On 09/14/2016 04:00 PM, Paolo Bonzini wrote:
On 14/09/2016 22:59, Brijesh Singh wrote:
I will look into hooking up the callback into ROM read/write ops. I was
thinking about adding a new argument in
cpu_physical_memory_write_rom_internal()
void cpu_physical_memory_write_rom(AddressSpace *as, hwaddr addr,
const uint8_t *buf, int len,
WriteCB *cb)
{
....
ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
if (cb)
cb(ptr, buf, len)
else
memcpy(ptr, buf, len)
....
}
In case of SEV, we pass a CB function pointer which calls SEV API's to
encrypt memory. Does this make sense?
I think a global as you have it in this series is just fine---just don't
hook it into address_space_read and address_space_write.
Actually in SEV RAM callback I check the Attrs, if attr.sev_debug flag
set then use SEV debug command otherwise default to memcpy so that DMA
and everything else works. I guest the main reason why i choose to hook
this up in address_space_read/write was that I found that
address_space_write and address_space_read is used in debug path. e.g
cpu_memory_rw_debug
address_space_rw
address_space_write/read
cpu_physical_memory_rw
address_space_rw
address_space_write/read
How do you want me to handle these cases? Having SEV RAM callback taking
care this internally was my simplest solution, I am certainly open to
new ideas.