[PATCH 3/9] kvm tools: Allow giving instance names

[Sasha Levin <levinsasha928@gmail.com>]

This will allow tracking instance names and sending commands
to specific instances if multiple instances are running.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
---
 tools/kvm/include/kvm/kvm.h |    5 +++-
 tools/kvm/kvm-run.c         |    5 +++-
 tools/kvm/kvm.c             |   55 ++++++++++++++++++++++++++++++++++++++++++-
 tools/kvm/term.c            |    3 ++
 4 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
index 7d90d35..5ad3236 100644
--- a/tools/kvm/include/kvm/kvm.h
+++ b/tools/kvm/include/kvm/kvm.h
@@ -41,9 +41,11 @@ struct kvm {
 	const char		*vmlinux;
 	struct disk_image       **disks;
 	int                     nr_disks;
+
+	const char		*name;
 };
 
-struct kvm *kvm__init(const char *kvm_dev, u64 ram_size);
+struct kvm *kvm__init(const char *kvm_dev, u64 ram_size, const char *name);
 int kvm__max_cpus(struct kvm *kvm);
 void kvm__init_ram(struct kvm *kvm);
 void kvm__delete(struct kvm *kvm);
@@ -61,6 +63,7 @@ bool kvm__deregister_mmio(struct kvm *kvm, u64 phys_addr);
 void kvm__pause(void);
 void kvm__continue(void);
 void kvm__notify_paused(void);
+int kvm__get_pid_by_instance(const char *name);
 
 /*
  * Debugging
diff --git a/tools/kvm/kvm-run.c b/tools/kvm/kvm-run.c
index 0dece2d..a4abf76 100644
--- a/tools/kvm/kvm-run.c
+++ b/tools/kvm/kvm-run.c
@@ -69,6 +69,7 @@ static const char *network;
 static const char *host_ip_addr;
 static const char *guest_mac;
 static const char *script;
+static const char *guest_name;
 static bool single_step;
 static bool readonly_image[MAX_DISK_IMAGES];
 static bool vnc;
@@ -132,6 +133,8 @@ static int virtio_9p_rootdir_parser(const struct option *opt, const char *arg, i
 
 static const struct option options[] = {
 	OPT_GROUP("Basic options:"),
+	OPT_STRING('\0', "name", &guest_name, "guest name",
+			"A name for the guest"),
 	OPT_INTEGER('c', "cpus", &nrcpus, "Number of CPUs"),
 	OPT_U64('m', "mem", &ram_size, "Virtual machine memory size in MiB."),
 	OPT_CALLBACK('d', "disk", NULL, "image", "Disk image", img_name_parser),
@@ -546,7 +549,7 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
 
 	term_init();
 
-	kvm = kvm__init(kvm_dev, ram_size);
+	kvm = kvm__init(kvm_dev, ram_size, guest_name);
 
 	ioeventfd__init();
 
diff --git a/tools/kvm/kvm.c b/tools/kvm/kvm.c
index c400c70..4f723a6 100644
--- a/tools/kvm/kvm.c
+++ b/tools/kvm/kvm.c
@@ -113,11 +113,60 @@ static struct kvm *kvm__new(void)
 	return kvm;
 }
 
+static void kvm__create_pidfile(struct kvm *kvm)
+{
+	int fd;
+	char full_name[PATH_MAX], pid[10];
+
+	if (!kvm->name)
+		return;
+
+	mkdir("/var/run/kvm-tools", 0777);
+	sprintf(full_name, "/var/run/kvm-tools/%s.pid", kvm->name);
+	fd = open(full_name, O_CREAT | O_WRONLY, 0666);
+	sprintf(pid, "%u\n", getpid());
+	if (write(fd, pid, strlen(pid)) <= 0)
+		die("Failed creating PID file");
+	close(fd);
+}
+
+static void kvm__remove_pidfile(struct kvm *kvm)
+{
+	char full_name[PATH_MAX];
+
+	if (!kvm->name)
+		return;
+
+	sprintf(full_name, "/var/run/kvm-tools/%s.pid", kvm->name);
+	unlink(full_name);
+}
+
+int kvm__get_pid_by_instance(const char *name)
+{
+	int fd, pid;
+	char pid_str[10], pid_file[PATH_MAX];
+
+	sprintf(pid_file, "/var/run/kvm-tools/%s.pid", name);
+	fd = open(pid_file, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	if (read(fd, pid_str, 10) == 0)
+		return -1;
+
+	pid = atoi(pid_str);
+	if (pid < 0)
+		return -1;
+
+	return pid;
+}
+
 void kvm__delete(struct kvm *kvm)
 {
 	kvm__stop_timer(kvm);
 
 	munmap(kvm->ram_start, kvm->ram_size);
+	kvm__remove_pidfile(kvm);
 	free(kvm);
 }
 
@@ -237,7 +286,7 @@ int kvm__max_cpus(struct kvm *kvm)
 	return ret;
 }
 
-struct kvm *kvm__init(const char *kvm_dev, u64 ram_size)
+struct kvm *kvm__init(const char *kvm_dev, u64 ram_size, const char *name)
 {
 	struct kvm_pit_config pit_config = { .flags = 0, };
 	struct kvm *kvm;
@@ -300,6 +349,10 @@ struct kvm *kvm__init(const char *kvm_dev, u64 ram_size)
 	if (ret < 0)
 		die_perror("KVM_CREATE_IRQCHIP ioctl");
 
+	kvm->name = name;
+
+	kvm__create_pidfile(kvm);
+
 	return kvm;
 }
 
diff --git a/tools/kvm/term.c b/tools/kvm/term.c
index 9947223..a0cb03f 100644
--- a/tools/kvm/term.c
+++ b/tools/kvm/term.c
@@ -9,7 +9,9 @@
 #include "kvm/read-write.h"
 #include "kvm/term.h"
 #include "kvm/util.h"
+#include "kvm/kvm.h"
 
+extern struct kvm *kvm;
 static struct termios	orig_term;
 
 int term_escape_char	= 0x01; /* ctrl-a is used for escape */
@@ -32,6 +34,7 @@ int term_getc(int who)
 	if (term_got_escape) {
 		term_got_escape = false;
 		if (c == 'x') {
+			kvm__delete(kvm);
 			printf("\n  # KVM session terminated.\n");
 			exit(1);
 		}
-- 
1.7.6