target-arm: Provide '-cpu host' when running KVM

Implement '-cpu host' for ARM when we're using KVM, broadly
in line with other KVM-supporting architectures.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Message-id: 1385140638-10444-11-git-send-email-peter.maydell@linaro.org

1 files changed, 55 insertions, 0 deletions

diff --git a/target-arm/kvm_arm.h b/target-arm/kvm_arm.h
index 5d14887e66..cd3d13ca2d 100644
--- a/target-arm/kvm_arm.h
+++ b/target-arm/kvm_arm.h
@@ -62,4 +62,59 @@ bool write_list_to_kvmstate(ARMCPU *cpu);
  */
 bool write_kvmstate_to_list(ARMCPU *cpu);
 
+#ifdef CONFIG_KVM
+/**
+ * kvm_arm_create_scratch_host_vcpu:
+ * @cpus_to_try: array of QEMU_KVM_ARM_TARGET_* values (terminated with
+ * QEMU_KVM_ARM_TARGET_NONE) to try as fallback if the kernel does not
+ * know the PREFERRED_TARGET ioctl
+ * @fdarray: filled in with kvmfd, vmfd, cpufd file descriptors in that order
+ * @init: filled in with the necessary values for creating a host vcpu
+ *
+ * Create a scratch vcpu in its own VM of the type preferred by the host
+ * kernel (as would be used for '-cpu host'), for purposes of probing it
+ * for capabilities.
+ *
+ * Returns: true on success (and fdarray and init are filled in),
+ * false on failure (and fdarray and init are not valid).
+ */
+bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try,
+                                      int *fdarray,
+                                      struct kvm_vcpu_init *init);
+
+/**
+ * kvm_arm_destroy_scratch_host_vcpu:
+ * @fdarray: array of fds as set up by kvm_arm_create_scratch_host_vcpu
+ *
+ * Tear down the scratch vcpu created by kvm_arm_create_scratch_host_vcpu.
+ */
+void kvm_arm_destroy_scratch_host_vcpu(int *fdarray);
+
+#define TYPE_ARM_HOST_CPU "host-" TYPE_ARM_CPU
+#define ARM_HOST_CPU_CLASS(klass) \
+    OBJECT_CLASS_CHECK(ARMHostCPUClass, (klass), TYPE_ARM_HOST_CPU)
+#define ARM_HOST_CPU_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(ARMHostCPUClass, (obj), TYPE_ARM_HOST_CPU)
+
+typedef struct ARMHostCPUClass {
+    /*< private >*/
+    ARMCPUClass parent_class;
+    /*< public >*/
+
+    uint64_t features;
+    uint32_t target;
+    const char *dtb_compatible;
+} ARMHostCPUClass;
+
+/**
+ * kvm_arm_get_host_cpu_features:
+ * @ahcc: ARMHostCPUClass to fill in
+ *
+ * Probe the capabilities of the host kernel's preferred CPU and fill
+ * in the ARMHostCPUClass struct accordingly.
+ */
+bool kvm_arm_get_host_cpu_features(ARMHostCPUClass *ahcc);
+
+#endif
+
 #endif