[PATCH v1] tools/xen-cpuid: show enqcmd

Olaf Hering posted 1 patch 1 week ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/xen tags/patchew/20200730163406.31020-1-olaf@aepfle.de
Maintainers: Wei Liu <wl@xen.org>, Jan Beulich <jbeulich@suse.com>, Andrew Cooper <andrew.cooper3@citrix.com>, "Roger Pau Monné" <roger.pau@citrix.com>, Ian Jackson <ian.jackson@eu.citrix.com>
tools/misc/xen-cpuid.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

[PATCH v1] tools/xen-cpuid: show enqcmd

Posted by Olaf Hering 1 week ago
Translate <29> into a feature string.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---

not compile nor runtime tested.

 tools/misc/xen-cpuid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/misc/xen-cpuid.c b/tools/misc/xen-cpuid.c
index ac3548dcfe..2446941a47 100644
--- a/tools/misc/xen-cpuid.c
+++ b/tools/misc/xen-cpuid.c
@@ -133,7 +133,7 @@ static const char *const str_7c0[32] =
     [22] = "rdpid",
     /* 24 */                   [25] = "cldemote",
     /* 26 */                   [27] = "movdiri",
-    [28] = "movdir64b",
+    [28] = "movdir64b",        [29] = "enqcmd",
     [30] = "sgx-lc",
 };
 

Re: [PATCH v1] tools/xen-cpuid: show enqcmd

Posted by Jan Beulich 1 week ago
On 30.07.2020 18:34, Olaf Hering wrote:
> Translate <29> into a feature string.
> 
> Signed-off-by: Olaf Hering <olaf@aepfle.de>

Acked-by: Jan Beulich <jbeulich@suse.com>

Albeit I'm pretty sure there are more missing than just this lone one.

Jan

> --- a/tools/misc/xen-cpuid.c
> +++ b/tools/misc/xen-cpuid.c
> @@ -133,7 +133,7 @@ static const char *const str_7c0[32] =
>      [22] = "rdpid",
>      /* 24 */                   [25] = "cldemote",
>      /* 26 */                   [27] = "movdiri",
> -    [28] = "movdir64b",
> +    [28] = "movdir64b",        [29] = "enqcmd",
>      [30] = "sgx-lc",
>  };
>  
> 


Re: [PATCH v1] tools/xen-cpuid: show enqcmd

Posted by Andrew Cooper 1 week ago
On 31/07/2020 13:03, Jan Beulich wrote:
> On 30.07.2020 18:34, Olaf Hering wrote:
>> Translate <29> into a feature string.
>>
>> Signed-off-by: Olaf Hering <olaf@aepfle.de>
> Acked-by: Jan Beulich <jbeulich@suse.com>
>
> Albeit I'm pretty sure there are more missing than just this lone one.

And in particular, probably missing from libxl_cpuid.c, which I was
meaning to check when I've got a free moment.

~Andrew

Re: [PATCH v1] tools/xen-cpuid: show enqcmd

Posted by Jan Beulich 1 week ago
On 31.07.2020 14:04, Andrew Cooper wrote:
> On 31/07/2020 13:03, Jan Beulich wrote:
>> On 30.07.2020 18:34, Olaf Hering wrote:
>>> Translate <29> into a feature string.
>>>
>>> Signed-off-by: Olaf Hering <olaf@aepfle.de>
>> Acked-by: Jan Beulich <jbeulich@suse.com>
>>
>> Albeit I'm pretty sure there are more missing than just this lone one.
> 
> And in particular, probably missing from libxl_cpuid.c, which I was
> meaning to check when I've got a free moment.

As it's not just this one, but e.g. also the two movdir* ones,
I thought I'd not require the other side to also be changed,
the more that enqcmd also doesn't get exposed to guests at all
right now.

Jan

Re: [PATCH v1] tools/xen-cpuid: show enqcmd

Posted by Olaf Hering 1 week ago
Am Fri, 31 Jul 2020 13:04:35 +0100
schrieb Andrew Cooper <andrew.cooper3@citrix.com>:

> And in particular, probably missing from libxl_cpuid.c, which I was
> meaning to check when I've got a free moment.

Will a ever domU see this flag? I just spotted the <29> when comparing 'xen-cpuid' output between recent Xen releases. It shows up just in the 'Known' section at this point.


Olaf

Re: [PATCH v1] tools/xen-cpuid: show enqcmd

Posted by Andrew Cooper 1 week ago
On 31/07/2020 13:15, Olaf Hering wrote:
> Am Fri, 31 Jul 2020 13:04:35 +0100
> schrieb Andrew Cooper <andrew.cooper3@citrix.com>:
>
>> And in particular, probably missing from libxl_cpuid.c, which I was
>> meaning to check when I've got a free moment.
> Will a ever domU see this flag? I just spotted the <29> when comparing 'xen-cpuid' output between recent Xen releases. It shows up just in the 'Known' section at this point.

For future platforms supporting Compute eXpress Link, PCIPassthrough
will be able to give various accelerators to VMs, and the ENQCMD{,S}
instructions is what the guest will use to talk to hardware.

As a set of functionality, think DPDK but with with userspace (or the
guest) able to submit work to hardware directly, through an interface
designed to be safe for this kind of thing.

~Andrew