On Sun, Dec 12, 2021 at 06:48:05AM -0800, Dan Williams wrote: > On Fri, Dec 10, 2021 at 6:05 AM Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: > > > > On Thu, Dec 09, 2021 at 07:38:28AM +0100, Christoph Hellwig wrote: > > > While using the MC-safe copy routines is rather pointless on a virtual device > > > like virtiofs, > > > > I was wondering about that. Is it completely pointless. > > > > Typically we are just mapping host page cache into qemu address space. > > That shows as virtiofs device pfn in guest and that pfn is mapped into > > guest application address space in mmap() call. > > > > Given on host its DRAM, so I would not expect machine check on load side > > so there was no need to use machine check safe variant. > > That's a broken assumption, DRAM experiences multi-bit ECC errors. > Machine checks, data aborts, etc existed before PMEM. So the conclusion here is that we should always use the mc safe variant?