diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h index 80ae110a52..35e13428b2 100644 --- a/tools/libxl/libxl.h +++ b/tools/libxl/libxl.h @@ -1268,6 +1268,14 @@ void libxl_mac_copy(libxl_ctx *ctx, libxl_mac *dst, const libxl_mac *src); */ #define LIBXL_HAVE_DOMAIN_NEED_MEMORY_CONFIG +/* + * LIBXL_HAVE_CREATEINFO_DOMID + * + * libxl_domain_create_new() and libxl_domain_create_restore() will use + * a domid specified in libxl_domain_create_info(). + */ +#define LIBXL_HAVE_CREATEINFO_DOMID + typedef char **libxl_string_list; void libxl_string_list_dispose(libxl_string_list *sl); int libxl_string_list_length(const libxl_string_list *sl); @@ -1528,6 +1536,7 @@ int libxl_ctx_free(libxl_ctx *ctx /* 0 is OK */); /* domain related functions */ #define INVALID_DOMID ~0 +#define RANDOM_DOMID (INVALID_DOMID - 1) /* If the result is ERROR_ABORTED, the domain may or may not exist * (in a half-created state). *domid will be valid and will be the diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c index 3a7364e2ac..ccc9e70990 100644 --- a/tools/libxl/libxl_create.c +++ b/tools/libxl/libxl_create.c @@ -600,11 +600,77 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config, goto out; } - ret = xc_domain_create(ctx->xch, domid, &create); - if (ret < 0) { - LOGED(ERROR, *domid, "domain creation fail"); - rc = ERROR_FAIL; - goto out; + for (;;) { + uint32_t local_domid; + bool recent; + + if (info->domid == RANDOM_DOMID) { + uint16_t v; + + ret = libxl__random_bytes(gc, (void *)&v, sizeof(v)); + if (ret < 0) + break; + + v &= DOMID_MASK; + if (!libxl_domid_valid_guest(v)) + continue; + + local_domid = v; + } else { + local_domid = info->domid; /* May not be valid */ + } + + ret = xc_domain_create(ctx->xch, &local_domid, &create); + if (ret < 0) { + /* + * If we generated a random domid and creation failed + * because that domid already exists then simply try + * again. + */ + if (errno == EEXIST && info->domid == RANDOM_DOMID) + continue; + + LOGED(ERROR, local_domid, "domain creation fail"); + rc = ERROR_FAIL; + goto out; + } + + /* A new domain now exists */ + *domid = local_domid; + + rc = libxl__is_domid_recent(gc, local_domid, &recent); + if (rc) + goto out; + + /* The domid is not recent, so we're done */ + if (!recent) + break; + + /* + * If the domid was specified then there's no point in + * trying again. + */ + if (libxl_domid_valid_guest(info->domid)) { + LOGED(ERROR, local_domid, "domain id recently used"); + rc = ERROR_FAIL; + goto out; + } + + /* + * The domain is recent and so cannot be used. Clear domid + * here since, if xc_domain_destroy() fails below there is + * little point calling it again in the error path. + */ + *domid = INVALID_DOMID; + + ret = xc_domain_destroy(ctx->xch, local_domid); + if (ret < 0) { + LOGED(ERROR, local_domid, "domain destroy fail"); + rc = ERROR_FAIL; + goto out; + } + + /* The domain was successfully destroyed, so we can try again */ } rc = libxl__arch_domain_save_config(gc, d_config, state, &create); diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl index 7921950f6a..d0d431614f 100644 --- a/tools/libxl/libxl_types.idl +++ b/tools/libxl/libxl_types.idl @@ -409,6 +409,7 @@ libxl_domain_create_info = Struct("domain_create_info",[ ("ssidref", uint32), ("ssid_label", string), ("name", string), + ("domid", libxl_domid), ("uuid", libxl_uuid), ("xsdata", libxl_key_value_list), ("platformdata", libxl_key_value_list),