> > On Thu, Oct 12, 2017 at 2:25 PM, Pankaj Gupta <pagu...@redhat.com> 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 <pagu...@redhat.com> > >> > --- > >> > 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. > >> > >> 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 a driver > >> call, so this is something distinctly different than "persistent > >> memory". For example, it's a bug if this memory range ends up backing > >> a device-dax range in the guest where there is no such thing as a > >> driver callback to perform the flushing. How does this solution > >> protect against that scenario? > > > > yes, you are right we are not providing device_dax in this case so it > > should > > be clear from name. Any suggestion for name? > > 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. > inject your own name into the resource tree the same way we do in the > NFIT driver. See acpi_nfit_insert_resource(). Sure! thank you. _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm
