vmm(4): add more specific error messages for vm-entry failures

To aid vmx debugging, specify if the error was related to vmresume
or vmlaunch. For vm-entry failures due to failed checks, decode the
errors per the SDM Vol. 3C 26.8.

diff --git a/sys/arch/amd64/amd64/vmm.c b/sys/arch/amd64/amd64/vmm.c
index 7e3ebf8..8ef4a14 100644 (file)
--- a/sys/arch/amd64/amd64/vmm.c
+++ b/sys/arch/amd64/amd64/vmm.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: vmm.c,v 1.283 2021/05/17 23:36:40 dv Exp $    */
+/*     $OpenBSD: vmm.c,v 1.284 2021/05/18 00:05:20 dv Exp $    */
 /*
  * Copyright (c) 2014 Mike Larkin <mlarkin@openbsd.org>
  *
@@ -4882,8 +4882,8 @@ vcpu_run_vmx(struct vcpu *vcpu, struct vm_run_params *vrp)
 #endif /* VMM_DEBUG */
                        ret = EINVAL;
                } else {
-                       printf("%s: failed launch for unknown reason %d\n",
-                           __func__, ret);
+                       printf("%s: failed %s for unknown reason %d\n",
+                           __func__, resume ? "vmresume" : "vmlaunch", ret);
 #ifdef VMM_DEBUG
                        vmx_vcpu_dump_regs(vcpu);
                        dump_vcpu(vcpu);
@@ -7596,6 +7596,9 @@ vmx_instruction_error_decode(uint32_t code)
        case 20: return "VMCALL: invalid VM exit control fields";
        case 26: return "VM entry: blocked by MOV SS";
        case 28: return "Invalid operand to INVEPT/INVVPID";
+       case 0x80000021: return "VM entry: invalid guest state";
+       case 0x80000022: return "VM entry: failure due to MSR loading";
+       case 0x80000029: return "VM entry: machine-check event";
        default: return "unknown";
        }
 }