As explained in the comment, this can help in scenarios where a shared filesystem can't be detected as such by libvirt, by giving the admin the opportunity to provide this information manually. https://issues.redhat.com/browse/RHEL-35752 Signed-off-by: Andrea Bolognani <abologna@xxxxxxxxxx> Reviewed-by: Peter Krempa <pkrempa@xxxxxxxxxx> --- src/qemu/libvirtd_qemu.aug | 3 +++ src/qemu/qemu.conf.in | 26 +++++++++++++++++++++++++ src/qemu/qemu_conf.c | 31 ++++++++++++++++++++++++++++++ src/qemu/qemu_conf.h | 2 ++ src/qemu/test_libvirtd_qemu.aug.in | 5 +++++ 5 files changed, 67 insertions(+) diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug index 2b6526538f..1377fd89cc 100644 --- a/src/qemu/libvirtd_qemu.aug +++ b/src/qemu/libvirtd_qemu.aug @@ -143,6 +143,8 @@ module Libvirtd_qemu = let storage_entry = bool_entry "storage_use_nbdkit" + let filesystem_entry = str_array_entry "shared_filesystems" + (* Entries that used to exist in the config which are now * deleted. We keep on parsing them so we don't break * ability to parse old configs after upgrade @@ -173,6 +175,7 @@ module Libvirtd_qemu = | swtpm_entry | capability_filters_entry | storage_entry + | filesystem_entry | obsolete_entry let comment = [ label "#comment" . del /#[ \t]*/ "# " . store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ] diff --git a/src/qemu/qemu.conf.in b/src/qemu/qemu.conf.in index 59af58b4d4..26c519f1ea 100644 --- a/src/qemu/qemu.conf.in +++ b/src/qemu/qemu.conf.in @@ -985,3 +985,29 @@ # note that the default might change in future releases. # #storage_use_nbdkit = @USE_NBDKIT_DEFAULT@ + +# libvirt will normally prevent migration if the storage backing the VM is not +# on a shared filesystems. Sometimes, however, the storage *is* shared despite +# not being detected as such: for example, this is the case when one of the +# hosts involved in the migration is exporting its local storage to the other +# one via NFS. +# +# Any directory listed here will be assumed to live on a shared filesystem, +# making migration possible in scenarios such as the one described above. It's +# the system's administrator responsibility to ensure that other hosts can +# access this directory. +# +# This option is not symmetrical and should only be used on hosts where the +# storage is being exported from. It must not be used on hosts accessing the +# storage via a remote protocol. +# +# NOTE: this option is intended to help in very specific scenarios that are +# rarely encountered. If you find yourself reaching for this option, consider +# reworking your environment so that it follows a more common architecture +# rather than using it. +# +#shared_filesystems = [ +# "/path/to/images", +# "/path/to/nvram", +# "/path/to/swtpm" +#] diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index a912790c3c..7c15c521c7 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -386,6 +386,8 @@ static void virQEMUDriverConfigDispose(void *obj) g_strfreev(cfg->capabilityfilters); + g_strfreev(cfg->sharedFilesystems); + g_free(cfg->deprecationBehavior); } @@ -1096,6 +1098,32 @@ virQEMUDriverConfigLoadStorageEntry(virQEMUDriverConfig *cfg, } +static int +virQEMUDriverConfigLoadFilesystemEntry(virQEMUDriverConfig *cfg, + virConf *conf) +{ + char **iter; + + if (virConfGetValueStringList(conf, "shared_filesystems", false, + &cfg->sharedFilesystems) < 0) + return -1; + + if (!cfg->sharedFilesystems) + return 0; + + /* The paths provided by the user might contain trailing slashes + * and other fun diversions, which would break the naive string + * comparisons that we're later going to use them for */ + for (iter = cfg->sharedFilesystems; *iter; iter++) { + char *canon = virFileCanonicalizePath(*iter); + g_free(*iter); + *iter = canon; + } + + return 0; +} + + int virQEMUDriverConfigLoadFile(virQEMUDriverConfig *cfg, const char *filename, bool privileged) @@ -1170,6 +1198,9 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfig *cfg, if (virQEMUDriverConfigLoadStorageEntry(cfg, conf) < 0) return -1; + if (virQEMUDriverConfigLoadFilesystemEntry(cfg, conf) < 0) + return -1; + return 0; } diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index c98b6137c1..157aba9e18 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -233,6 +233,8 @@ struct _virQEMUDriverConfig { bool storageUseNbdkit; virQEMUSchedCore schedCore; + + char **sharedFilesystems; }; G_DEFINE_AUTOPTR_CLEANUP_FUNC(virQEMUDriverConfig, virObjectUnref); diff --git a/src/qemu/test_libvirtd_qemu.aug.in b/src/qemu/test_libvirtd_qemu.aug.in index b97e6de11e..69fdae215a 100644 --- a/src/qemu/test_libvirtd_qemu.aug.in +++ b/src/qemu/test_libvirtd_qemu.aug.in @@ -119,3 +119,8 @@ module Test_libvirtd_qemu = { "deprecation_behavior" = "none" } { "sched_core" = "none" } { "storage_use_nbdkit" = "@USE_NBDKIT_DEFAULT@" } +{ "shared_filesystems" + { "1" = "/path/to/images" } + { "2" = "/path/to/nvram" } + { "3" = "/path/to/swtpm" } +} -- 2.46.2
