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qm: improve wording/style and fix typos in QEMU CPU Types section

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Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
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Fiona Ebner 2023-06-20 09:53:50 +02:00
parent 57bb28ef95
commit c85a1f5ae4
1 changed files with 28 additions and 13 deletions
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@ -480,30 +480,44 @@ https://en.wikipedia.org/wiki/List_of_AMD_processors[AMD Processors]
+
* 'EPYC-Milan-v2' : add missing flags (+vaes,+vpclmulqdq,+stibp-always-on,+amd-psfd,+no-nested-data-bp,+lfence-always-serializing,+null-sel-clr-base
Qemu CPU Types
QEMU CPU Types
^^^^^^^^^^^^^^
Qemu also provide virtual cpu types, compatible with both intel/amd.
QEMU also provide virtual CPU types, compatible with both Intel and AMD host
CPUs.
NOTE: To keep best compatibility, no security flag for spectre/meltdown/... exist in qemu virtual types, so you need to do it manually
NOTE: To mitigate the Spectre vulnerability for virtual CPU types, you need to
add the relevant CPU flags, see
xref:qm_meltdown_spectre[Meltdown / Spectre related CPU flags].
Historically, Proxmox had the kvm64 cpu model, with only pentium4 cpu flags enabled, so performance was not great for some workload.
Historically, {pve} had the 'kvm64' CPU model, with CPU flags at the level of
Pentium 4 enabled, so performance was not great for certain workloads.
In the summer of 2020, AMD, Intel, Red Hat, and SUSE collaborated to define three x86-64 microarchitecture levels on top of the x86-64 baseline,
with modern flags enabled. https://gitlab.com/x86-psABIs/x86-64-ABI[x86-64-ABI specs]
In the summer of 2020, AMD, Intel, Red Hat, and SUSE collaborated to define
three x86-64 microarchitecture levels on top of the x86-64 baseline, with modern
flags enabled. For details, see the
https://gitlab.com/x86-psABIs/x86-64-ABI[x86-64-ABI specification].
Some newer distro like Centos9 are now built with x86-64-v2 flags as minimum requirement !
NOTE: Some newer distributions like CentOS 9 are now built with 'x86-64-v2'
flags as a minimum requirement.
* 'kvm64 (v1)' : Compatible >=pentium4 , >= phenom
* 'kvm64 (x86-64-v1)': Compatible with Intel CPU >= Pentium 4, AMD CPU >=
Phenom.
+
* 'x86-64-v2' : Compatible >= Nehalem, >= Opteron_G3. add cx16,lahf-lm,popcnt,pni,sse4.1,sse4.2,ssse3
* 'x86-64-v2': Compatible with Intel CPU >= Nehalem, AMD CPU >= Opteron_G3.
Added CPU flags compared to 'x86-64-v1': '+cx16', '+lahf-lm', '+popcnt', '+pni',
'+sse4.1', '+sse4.2', '+ssse3'.
+
* 'x86-64-v2-AES' : Compatible >= Westmere, >= Opteron_G4 : add aes
* 'x86-64-v2-AES': Compatible with Intel CPU >= Westmere, AMD CPU >= Opteron_G4.
Added CPU flags compared to 'x86-64-v2': '+aes'.
+
* 'x86-64-v3' : Compatible >= Broadwell, >= Epyc : add +avx,+avx2,+bmi1,+bmi2,+f16c,+fma,+movbe,xsave
* 'x86-64-v3': Compatible with Intel CPU >= Broadwell, AMD CPU >= EPYC. Added
CPU flags compared to 'x86-64-v2-AES': '+avx', '+avx2', '+bmi1', '+bmi2',
'+f16c', '+fma', '+movbe', '+xsave'.
+
* 'x86-64-v4' : Compatible >= Skylake , >= EPYC-Genoa(V4) : add +avx512f, +avx512bw, +avx512cd,+avx512dq,+avx512vl
* 'x86-64-v4': Compatible with Intel CPU >= Skylake, AMD CPU >= EPYC v4 Genoa.
Added CPU flags compared to 'x86-64-v3': '+avx512f', '+avx512bw', '+avx512cd',
'+avx512dq', '+avx512vl'.
Custom CPU Types
^^^^^^^^^^^^^^^^
@ -516,6 +530,7 @@ Specified custom types can be selected by any user with the `Sys.Audit`
privilege on `/nodes`. When configuring a custom CPU type for a VM via the CLI
or API, the name needs to be prefixed with 'custom-'.
[[qm_meltdown_spectre]]
Meltdown / Spectre related CPU flags
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^