On Thu, 2017-10-12 at 18:18 -0400, Pankaj Gupta wrote: > > > > On Thu, Oct 12, 2017 at 2:25 PM, Pankaj Gupta <pagupta@xxxxxxxxxx> > > wrote: > > > > > > > > This patch adds virtio-pmem driver for KVM guest. > > > > > Guest reads the persistent memory range information > > > > > over virtio bus from Qemu and reserves the range > > > > > as persistent memory. Guest also allocates a block > > > > > device corresponding to the pmem range which later > > > > > can be accessed with DAX compatible file systems. > > > > > Idea is to use the virtio channel between guest and > > > > > host to perform the block device flush for guest pmem > > > > > DAX device. > > > > > > > > > > There is work to do including DAX file system support > > > > > and other advanced features. > > > > > > > > > > Signed-off-by: Pankaj Gupta <pagupta@xxxxxxxxxx> > > > > > --- > > > > > drivers/virtio/Kconfig | 10 ++ > > > > > drivers/virtio/Makefile | 1 + > > > > > drivers/virtio/virtio_pmem.c | 322 > > > > > +++++++++++++++++++++++++++++++++++++++ > > > > > include/uapi/linux/virtio_pmem.h | 55 +++++++ > > > > > 4 files changed, 388 insertions(+) > > > > > create mode 100644 drivers/virtio/virtio_pmem.c > > > > > create mode 100644 include/uapi/linux/virtio_pmem.h > > > > > > > > > > diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig > > > > > index cff773f15b7e..0192c4bda54b 100644 > > > > > --- a/drivers/virtio/Kconfig > > > > > +++ b/drivers/virtio/Kconfig > > > > > @@ -38,6 +38,16 @@ config VIRTIO_PCI_LEGACY > > > > > > > > > > If unsure, say Y. > > > > > > > > > > +config VIRTIO_PMEM > > > > > + tristate "Virtio pmem driver" > > > > > + depends on VIRTIO > > > > > + ---help--- > > > > > + This driver adds persistent memory range within a > > > > > KVM guest. With "Virtio Block Backed Pmem" we could name the config option VIRTIO_BLOCK_PMEM The documentation text could make it clear to people that the image shows up as a disk image on the host, but as a pmem memory range in the guest. > > > > I think we need to call this something other than persistent > > > > memory to > > > > make it clear that this not memory where the persistence can be > > > > managed from userspace. The persistence point always requires > > > > > > So currently /proc/iomem in a guest with a pmem device attached to > > a > > namespace looks like this: > > > > c00000000-13bfffffff : Persistent Memory > > c00000000-13bfffffff : namespace2.0 > > > > Can we call it "Virtio Shared Memory" to make it clear it is a > > different beast than typical "Persistent Memory"? You can likely > > I think somewhere we need persistent keyword 'Virtio Persistent > Memory' or > so. Still hoping for better ideas than "Virtio Block Backed Pmem" :) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
