linux: cpuid: Add HAX_VCPU_IOCTL_SET_CPUID support

Enables setting CPUID features for guest vCPUs in Linux platform.

Signed-off-by: Wenchao Wang <[email protected]>

Author: wcwang

include/linux/hax_interface_linux.h

@@ -70,6 +70,7 @@
 #define HAX_VM_IOCTL_NOTIFY_QEMU_VERSION _IOW(0, 0x84, struct hax_qemu_version)
 
 #define HAX_IOCTL_VCPU_DEBUG _IOW(0, 0xc9, struct hax_debug_t)
+#define HAX_VCPU_IOCTL_SET_CPUID _IOW(0, 0xca, struct hax_cpuid *)
 
 #define HAX_KERNEL64_CS 0x80
 #define HAX_KERNEL32_CS 0x08

platforms/linux/components.c

@@ -42,6 +42,40 @@
 #define HAX_VM_DEVFS_FMT    "hax_vm/vm%02d"
 #define HAX_VCPU_DEVFS_FMT  "hax_vm%02d/vcpu%02d"
 
+#define load_user_data(dest, src, body_len, body_max, arg_t, body_t)          \
+        arg_t __user *from = (arg_t __user *)(*(arg_t **)(src));              \
+        size_t size;                                                          \
+        arg_t header;                                                         \
+        (dest) = NULL;                                                        \
+        if (copy_from_user(&header, from, sizeof(arg_t))) {                   \
+            hax_log(HAX_LOGE, "%s: argument header read error.\n", __func__); \
+            ret = -EFAULT;                                                    \
+            break;                                                            \
+        }                                                                     \
+        if (header.body_len > (body_max)) {                                   \
+            hax_log(HAX_LOGW, "%s: %d exceeds argument body maximum %d.\n",   \
+                    __func__, header.body_len, (body_max));                   \
+            ret = -E2BIG;                                                     \
+            break;                                                            \
+        }                                                                     \
+        size = sizeof(arg_t) + header.body_len * sizeof(body_t);              \
+        (dest) = hax_vmalloc(size, HAX_MEM_NONPAGE);                          \
+        if ((dest) == NULL) {                                                 \
+            hax_log(HAX_LOGE, "%s: failed to allocate memory.\n", __func__);  \
+            ret = -ENOMEM;                                                    \
+            break;                                                            \
+        }                                                                     \
+        if (copy_from_user((dest), from, size)) {                             \
+            hax_log(HAX_LOGE, "%s: argument read error.\n", __func__);        \
+            unload_user_data(dest);                                           \
+            ret = -EFAULT;                                                    \
+            break;                                                            \
+        }
+
+#define unload_user_data(dest)         \
+        if ((dest) != NULL)            \
+            hax_vfree((dest), size);
+
 typedef struct hax_vm_linux_t {
     struct vm_t *cvm;
     int id;
@@ -445,6 +479,14 @@ static long hax_vcpu_ioctl(struct file *filp, unsigned int cmd,
         vcpu_debug(cvcpu, &hax_debug);
         break;
     }
+    case HAX_VCPU_IOCTL_SET_CPUID: {
+        struct hax_cpuid *cpuid;
+        load_user_data(cpuid, argp, total, HAX_MAX_CPUID_ENTRIES, hax_cpuid,
+                       hax_cpuid_entry);
+        ret = vcpu_set_cpuid(cvcpu, cpuid);
+        unload_user_data(cpuid);
+        break;
+    }
     default:
         // TODO: Print information about the process that sent the ioctl.
         hax_log(HAX_LOGE, "Unknown VCPU IOCTL 0x%lx\n", cmd);