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>
diff --git a/target-arm/kvm64.c b/target-arm/kvm64.c
new file mode 100644
index 0000000..1b7ca90
--- /dev/null
+++ b/target-arm/kvm64.c
@@ -0,0 +1,204 @@
+/*
+ * 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, ®);
+ 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, ®);
+ 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, ®);
+ 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, ®);
+ 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, ®);
+ 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, ®);
+ 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, ®);
+ 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, ®);
+ if (ret) {
+ return ret;
+ }
+
+ /* TODO: other registers */
+ return ret;
+}
+
+void kvm_arch_reset_vcpu(CPUState *cs)
+{
+}
