Re: [PATCH] kvm tools: Add 'kvm stat' command

[walimis <walimisdev@gmail.com>]

On Mon, Aug 15, 2011 at 05:32:59PM +0300, Sasha Levin wrote:
>This patch adds 'kvm stat' command that allows retrieving statistics out of
>a running guest.
>
>Currently the only supported statistics are memory statistics, available using the
>'--memory' parameter.
>
>Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
>---
> tools/kvm/Documentation/kvm-stat.txt |   19 ++++++
> tools/kvm/Makefile                   |    1 +
> tools/kvm/builtin-stat.c             |   79 +++++++++++++++++++++++++
> tools/kvm/command-list.txt           |    1 +
> tools/kvm/include/kvm/builtin-stat.h |    7 ++
> tools/kvm/include/kvm/kvm.h          |    1 +
> tools/kvm/kvm-cmd.c                  |    2 +
> tools/kvm/virtio/balloon.c           |  108 ++++++++++++++++++++++++++++++++-
> 8 files changed, 214 insertions(+), 4 deletions(-)
> create mode 100644 tools/kvm/Documentation/kvm-stat.txt
> create mode 100644 tools/kvm/builtin-stat.c
> create mode 100644 tools/kvm/include/kvm/builtin-stat.h
>
>diff --git a/tools/kvm/Documentation/kvm-stat.txt b/tools/kvm/Documentation/kvm-stat.txt
>new file mode 100644
>index 0000000..ce5ab54
>--- /dev/null
>+++ b/tools/kvm/Documentation/kvm-stat.txt
>@@ -0,0 +1,19 @@
>+kvm-stat(1)
>+================
>+
>+NAME
>+----
>+kvm-stat - Print statistics about a running instance
>+
>+SYNOPSIS
>+--------
>+[verse]
>+'kvm [command] [-n instance] [-p instance pid] [--all]'
>+
>+DESCRIPTION
>+-----------
>+The command prints statistics about a running instance.
>+For a list of running instances see 'kvm list'.
>+
>+Commands:
>+ --memory, -m	Display memory statistics
>diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
>index 3a06e10..85bbce7 100644
>--- a/tools/kvm/Makefile
>+++ b/tools/kvm/Makefile
>@@ -24,6 +24,7 @@ OBJS	+= builtin-balloon.o
> OBJS	+= builtin-debug.o
> OBJS	+= builtin-help.o
> OBJS	+= builtin-list.o
>+OBJS	+= builtin-stat.o
> OBJS	+= builtin-pause.o
> OBJS	+= builtin-resume.o
> OBJS	+= builtin-run.o
>diff --git a/tools/kvm/builtin-stat.c b/tools/kvm/builtin-stat.c
>new file mode 100644
>index 0000000..d9bc75d
>--- /dev/null
>+++ b/tools/kvm/builtin-stat.c
>@@ -0,0 +1,79 @@
>+#include <kvm/util.h>
>+#include <kvm/kvm-cmd.h>
>+#include <kvm/builtin-stat.h>
>+#include <kvm/kvm.h>
>+#include <kvm/parse-options.h>
>+
>+#include <stdio.h>
>+#include <string.h>
>+#include <signal.h>
>+
>+static bool mem;
>+static bool all;
>+static u64 instance_pid;
>+static const char *instance_name;
>+
>+static const char * const stat_usage[] = {
>+	"kvm stat [command] [--all] [-n name] [-p pid]",
>+	NULL
>+};
>+
>+static const struct option stat_options[] = {
>+	OPT_GROUP("Commands options:"),
>+	OPT_BOOLEAN('m', "memory", &mem, "Display memory statistics"),
>+	OPT_GROUP("Instance options:"),
>+	OPT_BOOLEAN('a', "all", &all, "All instances"),
>+	OPT_STRING('n', "name", &instance_name, "name", "Instance name"),
>+	OPT_U64('p', "pid", &instance_pid, "Instance pid"),
>+	OPT_END()
>+};
>+
>+static void parse_stat_options(int argc, const char **argv)
>+{
>+	while (argc != 0) {
>+		argc = parse_options(argc, argv, stat_options, stat_usage,
>+				PARSE_OPT_STOP_AT_NON_OPTION);
>+		if (argc != 0)
>+			kvm_stat_help();
>+	}
>+}
>+
>+void kvm_stat_help(void)
>+{
>+	usage_with_options(stat_usage, stat_options);
>+}
>+
>+static int do_memstat(const char *name, int pid)
>+{
>+	printf("Sending memstat command to %s, output should be on the targets' terminal.\n", name);
>+	return kill(pid, SIGKVMMEMSTAT);
>+}
>+
>+int kvm_cmd_stat(int argc, const char **argv, const char *prefix)
>+{
>+	parse_stat_options(argc, argv);
>+
>+	if (!mem)
>+		usage_with_options(stat_usage, stat_options);
>+
>+	if (mem && all)
>+		return kvm__enumerate_instances(do_memstat);
>+
>+	if (instance_name == NULL &&
>+	    instance_pid == 0)
>+		kvm_stat_help();
>+
>+	if (instance_name)
>+		instance_pid = kvm__get_pid_by_instance(instance_name);
>+
>+	if (instance_pid <= 0)
>+		die("Failed locating instance");
>+
>+	if (mem) {
>+		printf("Sending memstat command to designated instance, output should be on the targets' terminal.\n");
>+
>+		return kill(instance_pid, SIGKVMMEMSTAT);
>+	}
>+
>+	return 0;
>+}
>diff --git a/tools/kvm/command-list.txt b/tools/kvm/command-list.txt
>index 6a49d0a..f201d75 100644
>--- a/tools/kvm/command-list.txt
>+++ b/tools/kvm/command-list.txt
>@@ -10,3 +10,4 @@ kvm-list			common
> kvm-debug			common
> kvm-balloon			common
> kvm-stop			common
>+kvm-stat			common
>diff --git a/tools/kvm/include/kvm/builtin-stat.h b/tools/kvm/include/kvm/builtin-stat.h
>new file mode 100644
>index 0000000..e3ce292
>--- /dev/null
>+++ b/tools/kvm/include/kvm/builtin-stat.h
>@@ -0,0 +1,7 @@
>+#ifndef KVM__STAT_H
>+#define KVM__STAT_H
>+
>+int kvm_cmd_stat(int argc, const char **argv, const char *prefix);
>+void kvm_stat_help(void);
>+
>+#endif
>diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
>index d4fe2a1..c2d815c 100644
>--- a/tools/kvm/include/kvm/kvm.h
>+++ b/tools/kvm/include/kvm/kvm.h
>@@ -22,6 +22,7 @@
> #define SIGKVMDELMEM		(SIGRTMIN + 3)
> #define SIGKVMSTOP		(SIGRTMIN + 4)
> #define SIGKVMRESUME		(SIGRTMIN + 5)
>+#define SIGKVMMEMSTAT		(SIGRTMIN + 6)
> 
> struct kvm {
> 	int			sys_fd;		/* For system ioctls(), i.e. /dev/kvm */
>diff --git a/tools/kvm/kvm-cmd.c b/tools/kvm/kvm-cmd.c
>index 4e3ea22..8fc6d22 100644
>--- a/tools/kvm/kvm-cmd.c
>+++ b/tools/kvm/kvm-cmd.c
>@@ -12,6 +12,7 @@
> #include "kvm/builtin-list.h"
> #include "kvm/builtin-version.h"
> #include "kvm/builtin-stop.h"
>+#include "kvm/builtin-stat.h"
> #include "kvm/builtin-help.h"
> #include "kvm/kvm-cmd.h"
> #include "kvm/builtin-run.h"
>@@ -26,6 +27,7 @@ struct cmd_struct kvm_commands[] = {
> 	{ "version",	kvm_cmd_version,	NULL,			0 },
> 	{ "--version",	kvm_cmd_version,	NULL,			0 },
> 	{ "stop",	kvm_cmd_stop,		kvm_stop_help,		0 },
>+	{ "stat",	kvm_cmd_stat,		kvm_stat_help,		0 },
> 	{ "help",	kvm_cmd_help,		NULL,			0 },
> 	{ "run",	kvm_cmd_run,		kvm_run_help,		0 },
> 	{ NULL,		NULL,			NULL,			0 },
>diff --git a/tools/kvm/virtio/balloon.c b/tools/kvm/virtio/balloon.c
>index 983a114..c5853a5 100644
>--- a/tools/kvm/virtio/balloon.c
>+++ b/tools/kvm/virtio/balloon.c
>@@ -21,10 +21,11 @@
> #include <sys/stat.h>
> #include <pthread.h>
> 
>-#define NUM_VIRT_QUEUES		2
>+#define NUM_VIRT_QUEUES		3
> #define VIRTIO_BLN_QUEUE_SIZE	128
> #define VIRTIO_BLN_INFLATE	0
> #define VIRTIO_BLN_DEFLATE	1
>+#define VIRTIO_BLN_STATS	2
> 
> struct bln_dev {
> 	struct pci_device_header pci_hdr;
>@@ -41,6 +42,12 @@ struct bln_dev {
> 	struct virt_queue	vqs[NUM_VIRT_QUEUES];
> 	struct thread_pool__job	jobs[NUM_VIRT_QUEUES];
> 
>+	struct virtio_balloon_stat stats[VIRTIO_BALLOON_S_NR];
>+	struct virtio_balloon_stat *cur_stat;
>+	u32			cur_stat_head;
>+	u16			stat_count;
>+	int			stat_waitfd;
>+
> 	struct virtio_balloon_config config;
> };
> 
>@@ -127,7 +134,7 @@ static bool virtio_bln_do_io_request(struct kvm *kvm, struct bln_dev *bdev, stru
> 		if (queue == &bdev->vqs[VIRTIO_BLN_INFLATE]) {
> 			madvise(guest_ptr, 1 << VIRTIO_BALLOON_PFN_SHIFT, MADV_DONTNEED);
> 			bdev->config.actual++;
>-		} else {
>+		} else if (queue == &bdev->vqs[VIRTIO_BLN_DEFLATE]) {
> 			bdev->config.actual--;
> 		}
> 	}
>@@ -137,10 +144,46 @@ static bool virtio_bln_do_io_request(struct kvm *kvm, struct bln_dev *bdev, stru
> 	return true;
> }
> 
>+static bool virtio_bln_do_stat_request(struct kvm *kvm, struct bln_dev *bdev, struct virt_queue *queue)
>+{
>+	struct iovec iov[VIRTIO_BLN_QUEUE_SIZE];
>+	u16 out, in, head;
>+	struct virtio_balloon_stat *stat;
>+	u64 wait_val = 1;
>+
>+	head = virt_queue__get_iov(queue, iov, &out, &in, kvm);
>+	stat = iov[0].iov_base;
>+
>+	/* Initial empty stat buffer */
>+	if (bdev->cur_stat == NULL) {
>+		bdev->cur_stat = stat;
>+		bdev->cur_stat_head = head;
>+
>+		return true;
>+	}
>+
>+	memcpy(bdev->stats, stat, iov[0].iov_len);
>+
>+	bdev->stat_count = iov[0].iov_len / sizeof(struct virtio_balloon_stat);
>+	bdev->cur_stat = stat;
>+	bdev->cur_stat_head = head;
>+
>+	if (write(bdev->stat_waitfd, &wait_val, sizeof(wait_val)) <= 0)
>+		return -EFAULT;
>+
>+	return 1;
>+}
>+
> static void virtio_bln_do_io(struct kvm *kvm, void *param)
> {
> 	struct virt_queue *vq = param;
> 
>+	if (vq == &bdev.vqs[VIRTIO_BLN_STATS]) {
>+		virtio_bln_do_stat_request(kvm, &bdev, vq);
>+		virt_queue__trigger_irq(vq, bdev.pci_hdr.irq_line, &bdev.isr, kvm);
>+		return;
>+	}
>+
> 	while (virt_queue__available(vq)) {
> 		virtio_bln_do_io_request(kvm, &bdev, vq);
> 		virt_queue__trigger_irq(vq, bdev.pci_hdr.irq_line, &bdev.isr, kvm);
>@@ -218,15 +261,70 @@ static struct ioport_operations virtio_bln_io_ops = {
> 	.io_out				= virtio_bln_pci_io_out,
> };
> 
>+static int virtio_bln__collect_stats(void)
>+{
>+	u64 tmp;
>+
>+	virt_queue__set_used_elem(&bdev.vqs[VIRTIO_BLN_STATS], bdev.cur_stat_head,
>+				  sizeof(struct virtio_balloon_stat));
>+	virt_queue__trigger_irq(&bdev.vqs[VIRTIO_BLN_STATS], bdev.pci_hdr.irq_line,
>+				&bdev.isr, kvm);
>+
>+	if (read(bdev.stat_waitfd, &tmp, sizeof(tmp)) <= 0)
>+		return -EFAULT;
>+
>+	return 0;
>+}
>+
>+static int virtio_bln__print_stats(void)
>+{
>+	u16 i;
>+
>+	if (virtio_bln__collect_stats() < 0)
>+		return -EFAULT;
>+
>+	printf("\n\n\t*** Guest memory statistics ***\n\n");
>+	for (i = 0; i < bdev.stat_count; i++) {
>+		switch (bdev.stats[i].tag) {
>+		case VIRTIO_BALLOON_S_SWAP_IN:
>+			printf("The amount of memory that has been swapped in (in bytes):");
>+			break;
>+		case VIRTIO_BALLOON_S_SWAP_OUT:
>+			printf("The amount of memory that has been swapped out to disk (in bytes):");
>+			break;
>+		case VIRTIO_BALLOON_S_MAJFLT:
>+			printf("The number of major page faults that have occurred:");
>+			break;
>+		case VIRTIO_BALLOON_S_MINFLT:
>+			printf("The number of minor page faults that have occurred:");
>+			break;
>+		case VIRTIO_BALLOON_S_MEMFREE:
>+			printf("The amount of memory not being used for any purpose (in bytes):");
>+			break;
>+		case VIRTIO_BALLOON_S_MEMTOT:
>+			printf("The total amount of memory available (in bytes):");
>+			break;
>+		}
>+		printf("%llu\n", bdev.stats[i].val);
>+	}
>+	printf("\n");
>+
>+	return 0;
>+}
>+
> static void handle_sigmem(int sig)
> {
> 	if (sig == SIGKVMADDMEM) {
> 		bdev.config.num_pages += 256;
>-	} else {
>+	} else if (sig == SIGKVMDELMEM) {
> 		if (bdev.config.num_pages < 256)
> 			return;
> 
> 		bdev.config.num_pages -= 256;
>+	} else if (sig == SIGKVMMEMSTAT) {
>+		virtio_bln__print_stats();
>+
>+		return;
> 	}
> 
> 	/* Notify that the configuration space has changed */
>@@ -241,6 +339,7 @@ void virtio_bln__init(struct kvm *kvm)
> 
> 	signal(SIGKVMADDMEM, handle_sigmem);
> 	signal(SIGKVMDELMEM, handle_sigmem);
>+	signal(SIGKVMMEMSTAT, handle_sigmem);
We also should add SIG_IGN in builtin-run for this signal.

walimis
> 
> 	bdev_base_addr = ioport__register(IOPORT_EMPTY, &virtio_bln_io_ops, IOPORT_SIZE, &bdev);
> 
>@@ -262,7 +361,8 @@ void virtio_bln__init(struct kvm *kvm)
> 
> 	bdev.pci_hdr.irq_pin	= pin;
> 	bdev.pci_hdr.irq_line	= line;
>-	bdev.host_features	= 0;
>+	bdev.host_features	= 1 << VIRTIO_BALLOON_F_STATS_VQ;
>+	bdev.stat_waitfd	= eventfd(0, 0);
> 	memset(&bdev.config, 0, sizeof(struct virtio_balloon_config));
> 
> 	pci__register(&bdev.pci_hdr, dev);
>-- 
>1.7.6
>
>--
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