Re: [PATCH] powerpc/book3s_hv_uvmem: Check for failed page migration

2020-12-08 Thread Ram Pai
On Thu, Dec 03, 2020 at 04:08:12PM +1100, Alistair Popple wrote: > migrate_vma_pages() may still clear MIGRATE_PFN_MIGRATE on pages which > are not able to be migrated. Drivers may safely copy data prior to > calling migrate_vma_pages() however a remote mapping must not be > established until after

Re: [PATCH] powerpc/book3s_hv_uvmem: Check for failed page migration

2020-12-06 Thread Alistair Popple
On Saturday, 5 December 2020 3:52:44 AM AEDT Ram Pai wrote: > On Fri, Dec 04, 2020 at 03:48:41PM +0530, Bharata B Rao wrote: > > On Thu, Dec 03, 2020 at 04:08:12PM +1100, Alistair Popple wrote: > This patch certainly looks like the problem, that has been hurting > us for a while. Let me run this

Re: [PATCH] powerpc/book3s_hv_uvmem: Check for failed page migration

2020-12-06 Thread Alistair Popple
On Friday, 4 December 2020 9:18:41 PM AEDT Bharata B Rao wrote: > > Reviewed-by: Bharata B Rao > > Did you actually hit this scenario with secure VMs where a UV-paged-in > page was later found to be not migratable? No, this was found by inspection. I have no way of testing this but we had a si

Re: [PATCH] powerpc/book3s_hv_uvmem: Check for failed page migration

2020-12-04 Thread Ram Pai
On Fri, Dec 04, 2020 at 03:48:41PM +0530, Bharata B Rao wrote: > On Thu, Dec 03, 2020 at 04:08:12PM +1100, Alistair Popple wrote: > > migrate_vma_pages() may still clear MIGRATE_PFN_MIGRATE on pages which > > are not able to be migrated. Drivers may safely copy data prior to > > calling migrate_vma

Re: [PATCH] powerpc/book3s_hv_uvmem: Check for failed page migration

2020-12-04 Thread Bharata B Rao
On Thu, Dec 03, 2020 at 04:08:12PM +1100, Alistair Popple wrote: > migrate_vma_pages() may still clear MIGRATE_PFN_MIGRATE on pages which > are not able to be migrated. Drivers may safely copy data prior to > calling migrate_vma_pages() however a remote mapping must not be > established until after

[PATCH] powerpc/book3s_hv_uvmem: Check for failed page migration

2020-12-02 Thread Alistair Popple
migrate_vma_pages() may still clear MIGRATE_PFN_MIGRATE on pages which are not able to be migrated. Drivers may safely copy data prior to calling migrate_vma_pages() however a remote mapping must not be established until after migrate_vma_pages() has returned as the migration could still fail. UV_