[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: Re: [virtio-comment] Re: [PATCH v1] virtio-mem: minor clarification regarding read-access to unplugged blocks
On Fri, 27 Nov 2020 11:39:50 +0100 David Hildenbrand <david@redhat.com> wrote: > On 20.11.20 16:13, Cornelia Huck wrote: > > On Mon, 16 Nov 2020 20:16:29 +0100 > > David Hildenbrand <david@redhat.com> wrote: > > > >> Let's clarify that we don't expect all DMA to work with unplugged blocks. > >> We really only give guarantees when reading from unplugged memory blocks > >> via the CPU, e.g., as done by Linux when creating a system dump via > >> kdump: the new kernel will copy the content of the old (crashed) kernel > >> via the CPU to user space, from where it will find its final destination > >> inside the dump file. Note that dumping via makedumpfile under Linux will > >> avoid reading unplugged blocks completely. > >> > >> This is a preparation for device passthrough to VMs, whereby such > >> dedicated devices might not be able to read from unplugged memory blocks. > >> > >> Let's document that this scenario is possible, and why this handling is > >> in place at all. > >> > >> Cc: teawater <teawaterz@linux.alibaba.com> > >> Cc: Marek Kedzierski <mkedzier@redhat.com> > >> Cc: Michael S. Tsirkin <mst@redhat.com> > >> Cc: Cornelia Huck <cohuck@redhat.com> > >> Signed-off-by: David Hildenbrand <david@redhat.com> > >> --- > >> virtio-mem.tex | 9 +++++++-- > >> 1 file changed, 7 insertions(+), 2 deletions(-) > > > > Looks reasonable to me. > > > > Acked-by: Cornelia Huck <cohuck@redhat.com> > > Thanks! > > I assume I'll need a github issue etc. to get this in, right? > Yes; just open the issue, point to this patch in the archives, and reply with the issue here. (I don't think this is trivial enough to push without voting.)
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]