On Thu, Sep 22, 2016 at 10:51:05AM +0530, Bharata B Rao wrote: > Hi, > > Nikunj and I realized that migrating pseries-2.6 guest from QEMU-2.6 > to newer QEMU-2.7 is broken like this: > > qemu-system-ppc64: error while loading state for instance 0x0 of device 'cpu' > qemu-system-ppc64: load of migration failed: Invalid argument > > Bisecting tells us that 4e0806110c8b896ceff3490f15a616e8b3165efe > (ppc: Add PPC_64H instruction flag to POWER7 and POWER8) is the > first bad commit. Along with this there are other 3 similar commits > which add new bits to insns_flags and insns_flags2 fields of POWER7 > and POWER8 CPUs. > > 4e0806110c8b896ceff3490f15a616e8b3165efe Adds PPC_64H to POWER7 and POWER8 > dfdd3e43620a6cd4f2be31da5a257c84a16fc000 Adds PPC_64BX to POWER7 > b781537560e3b968b6fe1395e3d07bd67f0009ba Adds PPC_CILDST to POWER7 and POWER8 > 7778a575c7055276afdd01737e9d1029a65f923d Adds PPC2_PM_ISA206 to POWER7 and > POWER8 > > The flag values are expected to remain same for a machine version for > the migration to succeed, but this expectation is broken now. Should > we make the addition of these flags conditional on machine type version ? > But these flags are part of POWER8 CPU definition which is common for > both pseries and upcoming powernv.
Can you step me through how the new flags are breaking the migration? It's not immediately obvious to me. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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