xnu-7195.101.1.tar.gz

[apple/xnu.git] / bsd / dev / i386 / sysctl.c

diff --git a/bsd/dev/i386/sysctl.c b/bsd/dev/i386/sysctl.c
index 944df9f64644d47edb99442221052850604d591b..e3c16031246a684dd62bc165e0582dda3988e8a1 100644 (file)
--- a/bsd/dev/i386/sysctl.c
+++ b/bsd/dev/i386/sysctl.c
@@ -42,6 +42,10 @@
 #include <i386/mp.h>
 #include <kern/kalloc.h>
 
+#if DEBUG || DEVELOPMENT
+#include <kern/hvg_hypercall.h>
+#endif
+
 
 static int
 _i386_cpu_info SYSCTL_HANDLER_ARGS
@@ -1103,4 +1107,87 @@ SYSCTL_INT(_machdep_misc, OID_AUTO, traptrace_enabled,
     CTLFLAG_KERN | CTLFLAG_RW | CTLFLAG_LOCKED,
     &traptrace_enabled, 0, "Enabled/disable trap trace");
 
+
+/*
+ * Trigger a guest kernel core dump (internal only)
+ * Usage: sysctl kern.trigger_kernel_coredump = 1
+ * (option selector must be 1, other values reserved)
+ */
+
+static int
+sysctl_trigger_kernel_coredump(struct sysctl_oid *oidp __unused, void *arg1, int arg2, struct sysctl_req *req)
+{
+       int error = 0;
+       hvg_hcall_return_t hv_ret;
+       char buf[2]; // 1 digit for dump option + 1 '\0'
+
+       if (req->newptr) {
+               // Write request
+               if (req->newlen > 1) {
+                       return EINVAL;
+               }
+               error = SYSCTL_IN(req, buf, req->newlen);
+               buf[req->newlen] = '\0';
+               if (!error) {
+                       if (strcmp(buf, "1") != 0) {
+                               return EINVAL;
+                       }
+                       /* Issue hypercall to trigger a dump */
+                       hv_ret = hvg_hcall_trigger_dump(arg1, HVG_HCALL_DUMP_OPTION_REGULAR);
+
+                       /* Translate hypercall error code to syscall error code */
+                       switch (hv_ret) {
+                       case HVG_HCALL_SUCCESS:
+                               error = SYSCTL_OUT(req, arg1, 41);
+                               break;
+                       case HVG_HCALL_ACCESS_DENIED:
+                               error = EPERM;
+                               break;
+                       case HVG_HCALL_INVALID_CODE:
+                       case HVG_HCALL_INVALID_PARAMETER:
+                               error = EINVAL;
+                               break;
+                       case HVG_HCALL_IO_FAILED:
+                               error = EIO;
+                               break;
+                       case HVG_HCALL_FEAT_DISABLED:
+                       case HVG_HCALL_UNSUPPORTED:
+                               error = ENOTSUP;
+                               break;
+                       default:
+                               error = ENODEV;
+                       }
+               }
+       } else {
+               // Read request
+               error = SYSCTL_OUT(req, arg1, arg2);
+       }
+       return error;
+}
+
+
+static hvg_hcall_vmcore_file_t sysctl_vmcore;
+
+void
+hvg_bsd_init(void)
+{
+       if (!cpuid_vmm_present()) {
+               return;
+       }
+
+       if ((cpuid_vmm_get_applepv_features() & CPUID_LEAF_FEATURE_COREDUMP) != 0) {
+               /* Register an OID in the sysctl MIB tree for kern.trigger_kernel_coredump */
+               struct sysctl_oid *hcall_trigger_dump_oid = zalloc_permanent(sizeof(struct sysctl_oid), ZALIGN(struct sysctl_oid));
+               struct sysctl_oid oid = SYSCTL_STRUCT_INIT(_kern,
+                   OID_AUTO,
+                   trigger_kernel_coredump,
+                   CTLTYPE_STRING | CTLFLAG_RW,
+                   &sysctl_vmcore, sizeof(sysctl_vmcore),
+                   sysctl_trigger_kernel_coredump,
+                   "A", "Request that the hypervisor take a live kernel dump");
+               *hcall_trigger_dump_oid = oid;
+               sysctl_register_oid(hcall_trigger_dump_oid);
+       }
+}
+
 #endif /* DEVELOPMENT || DEBUG */