[PATCH v2] cpu_map: Introduce Neoverse N1/N2/V1

Tue Sep 27 08:42:02 UTC 2022

On Tue, Sep 27, 2022 at 10:31:15AM +0800, Zhenyu Zhang wrote:
>Hello Martin,
>
>Yes, I'm sending this patch because I'm having the following problem
>on a Neoverse-N1 machine.
># grep "Cannot find CPU model" /var/log/libvirt/libvirtd.log
>operation failed: Cannot find CPU model with PVR 0xd0c
>

Yes, that's the proper PVR for Neoverse N1, which Altra is based upon,
but the CPU vendor (or "implementer" in /proc/cpuinfo) is still Arm
('A', 0x41).  I dumped the MIDR_EL1 register on Altra and it is:

0x00000000413fd0c1
           ^^||^^^|
vendor ---/ || | |
version ----/| | |
architecture / | |
pvr -----------/ |
revision --------/

Ampere is only visible in the BIOS Vendor ID, but not for the CPU.  So
I'd say just remove the Ampere vendor (since we don't have any CPU in
the map from them) and change the vendor for the CPUs to ARM and it'll
also work as you expect.

>And I saw that Fujitsu sent a similar patch to support their CPU model
>https://listman.redhat.com/archives/libvir-list/2022-September/234118.html
>
>We have a lot of Ampere machines in our beaker, so we always get this error.
>QE has a tp-libvirt auto case that always fails with this error logging.
>So I want to send this patch to fix it.
>
>Thanks in advance :)
>Zhenyu
>
>On Mon, Sep 26, 2022 at 8:19 PM Martin Kletzander <mkletzan at redhat.com> wrote:
>>
>> On Mon, Sep 26, 2022 at 02:28:51AM -0400, Zhenyu Zhang wrote:
>> >Add Neoverse N1/N2/V1 as a supported cpu model.
>> >
>>
>> Sorry for misleading you earlier.  Looking at it now it seems that
>> all the Neoverse CPUs are from Arm and Ampere computing only makes the
>> Altra which is based on Neoverse N1.
>>
>> I guess I am not the right one to review this code, sorry for that.  But
>> I would guess we need to recognise Neoverse models as Arm and I have no
>> idea how the Ampere behaves wrt PVR.  Are you basing this on some HW as
>> well?
>>
>> Thanks,
>> Martin
>>
>> >Signed-off-by: Zhenyu Zhang <zhenyzha at redhat.com>
>> >
>> >v1: https://listman.redhat.com/archives/libvir-list/2022-September/234294.html
>> >
>> >Changelog
>> >=========
>> >v2:
>> >  * Introduce Neoverse N1/N2/V1                         (Martin)
>> >  * Corrected ampere vendor value                       (Martin)
>> >---
>> > src/cpu_map/arm_Neoverse-N1.xml | 7 +++++++
>> > src/cpu_map/arm_Neoverse-N2.xml | 7 +++++++
>> > src/cpu_map/arm_Neoverse-V1.xml | 7 +++++++
>> > src/cpu_map/arm_vendors.xml     | 1 +
>> > src/cpu_map/index.xml           | 5 +++++
>> > src/cpu_map/meson.build         | 3 +++
>> > 6 files changed, 30 insertions(+)
>> > create mode 100644 src/cpu_map/arm_Neoverse-N1.xml
>> > create mode 100644 src/cpu_map/arm_Neoverse-N2.xml
>> > create mode 100644 src/cpu_map/arm_Neoverse-V1.xml
>> >
>> >diff --git a/src/cpu_map/arm_Neoverse-N1.xml b/src/cpu_map/arm_Neoverse-N1.xml
>> >new file mode 100644
>> >index 0000000000..db25813cd9
>> >--- /dev/null
>> >+++ b/src/cpu_map/arm_Neoverse-N1.xml
>> >@@ -0,0 +1,7 @@
>> >+<cpus>
>> >+  <model name='Neoverse-N1'>
>> >+    <vendor name='Ampere'/>
>> >+    <pvr value='0xd0c'/>
>> >+  </model>
>> >+</cpus>
>> >+
>> >diff --git a/src/cpu_map/arm_Neoverse-N2.xml b/src/cpu_map/arm_Neoverse-N2.xml
>> >new file mode 100644
>> >index 0000000000..8e8c9d202c
>> >--- /dev/null
>> >+++ b/src/cpu_map/arm_Neoverse-N2.xml
>> >@@ -0,0 +1,7 @@
>> >+<cpus>
>> >+  <model name='Neoverse-N2'>
>> >+    <vendor name='Ampere'/>
>> >+    <pvr value='0xd49'/>
>> >+  </model>
>> >+</cpus>
>> >+
>> >diff --git a/src/cpu_map/arm_Neoverse-V1.xml b/src/cpu_map/arm_Neoverse-V1.xml
>> >new file mode 100644
>> >index 0000000000..82a7d86b08
>> >--- /dev/null
>> >+++ b/src/cpu_map/arm_Neoverse-V1.xml
>> >@@ -0,0 +1,7 @@
>> >+<cpus>
>> >+  <model name='Neoverse-V1'>
>> >+    <vendor name='Ampere'/>
>> >+    <pvr value='0xd40'/>
>> >+  </model>
>> >+</cpus>
>> >+
>> >diff --git a/src/cpu_map/arm_vendors.xml b/src/cpu_map/arm_vendors.xml
>> >index 92d10565f4..3bbaf35ab7 100644
>> >--- a/src/cpu_map/arm_vendors.xml
>> >+++ b/src/cpu_map/arm_vendors.xml
>> >@@ -13,4 +13,5 @@
>> >   <vendor name='Marvell' value='0x56'/>
>> >   <vendor name='Intel' value='0x69'/>
>> >   <vendor name='Phytium' value='0x70'/>
>> >+  <vendor name='Ampere' value='0xc0'/>
>> > </cpus>
>> >diff --git a/src/cpu_map/index.xml b/src/cpu_map/index.xml
>> >index d533a28865..01fa61f4a4 100644
>> >--- a/src/cpu_map/index.xml
>> >+++ b/src/cpu_map/index.xml
>> >@@ -98,6 +98,11 @@
>> >     <include filename='arm_cortex-a57.xml'/>
>> >     <include filename='arm_cortex-a72.xml'/>
>> >
>> >+    <!-- Ampere-based CPU models -->
>> >+    <include filename='arm_Neoverse-N1.xml'/>
>> >+    <include filename='arm_Neoverse-N2.xml'/>
>> >+    <include filename='arm_Neoverse-V1.xml'/>
>> >+
>> >     <!-- Qualcomm-based CPU models -->
>> >     <include filename='arm_Falkor.xml'/>
>> >
>> >diff --git a/src/cpu_map/meson.build b/src/cpu_map/meson.build
>> >index 99264289e2..55c3703006 100644
>> >--- a/src/cpu_map/meson.build
>> >+++ b/src/cpu_map/meson.build
>> >@@ -7,6 +7,9 @@ cpumap_data = [
>> >   'arm_FT-2000plus.xml',
>> >   'arm_features.xml',
>> >   'arm_Kunpeng-920.xml',
>> >+  'arm_Neoverse-N1.xml',
>> >+  'arm_Neoverse-N2.xml',
>> >+  'arm_Neoverse-V1.xml',
>> >   'arm_Tengyun-S2500.xml',
>> >   'arm_ThunderX299xx.xml',
>> >   'arm_vendors.xml',
>> >--
>> >2.31.1
>> >
>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20220927/202b8afa/attachment.sig>