From: Tianyu Lan <lantianyu1986@gmail.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
Lan Tianyu <Tianyu.Lan@microsoft.com>,
Radim Krcmar <rkrcmar@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
bp@alien8.de, "H. Peter Anvin" <hpa@zytor.com>,
"the arch/x86 maintainers" <x86@kernel.org>,
kvm <kvm@vger.kernel.org>,
"linux-kernel@vger kernel org" <linux-kernel@vger.kernel.org>,
michael.h.kelley@microsoft.com, kys@microsoft.com,
vkuznets@redhat.com, linux@armlinux.org.uk
Subject: Re: [PATCH 11/11] KVM/MMU: Flush tlb in the kvm_age_rmapp()
Date: Tue, 8 Jan 2019 11:42:05 +0800 [thread overview]
Message-ID: <CAOLK0pxrdWZ6RAJROw0cyfexjZnKqSsCrm-jUD=wUHWvWV47kQ@mail.gmail.com> (raw)
In-Reply-To: <d434edb8-5f09-7331-c89d-9b78907e896a@redhat.com>
Hi Paolo:
Thanks for your review.
On Tue, Jan 8, 2019 at 12:31 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 07/01/19 04:42, Tianyu Lan wrote:
> >> I'm assuming you're
> >> clearing young to avoid the flush in kvm_mmu_notifier_clear_flush_young(),
> >> but keeping that flush is silly since it will never be invoked. Just
> >> squash this patch with patch 10/11 so that you can remove the unnecessary
> >> flush in kvm_mmu_notifier_clear_flush_young() and preserve young.
> >>
> > The platform may provide tlb flush with address range as granularity. My changes
> > are to use range flush when it's available. kvm_mmu_notifier_clear_flush_young()
> > is common function for all platforms and most platforms still need the
> > flush in the
> > kvm_mmu_notifier_clear_flush_young(). I think it's better to separate
> > flush request and
> > "young" from return value of kvm_age_hva(). New flush parameter I
> > added in the patch 10
> > can be changed to a pointer and kvm_age_hva() can use it to return
> > flush request.
>
> There are two possibilities:
>
> - pass a "bool *flush". If NULL, kvm_age_hva should not flush. If not
> NULL, kvm_age_hva should receive a true *flush, and should change it to
> false if kvm_age_hva takes care of the flush
>
> - pass a "bool flush". In patch 10, change all kvm_age_hva
> implementation to do the flush if they return 1.
>
> I think I prefer the latter, in this case the small code duplication is
> offset by a simpler API.
>
From my understanding, this means to move the flush in the
kvm_mmu_notifier_clear_flush_young()
to kvm_age_hva() and do flush in kvm_age_hva() when young is >0 and "flush"
parameter is true, right?
--
Best regards
Tianyu Lan
next prev parent reply other threads:[~2019-01-08 3:42 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-04 8:53 [PATCH 00/11] X86/KVM/Hyper-V: Add HV ept tlb range list flush support in KVM lantianyu1986
2019-01-04 8:53 ` [PATCH 1/11] X86/Hyper-V: Add parameter offset for hyperv_fill_flush_guest_mapping_list() lantianyu1986
2019-01-04 8:53 ` [PATCH 2/11] KVM/VMX: Fill range list in kvm_fill_hv_flush_list_func() lantianyu1986
2019-01-04 8:53 ` [PATCH 3/11] KVM: Add spte's point in the struct kvm_mmu_page lantianyu1986
2019-01-07 16:34 ` Paolo Bonzini
2019-01-04 8:53 ` [PATCH 4/11] KVM/MMU: Introduce tlb flush with range list lantianyu1986
2019-01-07 16:39 ` Paolo Bonzini
2019-01-04 8:53 ` [PATCH 5/11] KVM/MMU: Flush tlb directly in the kvm_mmu_slot_gfn_write_protect() lantianyu1986
2019-01-04 8:54 ` [PATCH 6/11] KVM/MMU: Flush tlb with range list in sync_page() lantianyu1986
[not found] ` <20190104163035.GC11288@linux.intel.com>
2019-01-07 5:13 ` Tianyu Lan
2019-01-07 16:07 ` Paolo Bonzini
2019-01-04 8:54 ` [PATCH 7/11] KVM: Remove redundant check in the kvm_get_dirty_log_protect() lantianyu1986
[not found] ` <20190104155036.GA11288@linux.intel.com>
2019-01-04 21:27 ` Sean Christopherson
2019-01-07 16:20 ` Paolo Bonzini
2019-01-04 8:54 ` [PATCH 8/11] KVM: Make kvm_arch_mmu_enable_log_dirty_pt_masked() return value lantianyu1986
2019-01-04 8:54 ` [PATCH 9/11] KVM/MMU: Flush tlb in the kvm_mmu_write_protect_pt_masked() lantianyu1986
2019-01-07 16:26 ` Paolo Bonzini
2019-01-10 9:06 ` Tianyu Lan
2019-01-04 8:54 ` [PATCH 10/11] KVM: Add flush parameter for kvm_age_hva() lantianyu1986
2019-01-04 8:54 ` [PATCH 11/11] KVM/MMU: Flush tlb in the kvm_age_rmapp() lantianyu1986
[not found] ` <20190104161235.GB11288@linux.intel.com>
2019-01-07 3:42 ` Tianyu Lan
2019-01-07 16:31 ` Paolo Bonzini
2019-01-08 3:42 ` Tianyu Lan [this message]
2019-01-08 11:52 ` Paolo Bonzini
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