On Wed, May 08, 2019 at 09:31:53AM +0800, Tao Xu wrote:
> As noted in "c7a88b52f6 i386: Add new model of Cascadelake-Server"
> Because MSR based feature has been supported by QEMU, we add
> CPUID_7_0_EDX_ARCH_CAPABILITIES on Cascadelake-Server CPU model,
> and add IA32_ARCH_CAPABILITIES MSR based features (RDCL_NO,
> IBRS_ALL and SKIP_L1DFL_VMENTRY).
> 
> And "014018e19b i386: Make arch_capabilities migratable" has been
> in QEMU upstream, the CPUID_7_0_EDX_ARCH_CAPABILITIES can be
> safely added into CPU Model.
> 
> Signed-off-by: Tao Xu <[email protected]>

CPUID_7_0_EDX_ARCH_CAPABILITIES requires Linux >= v4.16.  This
means the patch will make "-cpu Cascadelake-Server" stop working
on Linux < v4.16 hosts, doesn't it?

For additional details, see:
https://www.mail-archive.com/[email protected]/msg603291.html
"[PATCH 2/2] i386: Add some MSR based features on
Cascadelake-Server CPU model"

and:
https://www.mail-archive.com/[email protected]/msg606373.html
"Cascadelake-Server missing MSR based features ?"

-- 
Eduardo

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