On 05/30/2013 05:49 PM, Paolo Bonzini wrote: > Il 30/05/2013 09:44, Alexey Kardashevskiy ha scritto: >> Hi! >> >> I found the migration broken on pseries platform, specifically, this patch >> broke it: >> >> f1c72795af573b24a7da5eb52375c9aba8a37972 >> migration: do not sent zero pages in bulk stage >> >> The idea is not to send zero pages to the destination guest which is >> expected to have 100% empty RAM. >> >> However on pseries plaftorm the guest always has some stuff in the RAM as a >> part of initialization (device tree, system firmware and rtas (?)) so it is >> not completely empty. As the source guest cannot detect this, it skips some >> pages during migration and we get a broken destination guest. Bug. >> >> While the idea is ok in general, I do not see any easy way to fix it as >> neither QEMUMachine::init nor QEMUMachine::reset callbacks has information >> about whether we are about to receive a migration or not (-incoming >> parameter) and we cannot move device-tree and system firmware >> initialization anywhere else. >> >> ram_bulk_stage is static and cannot be disabled from the platform >> initialization code. >> >> So what would the community suggest? > > Revert the patch. :)
I'll wait for 24 hours (forgot to cc: the author) and then post a revert patch :) -- Alexey