Re: [PATCH v2 02/12] hw/block/nvme: fix 64 bit register hi/lo split writes

2021-01-19 Thread Keith Busch
On Mon, Jan 18, 2021 at 08:53:24PM +0100, Klaus Jensen wrote: > On Jan 18 21:59, Minwoo Im wrote: > > > The spec requires aligned 32 bit accesses (or the size of the register), > > > so maybe it's about time we actually ignore instead of falling through. > > > > Agreed. > > > > On the other hand

Re: [PATCH v2 02/12] hw/block/nvme: fix 64 bit register hi/lo split writes

2021-01-18 Thread Minwoo Im
On 21-01-18 20:53:24, Klaus Jensen wrote: > On Jan 18 21:59, Minwoo Im wrote: > > > The spec requires aligned 32 bit accesses (or the size of the register), > > > so maybe it's about time we actually ignore instead of falling through. > > > > Agreed. > > > > On the other hand. > > The spec just

Re: [PATCH v2 02/12] hw/block/nvme: fix 64 bit register hi/lo split writes

2021-01-18 Thread Klaus Jensen
On Jan 18 21:59, Minwoo Im wrote: > > The spec requires aligned 32 bit accesses (or the size of the register), > > so maybe it's about time we actually ignore instead of falling through. > > Agreed. > On the other hand. The spec just allows undefined behavior if the alignment or size requiremen

Re: [PATCH v2 02/12] hw/block/nvme: fix 64 bit register hi/lo split writes

2021-01-18 Thread Minwoo Im
> The spec requires aligned 32 bit accesses (or the size of the register), > so maybe it's about time we actually ignore instead of falling through. Agreed.

Re: [PATCH v2 02/12] hw/block/nvme: fix 64 bit register hi/lo split writes

2021-01-18 Thread Klaus Jensen
On Jan 18 21:41, Minwoo Im wrote: > On 21-01-18 10:46:55, Klaus Jensen wrote: > > From: Klaus Jensen > > > > 64 bit registers like ASQ and ACQ should be writable by both a hi/lo 32 > > bit write combination as well as a plain 64 bit write. The spec does not > > define ordering on the hi/lo split,

Re: [PATCH v2 02/12] hw/block/nvme: fix 64 bit register hi/lo split writes

2021-01-18 Thread Minwoo Im
On 21-01-18 10:46:55, Klaus Jensen wrote: > From: Klaus Jensen > > 64 bit registers like ASQ and ACQ should be writable by both a hi/lo 32 > bit write combination as well as a plain 64 bit write. The spec does not > define ordering on the hi/lo split, but the code currently assumes that > the low

[PATCH v2 02/12] hw/block/nvme: fix 64 bit register hi/lo split writes

2021-01-18 Thread Klaus Jensen
From: Klaus Jensen 64 bit registers like ASQ and ACQ should be writable by both a hi/lo 32 bit write combination as well as a plain 64 bit write. The spec does not define ordering on the hi/lo split, but the code currently assumes that the low order bits are written first. Additionally, the code