From: Yang Weijiang <weijiang.yang@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Yang Weijiang <weijiang.yang@intel.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
sean.j.christopherson@intel.com, mst@redhat.com,
rkrcmar@redhat.com, jmattson@google.com, yu.c.zhang@intel.com,
alazar@bitdefender.com
Subject: Re: [PATCH RESEND v4 8/9] KVM: MMU: Enable Lazy mode SPPT setup
Date: Wed, 11 Sep 2019 08:23:44 +0800 [thread overview]
Message-ID: <20190911002344.GA28130@local-michael-cet-test> (raw)
In-Reply-To: <6cdea038-8d6f-6d75-47b2-bb23ff1c9f15@redhat.com>
On Mon, Sep 09, 2019 at 07:10:22PM +0200, Paolo Bonzini wrote:
> On 04/09/19 15:49, Yang Weijiang wrote:
> >>> This would not enable SPP if the guest is backed by huge pages.
> >>> Instead, either the PT_PAGE_TABLE_LEVEL level must be forced for all
> >>> pages covered by SPP ranges, or (better) kvm_enable_spp_protection must
> >>> be able to cover multiple pages at once.
> >>>
> >>> Paolo
> >> OK, I'll figure out how to make it, thanks!
> > Hi, Paolo,
> > Regarding this change, I have some concerns, splitting EPT huge page
> > entries(e.g., 1GB page)will take long time compared with normal EPT page
> > fault processing, especially for multiple vcpus/pages,so the in-flight time increases,
> > but HW walks EPT for translations in the meantime, would it bring any side effect?
> > or there's a way to mitigate it?
>
> Sub-page permissions are only defined on EPT PTEs, not on large pages.
> Therefore, in order to allow subpage permissions the EPT page tables
> must already be split.
>
> Paolo
Thanks, I've added code to handle hugepage, will be included in
next version patch.
next prev parent reply other threads:[~2019-09-11 0:22 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-14 7:03 [PATCH RESEND v4 0/9] Enable Sub-page Write Protection Support Yang Weijiang
2019-08-14 7:03 ` [PATCH RESEND v4 1/9] Documentation: Introduce EPT based Subpage Protection Yang Weijiang
2019-08-14 7:03 ` [PATCH RESEND v4 2/9] KVM: VMX: Add control flags for SPP enabling Yang Weijiang
2019-08-14 7:03 ` [PATCH RESEND v4 3/9] KVM: VMX: Implement functions for SPPT paging setup Yang Weijiang
2019-08-14 7:03 ` [PATCH RESEND v4 4/9] KVM: VMX: Introduce SPP access bitmap and operation functions Yang Weijiang
2019-08-14 7:03 ` [PATCH RESEND v4 5/9] KVM: VMX: Add init/set/get functions for SPP Yang Weijiang
2019-08-14 12:43 ` Vitaly Kuznetsov
2019-08-14 14:34 ` Yang Weijiang
2019-08-15 13:43 ` Yang Weijiang
2019-08-15 14:03 ` Vitaly Kuznetsov
2019-08-19 14:06 ` Yang Weijiang
2019-08-15 16:25 ` Jim Mattson
2019-08-15 16:38 ` Sean Christopherson
2019-08-16 13:31 ` Yang Weijiang
2019-08-16 18:19 ` Jim Mattson
2019-08-19 2:08 ` Yang Weijiang
2019-08-19 15:15 ` Paolo Bonzini
2019-08-20 12:33 ` Yang Weijiang
2019-08-19 15:05 ` Paolo Bonzini
2019-08-20 12:36 ` Yang Weijiang
2019-08-19 15:13 ` Paolo Bonzini
2019-08-20 13:09 ` Yang Weijiang
2019-08-14 7:04 ` [PATCH RESEND v4 6/9] KVM: VMX: Introduce SPP user-space IOCTLs Yang Weijiang
2019-08-14 7:04 ` [PATCH RESEND v4 7/9] KVM: VMX: Handle SPP induced vmexit and page fault Yang Weijiang
2019-08-19 14:43 ` Paolo Bonzini
2019-08-19 15:04 ` Paolo Bonzini
2019-08-20 13:44 ` Yang Weijiang
2019-08-22 13:17 ` Yang Weijiang
2019-08-22 16:38 ` Paolo Bonzini
2019-08-23 0:26 ` Yang Weijiang
2019-08-14 7:04 ` [PATCH RESEND v4 8/9] KVM: MMU: Enable Lazy mode SPPT setup Yang Weijiang
2019-08-19 14:46 ` Paolo Bonzini
2019-08-20 13:12 ` Yang Weijiang
2019-09-04 13:49 ` Yang Weijiang
2019-09-09 17:10 ` Paolo Bonzini
2019-09-11 0:23 ` Yang Weijiang [this message]
2019-08-14 7:04 ` [PATCH RESEND v4 9/9] KVM: MMU: Handle host memory remapping and reclaim Yang Weijiang
2019-08-14 12:36 ` [PATCH RESEND v4 0/9] Enable Sub-page Write Protection Support Paolo Bonzini
2019-08-14 14:02 ` Yang Weijiang
2019-08-14 14:06 ` Paolo Bonzini
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