In the past we added 1024 bytes of padding to saved state images so that users can run "virsh managedsave-edit $GUEST" and make XML changes which increase the size of the XML document. This padding was accidentally lost a while back commit 6b9b21db7079888a05d192b079e68290bdf14a76 Author: Peter Krempa <pkrempa@redhat.com> Date: Wed Feb 17 13:10:11 2016 +0100 qemu: Remove unnecessary calculations in qemuDomainSaveMemory The original 1024 bytes was unreasonably stingy when we consider that the QEMU state is typically going to be many 100's of MB in size. Thus this adds 64 KB of padding after the XML which should cope with any plausible modifications a user will want to make. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/qemu/qemu_driver.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 01330e55e7..d5aeeac66d 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -2922,20 +2922,23 @@ virQEMUSaveDataWrite(virQEMUSaveDataPtr data, len = xml_len + cookie_len; - if (header->data_len > 0) { + if (header->data_len == 0) { + /* This 64kb padding allows the user to edit the XML in + * a saved state image and have the new XML be larger + * that what was originally saved + */ + header->data_len = len + (64 * 1024); + } else { if (len > header->data_len) { virReportError(VIR_ERR_OPERATION_FAILED, "%s", _("new xml too large to fit in file")); return -1; } - - zerosLen = header->data_len - len; - if (VIR_ALLOC_N(zeros, zerosLen) < 0) - return -1; - } else { - header->data_len = len; } + zerosLen = header->data_len - len; + zeros = g_new0(char, zerosLen); + if (data->cookie) header->cookieOffset = xml_len; -- 2.25.3