Re: [PATCH v3 0/9] Do not allow set-partition immediate mode

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Wed, 23 Mar 2022 18:11:17 -0700
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> Blocking immediate mode in set-partition info triggered a
> refactoring of the send path of userspace mailbox commands.
> 
> The v1 to address the issue was a single patch [1] that inserted
> a new immediate mode check in the send path where the payload was
> available for examining. That was not in a validation function.
> 
> The v2 patchset [2] added refactoring of the send path so that
> validation work can all spawn from cxl_validate_cmd_from_user().
> 
> Here, v3 offers a finer level of refactoring:
> 
> Patches 1-7: Refactor existing code so that all validation work
> 	can spawn from cxl_validate_cmd_from_user().
> 
> 	The movement intends to cleanly rip the work of building a
> 	mailbox command away from handle_mailbox_command_from_user()
> 	and give it to cxl_validate_cmd_from_user().

This makes me wonder a bit if
cxl_validate_cmd_from_user() is an appropriate name given
it now does more than validation?

> 
> Patch 8: Blocks the immediate mode of the set-partition command.
> Patch 9: Removes CXL_PMEM exclusive commands restriction.
> 
> [1] https://lore.kernel.org/linux-cxl/20220103202100.784194-1-alison.schofield@intel.com/
> [2] https://lore.kernel.org/linux-cxl/a4daafc4b537a0b1a673c55300da7747784c4573.1645817416.git.alison.schofield@intel.com/
> 
> Changes in v3:
> - Split up the 'Centralize the validation...' patch into 6 pieces.
> Patch: cxl/mbox: Move cxl_mem_command construction to helper funcs
> - Safely initialize the cxl_mem_command structs. (Dan)
> - Remove unneeded memcpy (Dan)
> Patch: cxl/mbox: Block immediate mode in SET_PARTITION_INFO command
> - No Changes
> Patch: cxl/pmem: Remove CXL SET_PARTITION_INFO from exclusive_cmds list
> - No Changes
> 
> Changes in v2:
> - Refactor the send path of userspace mbox cmds. (Dan, Ben)
> - Patch 3 commit log - update the need to block. (Dan)
> - Return -EBUSY (not -EINVAL), when blocking immediate mode. (Ben)
> - Remove unneeded cast of void (payload_in). (dan)
> - s/u64/__le64 in struct cxl_mbox_set_partition_info. (Dan)
> 
> Alison Schofield (9):
>   cxl/mbox: Move cxl_mem_command construction to helper funcs
>   cxl/mbox: Move raw command warning to raw command validation
>   cxl/mbox: Move build of user mailbox cmd to a helper function
>   cxl/mbox: Construct a users cxl_mbox_cmd in the validation path
>   cxl/mbox: Remove dependency on cxl_mem_command for a debug msg
>   cxl/mbox: Make handle_mailbox_cmd_from_user() use a mbox param
>   cxl/mbox: Move cxl_mem_command param to a local variable
>   cxl/mbox: Block immediate mode in SET_PARTITION_INFO command
>   cxl/pmem: Remove CXL SET_PARTITION_INFO from exclusive_cmds list
> 
>  drivers/cxl/core/mbox.c | 311 +++++++++++++++++++++++++---------------
>  drivers/cxl/cxlmem.h    |   7 +
>  drivers/cxl/pmem.c      |   1 -
>  3 files changed, 200 insertions(+), 119 deletions(-)
> 
> 
> base-commit: 9b688fc651b9d2b633e8d959454670aba1c39162