Hello Paolo, On Fri, Sep 25, 2020 at 10:56:10PM +0200, Paolo Bonzini wrote: > On 25/09/20 22:46, Ashish Kalra wrote: > > I was also considering abstracting this vendor/SEV specific debug > > interface via the CPUClass object, the CPUClass object aleady has cpu > > specific methods for doing things like guest VA to GPA translations like the > > get_phys_page_attrs_debug() method and it will be a simple and clean > > approach to override this method with a SEV specific > > get_phys_page_attrs_debug() if SEV guest is active and SEV debug policy > > is allowed. [...] > > > > I can probably add new interfaces/methods to this CPUClass object for > > guest memory read/writes for debugging purpose and then invoke the same > > from the generic cpu_memory_rw_debug() interface. > > > > Let me know your thougts on abstracting this debug interface via the > > CPUClass object ? > > > > Or the other option is to introduce the new MemoryDebugOps you described > > above and additionally apply SEV/SEV-ES considerations in CPUClass > > methods such as gdb_read_register, gdb_write_register, etc. > > Yes, this makes the most sense, however you're right that you don't need > translate in MemoryDebugOps. I don't think read/write should be moved > to CPUClass, however, since you can use a MemTxAttr to tell the > read/write MemoryDebugOps whether the page is encrypted or not. >
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. 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 ? Thanks, Ashish
