Libvirt >= 2.1.0 now allows you to open files which have a "json:" QEMU pseudo-URL as backingfile, whereas previously it would fail hard in this case (RHBZ#1134878). When virt-v2v performs conversions from Xen (over SSH) or vCenter (over HTTPS) it uses these pseudo-URLs as backingfiles. We had to tell people to use LIBGUESTFS_BACKEND=direct to avoid libvirt in this situation. This commit narrows the check so it will now only print the error if libvirt < 2.1.0 and LIBGUESTFS_BACKEND=direct is not set. Also the error is modified to tell users they can either upgrade libvirt or set LIBGUESTFS_BACKEND=direct to work around the problem. Note there is not an easy way apart from checking the version number of libvirt to tell if the json pseudo-URL is supported. As a side-effect, this commit also prints the libvirt version number in debugging output when virt-v2v starts up, which is sometimes useful information for narrowing down bugs (it is in fact already printed by libguestfs, so this is duplicate information, but it's a bit easier to find when it's at the top of the debug). Thanks: Peter Krempa. --- v2v/domainxml-c.c | 38 ++++++++++++++++++++++++++++++++++++++ v2v/domainxml.ml | 3 +++ v2v/domainxml.mli | 4 ++++ v2v/input_libvirt_other.ml | 16 ++++++++++++---- v2v/input_libvirt_other.mli | 2 +- v2v/input_libvirt_vcenter_https.ml | 2 +- v2v/input_libvirt_xen_ssh.ml | 2 +- v2v/v2v.ml | 12 ++++++++++++ 8 files changed, 72 insertions(+), 7 deletions(-) diff --git a/v2v/domainxml-c.c b/v2v/domainxml-c.c index 3b00cad..eb6deab 100644 --- a/v2v/domainxml-c.c +++ b/v2v/domainxml-c.c @@ -487,6 +487,43 @@ v2v_domain_exists (value connv, value domnamev) CAMLreturn (Val_bool (domain_exists)); } +/* XXX This function is stuffed here for convenience (accessing + * libvirt), not because it belongs logically with the rest of the + * functions in this file. + */ +value +v2v_libvirt_get_version (value unitv) +{ + CAMLparam1 (unitv); + CAMLlocal1 (rv); + int major, minor, release; + /* We have to assemble the error on the stack because a dynamic + * string couldn't be freed. + */ + char errmsg[ERROR_MESSAGE_LEN]; + unsigned long ver; + virErrorPtr err; + + if (virGetVersion (&ver, NULL, NULL) == -1) { + err = virGetLastError (); + snprintf (errmsg, sizeof errmsg, + _("cannot get libvirt library version: %s"), + err->message); + caml_invalid_argument (errmsg); + } + + major = ver / 1000000UL; + minor = ver / 1000UL % 1000UL; + release = ver % 1000UL; + + rv = caml_alloc (3, 0); + Store_field (rv, 0, Val_int (major)); + Store_field (rv, 1, Val_int (minor)); + Store_field (rv, 2, Val_int (release)); + + CAMLreturn (rv); +} + #else /* !HAVE_LIBVIRT */ #define NO_LIBVIRT(proto) \ @@ -501,5 +538,6 @@ NO_LIBVIRT (value v2v_pool_dumpxml (value connv, value poolv)) NO_LIBVIRT (value v2v_vol_dumpxml (value connv, value poolnamev, value volnamev)) NO_LIBVIRT (value v2v_capabilities (value connv, value unitv)) NO_LIBVIRT (value v2v_domain_exists (value connv, value domnamev)) +NO_LIBVIRT (value v2v_libvirt_get_version (value unitv)) #endif /* !HAVE_LIBVIRT */ diff --git a/v2v/domainxml.ml b/v2v/domainxml.ml index af053a5..b9d547d 100644 --- a/v2v/domainxml.ml +++ b/v2v/domainxml.ml @@ -26,3 +26,6 @@ external vol_dumpxml : ?conn:string -> string -> string -> string = "v2v_vol_dum external capabilities : ?conn:string -> unit -> string = "v2v_capabilities" external domain_exists : ?conn:string -> string -> bool = "v2v_domain_exists" + +external libvirt_get_version : unit -> int * int * int + = "v2v_libvirt_get_version" diff --git a/v2v/domainxml.mli b/v2v/domainxml.mli index 17289bb..6d933e4 100644 --- a/v2v/domainxml.mli +++ b/v2v/domainxml.mli @@ -49,3 +49,7 @@ val domain_exists : ?conn:string -> string -> bool the libvirt XML domain [dom] exists. The optional [?conn] parameter is the libvirt connection URI. [dom] may be a guest name, but not a UUID. *) + +val libvirt_get_version : unit -> int * int * int +(** [libvirt_get_version] returns the triple [(major, minor, release)] + version number of the libvirt library that we are linked against. *) diff --git a/v2v/input_libvirt_other.ml b/v2v/input_libvirt_other.ml index 6fd8d52..b2f3dc0 100644 --- a/v2v/input_libvirt_other.ml +++ b/v2v/input_libvirt_other.ml @@ -24,13 +24,21 @@ open Common_utils open Types open Utils -(* Check the backend is not libvirt. Works around a libvirt bug - * (RHBZ#1134592). This can be removed once the libvirt bug is fixed. +(* Libvirt < 2.1.0 did not support the "json:" pseudo-URLs that + * we use as backingfiles, when accessing Xen over SSH or vCenter + * over HTTPS. Check this and print a workaround. + * + * We can remove this when/if we ever require libvirt >= 2.1.0 as + * a minimum version. + * + * See also RHBZ#1134878. *) -let error_if_libvirt_backend () = +let error_if_libvirt_does_not_support_json_backingfile () = let libguestfs_backend = (open_guestfs ())#get_backend () in if libguestfs_backend = "libvirt" then ( - error (f_"because of libvirt bug https://bugzilla.redhat.com/show_bug.cgi?id=1134592 you must set this environment variable:\n\nexport LIBGUESTFS_BACKEND=direct\n\nand then rerun the virt-v2v command.") + let major, minor, _ = Domainxml.libvirt_get_version () in + if major < 2 || (major = 2 && minor < 1) then + error (f_"because of libvirt bug https://bugzilla.redhat.com/1134878 you must EITHER upgrade to libvirt >= 2.1.0, OR set this environment variable:\n\nexport LIBGUESTFS_BACKEND=direct\n\nand then rerun the virt-v2v command.") ) (* xen+ssh URLs use the SSH driver in CURL. Currently this requires diff --git a/v2v/input_libvirt_other.mli b/v2v/input_libvirt_other.mli index 22cc21c..5b97f2f 100644 --- a/v2v/input_libvirt_other.mli +++ b/v2v/input_libvirt_other.mli @@ -18,7 +18,7 @@ (** [-i libvirt] source. *) -val error_if_libvirt_backend : unit -> unit +val error_if_libvirt_does_not_support_json_backingfile : unit -> unit val error_if_no_ssh_agent : unit -> unit class virtual input_libvirt : string option -> string option -> string -> object diff --git a/v2v/input_libvirt_vcenter_https.ml b/v2v/input_libvirt_vcenter_https.ml index 137f3d3..bcedf3f 100644 --- a/v2v/input_libvirt_vcenter_https.ml +++ b/v2v/input_libvirt_vcenter_https.ml @@ -45,7 +45,7 @@ object debug "input_libvirt_vcenter_https: source: scheme %s server %s" scheme server; - error_if_libvirt_backend (); + error_if_libvirt_does_not_support_json_backingfile (); (* Get the libvirt XML. This also checks (as a side-effect) * that the domain is not running. (RHBZ#1138586) diff --git a/v2v/input_libvirt_xen_ssh.ml b/v2v/input_libvirt_xen_ssh.ml index 310b38b..f9adc58 100644 --- a/v2v/input_libvirt_xen_ssh.ml +++ b/v2v/input_libvirt_xen_ssh.ml @@ -38,7 +38,7 @@ object debug "input_libvirt_xen_ssh: source: scheme %s server %s" scheme server; - error_if_libvirt_backend (); + error_if_libvirt_does_not_support_json_backingfile (); error_if_no_ssh_agent (); (* Get the libvirt XML. This also checks (as a side-effect) diff --git a/v2v/v2v.ml b/v2v/v2v.ml index ccd369c..39054f7 100644 --- a/v2v/v2v.ml +++ b/v2v/v2v.ml @@ -44,6 +44,18 @@ let rec main () = prog Guestfs_config.package_name Guestfs_config.package_version Guestfs_config.host_cpu; + (* Print the libvirt version if debugging. Note that if + * we're configured --without-libvirt, then this will throw + * an exception, but some conversions should still be possible, + * hence the try block. + *) + if verbose () then ( + try + let major, minor, release = Domainxml.libvirt_get_version () in + debug "libvirt version: %d.%d.%d" major minor release + with _ -> () + ); + let source = open_source cmdline input in let source = amend_source cmdline source in -- 2.7.4