>>> On 27.01.17 at 20:48, <t...@xen.org> wrote: > At 09:40 -0700 on 27 Jan (1485510008), Jan Beulich wrote: >> - vmx_set_segment_register() should initialize the TSS every >> time (including setting the I/O bitmap address to no lower >> than 32) > > Probably to no lower than 136, to avoid having the bits of that field > itself appearing in either the IO or interrupt bitmap.
Indeed. >> - hvmloader's init_vm86_tss() will need to allocate 160 bytes >> rather than 128 (and we should expose this number, so that >> Roger can also use it) >> >> Perhaps we should even introduce a hypercall for hvmloader >> to query the needed value, rather than exposing a hardcoded >> number? > > I think Andrew's suggestion of just using a whole page is a good > one. The TSS is a 32-bit one, after all, and doesn't need to live in > BIOS space. Hmm, any size increase will need to come with further changes, as it looks, including the use of a new HVM param: The VM86_TSS param is being migrated, and hence for an incoming VM we need to be able to tell whether the guest has set aside 128 bytes or a full page. This of course implies that we need to keep Xen handle the 128-byte case, too. And if we somehow expect that a single page may not suffice in the future, it may even be advisable to store an (address,size) pair as param. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
