Alexander Graf <ag...@suse.de> writes: > On 08.07.2013, at 20:45, Anthony Liguori wrote: > >> Alexey Kardashevskiy <a...@ozlabs.ru> writes: >> >>> From: David Gibson <da...@gibson.dropbear.id.au> >>> >>> This adds the necessary pieces to implement savevm / migration for the >>> pseries machine. The most complex part here is migrating the hash >>> table - for the paravirtualized pseries machine the guest's hash page >>> table is not stored within guest memory, but externally and the guest >>> accesses it via hypercalls. >>> >>> This patch uses a hypervisor reserved bit of the HPTE as a dirty bit >>> (tracking changes to the HPTE itself, not the page it references). >>> This is used to implement a live migration style incremental save and >>> restore of the hash table contents. >>> >>> In addition it adds VMStateDescription information to save and restore >>> the (few) remaining pieces of state information needed by the pseries >>> machine. >>> >>> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> >>> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> >> >> I vaguely recall making the suggestion to use a live section like this. >> How large is the HTAB typically? > > The default for HV KVM is at 16MB IIRC.
And if I recall since it's a hash table, updates are random access and not at all page aligned making using qemu ram quite unusable for this purpose. I guess: Reviewed-by: Anthony Liguori <aligu...@us.ibm.com> Regards, Anthony Liguori > > > Alex
