From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Aneesh Kumar K.V" Date: Mon, 05 Apr 2021 03:59:03 +0000 Subject: Re: [PATCH v3] powerpc/papr_scm: Implement support for H_SCM_FLUSH hcall Message-Id: List-Id: References: <161703936121.36.7260632399582101498.stgit@e1fbed493c87> <87mtul6xzj.fsf@linux.ibm.com> <87zgyjwrnv.fsf@mpe.ellerman.id.au> In-Reply-To: <87zgyjwrnv.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Michael Ellerman , Shivaprasad G Bhat , sbhat@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, linux-nvdimm@lists.01.org Cc: linux-doc@vger.kernel.org, vaibhav@linux.ibm.com On 3/31/21 3:50 PM, Michael Ellerman wrote: > "Aneesh Kumar K.V" writes: >> Shivaprasad G Bhat writes: >> >>> Add support for ND_REGION_ASYNC capability if the device tree >>> indicates 'ibm,hcall-flush-required' property in the NVDIMM node. >>> Flush is done by issuing H_SCM_FLUSH hcall to the hypervisor. >>> >>> If the flush request failed, the hypervisor is expected to >>> to reflect the problem in the subsequent nvdimm H_SCM_HEALTH call. >>> >>> This patch prevents mmap of namespaces with MAP_SYNC flag if the >>> nvdimm requires an explicit flush[1]. >>> >>> References: >>> [1] https://github.com/avocado-framework-tests/avocado-misc-tests/blob/master/memory/ndctl.py.data/map_sync.c >> >> >> Reviewed-by: Aneesh Kumar K.V > > Do we need an ack from nvdimm folks on this? > > Or is it entirely powerpc internal (seems like it from the diffstat)? > This is within powerpc and we are implementing details w.r.t PAPR spec. There is a Qemu implementation that is getting reviewed here https://lore.kernel.org/linux-nvdimm/161650723087.2959.8703728357980727008.stgit@6532096d84d3 But with respect to this patch, we can take that independent of the Qemu backend implementation. -aneesh