Bug 1445834
Summary: | Add support for AMD EPYC processors | |||
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Product: | Red Hat Enterprise Linux 7 | Reporter: | Paolo Bonzini <pbonzini> | |
Component: | qemu-kvm-rhev | Assignee: | Eduardo Habkost <ehabkost> | |
Status: | CLOSED ERRATA | QA Contact: | Guo, Zhiyi <zhguo> | |
Severity: | high | Docs Contact: | ||
Priority: | high | |||
Version: | 7.4 | CC: | ailan, chayang, c.justin88, ctatman, ehabkost, jan.public, jinzhao, juzhang, knoel, michen, mtessun, pasteur, pbonzini, rui.gouveia, virt-maint, zhguo | |
Target Milestone: | rc | Keywords: | FutureFeature | |
Target Release: | --- | |||
Hardware: | Unspecified | |||
OS: | Unspecified | |||
Whiteboard: | ||||
Fixed In Version: | qemu-kvm-rhev-2.10.0-3.el7 | Doc Type: | If docs needed, set a value | |
Doc Text: | Story Points: | --- | ||
Clone Of: | ||||
: | 1445836 1450396 1481252 1524824 (view as bug list) | Environment: | ||
Last Closed: | 2018-04-11 00:16:25 UTC | Type: | Bug | |
Regression: | --- | Mount Type: | --- | |
Documentation: | --- | CRM: | ||
Verified Versions: | Category: | --- | ||
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
Cloudforms Team: | --- | Target Upstream Version: | ||
Embargoed: | ||||
Bug Depends On: | ||||
Bug Blocks: | 1445836, 1450396, 1481252, 1524824 |
Description
Paolo Bonzini
2017-04-26 15:32:12 UTC
> BTW, search from beaker, I have two suspects that maybe engineer samples of
> Ryzen, but they lack some of flags comparing with yours: clzero bpext mwaitx
Yes, they are engineering samples of Ryzen. I'm not sure whether we have any machines with final parts.
I added a similar issue for Fedora: bug 1456273 Jan, rhis is not related to your issue; it is only about adding a "-cpu" flag that enables Ryzen features for the virtual machine. There's also SMT ("Simultaneous multithreading") support. See upstream bug: https://bugs.launchpad.net/qemu/+bug/1703506 libvirt bug created: bug 1481252. SMT will be tracked at bug 1481253. Changing BZ summary to mention EPYC to avoid confusion. EPYC CPU model was already submitted by AMD queued for inclusion upstream. Upstream commit: commit 2e2efc7dbe2b0adc1200b5aa286cdbed729f6751 Author: Brijesh Singh <brijesh.singh> Date: Tue Aug 15 12:00:51 2017 -0500 target-i386/cpu: Add new EPYC CPU model Add a new base CPU model called 'EPYC' to model processors from AMD EPYC family (which includes EPYC 76xx,75xx,74xx, 73xx and 72xx). The following features bits have been added/removed compare to Opteron_G5 Added: monitor, movbe, rdrand, mmxext, ffxsr, rdtscp, cr8legacy, osvw, fsgsbase, bmi1, avx2, smep, bmi2, rdseed, adx, smap, clfshopt, sha xsaveopt, xsavec, xgetbv1, arat Removed: xop, fma4, tbm Cc: Paolo Bonzini <pbonzini> Cc: Richard Henderson <rth> Cc: Eduardo Habkost <ehabkost> Cc: Tom Lendacky <Thomas.Lendacky> Signed-off-by: Brijesh Singh <brijesh.singh> Message-Id: <20170815170051.127257-1-brijesh.singh> Reviewed-by: Eduardo Habkost <ehabkost> Signed-off-by: Eduardo Habkost <ehabkost> Fix included in qemu-kvm-rhev-2.10.0-3.el7 Hi Edurado, Can I continue my test with -cpu EPYC,-rdtscp,enforce since rdtscp block the enforce option. Another interesting part is EPYC also delete some flags like fma4, does AMD not want guest boot with default, no customized cpu model like Opteron_G5 to be migrated to new EPYC host? Do I need to test migration from old host to new EPYC host?(Since intel really allow this) BR/ Guo, Zhiyi If the RHEL-7.5 kernel doesn't support virtualizing RDTSCP yet (the upstream kernel does), we need to manually disable RDTSCP in the RHEL-7 machine-types. I plan to do that soon, so please continue testing using "-cpu EPYC,-rdtscp,enforce". About the missing fma4 feature: if the host really doesn't support it, migration of existing VMs with the FMA4 feature to a EPYC host will be impossible, and in this case all we can do is to ensure libvirt is preventing migration before it starts. We can add a note about this on the test plan. Eduardo, adding support for RDTSCP on RHEL 7 is easy. zhguo is opening a new bug for that. Kernel side rdtscp bug: Bug 1511805 - Kernel missing rdtscp for amd Ryzen/EPYC cpu model Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2018:1104 |