From: David Hildenbrand <david@redhat.com>
To: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Bandan Das <bsd@redhat.com>
Subject: Re: [PATCH v1 0/2] KVM: VMX: require EPTP WB (write-back) support
Date: Thu, 10 Aug 2017 16:25:49 +0200 [thread overview]
Message-ID: <8cdac71b-8d69-e789-082d-fd32b3591755@redhat.com> (raw)
In-Reply-To: <20170810142309.GA22461@flask>
On 10.08.2017 16:23, Radim Krčmář wrote:
> 2017-08-10 15:35+0200, David Hildenbrand:
>> I also have a patch that allows VMX and nVMX to use the UC (unchached)
>> memory type.
>> .
>> However I am not sure if we have to take care of anything special in that
>> case? Any insights?
>
> We're modifying the EPT structure through cache in root mode and I think
> the cache would have to be manually flushed before entering non-root
> mode.
>
> And UC accesses are going to be slower, so I don't see the benefits for
> VMX. We can allow UC in nVMX as it will make no difference.
>
That would mean, even fake it's existence but always create EPTP with WB
for nVMX?
--
Thanks,
David
next prev parent reply other threads:[~2017-08-10 14:25 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-10 13:35 [PATCH v1 0/2] KVM: VMX: require EPTP WB (write-back) support David Hildenbrand
2017-08-10 13:35 ` [PATCH v1 1/2] KVM: VMX: cleanup EPTP definitions David Hildenbrand
2017-08-10 19:38 ` Bandan Das
2017-08-10 19:53 ` David Hildenbrand
2017-08-10 20:58 ` David Hildenbrand
2017-08-10 13:35 ` [PATCH v1 2/2] KVM: VMX: always require WB memory type for EPT David Hildenbrand
2017-08-10 14:42 ` Paolo Bonzini
2017-08-10 18:30 ` Konrad Rzeszutek Wilk
2017-08-10 20:09 ` David Hildenbrand
2017-08-10 19:40 ` Bandan Das
2017-08-10 19:54 ` David Hildenbrand
2017-08-10 14:23 ` [PATCH v1 0/2] KVM: VMX: require EPTP WB (write-back) support Radim Krčmář
2017-08-10 14:25 ` David Hildenbrand [this message]
2017-08-10 16:34 ` Radim Krčmář
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