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[xen master] tools: add example application to initialize dom0less PV drivers

Date: Wed, 25 May 2022 23:11:52 +0000

Delivery-date: Wed, 25 May 2022 23:11:53 +0000

List-id: "Change log for Mercurial $receive only$" <xen-changelog.lists.xenproject.org>

commit ec53e0c4ea94c4442fe31e91170df4cca9f49fbe Author: Luca Miccio <lucmiccio@xxxxxxxxx> AuthorDate: Fri May 13 14:07:29 2022 -0700 Commit: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx> CommitDate: Tue May 24 16:20:12 2022 -0700 tools: add example application to initialize dom0less PV drivers Add an example application that can be run in dom0 to complete the dom0less domains initialization so that they can get access to xenstore and use PV drivers. The application sets "connection" to XENSTORE_RECONNECT on the xenstore page before calling xs_introduce_domain to signal that the connection is not ready yet to be used. XENSTORE_RECONNECT is reset soon after by xenstored. Signed-off-by: Luca Miccio <lucmiccio@xxxxxxxxx> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx> Acked-by: Julien Grall <jgrall@xxxxxxxxxx> CC: Wei Liu <wl@xxxxxxx> CC: Anthony PERARD <anthony.perard@xxxxxxxxxx> CC: Juergen Gross <jgross@xxxxxxxx> --- tools/helpers/Makefile | 13 ++ tools/helpers/init-dom0less.c | 345 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 358 insertions(+) diff --git a/tools/helpers/Makefile b/tools/helpers/Makefile index 7f6c422440..8d78ab1e90 100644 --- a/tools/helpers/Makefile +++ b/tools/helpers/Makefile @@ -10,6 +10,9 @@ ifeq ($(CONFIG_Linux),y) ifeq ($(CONFIG_X86),y) PROGS += init-xenstore-domain endif +ifeq ($(CONFIG_ARM),y) +PROGS += init-dom0less +endif endif XEN_INIT_DOM0_OBJS = xen-init-dom0.o init-dom-json.o @@ -26,6 +29,13 @@ $(INIT_XENSTORE_DOMAIN_OBJS): CFLAGS += $(CFLAGS_libxenstore) $(INIT_XENSTORE_DOMAIN_OBJS): CFLAGS += $(CFLAGS_libxenlight) $(INIT_XENSTORE_DOMAIN_OBJS): CFLAGS += -include $(XEN_ROOT)/tools/config.h +INIT_DOM0LESS_OBJS = init-dom0less.o init-dom-json.o +$(INIT_DOM0LESS_OBJS): CFLAGS += $(CFLAGS_libxentoollog) +$(INIT_DOM0LESS_OBJS): CFLAGS += $(CFLAGS_libxenstore) +$(INIT_DOM0LESS_OBJS): CFLAGS += $(CFLAGS_libxenlight) +$(INIT_DOM0LESS_OBJS): CFLAGS += $(CFLAGS_libxenctrl) +$(INIT_DOM0LESS_OBJS): CFLAGS += $(CFLAGS_libxenevtchn) + .PHONY: all all: $(PROGS) @@ -35,6 +45,9 @@ xen-init-dom0: $(XEN_INIT_DOM0_OBJS) init-xenstore-domain: $(INIT_XENSTORE_DOMAIN_OBJS) $(CC) $(LDFLAGS) -o $@ $(INIT_XENSTORE_DOMAIN_OBJS) $(LDLIBS_libxentoollog) $(LDLIBS_libxenstore) $(LDLIBS_libxenctrl) $(LDLIBS_libxenguest) $(LDLIBS_libxenlight) $(APPEND_LDFLAGS) +init-dom0less: $(INIT_DOM0LESS_OBJS) + $(CC) $(LDFLAGS) -o $@ $(INIT_DOM0LESS_OBJS) $(LDLIBS_libxenctrl) $(LDLIBS_libxenevtchn) $(LDLIBS_libxentoollog) $(LDLIBS_libxenstore) $(LDLIBS_libxenlight) $(LDLIBS_libxenguest) $(LDLIBS_libxenforeignmemory) $(APPEND_LDFLAGS) + .PHONY: install install: all $(INSTALL_DIR) $(DESTDIR)$(LIBEXEC_BIN) diff --git a/tools/helpers/init-dom0less.c b/tools/helpers/init-dom0less.c new file mode 100644 index 0000000000..42e74c4153 --- /dev/null +++ b/tools/helpers/init-dom0less.c @@ -0,0 +1,345 @@ +#include <stdbool.h> +#include <syslog.h> +#include <stdio.h> +#include <err.h> +#include <stdlib.h> +#include <sys/mman.h> +#include <sys/time.h> +#include <xenstore.h> +#include <xenctrl.h> +#include <xenguest.h> +#include <libxl.h> +#include <xenevtchn.h> +#include <xenforeignmemory.h> +#include <xen/io/xs_wire.h> + +#include "init-dom-json.h" + +#define XENSTORE_PFN_OFFSET 1 +#define STR_MAX_LENGTH 128 + +static int alloc_xs_page(struct xc_interface_core *xch, + libxl_dominfo *info, + uint64_t *xenstore_pfn) +{ + int rc; + const xen_pfn_t base = GUEST_MAGIC_BASE >> XC_PAGE_SHIFT; + xen_pfn_t p2m = (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET; + + rc = xc_domain_setmaxmem(xch, info->domid, + info->max_memkb + (XC_PAGE_SIZE/1024)); + if (rc < 0) + return rc; + + rc = xc_domain_populate_physmap_exact(xch, info->domid, 1, 0, 0, &p2m); + if (rc < 0) + return rc; + + *xenstore_pfn = base + XENSTORE_PFN_OFFSET; + rc = xc_clear_domain_page(xch, info->domid, *xenstore_pfn); + if (rc < 0) + return rc; + + return 0; +} + +static bool do_xs_write_dom(struct xs_handle *xsh, xs_transaction_t t, + domid_t domid, char *path, char *val) +{ + char full_path[STR_MAX_LENGTH]; + struct xs_permissions perms[2]; + + perms[0].id = domid; + perms[0].perms = XS_PERM_NONE; + perms[1].id = 0; + perms[1].perms = XS_PERM_READ; + + if (snprintf(full_path, STR_MAX_LENGTH, + "/local/domain/%u/%s", domid, path) < 0) + return false; + if (!xs_write(xsh, t, full_path, val, strlen(val))) + return false; + return xs_set_permissions(xsh, t, full_path, perms, 2); +} + +static bool do_xs_write_libxl(struct xs_handle *xsh, xs_transaction_t t, + domid_t domid, char *path, char *val) +{ + char full_path[STR_MAX_LENGTH]; + + if (snprintf(full_path, STR_MAX_LENGTH, + "/libxl/%u/%s", domid, path) < 0) + return false; + return xs_write(xsh, t, full_path, val, strlen(val)); +} + +static bool do_xs_write_vm(struct xs_handle *xsh, xs_transaction_t t, + libxl_uuid uuid, char *path, char *val) +{ + char full_path[STR_MAX_LENGTH]; + + if (snprintf(full_path, STR_MAX_LENGTH, + "/vm/" LIBXL_UUID_FMT "/%s", LIBXL_UUID_BYTES(uuid), path) < 0) + return false; + return xs_write(xsh, t, full_path, val, strlen(val)); +} + +/* + * The xenstore nodes are the xenstore nodes libxl writes at domain + * creation. + * + * The list was retrieved by running xenstore-ls on a corresponding + * domain started by xl/libxl. + */ +static int create_xenstore(struct xs_handle *xsh, + libxl_dominfo *info, libxl_uuid uuid, + evtchn_port_t xenstore_port) +{ + domid_t domid; + unsigned int i; + char uuid_str[STR_MAX_LENGTH]; + char dom_name_str[STR_MAX_LENGTH]; + char vm_val_str[STR_MAX_LENGTH]; + char id_str[STR_MAX_LENGTH]; + char max_memkb_str[STR_MAX_LENGTH]; + char target_memkb_str[STR_MAX_LENGTH]; + char cpu_str[STR_MAX_LENGTH]; + char xenstore_port_str[STR_MAX_LENGTH]; + char ring_ref_str[STR_MAX_LENGTH]; + xs_transaction_t t; + struct timeval start_time; + char start_time_str[STR_MAX_LENGTH]; + int rc; + + if (gettimeofday(&start_time, NULL) < 0) + return -errno; + rc = snprintf(start_time_str, STR_MAX_LENGTH, "%jd.%02d", + (intmax_t)start_time.tv_sec, (int)start_time.tv_usec / 10000); + if (rc < 0) + return rc; + + domid = info->domid; + rc = snprintf(id_str, STR_MAX_LENGTH, "%u", domid); + if (rc < 0) + return rc; + rc = snprintf(dom_name_str, STR_MAX_LENGTH, "dom0less-%u", domid); + if (rc < 0) + return rc; + rc = snprintf(uuid_str, STR_MAX_LENGTH, LIBXL_UUID_FMT, LIBXL_UUID_BYTES(uuid)); + if (rc < 0) + return rc; + rc = snprintf(vm_val_str, STR_MAX_LENGTH, + "vm/" LIBXL_UUID_FMT, LIBXL_UUID_BYTES(uuid)); + if (rc < 0) + return rc; + rc = snprintf(max_memkb_str, STR_MAX_LENGTH, "%lu", info->max_memkb); + if (rc < 0) + return rc; + rc = snprintf(target_memkb_str, STR_MAX_LENGTH, "%lu", info->current_memkb); + if (rc < 0) + return rc; + rc = snprintf(ring_ref_str, STR_MAX_LENGTH, "%lld", + (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET); + if (rc < 0) + return rc; + rc = snprintf(xenstore_port_str, STR_MAX_LENGTH, "%u", xenstore_port); + if (rc < 0) + return rc; + +retry_transaction: + t = xs_transaction_start(xsh); + if (t == XBT_NULL) + return -errno; + + rc = -EIO; + /* /vm */ + if (!do_xs_write_vm(xsh, t, uuid, "name", dom_name_str)) goto err; + if (!do_xs_write_vm(xsh, t, uuid, "uuid", uuid_str)) goto err; + if (!do_xs_write_vm(xsh, t, uuid, "start_time", start_time_str)) goto err; + + /* /domain */ + if (!do_xs_write_dom(xsh, t, domid, "vm", vm_val_str)) goto err; + if (!do_xs_write_dom(xsh, t, domid, "name", dom_name_str)) goto err; + if (!do_xs_write_dom(xsh, t, domid, "cpu", "")) goto err; + for (i = 0; i < info->vcpu_max_id; i++) { + rc = snprintf(cpu_str, STR_MAX_LENGTH, "cpu/%u/availability/", i); + if (rc < 0) + goto err; + rc = -EIO; + if (!do_xs_write_dom(xsh, t, domid, cpu_str, + (info->cpupool & (1 << i)) ? "online" : "offline")) + goto err; + } + + if (!do_xs_write_dom(xsh, t, domid, "memory", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "memory/static-max", max_memkb_str)) goto err; + if (!do_xs_write_dom(xsh, t, domid, "memory/target", target_memkb_str)) goto err; + if (!do_xs_write_dom(xsh, t, domid, "memory/videoram", "-1")) goto err; + + if (!do_xs_write_dom(xsh, t, domid, "device", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "device/suspend", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "device/suspend/event-channel", "")) goto err; + + if (!do_xs_write_dom(xsh, t, domid, "control", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "control/shutdown", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "control/feature-poweroff", "1")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "control/feature-reboot", "1")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "control/feature-suspend", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "control/sysrq", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "control/platform-feature-multiprocessor-suspend", "1")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "control/platform-feature-xs_reset_watches", "1")) goto err; + + if (!do_xs_write_dom(xsh, t, domid, "domid", id_str)) goto err; + if (!do_xs_write_dom(xsh, t, domid, "data", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "drivers", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "feature", "")) goto err; + if (!do_xs_write_dom(xsh, t, domid, "attr", "")) goto err; + + if (!do_xs_write_dom(xsh, t, domid, "store/port", xenstore_port_str)) goto err; + if (!do_xs_write_dom(xsh, t, domid, "store/ring-ref", ring_ref_str)) goto err; + + if (!do_xs_write_libxl(xsh, t, domid, "type", "pvh")) goto err; + if (!do_xs_write_libxl(xsh, t, domid, "dm-version", "qemu_xen")) goto err; + + if (!xs_transaction_end(xsh, t, false)) { + if (errno == EAGAIN) + goto retry_transaction; + else + return -errno; + } + + return 0; + +err: + xs_transaction_end(xsh, t, true); + return rc; +} + +static int init_domain(struct xs_handle *xsh, + struct xc_interface_core *xch, + xenforeignmemory_handle *xfh, + libxl_dominfo *info) +{ + libxl_uuid uuid; + uint64_t xenstore_evtchn, xenstore_pfn; + int rc; + struct xenstore_domain_interface *intf; + + printf("Init dom0less domain: %u\n", info->domid); + + rc = xc_hvm_param_get(xch, info->domid, HVM_PARAM_STORE_EVTCHN, + &xenstore_evtchn); + if (rc != 0) { + printf("Failed to get HVM_PARAM_STORE_EVTCHN\n"); + return 1; + } + + /* no xen,enhanced; nothing to do */ + if (!xenstore_evtchn) + return 0; + + /* Alloc xenstore page */ + if (alloc_xs_page(xch, info, &xenstore_pfn) != 0) { + printf("Error on alloc magic pages\n"); + return 1; + } + + intf = xenforeignmemory_map(xfh, info->domid, PROT_READ | PROT_WRITE, 1, + &xenstore_pfn, NULL); + if (!intf) { + printf("Error mapping xenstore page\n"); + return 1; + } + intf->connection = XENSTORE_RECONNECT; + xenforeignmemory_unmap(xfh, intf, 1); + + rc = xc_dom_gnttab_seed(xch, info->domid, true, + (xen_pfn_t)-1, xenstore_pfn, 0, 0); + if (rc) + err(1, "xc_dom_gnttab_seed"); + + libxl_uuid_generate(&uuid); + xc_domain_sethandle(xch, info->domid, libxl_uuid_bytearray(&uuid)); + + rc = gen_stub_json_config(info->domid, &uuid); + if (rc) + err(1, "gen_stub_json_config"); + + /* Now everything is ready: set HVM_PARAM_STORE_PFN */ + rc = xc_hvm_param_set(xch, info->domid, HVM_PARAM_STORE_PFN, + xenstore_pfn); + if (rc < 0) + return rc; + + rc = create_xenstore(xsh, info, uuid, xenstore_evtchn); + if (rc) + err(1, "writing to xenstore"); + + rc = xs_introduce_domain(xsh, info->domid, + (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET, + xenstore_evtchn); + if (!rc) + err(1, "xs_introduce_domain"); + return 0; +} + +/* Check if domain has been configured in XS */ +static bool domain_exists(struct xs_handle *xsh, int domid) +{ + return xs_is_domain_introduced(xsh, domid); +} + +int main(int argc, char **argv) +{ + libxl_dominfo *info = NULL; + libxl_ctx *ctx; + int nb_vm = 0, rc = 0, i; + struct xs_handle *xsh = NULL; + struct xc_interface_core *xch = NULL; + xenforeignmemory_handle *xfh = NULL; + + /* TODO reuse libxl xsh connection */ + xsh = xs_open(0); + xch = xc_interface_open(0, 0, 0); + xfh = xenforeignmemory_open(0, 0); + if (xsh == NULL || xch == NULL || xfh == NULL) { + fprintf(stderr, "Cannot open xc/xs/xenforeignmemory interfaces"); + rc = -errno; + goto out; + } + + rc = libxl_ctx_alloc(&ctx, LIBXL_VERSION, 0, NULL); + if (rc) { + fprintf(stderr, "cannot init xl context\n"); + goto out; + } + + info = libxl_list_domain(ctx, &nb_vm); + if (!info) { + fprintf(stderr, "libxl_list_vm failed.\n"); + rc = -1; + goto out; + } + + for (i = 0; i < nb_vm; i++) { + domid_t domid = info[i].domid; + + /* Don't need to check for Dom0 */ + if (!domid) + continue; + + printf("Checking domid: %u\n", domid); + if (!domain_exists(xsh, domid)) { + rc = init_domain(xsh, xch, xfh, &info[i]); + if (rc < 0) { + fprintf(stderr, "init_domain failed.\n"); + goto out; + } + } else { + printf("Domain %u has already been initialized\n", domid); + } + } +out: + libxl_dominfo_list_free(info, nb_vm); + return rc; +} -- generated by git-patchbot for /home/xen/git/xen.git#master

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