xen: pv domain builder. (Gerd Hoffmann) (9306acb5) · Commits · SUMMER2020 / students / proj-2021291

Makefile.target

+1 −1

Original line number	Diff line number	Diff line
		@@ -561,7 +561,7 @@ LIBS += $(CONFIG_BLUEZ_LIBS)
		endif

		# xen backend driver support
		XEN_OBJS := xen_machine_pv.o xen_backend.o xen_devconfig.o
		XEN_OBJS := xen_machine_pv.o xen_backend.o xen_devconfig.o xen_domainbuild.o
		XEN_OBJS += xen_console.o xenfb.o xen_disk.o xen_nic.o
		ifeq ($(CONFIG_XEN), yes)
		OBJS += $(XEN_OBJS)

configure

+1 −1

Original line number	Diff line number	Diff line
		@@ -1634,7 +1634,7 @@ if test "$bluez" = "yes" ; then
		echo "#define CONFIG_BLUEZ 1" >> $config_h
		fi
		if test "$xen" = "yes" ; then
		echo "XEN_LIBS=-lxenstore -lxenctrl" >> $config_mak
		echo "XEN_LIBS=-lxenstore -lxenctrl -lxenguest" >> $config_mak
		fi
		if test "$aio" = "yes" ; then
		echo "#define CONFIG_AIO 1" >> $config_h

hw/xen_backend.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -100,5 +100,8 @@ void xen_init_display(int domid);
		void xen_config_cleanup(void);
		int xen_config_dev_blk(DriveInfo *disk);
		int xen_config_dev_nic(NICInfo *nic);
		int xen_config_dev_vfb(int vdev, const char *type);
		int xen_config_dev_vkbd(int vdev);
		int xen_config_dev_console(int vdev);

		#endif /* QEMU_HW_XEN_BACKEND_H */

hw/xen_devconfig.c

+29 −0

Original line number	Diff line number	Diff line
		@@ -140,3 +140,32 @@ int xen_config_dev_nic(NICInfo *nic)
		/* common stuff */
		return xen_config_dev_all(fe, be);
		}

		int xen_config_dev_vfb(int vdev, const char *type)
		{
		char fe[256], be[256];

		xen_config_dev_dirs("vfb", "vfb", vdev, fe, be, sizeof(fe));

		/* backend */
		xenstore_write_str(be, "type", type);

		/* common stuff */
		return xen_config_dev_all(fe, be);
		}

		int xen_config_dev_vkbd(int vdev)
		{
		char fe[256], be[256];

		xen_config_dev_dirs("vkbd", "vkbd", vdev, fe, be, sizeof(fe));
		return xen_config_dev_all(fe, be);
		}

		int xen_config_dev_console(int vdev)
		{
		char fe[256], be[256];

		xen_config_dev_dirs("console", "console", vdev, fe, be, sizeof(fe));
		return xen_config_dev_all(fe, be);
		}

hw/xen_domainbuild.c

0 → 100644

+294 −0

Original line number	Diff line number	Diff line
		#include <signal.h>
		#include "xen_backend.h"
		#include "xen_domainbuild.h"
		#include "sysemu.h"
		#include "qemu-timer.h"

		#include <xenguest.h>

		static int xenstore_domain_mkdir(char *path)
		{
		struct xs_permissions perms_ro[] = {{
		.id = 0, /* set owner: dom0 */
		},{
		.id = xen_domid,
		.perms = XS_PERM_READ,
		}};
		struct xs_permissions perms_rw[] = {{
		.id = 0, /* set owner: dom0 */
		},{
		.id = xen_domid,
		.perms = XS_PERM_READ \| XS_PERM_WRITE,
		}};
		const char *writable[] = { "device", "control", "error", NULL };
		char subpath[256];
		int i;

		if (!xs_mkdir(xenstore, 0, path)) {
		fprintf(stderr, "%s: xs_mkdir %s: failed\n", __FUNCTION__, path);
		return -1;
		}
		if (!xs_set_permissions(xenstore, 0, path, perms_ro, 2)) {
		fprintf(stderr, "%s: xs_set_permissions failed\n", __FUNCTION__);
		return -1;
		}

		for (i = 0; writable[i]; i++) {
		snprintf(subpath, sizeof(subpath), "%s/%s", path, writable[i]);
		if (!xs_mkdir(xenstore, 0, subpath)) {
		fprintf(stderr, "%s: xs_mkdir %s: failed\n", __FUNCTION__, subpath);
		return -1;
		}
		if (!xs_set_permissions(xenstore, 0, subpath, perms_rw, 2)) {
		fprintf(stderr, "%s: xs_set_permissions failed\n", __FUNCTION__);
		return -1;
		}
		}
		return 0;
		}

		int xenstore_domain_init1(const char kernel, const char ramdisk,
		const char *cmdline)
		{
		char *dom, uuid_string[42], vm[256], path[256];
		int i;

		snprintf(uuid_string, sizeof(uuid_string), UUID_FMT,
		qemu_uuid[0], qemu_uuid[1], qemu_uuid[2], qemu_uuid[3],
		qemu_uuid[4], qemu_uuid[5], qemu_uuid[6], qemu_uuid[7],
		qemu_uuid[8], qemu_uuid[9], qemu_uuid[10], qemu_uuid[11],
		qemu_uuid[12], qemu_uuid[13], qemu_uuid[14], qemu_uuid[15]);
		dom = xs_get_domain_path(xenstore, xen_domid);
		snprintf(vm, sizeof(vm), "/vm/%s", uuid_string);

		xenstore_domain_mkdir(dom);

		xenstore_write_str(vm, "image/ostype", "linux");
		if (kernel)
		xenstore_write_str(vm, "image/kernel", kernel);
		if (ramdisk)
		xenstore_write_str(vm, "image/ramdisk", ramdisk);
		if (cmdline)
		xenstore_write_str(vm, "image/cmdline", cmdline);

		/* name + id */
		xenstore_write_str(vm, "name", qemu_name ? qemu_name : "no-name");
		xenstore_write_str(vm, "uuid", uuid_string);
		xenstore_write_str(dom, "name", qemu_name ? qemu_name : "no-name");
		xenstore_write_int(dom, "domid", xen_domid);
		xenstore_write_str(dom, "vm", vm);

		/* memory */
		xenstore_write_int(dom, "memory/target", ram_size >> 10); // kB
		xenstore_write_int(vm, "memory", ram_size >> 20); // MB
		xenstore_write_int(vm, "maxmem", ram_size >> 20); // MB

		/* cpus */
		for (i = 0; i < smp_cpus; i++) {
		snprintf(path, sizeof(path), "cpu/%d/availability",i);
		xenstore_write_str(dom, path, "online");
		}
		xenstore_write_int(vm, "vcpu_avail", smp_cpus);
		xenstore_write_int(vm, "vcpus", smp_cpus);

		/* vnc password */
		xenstore_write_str(vm, "vncpassword", "" /* FIXME */);

		free(dom);
		return 0;
		}

		int xenstore_domain_init2(int xenstore_port, int xenstore_mfn,
		int console_port, int console_mfn)
		{
		char *dom;

		dom = xs_get_domain_path(xenstore, xen_domid);

		/* signal new domain */
		xs_introduce_domain(xenstore,
		xen_domid,
		xenstore_mfn,
		xenstore_port);

		/* xenstore */
		xenstore_write_int(dom, "store/ring-ref", xenstore_mfn);
		xenstore_write_int(dom, "store/port", xenstore_port);

		/* console */
		xenstore_write_str(dom, "console/type", "ioemu");
		xenstore_write_int(dom, "console/limit", 128 * 1024);
		xenstore_write_int(dom, "console/ring-ref", console_mfn);
		xenstore_write_int(dom, "console/port", console_port);
		xen_config_dev_console(0);

		free(dom);
		return 0;
		}

		/* ------------------------------------------------------------- */

		static QEMUTimer *xen_poll;

		/* check domain state once per second */
		static void xen_domain_poll(void *opaque)
		{
		struct xc_dominfo info;
		int rc;

		rc = xc_domain_getinfo(xen_xc, xen_domid, 1, &info);
		if ((1 != rc) \|\| (info.domid != xen_domid)) {
		qemu_log("xen: domain %d is gone\n", xen_domid);
		goto quit;
		}
		if (info.dying) {
		qemu_log("xen: domain %d is dying (%s%s)\n", xen_domid,
		info.crashed ? "crashed" : "",
		info.shutdown ? "shutdown" : "");
		goto quit;
		}

		qemu_mod_timer(xen_poll, qemu_get_clock(rt_clock) + 1000);
		return;

		quit:
		qemu_system_shutdown_request();
		return;
		}

		static void xen_domain_watcher(void)
		{
		int qemu_running = 1;
		int fd[2], i, n, rc;
		char byte;

		pipe(fd);
		if (fork() != 0)
		return; /* not child */

		/* close all file handles, except stdio/out/err,
		* our watch pipe and the xen interface handle */
		n = getdtablesize();
		for (i = 3; i < n; i++) {
		if (i == fd[0])
		continue;
		if (i == xen_xc)
		continue;
		close(i);
		}

		/* ignore term signals */
		signal(SIGINT, SIG_IGN);
		signal(SIGTERM, SIG_IGN);

		/* wait for qemu exiting */
		while (qemu_running) {
		rc = read(fd[0], &byte, 1);
		switch (rc) {
		case -1:
		if (EINTR == errno)
		continue;
		qemu_log("%s: Huh? read error: %s\n", __FUNCTION__, strerror(errno));
		qemu_running = 0;
		break;
		case 0:
		/* EOF -> qemu exited */
		qemu_running = 0;
		break;
		default:
		qemu_log("%s: Huh? data on the watch pipe?\n", __FUNCTION__);
		break;
		}
		}

		/* cleanup */
		qemu_log("%s: destroy domain %d\n", __FUNCTION__, xen_domid);
		xc_domain_destroy(xen_xc, xen_domid);
		_exit(0);
		}

		/* normal cleanup */
		static void xen_domain_cleanup(void)
		{
		char *dom;

		dom = xs_get_domain_path(xenstore, xen_domid);
		if (dom) {
		xs_rm(xenstore, 0, dom);
		free(dom);
		}
		xs_release_domain(xenstore, xen_domid);
		}

		int xen_domain_build_pv(const char kernel, const char ramdisk,
		const char *cmdline)
		{
		uint32_t ssidref = 0;
		uint32_t flags = 0;
		xen_domain_handle_t uuid;
		unsigned int xenstore_port = 0, console_port = 0;
		unsigned long xenstore_mfn = 0, console_mfn = 0;
		int rc;

		memcpy(uuid, qemu_uuid, sizeof(uuid));
		rc = xc_domain_create(xen_xc, ssidref, uuid, flags, &xen_domid);
		if (rc < 0) {
		fprintf(stderr, "xen: xc_domain_create() failed\n");
		goto err;
		}
		qemu_log("xen: created domain %d\n", xen_domid);
		atexit(xen_domain_cleanup);
		xen_domain_watcher();

		xenstore_domain_init1(kernel, ramdisk, cmdline);

		rc = xc_domain_max_vcpus(xen_xc, xen_domid, smp_cpus);
		if (rc < 0) {
		fprintf(stderr, "xen: xc_domain_max_vcpus() failed\n");
		goto err;
		}

		#if 0
		rc = xc_domain_setcpuweight(xen_xc, xen_domid, 256);
		if (rc < 0) {
		fprintf(stderr, "xen: xc_domain_setcpuweight() failed\n");
		goto err;
		}
		#endif

		rc = xc_domain_setmaxmem(xen_xc, xen_domid, ram_size >> 10);
		if (rc < 0) {
		fprintf(stderr, "xen: xc_domain_setmaxmem() failed\n");
		goto err;
		}

		xenstore_port = xc_evtchn_alloc_unbound(xen_xc, xen_domid, 0);
		console_port = xc_evtchn_alloc_unbound(xen_xc, xen_domid, 0);

		rc = xc_linux_build(xen_xc, xen_domid, ram_size >> 20,
		kernel, ramdisk, cmdline,
		0, flags,
		xenstore_port, &xenstore_mfn,
		console_port, &console_mfn);
		if (rc < 0) {
		fprintf(stderr, "xen: xc_linux_build() failed\n");
		goto err;
		}

		xenstore_domain_init2(xenstore_port, xenstore_mfn,
		console_port, console_mfn);

		qemu_log("xen: unpausing domain %d\n", xen_domid);
		rc = xc_domain_unpause(xen_xc, xen_domid);
		if (rc < 0) {
		fprintf(stderr, "xen: xc_domain_unpause() failed\n");
		goto err;
		}

		xen_poll = qemu_new_timer(rt_clock, xen_domain_poll, NULL);
		qemu_mod_timer(xen_poll, qemu_get_clock(rt_clock) + 1000);
		return 0;

		err:
		return -1;
		}