On Wed, Mar 19, 2025 at 10:18:08AM +0000, Peter Maydell wrote: > On Wed, 19 Mar 2025 at 08:29, Gerd Hoffmann <kra...@redhat.com> wrote: > > qemu_create() works only once in case libvirt hands us a > > file handle instead of a filename. > > If we have to work on a filehandle, we have the problem > that if the host crashes after the ftruncate() and > before the write() of the new data then we just lost > the contents of the var store. Working on filenames > would let us do "write new file and then rename in to > position".
Yes. Drawback of the libvirt filehandle passing is that this rename trick is not going to work. > If you need to try to operate on a filehandle > in a "don't lose the data for crashes mid-write" that > gets tricky. Do we care ? Do we have a chance to care? Probably this is still better than what we had before. Pflash updates are slow and need lots of vmexits, so I guess there is a higher chance to end up with a corrupted varstore in case of a host reset in a unpleasent moment. take care, Gerd
