From 1f9cff2305a1946a3680c7a1a955d445a67a7d3a Mon Sep 17 00:00:00 2001
From: Pekka Enberg <penberg@cs.helsinki.fi>
Date: Tue, 23 Mar 2010 21:51:54 +0200
Subject: [PATCH] Mmap the kvm_run structure

Mmap the kvm_run structure and print out ->exit_reason in human-readable form
upon exit to make it more visible what's happening after KVM_RUN ioctl() is
called.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
---
 kvm.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/kvm.c b/kvm.c
index b63dead..4a2a04a 100644
--- a/kvm.c
+++ b/kvm.c
@@ -1,14 +1,25 @@
 #include "kvm/cpu.h"
 
 #include <linux/kvm.h>
+#include <inttypes.h>
+#include <sys/mman.h>
 #include <stdbool.h>
 #include <stdlib.h>
+#include <stdio.h>
 #include <fcntl.h>
 
+/*
+ * Compatibility code. Remove this when we move to tools/kvm.
+ */
+#ifndef KVM_EXIT_INTERNAL_ERROR
+# define KVM_EXIT_INTERNAL_ERROR		17
+#endif
+
 struct kvm {
 	int			sys_fd;		/* For system ioctls(), i.e. /dev/kvm */
 	int			vm_fd;		/* For VM ioctls() */
 	int			vcpu_fd;	/* For VCPU ioctls() */
+	struct kvm_run		*kvm_run;
 };
 
 static void die(const char *s)
@@ -53,6 +64,7 @@ static struct kvm *kvm__init(void)
 {
 	struct kvm_userspace_memory_region mem;
 	struct kvm *self;
+	int mmap_size;
 	int ret;
 
 	self = kvm__new();
@@ -93,6 +105,14 @@ static struct kvm *kvm__init(void)
 	if (self->vcpu_fd < 0)
 		die("ioctl(KVM_CREATE_VCPU)");
 
+	mmap_size = ioctl(self->sys_fd, KVM_GET_VCPU_MMAP_SIZE, 0);
+	if (mmap_size < 0)
+		die("KVM_GET_VCPU_MMAP_SIZE ioctl() failed");
+
+	self->kvm_run = mmap(NULL, mmap_size, PROT_READ|PROT_WRITE, MAP_SHARED, self->vcpu_fd, 0);
+	if (self->kvm_run == MAP_FAILED)
+		die("unable to mmap vcpu fd");
+
 	return self;
 }
 
@@ -105,6 +125,27 @@ static void kvm__run(struct kvm *self)
 		die("KVM_RUN");
 }
 
+static const char *exit_reasons[] = {
+	[KVM_EXIT_UNKNOWN]		= "unknown",
+	[KVM_EXIT_EXCEPTION]		= "exception",
+	[KVM_EXIT_IO]			= "io",
+	[KVM_EXIT_HYPERCALL]		= "hypercall",
+	[KVM_EXIT_DEBUG]		= "debug",
+	[KVM_EXIT_HLT]			= "hlt",
+	[KVM_EXIT_MMIO]			= "mmio",
+	[KVM_EXIT_IRQ_WINDOW_OPEN]	= "irq window open",
+	[KVM_EXIT_SHUTDOWN]		= "shutdown",
+	[KVM_EXIT_FAIL_ENTRY]		= "fail entry",
+	[KVM_EXIT_INTR]			= "intr",
+	[KVM_EXIT_SET_TPR]		= "set tpr",
+	[KVM_EXIT_TPR_ACCESS]		= "trp access",
+	[KVM_EXIT_S390_SIEIC]		= "s390 sieic",
+	[KVM_EXIT_S390_RESET]		= "s390 reset",
+	[KVM_EXIT_DCR]			= "dcr",
+	[KVM_EXIT_NMI]			= "dmi",
+	[KVM_EXIT_INTERNAL_ERROR]	= "internal error",
+};
+
 int main(int argc, char *argv[])
 {
 	struct cpu *cpu;
@@ -119,5 +160,8 @@ int main(int argc, char *argv[])
 
 	kvm__run(kvm);
 
+	fprintf(stderr, "KVM exit reason: %" PRIu32 " (\"%s\")\n",
+		kvm->kvm_run->exit_reason, exit_reasons[kvm->kvm_run->exit_reason]);
+
 	return 0;
 }