[RFC v2 2/6] ARM: KVM: Add support for KVM on ARM architecture

[Peter Maydell <peter.maydell@linaro.org>]

From: Christoffer Dall <cdall@cs.columbia.edu>

Add basic support for KVM on ARM architecture.

Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
[PMM: Minor tweaks and code cleanup, switch to ONE_REG]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm_pic.c             |   28 ++++
 target-arm/Makefile.objs |    1 +
 target-arm/cpu.h         |    1 +
 target-arm/helper.c      |    2 +-
 target-arm/kvm.c         |  328 ++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 359 insertions(+), 1 deletion(-)
 create mode 100644 target-arm/kvm.c

diff --git a/hw/arm_pic.c b/hw/arm_pic.c
index ffb4d41..72272dc 100644
--- a/hw/arm_pic.c
+++ b/hw/arm_pic.c
@@ -9,6 +9,7 @@
 
 #include "hw.h"
 #include "arm-misc.h"
+#include "kvm.h"
 
 /* Input 0 is IRQ and input 1 is FIQ.  */
 static void arm_pic_cpu_handler(void *opaque, int irq, int level)
@@ -34,7 +35,34 @@ static void arm_pic_cpu_handler(void *opaque, int irq, int level)
     }
 }
 
+#ifdef CONFIG_KVM
+static void kvm_arm_pic_cpu_handler(void *opaque, int irq, int level)
+{
+    ARMCPU *cpu = opaque;
+    CPUARMState *env = &cpu->env;
+    int kvm_irq = KVM_ARM_IRQ_TYPE_CPU << KVM_ARM_IRQ_TYPE_SHIFT;
+
+    switch (irq) {
+    case ARM_PIC_CPU_IRQ:
+        kvm_irq |= KVM_ARM_IRQ_CPU_IRQ;
+        break;
+    case ARM_PIC_CPU_FIQ:
+        kvm_irq |= KVM_ARM_IRQ_CPU_FIQ;
+        break;
+    default:
+        hw_error("kvm_arm_pic_cpu_handler: Bad interrupt line %d\n", irq);
+    }
+    kvm_irq |= env->cpu_index << KVM_ARM_IRQ_VCPU_SHIFT;
+    kvm_set_irq(kvm_state, kvm_irq, level ? 1 : 0);
+}
+#endif
+
 qemu_irq *arm_pic_init_cpu(ARMCPU *cpu)
 {
+#ifdef CONFIG_KVM
+    if (kvm_enabled()) {
+        return qemu_allocate_irqs(kvm_arm_pic_cpu_handler, cpu, 2);
+    }
+#endif
     return qemu_allocate_irqs(arm_pic_cpu_handler, cpu, 2);
 }
diff --git a/target-arm/Makefile.objs b/target-arm/Makefile.objs
index b6f1a9e..d89b57c 100644
--- a/target-arm/Makefile.objs
+++ b/target-arm/Makefile.objs
@@ -1,4 +1,5 @@
 obj-y += arm-semi.o
 obj-$(CONFIG_SOFTMMU) += machine.o
+obj-$(CONFIG_KVM) += kvm.o
 obj-y += translate.o op_helper.o helper.o cpu.o
 obj-y += neon_helper.o iwmmxt_helper.o
diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index ff4de10..8c7e574 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -236,6 +236,7 @@ ARMCPU *cpu_arm_init(const char *cpu_model);
 void arm_translate_init(void);
 int cpu_arm_exec(CPUARMState *s);
 void do_interrupt(CPUARMState *);
+int bank_number(CPUARMState *env, int mode);
 void switch_mode(CPUARMState *, int);
 uint32_t do_arm_semihosting(CPUARMState *env);
 
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 58340bd..f62f3da 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -1619,7 +1619,7 @@ uint32_t HELPER(get_r13_banked)(CPUARMState *env, uint32_t mode)
 #else
 
 /* Map CPU modes onto saved register banks.  */
-static inline int bank_number(CPUARMState *env, int mode)
+int bank_number(CPUARMState *env, int mode)
 {
     switch (mode) {
     case ARM_CPU_MODE_USR:
diff --git a/target-arm/kvm.c b/target-arm/kvm.c
new file mode 100644
index 0000000..fee60e1
--- /dev/null
+++ b/target-arm/kvm.c
@@ -0,0 +1,328 @@
+/*
+ * ARM implementation of KVM hooks
+ *
+ * Copyright Christoffer Dall 2009-2010
+ *
+ * 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.h"
+#include "kvm.h"
+#include "cpu.h"
+#include "device_tree.h"
+#include "hw/arm-misc.h"
+
+const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
+    KVM_CAP_LAST_INFO
+};
+
+int kvm_arch_init(KVMState *s)
+{
+    /* For ARM interrupt delivery is always asynchronous,
+     * whether we are using an in-kernel VGIC or not.
+     */
+    kvm_async_interrupts_allowed = true;
+    return 0;
+}
+
+int kvm_arch_init_vcpu(CPUARMState *env)
+{
+    struct kvm_vcpu_init init;
+
+    init.target = KVM_ARM_TARGET_CORTEX_A15;
+    memset(init.features, 0, sizeof(init.features));
+    return kvm_vcpu_ioctl(env, KVM_ARM_VCPU_INIT, &init);
+}
+
+struct reg {
+    uint64_t id;
+    int offset;
+};
+
+#define COREREG(KERNELNAME, QEMUFIELD)                       \
+    {                                                        \
+        KVM_REG_ARM | KVM_REG_SIZE_U32 |                     \
+        KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(KERNELNAME), \
+        offsetof(CPUARMState, QEMUFIELD)                     \
+    }
+
+#define CP15REG(CRN, CRM, OPC1, OPC2, QEMUFIELD) \
+    {                                            \
+        KVM_REG_ARM | KVM_REG_SIZE_U32 |         \
+        (15 << KVM_REG_ARM_COPROC_SHIFT) |       \
+        ((CRN) << KVM_REG_ARM_32_CRN_SHIFT) |    \
+        ((CRM) << KVM_REG_ARM_CRM_SHIFT) |       \
+        ((OPC1) << KVM_REG_ARM_OPC1_SHIFT) |     \
+        ((OPC2) << KVM_REG_ARM_32_OPC2_SHIFT),   \
+        offsetof(CPUARMState, QEMUFIELD)         \
+    }
+
+const struct reg regs[] = {
+    /* R0_usr .. R14_usr */
+    COREREG(usr_regs[0], regs[0]),
+    COREREG(usr_regs[1], regs[1]),
+    COREREG(usr_regs[2], regs[2]),
+    COREREG(usr_regs[3], regs[3]),
+    COREREG(usr_regs[4], regs[4]),
+    COREREG(usr_regs[5], regs[5]),
+    COREREG(usr_regs[6], regs[6]),
+    COREREG(usr_regs[7], regs[7]),
+    COREREG(usr_regs[8], usr_regs[0]),
+    COREREG(usr_regs[9], usr_regs[1]),
+    COREREG(usr_regs[10], usr_regs[2]),
+    COREREG(usr_regs[11], usr_regs[3]),
+    COREREG(usr_regs[12], usr_regs[4]),
+    COREREG(usr_regs[13], banked_r13[0]),
+    COREREG(usr_regs[14], banked_r14[0]),
+    /* R13, R14, SPSR for SVC, ABT, UND, IRQ banks */
+    COREREG(svc_regs[0], banked_r13[1]),
+    COREREG(svc_regs[1], banked_r14[1]),
+    COREREG(svc_regs[2], banked_spsr[1]),
+    COREREG(abt_regs[0], banked_r13[2]),
+    COREREG(abt_regs[1], banked_r14[2]),
+    COREREG(abt_regs[2], banked_spsr[2]),
+    COREREG(und_regs[0], banked_r13[3]),
+    COREREG(und_regs[1], banked_r14[3]),
+    COREREG(und_regs[2], banked_spsr[3]),
+    COREREG(irq_regs[0], banked_r13[4]),
+    COREREG(irq_regs[1], banked_r14[4]),
+    COREREG(irq_regs[2], banked_spsr[4]),
+    /* R8_fiq .. R14_fiq and SPSR_fiq */
+    COREREG(fiq_regs[0], fiq_regs[0]),
+    COREREG(fiq_regs[1], fiq_regs[1]),
+    COREREG(fiq_regs[2], fiq_regs[2]),
+    COREREG(fiq_regs[3], fiq_regs[3]),
+    COREREG(fiq_regs[4], fiq_regs[4]),
+    COREREG(fiq_regs[0], banked_r13[5]),
+    COREREG(fiq_regs[1], banked_r14[5]),
+    COREREG(fiq_regs[2], banked_spsr[5]),
+    /* R15 */
+    COREREG(pc, regs[15]),
+    /* A non-comprehensive set of cp15 registers.
+     * TODO: drive this from the cp_regs hashtable instead.
+     */
+    CP15REG(1, 0, 0, 0, cp15.c1_sys), /* SCTLR */
+    CP15REG(2, 0, 0, 2, cp15.c2_control), /* TTBCR */
+    CP15REG(3, 0, 0, 0, cp15.c3), /* DACR */
+};
+
+int kvm_arch_put_registers(CPUARMState *env, int level)
+{
+    struct kvm_one_reg r;
+    int mode, bn;
+    int ret, i;
+    uint32_t cpsr;
+    uint64_t ttbr;
+
+    /* Make sure the banked regs are properly set */
+    mode = env->uncached_cpsr & CPSR_M;
+    bn = bank_number(env, mode);
+    if (mode == ARM_CPU_MODE_FIQ) {
+        memcpy(env->fiq_regs, env->regs + 8, 5 * sizeof(uint32_t));
+    } else {
+        memcpy(env->usr_regs, env->regs + 8, 5 * sizeof(uint32_t));
+    }
+    env->banked_r13[bn] = env->regs[13];
+    env->banked_r14[bn] = env->regs[14];
+    env->banked_spsr[bn] = env->spsr;
+
+    /* Now we can safely copy stuff down to the kernel */
+    for (i = 0; i < ARRAY_SIZE(regs); i++) {
+        r.id = regs[i].id;
+        r.addr = (uintptr_t)(env) + regs[i].offset;
+        ret = kvm_vcpu_ioctl(env, KVM_SET_ONE_REG, &r);
+        if (ret) {
+            return ret;
+        }
+    }
+
+    /* Special cases which aren't a single CPUARMState field */
+    cpsr = cpsr_read(env);
+    r.id = KVM_REG_ARM | KVM_REG_SIZE_U32 |
+        KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(cpsr);
+    r.addr = (uintptr_t)(&cpsr);
+    ret = kvm_vcpu_ioctl(env, KVM_SET_ONE_REG, &r);
+    if (ret) {
+        return ret;
+    }
+
+    /* TTBR0: cp15 crm=2 opc1=0 */
+    ttbr = ((uint64_t)env->cp15.c2_base0_hi << 32) | env->cp15.c2_base0;
+    r.id = KVM_REG_ARM | KVM_REG_SIZE_U64 | (15 << KVM_REG_ARM_COPROC_SHIFT) |
+        (2 << KVM_REG_ARM_CRM_SHIFT) | (0 << KVM_REG_ARM_OPC1_SHIFT);
+    r.addr = (uintptr_t)(&ttbr);
+    ret = kvm_vcpu_ioctl(env, KVM_SET_ONE_REG, &r);
+    if (ret) {
+        return ret;
+    }
+
+    /* TTBR1: cp15 crm=2 opc1=1 */
+    ttbr = ((uint64_t)env->cp15.c2_base1_hi << 32) | env->cp15.c2_base1;
+    r.id = KVM_REG_ARM | KVM_REG_SIZE_U64 | (15 << KVM_REG_ARM_COPROC_SHIFT) |
+        (2 << KVM_REG_ARM_CRM_SHIFT) | (1 << KVM_REG_ARM_OPC1_SHIFT);
+    r.addr = (uintptr_t)(&ttbr);
+    ret = kvm_vcpu_ioctl(env, KVM_SET_ONE_REG, &r);
+
+    return ret;
+}
+
+int kvm_arch_get_registers(CPUARMState *env)
+{
+    struct kvm_one_reg r;
+    int mode, bn;
+    int ret, i;
+    uint32_t cpsr;
+    uint64_t ttbr;
+
+    for (i = 0; i < ARRAY_SIZE(regs); i++) {
+        r.id = regs[i].id;
+        r.addr = (uintptr_t)(env) + regs[i].offset;
+        ret = kvm_vcpu_ioctl(env, KVM_GET_ONE_REG, &r);
+        if (ret) {
+            return ret;
+        }
+    }
+
+    /* Special cases which aren't a single CPUARMState field */
+    r.id = KVM_REG_ARM | KVM_REG_SIZE_U32 |
+        KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(cpsr);
+    r.addr = (uintptr_t)(&cpsr);
+    ret = kvm_vcpu_ioctl(env, KVM_GET_ONE_REG, &r);
+    if (ret) {
+        return ret;
+    }
+    cpsr_write(env, cpsr, 0xffffffff);
+
+    /* TTBR0: cp15 crm=2 opc1=0 */
+    r.id = KVM_REG_ARM | KVM_REG_SIZE_U64 | (15 << KVM_REG_ARM_COPROC_SHIFT) |
+        (2 << KVM_REG_ARM_CRM_SHIFT) | (0 << KVM_REG_ARM_OPC1_SHIFT);
+    r.addr = (uintptr_t)(&ttbr);
+    ret = kvm_vcpu_ioctl(env, KVM_GET_ONE_REG, &r);
+    if (ret) {
+        return ret;
+    }
+    env->cp15.c2_base0_hi = ttbr >> 32;
+    env->cp15.c2_base0 = ttbr;
+
+    /* TTBR1: cp15 crm=2 opc1=1 */
+    r.id = KVM_REG_ARM | KVM_REG_SIZE_U64 | (15 << KVM_REG_ARM_COPROC_SHIFT) |
+        (2 << KVM_REG_ARM_CRM_SHIFT) | (1 << KVM_REG_ARM_OPC1_SHIFT);
+    r.addr = (uintptr_t)(&ttbr);
+    ret = kvm_vcpu_ioctl(env, KVM_GET_ONE_REG, &r);
+    if (ret) {
+        return ret;
+    }
+    env->cp15.c2_base1_hi = ttbr >> 32;
+    env->cp15.c2_base1 = ttbr;
+
+    /* Make sure the current mode regs are properly set */
+    mode = env->uncached_cpsr & CPSR_M;
+    bn = bank_number(env, mode);
+    if (mode == ARM_CPU_MODE_FIQ) {
+        memcpy(env->regs + 8, env->fiq_regs, 5 * sizeof(uint32_t));
+    } else {
+        memcpy(env->regs + 8, env->usr_regs, 5 * sizeof(uint32_t));
+    }
+    env->regs[13] = env->banked_r13[bn];
+    env->regs[14] = env->banked_r14[bn];
+    env->spsr = env->banked_spsr[bn];
+
+    /* The main GET_ONE_REG loop above set c2_control, but we need to
+     * update some extra cached precomputed values too.
+     * When this is driven from the cp_regs hashtable then this ugliness
+     * can disappear because we'll use the access function which sets
+     * these values automatically.
+     */
+    env->cp15.c2_mask = ~(((uint32_t)0xffffffffu) >> env->cp15.c2_control);
+    env->cp15.c2_base_mask = ~((uint32_t)0x3fffu >> env->cp15.c2_control);
+
+    return 0;
+}
+
+void kvm_arch_pre_run(CPUARMState *env, struct kvm_run *run)
+{
+}
+
+void kvm_arch_post_run(CPUARMState *env, struct kvm_run *run)
+{
+}
+
+int kvm_arch_handle_exit(CPUARMState *env, struct kvm_run *run)
+{
+    int ret = 0;
+
+    return ret;
+}
+
+void kvm_arch_reset_vcpu(CPUARMState *env)
+{
+}
+
+bool kvm_arch_stop_on_emulation_error(CPUARMState *env)
+{
+    return true;
+}
+
+int kvm_arch_process_async_events(CPUARMState *env)
+{
+    return 0;
+}
+
+int kvm_arch_on_sigbus_vcpu(CPUARMState *env, int code, void *addr)
+{
+    return 1;
+}
+
+int kvm_arch_on_sigbus(int code, void *addr)
+{
+    return 1;
+}
+
+void kvm_arch_update_guest_debug(CPUARMState *env, struct kvm_guest_debug *dbg)
+{
+    fprintf(stderr, "%s: not implemented\n", __func__);
+}
+
+int kvm_arch_insert_sw_breakpoint(CPUARMState *env,
+                                  struct kvm_sw_breakpoint *bp)
+{
+    fprintf(stderr, "%s: not implemented\n", __func__);
+    return -EINVAL;
+}
+
+int kvm_arch_insert_hw_breakpoint(target_ulong addr,
+                                  target_ulong len, int type)
+{
+    fprintf(stderr, "%s: not implemented\n", __func__);
+    return -EINVAL;
+}
+
+int kvm_arch_remove_hw_breakpoint(target_ulong addr,
+                                  target_ulong len, int type)
+{
+    fprintf(stderr, "%s: not implemented\n", __func__);
+    return -EINVAL;
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUARMState *env,
+                                  struct kvm_sw_breakpoint *bp)
+{
+    fprintf(stderr, "%s: not implemented\n", __func__);
+    return -EINVAL;
+}
+
+void kvm_arch_remove_all_hw_breakpoints(void)
+{
+    fprintf(stderr, "%s: not implemented\n", __func__);
+}
-- 
1.7.9.5