Il lun 28 set 2020, 15:26 Ashish Kalra <ashish.ka...@amd.com> ha scritto:
> Hello Paolo, > > On Sat, Sep 26, 2020 at 02:02:20AM +0200, Paolo Bonzini wrote: > > On 26/09/20 01:48, Ashish Kalra wrote: > > > Thanks for your input, i have one additional query with reference to > this support : > > > > > > For all explicitly unecrypted guest memory regions such as S/W IOTLB > bounce buffers, > > > dma_decrypted() allocated regions and for guest regions marked as > "__bss_decrypted", > > > we need to ensure that DBG_DECRYPT API calls are bypassed for such > > > regions and those regions are dumped as un-encrypted. > > > > Yes those would be a bit different as they would be physical memory > > accesses. Those currently go through address_space_read in memory_dump > > (monitor/misc.c), and would have to use the MemoryDebugOps instead. > > That is the place to hook into in order to read the KVM page encryption > > bitmap (which is not per-CPU, so another MemoryDebugOps entry > > get_phys_addr_attrs?); the MemTxAttrs can then be passed to the read > > function in the MemoryDebugOps. > > > > Actually, currently we do this in sev_dbg_crypt() in KVM itself by > checking the page encryption bitmap and if it is an un-encrypted guest > memory region then returning the un-encrypted buffer read from user > back to it as it is. > Fair enough. :-) Paolo > > > This guest memory regions encryption status is found using KVM's page > encryption bitmap > > > support which is part of the page encryption bitmap hypercall > interface of the > > > KVM/QEMU SEV live migration patches. > > > > > > As this additional debug support is dependent on the KVM's page > encryption bitmap > > > support, are there any updates on KVM SEV live migration patches ? > > > > Sorry about that, I've been busy with QEMU. I'll review them as soon as > > possible.H > > Looking forward to your updates and reviews regarding the same. > > Thanks, > Ashish > >
