[dpdk-dev] [PATCH] eal/windows: detect insufficient privileges for hugepages

[dpdk-dev] [PATCH] eal/windows: detect insufficient privileges for hugepages

[Dmitry Kozlyuk]

AdjustTokenPrivileges() succeeds even if no requested privileges have
been granted; this behavior is documented. Check last error code in
addition to return value to detect such case.

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
---
 lib/librte_eal/windows/eal_hugepages.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/librte_eal/windows/eal_hugepages.c b/lib/librte_eal/windows/eal_hugepages.c
index 5779cd325..07a5467d0 100644
--- a/lib/librte_eal/windows/eal_hugepages.c
+++ b/lib/librte_eal/windows/eal_hugepages.c
@@ -41,6 +41,10 @@ hugepage_claim_privilege(void)
 		goto exit;
 	}
 
+	/* AdjustTokenPrivileges() may succeed with ERROR_NOT_ALL_ASSIGNED. */
+	if (GetLastError() != ERROR_SUCCESS)
+		goto exit;
+
 	ret = 0;
 
 exit:
-- 
2.25.4

Re: [dpdk-dev] [PATCH] eal/windows: detect insufficient privileges for hugepages

[Ranjit Menon]

On 7/7/2020 1:22 PM, Dmitry Kozlyuk wrote:
> AdjustTokenPrivileges() succeeds even if no requested privileges have
> been granted; this behavior is documented. Check last error code in
> addition to return value to detect such case.
>
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
>   lib/librte_eal/windows/eal_hugepages.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/lib/librte_eal/windows/eal_hugepages.c b/lib/librte_eal/windows/eal_hugepages.c
> index 5779cd325..07a5467d0 100644
> --- a/lib/librte_eal/windows/eal_hugepages.c
> +++ b/lib/librte_eal/windows/eal_hugepages.c
> @@ -41,6 +41,10 @@ hugepage_claim_privilege(void)
>   		goto exit;
>   	}
>   
> +	/* AdjustTokenPrivileges() may succeed with ERROR_NOT_ALL_ASSIGNED. */
> +	if (GetLastError() != ERROR_SUCCESS)
> +		goto exit;
> +
>   	ret = 0;
>   
>   exit:

Wouldn't this be better if we could print a message here after 
explicitly checking for the ERROR_NOT_ALL_ASSIGNED return value?

Otherwise, the caller simply gets a -1 return value for a failure with 
no message.


ranjit m.

Re: [dpdk-dev] [PATCH] eal/windows: detect insufficient privileges for hugepages

[Dmitry Kozlyuk]

On Tue, 7 Jul 2020 16:45:07 -0700, Ranjit Menon wrote:
> On 7/7/2020 1:22 PM, Dmitry Kozlyuk wrote:
> > AdjustTokenPrivileges() succeeds even if no requested privileges have
> > been granted; this behavior is documented. Check last error code in
> > addition to return value to detect such case.
> >
> > Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> > ---
> >   lib/librte_eal/windows/eal_hugepages.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/lib/librte_eal/windows/eal_hugepages.c b/lib/librte_eal/windows/eal_hugepages.c
> > index 5779cd325..07a5467d0 100644
> > --- a/lib/librte_eal/windows/eal_hugepages.c
> > +++ b/lib/librte_eal/windows/eal_hugepages.c
> > @@ -41,6 +41,10 @@ hugepage_claim_privilege(void)
> >   		goto exit;
> >   	}
> >   
> > +	/* AdjustTokenPrivileges() may succeed with ERROR_NOT_ALL_ASSIGNED. */
> > +	if (GetLastError() != ERROR_SUCCESS)
> > +		goto exit;
> > +
> >   	ret = 0;
> >   
> >   exit:  
> 
> Wouldn't this be better if we could print a message here after 
> explicitly checking for the ERROR_NOT_ALL_ASSIGNED return value?
> 
> Otherwise, the caller simply gets a -1 return value for a failure with 
> no message.

Message is printed at ERR level by the caller. There's no context to add here.

-- 
Dmitry Kozlyuk

Re: [dpdk-dev] [PATCH] eal/windows: detect insufficient privileges for hugepages

[Tal Shnaiderman]

> Subject: Re: [PATCH] eal/windows: detect insufficient privileges for
> hugepages
> 
> On Tue, 7 Jul 2020 16:45:07 -0700, Ranjit Menon wrote:
> > On 7/7/2020 1:22 PM, Dmitry Kozlyuk wrote:
> > > AdjustTokenPrivileges() succeeds even if no requested privileges
> > > have been granted; this behavior is documented. Check last error
> > > code in addition to return value to detect such case.
> > >
> > > Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> > > ---
> > >   lib/librte_eal/windows/eal_hugepages.c | 4 ++++
> > >   1 file changed, 4 insertions(+)
> > >
> > > diff --git a/lib/librte_eal/windows/eal_hugepages.c
> > > b/lib/librte_eal/windows/eal_hugepages.c
> > > index 5779cd325..07a5467d0 100644
> > > --- a/lib/librte_eal/windows/eal_hugepages.c
> > > +++ b/lib/librte_eal/windows/eal_hugepages.c
> > > @@ -41,6 +41,10 @@ hugepage_claim_privilege(void)
> > >   		goto exit;
> > >   	}
> > >
> > > +	/* AdjustTokenPrivileges() may succeed with
> ERROR_NOT_ALL_ASSIGNED. */
> > > +	if (GetLastError() != ERROR_SUCCESS)
> > > +		goto exit;
> > > +
> > >   	ret = 0;
> > >
> > >   exit:
> >
> > Wouldn't this be better if we could print a message here after
> > explicitly checking for the ERROR_NOT_ALL_ASSIGNED return value?
> >
> > Otherwise, the caller simply gets a -1 return value for a failure with
> > no message.
> 
> Message is printed at ERR level by the caller. There's no context to add here.
> 

Tested successfully on Windows server 2019.
 
The output in case of missing privilege is:

EAL: Cannot claim hugepage privilege
EAL: FATAL: Cannot get hugepage information
EAL: Cannot get hugepage information

Do you think this is enough or do we want to give the user further indication that configuration action from his side might be needed? Something alike "Please verify OS Large-Page support is enabled for the current user"

> --
> Dmitry Kozlyuk
Tested-by: Tal Shnaiderman <talshn@mellanox.com>

Re: [dpdk-dev] [PATCH] eal/windows: detect insufficient privileges for hugepages

[Dmitry Kozlyuk]

On Wed, 8 Jul 2020 06:43:57 +0000, Tal Shnaiderman wrote:
[snip]

Thanks for the testing.

> Do you think this is enough or do we want to give the user further indication that configuration action from his side might be needed? Something alike "Please verify OS Large-Page support is enabled for the current user"

Yes, troubleshooting suggestions would be useful.

From Microsoft "Error Message Guidelines" [1]:

	Avoid the word "please". It can be interpreted to mean that a
	required action is optional.

[1]:
https://docs.microsoft.com/en-us/windows/win32/debug/error-message-guidelines

-- 
Dmitry Kozlyuk

[dpdk-dev] [PATCH v2] eal/windows: detect insufficient privileges for hugepages

[Dmitry Kozlyuk]

AdjustTokenPrivileges() succeeds even if no requested privileges have
been granted; this behavior is documented. Check last error code in
addition to return value to detect such case.

Make error messages more specific and add troubleshooting hint.

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
---

v2:
    Improve error reporting (Tal Shnaiderman).

 lib/librte_eal/windows/eal_hugepages.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/windows/eal_hugepages.c b/lib/librte_eal/windows/eal_hugepages.c
index 5779cd325..7f8a7dfca 100644
--- a/lib/librte_eal/windows/eal_hugepages.c
+++ b/lib/librte_eal/windows/eal_hugepages.c
@@ -41,6 +41,10 @@ hugepage_claim_privilege(void)
 		goto exit;
 	}
 
+	/* AdjustTokenPrivileges() may succeed with ERROR_NOT_ALL_ASSIGNED. */
+	if (GetLastError() != ERROR_SUCCESS)
+		goto exit;
+
 	ret = 0;
 
 exit:
@@ -98,12 +102,14 @@ int
 eal_hugepage_info_init(void)
 {
 	if (hugepage_claim_privilege() < 0) {
-		RTE_LOG(ERR, EAL, "Cannot claim hugepage privilege\n");
+		RTE_LOG(ERR, EAL, "Cannot claim hugepage privilege\n"
+			"Verify that large-page support privilege "
+			"is assigned to the current user\n");
 		return -1;
 	}
 
 	if (hugepage_info_init() < 0) {
-		RTE_LOG(ERR, EAL, "Cannot get hugepage information\n");
+		RTE_LOG(ERR, EAL, "Cannot discover available hugepages\n");
 		return -1;
 	}
 
-- 
2.25.4

Re: [dpdk-dev] [PATCH v2] eal/windows: detect insufficient privileges for hugepages

[Ranjit Menon]

On 7/8/2020 2:48 PM, Dmitry Kozlyuk wrote:
> AdjustTokenPrivileges() succeeds even if no requested privileges have
> been granted; this behavior is documented. Check last error code in
> addition to return value to detect such case.
>
> Make error messages more specific and add troubleshooting hint.
>
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
>
> v2:
>      Improve error reporting (Tal Shnaiderman).
>
>   lib/librte_eal/windows/eal_hugepages.c | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_eal/windows/eal_hugepages.c b/lib/librte_eal/windows/eal_hugepages.c
> index 5779cd325..7f8a7dfca 100644
> --- a/lib/librte_eal/windows/eal_hugepages.c
> +++ b/lib/librte_eal/windows/eal_hugepages.c
> @@ -41,6 +41,10 @@ hugepage_claim_privilege(void)
>   		goto exit;
>   	}
>   
> +	/* AdjustTokenPrivileges() may succeed with ERROR_NOT_ALL_ASSIGNED. */
> +	if (GetLastError() != ERROR_SUCCESS)
> +		goto exit;
> +
>   	ret = 0;
>   
>   exit:
> @@ -98,12 +102,14 @@ int
>   eal_hugepage_info_init(void)
>   {
>   	if (hugepage_claim_privilege() < 0) {
> -		RTE_LOG(ERR, EAL, "Cannot claim hugepage privilege\n");
> +		RTE_LOG(ERR, EAL, "Cannot claim hugepage privilege\n"
> +			"Verify that large-page support privilege "
> +			"is assigned to the current user\n");
>   		return -1;
>   	}
>   
>   	if (hugepage_info_init() < 0) {
> -		RTE_LOG(ERR, EAL, "Cannot get hugepage information\n");
> +		RTE_LOG(ERR, EAL, "Cannot discover available hugepages\n");
>   		return -1;
>   	}
>   


Acked-by: Ranjit Menon <ranjit.menon@intel.com>

Re: [dpdk-dev] [PATCH v2] eal/windows: detect insufficient privileges for hugepages

[Thomas Monjalon]

09/07/2020 00:27, Ranjit Menon:
> On 7/8/2020 2:48 PM, Dmitry Kozlyuk wrote:
> > AdjustTokenPrivileges() succeeds even if no requested privileges have
> > been granted; this behavior is documented. Check last error code in
> > addition to return value to detect such case.
> >
> > Make error messages more specific and add troubleshooting hint.
> >
> > Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
[...]
> >   	if (hugepage_claim_privilege() < 0) {
> > -		RTE_LOG(ERR, EAL, "Cannot claim hugepage privilege\n");
> > +		RTE_LOG(ERR, EAL, "Cannot claim hugepage privilege\n"
> > +			"Verify that large-page support privilege "
> > +			"is assigned to the current user\n");

The error message can be searched in the code,
so it is better not to break lines.

> Acked-by: Ranjit Menon <ranjit.menon@intel.com>

Applied with merged log lines, thanks.