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. > > 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
