target-mips: kvm: Add main KVM support for MIPS

Implement the main KVM arch API for MIPS.

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andreas Färber <afaerber@suse.de>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 709 insertions, 0 deletions

diff --git a/target-mips/kvm.c b/target-mips/kvm.c
new file mode 100644
index 0000000..844e5bb
--- /dev/null
+++ b/target-mips/kvm.c
@@ -0,0 +1,683 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * KVM/MIPS: MIPS specific KVM APIs
+ *
+ * Copyright (C) 2012-2014 Imagination Technologies Ltd.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+*/
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include <linux/kvm.h>
+
+#include "qemu-common.h"
+#include "qemu/error-report.h"
+#include "qemu/timer.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/kvm.h"
+#include "cpu.h"
+#include "sysemu/cpus.h"
+#include "kvm_mips.h"
+
+#define DEBUG_KVM 0
+
+#define DPRINTF(fmt, ...) \
+    do { if (DEBUG_KVM) { fprintf(stderr, fmt, ## __VA_ARGS__); } } while (0)
+
+const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
+    KVM_CAP_LAST_INFO
+};
+
+static void kvm_mips_update_state(void *opaque, int running, RunState state);
+
+unsigned long kvm_arch_vcpu_id(CPUState *cs)
+{
+    return cs->cpu_index;
+}
+
+int kvm_arch_init(KVMState *s)
+{
+    /* MIPS has 128 signals */
+    kvm_set_sigmask_len(s, 16);
+
+    DPRINTF("%s\n", __func__);
+    return 0;
+}
+
+int kvm_arch_init_vcpu(CPUState *cs)
+{
+    int ret = 0;
+
+    qemu_add_vm_change_state_handler(kvm_mips_update_state, cs);
+
+    DPRINTF("%s\n", __func__);
+    return ret;
+}
+
+void kvm_mips_reset_vcpu(MIPSCPU *cpu)
+{
+    DPRINTF("%s\n", __func__);
+}
+
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+{
+    DPRINTF("%s\n", __func__);
+    return 0;
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+{
+    DPRINTF("%s\n", __func__);
+    return 0;
+}
+
+static inline int cpu_mips_io_interrupts_pending(MIPSCPU *cpu)
+{
+    CPUMIPSState *env = &cpu->env;
+
+    DPRINTF("%s: %#x\n", __func__, env->CP0_Cause & (1 << (2 + CP0Ca_IP)));
+    return env->CP0_Cause & (0x1 << (2 + CP0Ca_IP));
+}
+
+
+void kvm_arch_pre_run(CPUState *cs, struct kvm_run *run)
+{
+    MIPSCPU *cpu = MIPS_CPU(cs);
+    int r;
+    struct kvm_mips_interrupt intr;
+
+    if ((cs->interrupt_request & CPU_INTERRUPT_HARD) &&
+            cpu_mips_io_interrupts_pending(cpu)) {
+        intr.cpu = -1;
+        intr.irq = 2;
+        r = kvm_vcpu_ioctl(cs, KVM_INTERRUPT, &intr);
+        if (r < 0) {
+            error_report("%s: cpu %d: failed to inject IRQ %x",
+                         __func__, cs->cpu_index, intr.irq);
+        }
+    }
+}
+
+void kvm_arch_post_run(CPUState *cs, struct kvm_run *run)
+{
+    DPRINTF("%s\n", __func__);
+}
+
+int kvm_arch_process_async_events(CPUState *cs)
+{
+    return cs->halted;
+}
+
+int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
+{
+    int ret;
+
+    DPRINTF("%s\n", __func__);
+    switch (run->exit_reason) {
+    default:
+        error_report("%s: unknown exit reason %d",
+                     __func__, run->exit_reason);
+        ret = -1;
+        break;
+    }
+
+    return ret;
+}
+
+bool kvm_arch_stop_on_emulation_error(CPUState *cs)
+{
+    DPRINTF("%s\n", __func__);
+    return true;
+}
+
+int kvm_arch_on_sigbus_vcpu(CPUState *cs, int code, void *addr)
+{
+    DPRINTF("%s\n", __func__);
+    return 1;
+}
+
+int kvm_arch_on_sigbus(int code, void *addr)
+{
+    DPRINTF("%s\n", __func__);
+    return 1;
+}
+
+void kvm_arch_init_irq_routing(KVMState *s)
+{
+}
+
+int kvm_mips_set_interrupt(MIPSCPU *cpu, int irq, int level)
+{
+    CPUState *cs = CPU(cpu);
+    struct kvm_mips_interrupt intr;
+
+    if (!kvm_enabled()) {
+        return 0;
+    }
+
+    intr.cpu = -1;
+
+    if (level) {
+        intr.irq = irq;
+    } else {
+        intr.irq = -irq;
+    }
+
+    kvm_vcpu_ioctl(cs, KVM_INTERRUPT, &intr);
+
+    return 0;
+}
+
+int kvm_mips_set_ipi_interrupt(MIPSCPU *cpu, int irq, int level)
+{
+    CPUState *cs = current_cpu;
+    CPUState *dest_cs = CPU(cpu);
+    struct kvm_mips_interrupt intr;
+
+    if (!kvm_enabled()) {
+        return 0;
+    }
+
+    intr.cpu = dest_cs->cpu_index;
+
+    if (level) {
+        intr.irq = irq;
+    } else {
+        intr.irq = -irq;
+    }
+
+    DPRINTF("%s: CPU %d, IRQ: %d\n", __func__, intr.cpu, intr.irq);
+
+    kvm_vcpu_ioctl(cs, KVM_INTERRUPT, &intr);
+
+    return 0;
+}
+
+#define MIPS_CP0_32(_R, _S)                                     \
+    (KVM_REG_MIPS | KVM_REG_SIZE_U32 | 0x10000 | (8 * (_R) + (_S)))
+
+#define MIPS_CP0_64(_R, _S)                                     \
+    (KVM_REG_MIPS | KVM_REG_SIZE_U64 | 0x10000 | (8 * (_R) + (_S)))
+
+#define KVM_REG_MIPS_CP0_INDEX          MIPS_CP0_32(0, 0)
+#define KVM_REG_MIPS_CP0_CONTEXT        MIPS_CP0_64(4, 0)
+#define KVM_REG_MIPS_CP0_USERLOCAL      MIPS_CP0_64(4, 2)
+#define KVM_REG_MIPS_CP0_PAGEMASK       MIPS_CP0_32(5, 0)
+#define KVM_REG_MIPS_CP0_WIRED          MIPS_CP0_32(6, 0)
+#define KVM_REG_MIPS_CP0_HWRENA         MIPS_CP0_32(7, 0)
+#define KVM_REG_MIPS_CP0_BADVADDR       MIPS_CP0_64(8, 0)
+#define KVM_REG_MIPS_CP0_COUNT          MIPS_CP0_32(9, 0)
+#define KVM_REG_MIPS_CP0_ENTRYHI        MIPS_CP0_64(10, 0)
+#define KVM_REG_MIPS_CP0_COMPARE        MIPS_CP0_32(11, 0)
+#define KVM_REG_MIPS_CP0_STATUS         MIPS_CP0_32(12, 0)
+#define KVM_REG_MIPS_CP0_CAUSE          MIPS_CP0_32(13, 0)
+#define KVM_REG_MIPS_CP0_EPC            MIPS_CP0_64(14, 0)
+#define KVM_REG_MIPS_CP0_ERROREPC       MIPS_CP0_64(30, 0)
+
+/* CP0_Count control */
+#define KVM_REG_MIPS_COUNT_CTL          (KVM_REG_MIPS | KVM_REG_SIZE_U64 | \
+                                         0x20000 | 0)
+#define KVM_REG_MIPS_COUNT_CTL_DC       0x00000001      /* master disable */
+/* CP0_Count resume monotonic nanoseconds */
+#define KVM_REG_MIPS_COUNT_RESUME       (KVM_REG_MIPS | KVM_REG_SIZE_U64 | \
+                                         0x20000 | 1)
+/* CP0_Count rate in Hz */
+#define KVM_REG_MIPS_COUNT_HZ           (KVM_REG_MIPS | KVM_REG_SIZE_U64 | \
+                                         0x20000 | 2)
+
+static inline int kvm_mips_put_one_reg(CPUState *cs, uint64_t reg_id,
+                                       int32_t *addr)
+{
+    uint64_t val64 = *addr;
+    struct kvm_one_reg cp0reg = {
+        .id = reg_id,
+        .addr = (uintptr_t)&val64
+    };
+
+    return kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &cp0reg);
+}
+
+static inline int kvm_mips_put_one_ulreg(CPUState *cs, uint64_t reg_id,
+                                         target_ulong *addr)
+{
+    uint64_t val64 = *addr;
+    struct kvm_one_reg cp0reg = {
+        .id = reg_id,
+        .addr = (uintptr_t)&val64
+    };
+
+    return kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &cp0reg);
+}
+
+static inline int kvm_mips_put_one_reg64(CPUState *cs, uint64_t reg_id,
+                                         uint64_t *addr)
+{
+    struct kvm_one_reg cp0reg = {
+        .id = reg_id,
+        .addr = (uintptr_t)addr
+    };
+
+    return kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &cp0reg);
+}
+
+static inline int kvm_mips_get_one_reg(CPUState *cs, uint64_t reg_id,
+                                       int32_t *addr)
+{
+    int ret;
+    uint64_t val64 = 0;
+    struct kvm_one_reg cp0reg = {
+        .id = reg_id,
+        .addr = (uintptr_t)&val64
+    };
+
+    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &cp0reg);
+    if (ret >= 0) {
+        *addr = val64;
+    }
+    return ret;
+}
+
+static inline int kvm_mips_get_one_ulreg(CPUState *cs, uint64 reg_id,
+                                         target_ulong *addr)
+{
+    int ret;
+    uint64_t val64 = 0;
+    struct kvm_one_reg cp0reg = {
+        .id = reg_id,
+        .addr = (uintptr_t)&val64
+    };
+
+    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &cp0reg);
+    if (ret >= 0) {
+        *addr = val64;
+    }
+    return ret;
+}
+
+static inline int kvm_mips_get_one_reg64(CPUState *cs, uint64 reg_id,
+                                         uint64_t *addr)
+{
+    struct kvm_one_reg cp0reg = {
+        .id = reg_id,
+        .addr = (uintptr_t)addr
+    };
+
+    return kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &cp0reg);
+}
+
+/*
+ * We freeze the KVM timer when either the VM clock is stopped or the state is
+ * saved (the state is dirty).
+ */
+
+/*
+ * Save the state of the KVM timer when VM clock is stopped or state is synced
+ * to QEMU.
+ */
+static int kvm_mips_save_count(CPUState *cs)
+{
+    MIPSCPU *cpu = MIPS_CPU(cs);
+    CPUMIPSState *env = &cpu->env;
+    uint64_t count_ctl;
+    int err, ret = 0;
+
+    /* freeze KVM timer */
+    err = kvm_mips_get_one_reg64(cs, KVM_REG_MIPS_COUNT_CTL, &count_ctl);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get COUNT_CTL (%d)\n", __func__, err);
+        ret = err;
+    } else if (!(count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)) {
+        count_ctl |= KVM_REG_MIPS_COUNT_CTL_DC;
+        err = kvm_mips_put_one_reg64(cs, KVM_REG_MIPS_COUNT_CTL, &count_ctl);
+        if (err < 0) {
+            DPRINTF("%s: Failed to set COUNT_CTL.DC=1 (%d)\n", __func__, err);
+            ret = err;
+        }
+    }
+
+    /* read CP0_Cause */
+    err = kvm_mips_get_one_reg(cs, KVM_REG_MIPS_CP0_CAUSE, &env->CP0_Cause);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_CAUSE (%d)\n", __func__, err);
+        ret = err;
+    }
+
+    /* read CP0_Count */
+    err = kvm_mips_get_one_reg(cs, KVM_REG_MIPS_CP0_COUNT, &env->CP0_Count);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_COUNT (%d)\n", __func__, err);
+        ret = err;
+    }
+
+    return ret;
+}
+
+/*
+ * Restore the state of the KVM timer when VM clock is restarted or state is
+ * synced to KVM.
+ */
+static int kvm_mips_restore_count(CPUState *cs)
+{
+    MIPSCPU *cpu = MIPS_CPU(cs);
+    CPUMIPSState *env = &cpu->env;
+    uint64_t count_ctl;
+    int err_dc, err, ret = 0;
+
+    /* check the timer is frozen */
+    err_dc = kvm_mips_get_one_reg64(cs, KVM_REG_MIPS_COUNT_CTL, &count_ctl);
+    if (err_dc < 0) {
+        DPRINTF("%s: Failed to get COUNT_CTL (%d)\n", __func__, err_dc);
+        ret = err_dc;
+    } else if (!(count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)) {
+        /* freeze timer (sets COUNT_RESUME for us) */
+        count_ctl |= KVM_REG_MIPS_COUNT_CTL_DC;
+        err = kvm_mips_put_one_reg64(cs, KVM_REG_MIPS_COUNT_CTL, &count_ctl);
+        if (err < 0) {
+            DPRINTF("%s: Failed to set COUNT_CTL.DC=1 (%d)\n", __func__, err);
+            ret = err;
+        }
+    }
+
+    /* load CP0_Cause */
+    err = kvm_mips_put_one_reg(cs, KVM_REG_MIPS_CP0_CAUSE, &env->CP0_Cause);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_CAUSE (%d)\n", __func__, err);
+        ret = err;
+    }
+
+    /* load CP0_Count */
+    err = kvm_mips_put_one_reg(cs, KVM_REG_MIPS_CP0_COUNT, &env->CP0_Count);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_COUNT (%d)\n", __func__, err);
+        ret = err;
+    }
+
+    /* resume KVM timer */
+    if (err_dc >= 0) {
+        count_ctl &= ~KVM_REG_MIPS_COUNT_CTL_DC;
+        err = kvm_mips_put_one_reg64(cs, KVM_REG_MIPS_COUNT_CTL, &count_ctl);
+        if (err < 0) {
+            DPRINTF("%s: Failed to set COUNT_CTL.DC=0 (%d)\n", __func__, err);
+            ret = err;
+        }
+    }
+
+    return ret;
+}
+
+/*
+ * Handle the VM clock being started or stopped
+ */
+static void kvm_mips_update_state(void *opaque, int running, RunState state)
+{
+    CPUState *cs = opaque;
+    int ret;
+    uint64_t count_resume;
+
+    /*
+     * If state is already dirty (synced to QEMU) then the KVM timer state is
+     * already saved and can be restored when it is synced back to KVM.
+     */
+    if (!running) {
+        if (!cs->kvm_vcpu_dirty) {
+            ret = kvm_mips_save_count(cs);
+            if (ret < 0) {
+                fprintf(stderr, "Failed saving count\n");
+            }
+        }
+    } else {
+        /* Set clock restore time to now */
+        count_resume = get_clock();
+        ret = kvm_mips_put_one_reg64(cs, KVM_REG_MIPS_COUNT_RESUME,
+                                     &count_resume);
+        if (ret < 0) {
+            fprintf(stderr, "Failed setting COUNT_RESUME\n");
+            return;
+        }
+
+        if (!cs->kvm_vcpu_dirty) {
+            ret = kvm_mips_restore_count(cs);
+            if (ret < 0) {
+                fprintf(stderr, "Failed restoring count\n");
+            }
+        }
+    }
+}
+
+static int kvm_mips_put_cp0_registers(CPUState *cs, int level)
+{
+    MIPSCPU *cpu = MIPS_CPU(cs);
+    CPUMIPSState *env = &cpu->env;
+    int err, ret = 0;
+
+    (void)level;
+
+    err = kvm_mips_put_one_reg(cs, KVM_REG_MIPS_CP0_INDEX, &env->CP0_Index);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_INDEX (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_ulreg(cs, KVM_REG_MIPS_CP0_CONTEXT,
+                                 &env->CP0_Context);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_CONTEXT (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_ulreg(cs, KVM_REG_MIPS_CP0_USERLOCAL,
+                                 &env->active_tc.CP0_UserLocal);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_USERLOCAL (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_reg(cs, KVM_REG_MIPS_CP0_PAGEMASK,
+                               &env->CP0_PageMask);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_PAGEMASK (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_reg(cs, KVM_REG_MIPS_CP0_WIRED, &env->CP0_Wired);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_WIRED (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_reg(cs, KVM_REG_MIPS_CP0_HWRENA, &env->CP0_HWREna);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_HWRENA (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_ulreg(cs, KVM_REG_MIPS_CP0_BADVADDR,
+                                 &env->CP0_BadVAddr);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_BADVADDR (%d)\n", __func__, err);
+        ret = err;
+    }
+
+    /* If VM clock stopped then state will be restored when it is restarted */
+    if (runstate_is_running()) {
+        err = kvm_mips_restore_count(cs);
+        if (err < 0) {
+            ret = err;
+        }
+    }
+
+    err = kvm_mips_put_one_ulreg(cs, KVM_REG_MIPS_CP0_ENTRYHI,
+                                 &env->CP0_EntryHi);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_ENTRYHI (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_reg(cs, KVM_REG_MIPS_CP0_COMPARE,
+                               &env->CP0_Compare);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_COMPARE (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_reg(cs, KVM_REG_MIPS_CP0_STATUS, &env->CP0_Status);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_STATUS (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_ulreg(cs, KVM_REG_MIPS_CP0_EPC, &env->CP0_EPC);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_EPC (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_put_one_ulreg(cs, KVM_REG_MIPS_CP0_ERROREPC,
+                                 &env->CP0_ErrorEPC);
+    if (err < 0) {
+        DPRINTF("%s: Failed to put CP0_ERROREPC (%d)\n", __func__, err);
+        ret = err;
+    }
+
+    return ret;
+}
+
+static int kvm_mips_get_cp0_registers(CPUState *cs)
+{
+    MIPSCPU *cpu = MIPS_CPU(cs);
+    CPUMIPSState *env = &cpu->env;
+    int err, ret = 0;
+
+    err = kvm_mips_get_one_reg(cs, KVM_REG_MIPS_CP0_INDEX, &env->CP0_Index);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_INDEX (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_ulreg(cs, KVM_REG_MIPS_CP0_CONTEXT,
+                                 &env->CP0_Context);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_CONTEXT (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_ulreg(cs, KVM_REG_MIPS_CP0_USERLOCAL,
+                                 &env->active_tc.CP0_UserLocal);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_USERLOCAL (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_reg(cs, KVM_REG_MIPS_CP0_PAGEMASK,
+                               &env->CP0_PageMask);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_PAGEMASK (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_reg(cs, KVM_REG_MIPS_CP0_WIRED, &env->CP0_Wired);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_WIRED (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_reg(cs, KVM_REG_MIPS_CP0_HWRENA, &env->CP0_HWREna);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_HWRENA (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_ulreg(cs, KVM_REG_MIPS_CP0_BADVADDR,
+                                 &env->CP0_BadVAddr);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_BADVADDR (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_ulreg(cs, KVM_REG_MIPS_CP0_ENTRYHI,
+                                 &env->CP0_EntryHi);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_ENTRYHI (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_reg(cs, KVM_REG_MIPS_CP0_COMPARE,
+                               &env->CP0_Compare);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_COMPARE (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_reg(cs, KVM_REG_MIPS_CP0_STATUS, &env->CP0_Status);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_STATUS (%d)\n", __func__, err);
+        ret = err;
+    }
+
+    /* If VM clock stopped then state was already saved when it was stopped */
+    if (runstate_is_running()) {
+        err = kvm_mips_save_count(cs);
+        if (err < 0) {
+            ret = err;
+        }
+    }
+
+    err = kvm_mips_get_one_ulreg(cs, KVM_REG_MIPS_CP0_EPC, &env->CP0_EPC);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_EPC (%d)\n", __func__, err);
+        ret = err;
+    }
+    err = kvm_mips_get_one_ulreg(cs, KVM_REG_MIPS_CP0_ERROREPC,
+                                 &env->CP0_ErrorEPC);
+    if (err < 0) {
+        DPRINTF("%s: Failed to get CP0_ERROREPC (%d)\n", __func__, err);
+        ret = err;
+    }
+
+    return ret;
+}
+
+int kvm_arch_put_registers(CPUState *cs, int level)
+{
+    MIPSCPU *cpu = MIPS_CPU(cs);
+    CPUMIPSState *env = &cpu->env;
+    struct kvm_regs regs;
+    int ret;
+    int i;
+
+    /* Set the registers based on QEMU's view of things */
+    for (i = 0; i < 32; i++) {
+        regs.gpr[i] = env->active_tc.gpr[i];
+    }
+
+    regs.hi = env->active_tc.HI[0];
+    regs.lo = env->active_tc.LO[0];
+    regs.pc = env->active_tc.PC;
+
+    ret = kvm_vcpu_ioctl(cs, KVM_SET_REGS, &regs);
+
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = kvm_mips_put_cp0_registers(cs, level);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return ret;
+}
+
+int kvm_arch_get_registers(CPUState *cs)
+{
+    MIPSCPU *cpu = MIPS_CPU(cs);
+    CPUMIPSState *env = &cpu->env;
+    int ret = 0;
+    struct kvm_regs regs;
+    int i;
+
+    /* Get the current register set as KVM seems it */
+    ret = kvm_vcpu_ioctl(cs, KVM_GET_REGS, &regs);
+
+    if (ret < 0) {
+        return ret;
+    }
+
+    for (i = 0; i < 32; i++) {
+        env->active_tc.gpr[i] = regs.gpr[i];
+    }
+
+    env->active_tc.HI[0] = regs.hi;
+    env->active_tc.LO[0] = regs.lo;
+    env->active_tc.PC = regs.pc;
+
+    kvm_mips_get_cp0_registers(cs);
+
+    return ret;
+}
diff --git a/target-mips/kvm_mips.h b/target-mips/kvm_mips.h
new file mode 100644
index 0000000..54f5965
--- /dev/null
+++ b/target-mips/kvm_mips.h
@@ -0,0 +1,26 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * KVM/MIPS: MIPS specific KVM APIs
+ *
+ * Copyright (C) 2012-2014 Imagination Technologies Ltd.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+*/
+
+#ifndef __KVM_MIPS_H__
+#define __KVM_MIPS_H__
+
+/**
+ * kvm_mips_reset_vcpu:
+ * @cpu: MIPSCPU
+ *
+ * Called at reset time to set kernel registers to their initial values.
+ */
+void kvm_mips_reset_vcpu(MIPSCPU *cpu);
+
+int kvm_mips_set_interrupt(MIPSCPU *cpu, int irq, int level);
+int kvm_mips_set_ipi_interrupt(MIPSCPU *cpu, int irq, int level);
+
+#endif /* __KVM_MIPS_H__ */