On Tue Jun 3, 2025 at 1:04 AM CEST, Alan Adamson wrote:
> This patch set is a follow on to commit ebd1568fc732 ("hw/nvme: add atomic
> write support"). These patches introduces two updates to the NVMe subsystem
> in QEMU,
> both aimed at enhancing atomic write support for namespaces.
>
> hw/nvme: enable ns atomic writes
> --------------------------------
> This patch introduces support for namespace-specific atomic write parameters:
> NAWUN
> and NAWUPF, as defined by the NVMe specification. The atomic parameters are
> utilized to guarantee that writes conforming to these boundaries will be
> atomic,
> improving data integrity for namespaces that require atomic operations.
>
> The patch introduces new NVMe QEMU parameters:
> atomic.nawun (default: 0)
> atomic.nawupf (default: 0)
> atomic.nsfeat (default: off)
>
> The addition of atomic.nsfeat sets the Namespace Supported Atomic Boundary &
> Power (NSABP) bit in the Identify Namespace Data Structure, enabling
> namespace-specific
> atomic write features. The patch also ensures that atomic write behavior
> adheres to the
> NACWU and NAWUPF parameters.
>
> hw/nvme: add atomic boundary support
> ------------------------------------
> The second patch expands on the atomic write capabilities by adding support
> for atomic
> boundary parameters: NABO, NABSN, and NABSPF. These parameters define the
> atomic
> boundary size for writes and ensure that any writes crossing these boundaries
> are
> treated atomically, based on the AWUN and AWUPF values.
>
> The following parameters are added:
> atomic.nabo (default: 0)
> atomic.nabsn (default: 0)
> atomic.nabspf (default: 0)
>
> If the atomic boundary is crossed, the writes are guaranteed to be atomic
> only if their
> size does not exceed the values defined by AWUN and AWUPF. This ensures that
> larger
> writes crossing atomic boundaries are not subject to partial updates, thereby
> improving
> the robustness of atomic operations across boundaries.
>
> See the NVMe Specification for more information.
>
> Alan Adamson (2):
> hw/nvme: enable ns atomic writes
> hw/nvme: add atomic boundary support
>
> hw/nvme/ctrl.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++
> hw/nvme/ns.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++
> hw/nvme/nvme.h | 14 ++++++++++
> 3 files changed, 164 insertions(+)
Follows the spec far as I can see.
Read the code, seems good
Reviewed-by: Jesper Wendel Devantier <f...@defmacro.it>
