[v2] nvdimm: read-only file support

[PATCH v2 0/3] nvdimm: read-only file support

Posted by Stefan Hajnoczi 3 years, 7 months ago

v2:
 * s/the the/the/ in documentation [Philippe]
 * Assign nvdimm->unarmed earlier [Philippe]

There is currently no way to back an NVDIMM with a read-only file so it can be
safely shared between untrusted guests.

Introduce an -object memory-backend-file,readonly=on|off option.

Julio Montes sent an earlier patch here:
https://patchew.org/QEMU/20190708211936.8037-1-julio.montes@intel.com/

Eric Ernst requested this feature again for Kata Containers so I gave it a try.

Stefan Hajnoczi (3):
  memory: add readonly support to memory_region_init_ram_from_file()
  hostmem-file: add readonly=on|off option
  nvdimm: honor -object memory-backend-file,readonly=on option

 docs/nvdimm.txt           |  8 +++++++-
 include/exec/memory.h     |  2 ++
 include/exec/ram_addr.h   |  5 +++--
 include/qemu/mmap-alloc.h |  2 ++
 backends/hostmem-file.c   | 26 +++++++++++++++++++++++++-
 exec.c                    | 18 +++++++++++-------
 hw/mem/nvdimm.c           |  4 ++++
 softmmu/memory.c          |  7 +++++--
 util/mmap-alloc.c         | 10 ++++++----
 util/oslib-posix.c        |  2 +-
 qemu-options.hx           |  5 ++++-
 11 files changed, 70 insertions(+), 19 deletions(-)

-- 
2.26.2

Re: [PATCH v2 0/3] nvdimm: read-only file support

Posted by Stefan Hajnoczi 3 years, 6 months ago

On Wed, Sep 16, 2020 at 10:51:47AM +0100, Stefan Hajnoczi wrote:
> v2:
>  * s/the the/the/ in documentation [Philippe]
>  * Assign nvdimm->unarmed earlier [Philippe]

Ping

> There is currently no way to back an NVDIMM with a read-only file so it can be
> safely shared between untrusted guests.
> 
> Introduce an -object memory-backend-file,readonly=on|off option.
> 
> Julio Montes sent an earlier patch here:
> https://patchew.org/QEMU/20190708211936.8037-1-julio.montes@intel.com/
> 
> Eric Ernst requested this feature again for Kata Containers so I gave it a try.
> 
> Stefan Hajnoczi (3):
>   memory: add readonly support to memory_region_init_ram_from_file()
>   hostmem-file: add readonly=on|off option
>   nvdimm: honor -object memory-backend-file,readonly=on option
> 
>  docs/nvdimm.txt           |  8 +++++++-
>  include/exec/memory.h     |  2 ++
>  include/exec/ram_addr.h   |  5 +++--
>  include/qemu/mmap-alloc.h |  2 ++
>  backends/hostmem-file.c   | 26 +++++++++++++++++++++++++-
>  exec.c                    | 18 +++++++++++-------
>  hw/mem/nvdimm.c           |  4 ++++
>  softmmu/memory.c          |  7 +++++--
>  util/mmap-alloc.c         | 10 ++++++----
>  util/oslib-posix.c        |  2 +-
>  qemu-options.hx           |  5 ++++-
>  11 files changed, 70 insertions(+), 19 deletions(-)
> 
> -- 
> 2.26.2
>

Re: [PATCH v2 0/3] nvdimm: read-only file support

Posted by Liam Merwick 3 years, 4 months ago

On 16/09/2020 10:51, Stefan Hajnoczi wrote:
> v2:
>   * s/the the/the/ in documentation [Philippe]
>   * Assign nvdimm->unarmed earlier [Philippe]
> 
> There is currently no way to back an NVDIMM with a read-only file so it can be
> safely shared between untrusted guests.
> 
> Introduce an -object memory-backend-file,readonly=on|off option.
> 
> Julio Montes sent an earlier patch here:
> https://patchew.org/QEMU/20190708211936.8037-1-julio.montes@intel.com/
> 
> Eric Ernst requested this feature again for Kata Containers so I gave it a try.
> 
> Stefan Hajnoczi (3):
>    memory: add readonly support to memory_region_init_ram_from_file()
>    hostmem-file: add readonly=on|off option
>    nvdimm: honor -object memory-backend-file,readonly=on option
> 


Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Tested-by: Liam Merwick <liam.merwick@oracle.com>

(I just quickly modified kata-runtime to unconditionally pass 
readonly=on and verified that the root filesystem couldn't be remounted 
as rw)

Is this a candidate for 6.0?

Regards,
Liam


>   docs/nvdimm.txt           |  8 +++++++-
>   include/exec/memory.h     |  2 ++
>   include/exec/ram_addr.h   |  5 +++--
>   include/qemu/mmap-alloc.h |  2 ++
>   backends/hostmem-file.c   | 26 +++++++++++++++++++++++++-
>   exec.c                    | 18 +++++++++++-------
>   hw/mem/nvdimm.c           |  4 ++++
>   softmmu/memory.c          |  7 +++++--
>   util/mmap-alloc.c         | 10 ++++++----
>   util/oslib-posix.c        |  2 +-
>   qemu-options.hx           |  5 ++++-
>   11 files changed, 70 insertions(+), 19 deletions(-)
>

Re: [PATCH v2 0/3] nvdimm: read-only file support

Posted by Stefan Hajnoczi 3 years, 3 months ago

On Thu, Dec 10, 2020 at 04:48:57PM +0000, Liam Merwick wrote:
> On 16/09/2020 10:51, Stefan Hajnoczi wrote:
> > v2:
> >   * s/the the/the/ in documentation [Philippe]
> >   * Assign nvdimm->unarmed earlier [Philippe]
> > 
> > There is currently no way to back an NVDIMM with a read-only file so it can be
> > safely shared between untrusted guests.
> > 
> > Introduce an -object memory-backend-file,readonly=on|off option.
> > 
> > Julio Montes sent an earlier patch here:
> > https://patchew.org/QEMU/20190708211936.8037-1-julio.montes@intel.com/
> > 
> > Eric Ernst requested this feature again for Kata Containers so I gave it a try.
> > 
> > Stefan Hajnoczi (3):
> >    memory: add readonly support to memory_region_init_ram_from_file()
> >    hostmem-file: add readonly=on|off option
> >    nvdimm: honor -object memory-backend-file,readonly=on option
> > 
> 
> 
> Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
> Tested-by: Liam Merwick <liam.merwick@oracle.com>
> 
> (I just quickly modified kata-runtime to unconditionally pass readonly=on
> and verified that the root filesystem couldn't be remounted as rw)
> 
> Is this a candidate for 6.0?

Thanks! Yes, this is for 6.0.

Stefan