20/02/2023 10:43, Morten Brørup: > > From: Thomas Monjalon [mailto:tho...@monjalon.net] > > Sent: Monday, 20 February 2023 08.45 > > > > 16/02/2023 09:36, Ruifeng Wang: > > > From: Chengwen Feng <fengcheng...@huawei.com> > > > > Subject: [PATCH] net/hns3: support disable IOVA as PA mode > > > > Could we change the title to "support IOVA as VA" ? > > The underlying problem is the meson configuration option name for this > feature [1]: > > option('enable_iova_as_pa', type: 'boolean', value: true, description: > 'Support for IOVA as physical address. Disabling removes the buf_iova > field of mbuf.') > > [1]: https://elixir.bootlin.com/dpdk/v22.11.1/source/meson_options.txt#L43 > > Formally, the patch provides the ability to set a boolean configuration value > ("enable_iova_as_pa") to false, and thus the patch title is correct. > > Nonetheless, I agree that the title suggested by Thomas is an improvement. > > > Going back to the root cause, I think the configuration option should be an > enum instead of a boolean, e.g. "iova_mode" with values "iova_pa" and > "iova_va".
We can enable both and have it decided at runtime. So I think the boolean is OK. > It's somewhat similar to CPU endian macros. We have macros defining both Big > Endian and Little Endian, not just one macro defining Big Endian or not. > > @Bruce, would it be hard for you to change the IOVA configuration option from > a boolean to a two-value enum? > > Or - also considering the resulting #define's - would it be too difficult to > keep a sufficient level of backwards/API compatibility?
