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Subject: Re: [PATCHv3 1/1] locking/qspinlock/x86: Avoid test-and-set when
 PV_DEDICATED is set
To: Wanpeng Li <kernellwp@gmail.com>, Radim Krcmar <rkrcmar@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>, Matt Wilson <msw@amazon.com>,
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From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <bbeaf134-b948-6ed4-d8a6-cdcb5279d1b3@redhat.com>
Date: Fri, 10 Nov 2017 09:19:06 +0100
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On 10/11/2017 07:07, Wanpeng Li wrote:
>>> You should also add a cpuid flag in kvm part.
>> It is better without that.  The flag has no dependency on KVM (kernel
>> hypervisor) code.
> Do you mean -cpu host, +xxxx，I think it will result in "warning: host
> doesn't support requested feature: CPUID.40000001H:eax.XXXXXX"

There are some exceptions where QEMU overrides the values of
KVM_GET_SUPPORTED_CPUID.

I think it is better to add the flag to KVM *and* to QEMU's override in
kvm_arch_get_supported_cpuid (target/i386/kvm.c).

Paolo