; most notably:
 * code lives in kvm64.c rather than using #ifdefs
 * support '-cpu host' rather than implicitly using whatever the
   host's CPU is regardless of what the user requests
 * fix bug attempting to get/set nonexistent X[31]
 * fix bug writing 64 bit kernel pstate into uint32_t env field
]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-12-17 19:42:30 +00:00

205 lines
5.2 KiB
C

/*
* ARM implementation of KVM hooks, 64 bit specific code
*
* Copyright Mian-M. Hamayun 2013, Virtual Open Systems
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/kvm.h>
#include "qemu-common.h"
#include "qemu/timer.h"
#include "sysemu/sysemu.h"
#include "sysemu/kvm.h"
#include "kvm_arm.h"
#include "cpu.h"
#include "hw/arm/arm.h"
static inline void set_feature(uint64_t *features, int feature)
{
*features |= 1ULL << feature;
}
bool kvm_arm_get_host_cpu_features(ARMHostCPUClass *ahcc)
{
/* Identify the feature bits corresponding to the host CPU, and
* fill out the ARMHostCPUClass fields accordingly. To do this
* we have to create a scratch VM, create a single CPU inside it,
* and then query that CPU for the relevant ID registers.
* For AArch64 we currently don't care about ID registers at
* all; we just want to know the CPU type.
*/
int fdarray[3];
uint64_t features = 0;
/* Old kernels may not know about the PREFERRED_TARGET ioctl: however
* we know these will only support creating one kind of guest CPU,
* which is its preferred CPU type. Fortunately these old kernels
* support only a very limited number of CPUs.
*/
static const uint32_t cpus_to_try[] = {
KVM_ARM_TARGET_AEM_V8,
KVM_ARM_TARGET_FOUNDATION_V8,
KVM_ARM_TARGET_CORTEX_A57,
QEMU_KVM_ARM_TARGET_NONE
};
struct kvm_vcpu_init init;
if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) {
return false;
}
ahcc->target = init.target;
ahcc->dtb_compatible = "arm,arm-v8";
kvm_arm_destroy_scratch_host_vcpu(fdarray);
/* We can assume any KVM supporting CPU is at least a v8
* with VFPv4+Neon; this in turn implies most of the other
* feature bits.
*/
set_feature(&features, ARM_FEATURE_V8);
set_feature(&features, ARM_FEATURE_VFP4);
set_feature(&features, ARM_FEATURE_NEON);
set_feature(&features, ARM_FEATURE_AARCH64);
ahcc->features = features;
return true;
}
int kvm_arch_init_vcpu(CPUState *cs)
{
ARMCPU *cpu = ARM_CPU(cs);
struct kvm_vcpu_init init;
int ret;
if (cpu->kvm_target == QEMU_KVM_ARM_TARGET_NONE ||
!arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
fprintf(stderr, "KVM is not supported for this guest CPU type\n");
return -EINVAL;
}
init.target = cpu->kvm_target;
memset(init.features, 0, sizeof(init.features));
if (cpu->start_powered_off) {
init.features[0] = 1 << KVM_ARM_VCPU_POWER_OFF;
}
ret = kvm_vcpu_ioctl(cs, KVM_ARM_VCPU_INIT, &init);
/* TODO : support for save/restore/reset of system regs via tuple list */
return ret;
}
#define AARCH64_CORE_REG(x) (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \
KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(x))
int kvm_arch_put_registers(CPUState *cs, int level)
{
struct kvm_one_reg reg;
uint64_t val;
int i;
int ret;
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
for (i = 0; i < 31; i++) {
reg.id = AARCH64_CORE_REG(regs.regs[i]);
reg.addr = (uintptr_t) &env->xregs[i];
ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
if (ret) {
return ret;
}
}
reg.id = AARCH64_CORE_REG(regs.sp);
reg.addr = (uintptr_t) &env->xregs[31];
ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
if (ret) {
return ret;
}
/* Note that KVM thinks pstate is 64 bit but we use a uint32_t */
val = pstate_read(env);
reg.id = AARCH64_CORE_REG(regs.pstate);
reg.addr = (uintptr_t) &val;
ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
if (ret) {
return ret;
}
reg.id = AARCH64_CORE_REG(regs.pc);
reg.addr = (uintptr_t) &env->pc;
ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
if (ret) {
return ret;
}
/* TODO:
* SP_EL1
* ELR_EL1
* SPSR[]
* FP state
* system registers
*/
return ret;
}
int kvm_arch_get_registers(CPUState *cs)
{
struct kvm_one_reg reg;
uint64_t val;
int i;
int ret;
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
for (i = 0; i < 31; i++) {
reg.id = AARCH64_CORE_REG(regs.regs[i]);
reg.addr = (uintptr_t) &env->xregs[i];
ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
if (ret) {
return ret;
}
}
reg.id = AARCH64_CORE_REG(regs.sp);
reg.addr = (uintptr_t) &env->xregs[31];
ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
if (ret) {
return ret;
}
reg.id = AARCH64_CORE_REG(regs.pstate);
reg.addr = (uintptr_t) &val;
ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
if (ret) {
return ret;
}
pstate_write(env, val);
reg.id = AARCH64_CORE_REG(regs.pc);
reg.addr = (uintptr_t) &env->pc;
ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
if (ret) {
return ret;
}
/* TODO: other registers */
return ret;
}
void kvm_arch_reset_vcpu(CPUState *cs)
{
}