From: Sean Christopherson <seanjc@google.com>
To: bibo mao <maobibo@loongson.cn>
Cc: Yan Zhao <yan.y.zhao@intel.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, pbonzini@redhat.com,
mike.kravetz@oracle.com, apopple@nvidia.com, jgg@nvidia.com,
rppt@kernel.org, akpm@linux-foundation.org,
kevin.tian@intel.com, david@redhat.com
Subject: Re: [RFC PATCH v2 5/5] KVM: Unmap pages only when it's indeed protected for NUMA migration
Date: Wed, 16 Aug 2023 06:39:20 -0700 [thread overview]
Message-ID: <ZNzRiL9e2wzmB7KI@google.com> (raw)
In-Reply-To: <624efb22-8723-d813-0943-edab2870b51d@loongson.cn>
On Wed, Aug 16, 2023, bibo mao wrote:
>
>
> 在 2023/8/16 15:18, Yan Zhao 写道:
> > On Wed, Aug 16, 2023 at 03:29:22PM +0800, bibo mao wrote:
> >>> Flush must be done before kvm->mmu_lock is unlocked, otherwise,
> >>> confusion will be caused when multiple threads trying to update the
> >>> secondary MMU.
> >> Since tlb flush is delayed after all pte entries are cleared, and currently
> >> there is no tlb flush range supported for secondary mmu. I do know why there
> >> is confusion before or after kvm->mmu_lock.
> >
> > Oh, do you mean only do kvm_unmap_gfn_range() in .invalidate_range_end()?
> yes, it is just sketchy thought for numa balance scenery,
> do kvm_unmap_gfn_range() in invalidate_range_end rather than
> invalidate_range_start.
That is not an option, it's a direction violation of the mmu_notifier contract.
Secondary MMUs must drop all references before returning from invalidate_range_start().
next prev parent reply other threads:[~2023-08-16 13:39 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-10 8:56 [RFC PATCH v2 0/5] Reduce NUMA balance caused TLB-shootdowns in a VM Yan Zhao
2023-08-10 8:57 ` [RFC PATCH v2 1/5] mm/mmu_notifier: introduce a new mmu notifier flag MMU_NOTIFIER_RANGE_NUMA Yan Zhao
2023-08-10 8:58 ` [RFC PATCH v2 2/5] mm: don't set PROT_NONE to maybe-dma-pinned pages for NUMA-migrate purpose Yan Zhao
2023-08-10 9:00 ` [RFC PATCH v2 3/5] mm/mmu_notifier: introduce a new callback .numa_protect Yan Zhao
2023-08-10 9:00 ` [RFC PATCH v2 4/5] mm/autonuma: call .numa_protect() when page is protected for NUMA migrate Yan Zhao
2023-08-11 18:52 ` Nadav Amit
2023-08-14 7:52 ` Yan Zhao
2023-08-10 9:02 ` [RFC PATCH v2 5/5] KVM: Unmap pages only when it's indeed protected for NUMA migration Yan Zhao
2023-08-10 13:16 ` bibo mao
2023-08-11 3:45 ` Yan Zhao
2023-08-11 7:40 ` bibo mao
2023-08-11 8:01 ` Yan Zhao
2023-08-11 17:14 ` Sean Christopherson
2023-08-11 17:18 ` Jason Gunthorpe
2023-08-14 6:52 ` Yan Zhao
2023-08-14 7:44 ` Yan Zhao
2023-08-14 16:40 ` Sean Christopherson
2023-08-15 1:54 ` Yan Zhao
2023-08-15 14:50 ` Sean Christopherson
2023-08-16 2:43 ` bibo mao
2023-08-16 3:44 ` bibo mao
2023-08-16 5:14 ` Yan Zhao
2023-08-16 7:29 ` bibo mao
2023-08-16 7:18 ` Yan Zhao
2023-08-16 7:53 ` bibo mao
2023-08-16 13:39 ` Sean Christopherson [this message]
2023-08-10 9:34 ` [RFC PATCH v2 0/5] Reduce NUMA balance caused TLB-shootdowns in a VM David Hildenbrand
2023-08-10 9:50 ` Yan Zhao
2023-08-11 17:25 ` David Hildenbrand
2023-08-11 18:20 ` John Hubbard
2023-08-11 18:39 ` David Hildenbrand
2023-08-11 19:35 ` John Hubbard
2023-08-14 9:09 ` Yan Zhao
2023-08-15 2:34 ` John Hubbard
2023-08-16 7:43 ` David Hildenbrand
2023-08-16 9:06 ` Yan Zhao
2023-08-16 9:49 ` David Hildenbrand
2023-08-16 18:00 ` John Hubbard
2023-08-17 5:05 ` Yan Zhao
2023-08-17 7:38 ` David Hildenbrand
2023-08-18 0:13 ` Yan Zhao
2023-08-18 2:29 ` John Hubbard
2023-09-04 9:18 ` Yan Zhao
2023-08-15 2:36 ` Yuan Yao
2023-08-15 2:37 ` Yan Zhao
2023-08-10 13:58 ` Chao Gao
2023-08-11 5:22 ` Yan Zhao
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