2023-09-13 03:57:48

by Dan Williams

[permalink] [raw]
Subject: RE: [PATCH] cxl/mbox: Fix CEL logic for poison and security commands

Ira Weiny wrote:
> The following debug output was observed while testing CXL
>
> cxl_core:cxl_walk_cel:721: cxl_mock_mem cxl_mem.0: Opcode 0x4300 unsupported by driver
>
> opcode 0x4300 (Get Poison) is supported by the driver and the mock
> device supports it. The logic should be checking that the opcode is
> both not poison and not security.
>
> Fix the logic to allow poison and security commands.
>
> Fixes: ad64f5952ce3 ("cxl/memdev: Only show sanitize sysfs files when supported")
> Cc: Davidlohr Bueso <[email protected]>
> Signed-off-by: Ira Weiny <[email protected]>
> ---
> drivers/cxl/core/mbox.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index ca60bb8114f2..b315bdab9197 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -716,8 +716,8 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
> u16 opcode = le16_to_cpu(cel_entry[i].opcode);
> struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
>
> - if (!cmd && (!cxl_is_poison_command(opcode) ||
> - !cxl_is_security_command(opcode))) {
> + if (!cmd && !cxl_is_poison_command(opcode) &&
> + !cxl_is_security_command(opcode)) {

Given that this is going to be a recurring pattern to add optional
command support, I am not a fan of continuing to expand this boolean
algebra eye exam.

How about the following to only do the validation check and enabling in
one place:


diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index ca60bb8114f2..4df4f614f490 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -715,24 +715,25 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
for (i = 0; i < cel_entries; i++) {
u16 opcode = le16_to_cpu(cel_entry[i].opcode);
struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
+ int enabled = 0;

- if (!cmd && (!cxl_is_poison_command(opcode) ||
- !cxl_is_security_command(opcode))) {
- dev_dbg(dev,
- "Opcode 0x%04x unsupported by driver\n", opcode);
- continue;
- }
-
- if (cmd)
+ if (cmd) {
set_bit(cmd->info.id, mds->enabled_cmds);
+ enabled++;
+ }

- if (cxl_is_poison_command(opcode))
+ if (cxl_is_poison_command(opcode)) {
cxl_set_poison_cmd_enabled(&mds->poison, opcode);
+ enabled++;
+ }

- if (cxl_is_security_command(opcode))
+ if (cxl_is_security_command(opcode)) {
cxl_set_security_cmd_enabled(&mds->security, opcode);
+ enabled++;
+ }

- dev_dbg(dev, "Opcode 0x%04x enabled\n", opcode);
+ dev_dbg(dev, "Opcode 0x%04x %s\n", opcode,
+ enabled ? "enabled" : "unsupported by driver");
}
}


2023-09-13 18:23:51

by Ira Weiny

[permalink] [raw]
Subject: RE: [PATCH] cxl/mbox: Fix CEL logic for poison and security commands

Dan Williams wrote:
> Ira Weiny wrote:
> > The following debug output was observed while testing CXL
> >
> > cxl_core:cxl_walk_cel:721: cxl_mock_mem cxl_mem.0: Opcode 0x4300 unsupported by driver
> >
> > opcode 0x4300 (Get Poison) is supported by the driver and the mock
> > device supports it. The logic should be checking that the opcode is
> > both not poison and not security.
> >
> > Fix the logic to allow poison and security commands.
> >
> > Fixes: ad64f5952ce3 ("cxl/memdev: Only show sanitize sysfs files when supported")
> > Cc: Davidlohr Bueso <[email protected]>
> > Signed-off-by: Ira Weiny <[email protected]>
> > ---
> > drivers/cxl/core/mbox.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> > index ca60bb8114f2..b315bdab9197 100644
> > --- a/drivers/cxl/core/mbox.c
> > +++ b/drivers/cxl/core/mbox.c
> > @@ -716,8 +716,8 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
> > u16 opcode = le16_to_cpu(cel_entry[i].opcode);
> > struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
> >
> > - if (!cmd && (!cxl_is_poison_command(opcode) ||
> > - !cxl_is_security_command(opcode))) {
> > + if (!cmd && !cxl_is_poison_command(opcode) &&
> > + !cxl_is_security_command(opcode)) {
>
> Given that this is going to be a recurring pattern to add optional
> command support, I am not a fan of continuing to expand this boolean
> algebra eye exam.
>
> How about the following to only do the validation check and enabling in
> one place:

I like it.

Reviewed-by: Ira Weiny <[email protected]>

>
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index ca60bb8114f2..4df4f614f490 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -715,24 +715,25 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
> for (i = 0; i < cel_entries; i++) {
> u16 opcode = le16_to_cpu(cel_entry[i].opcode);
> struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
> + int enabled = 0;
>
> - if (!cmd && (!cxl_is_poison_command(opcode) ||
> - !cxl_is_security_command(opcode))) {
> - dev_dbg(dev,
> - "Opcode 0x%04x unsupported by driver\n", opcode);
> - continue;
> - }
> -
> - if (cmd)
> + if (cmd) {
> set_bit(cmd->info.id, mds->enabled_cmds);
> + enabled++;
> + }
>
> - if (cxl_is_poison_command(opcode))
> + if (cxl_is_poison_command(opcode)) {
> cxl_set_poison_cmd_enabled(&mds->poison, opcode);
> + enabled++;
> + }
>
> - if (cxl_is_security_command(opcode))
> + if (cxl_is_security_command(opcode)) {
> cxl_set_security_cmd_enabled(&mds->security, opcode);
> + enabled++;
> + }
>
> - dev_dbg(dev, "Opcode 0x%04x enabled\n", opcode);
> + dev_dbg(dev, "Opcode 0x%04x %s\n", opcode,
> + enabled ? "enabled" : "unsupported by driver");
> }
> }
>


2023-09-13 19:49:23

by Davidlohr Bueso

[permalink] [raw]
Subject: Re: [PATCH] cxl/mbox: Fix CEL logic for poison and security commands

On Tue, 12 Sep 2023, Dan Williams wrote:

>Ira Weiny wrote:
>> The following debug output was observed while testing CXL
>>
>> cxl_core:cxl_walk_cel:721: cxl_mock_mem cxl_mem.0: Opcode 0x4300 unsupported by driver
>>
>> opcode 0x4300 (Get Poison) is supported by the driver and the mock
>> device supports it. The logic should be checking that the opcode is
>> both not poison and not security.
>>
>> Fix the logic to allow poison and security commands.
>>
>> Fixes: ad64f5952ce3 ("cxl/memdev: Only show sanitize sysfs files when supported")
>> Cc: Davidlohr Bueso <[email protected]>
>> Signed-off-by: Ira Weiny <[email protected]>
>> ---
>> drivers/cxl/core/mbox.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
>> index ca60bb8114f2..b315bdab9197 100644
>> --- a/drivers/cxl/core/mbox.c
>> +++ b/drivers/cxl/core/mbox.c
>> @@ -716,8 +716,8 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
>> u16 opcode = le16_to_cpu(cel_entry[i].opcode);
>> struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
>>
>> - if (!cmd && (!cxl_is_poison_command(opcode) ||
>> - !cxl_is_security_command(opcode))) {
>> + if (!cmd && !cxl_is_poison_command(opcode) &&
>> + !cxl_is_security_command(opcode)) {
>
>Given that this is going to be a recurring pattern to add optional
>command support, I am not a fan of continuing to expand this boolean
>algebra eye exam.
>
>How about the following to only do the validation check and enabling in
>one place:

Agreed.

Reviewed-by: Davidlohr Bueso <[email protected]>

... this also is a reminder of the need for regression testing/CI.

Thanks,
Davidlohr