On Thu, 21 Mar 2019 at 15:32, Catherine Ho <catherine.h...@gmail.com> wrote: > So in igore-shared case, dtb is not required here ?
Can you explain what the "ignore-shared" case is? In general, when we reset the system, we want to bring it back to exactly the state that it was in when QEMU was first started. That means we need to reload all the rom blob data into memory (because the guest might have modified that memory while it was running). If I understand correctly from other threads, the idea is that some of the RAM is shared between source and destination so it does not need to be manually copied during migration. If that is correct, then perhaps the right thing is that in the rom_reset code: * if this rom blob is being loaded into a "shared" ram block * and this reset is happening specifically before an inbound migration * then skip loading the rom blob data ? I don't know the right way to determine either the "is this a shared ram area" or "is this the reset prior to inbound migration", but perhaps you can fill that in. > Maybe I could add a flag in struct Rom to set it when the rom is created by > rom_add_blob_fixed_as()? And in rom_reset, just bypass this rom when > in_incoming_migration && ignore_shared No, I think this is wrong -- the particular function used to create the rom blob data should not affect how we are treating it. thanks -- PMM
