[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v3 kvm/queue 11/16] KVM: Add kvm_map_gfn_range
From: |
Chao Peng |
Subject: |
Re: [PATCH v3 kvm/queue 11/16] KVM: Add kvm_map_gfn_range |
Date: |
Fri, 31 Dec 2021 10:33:34 +0800 |
User-agent: |
Mutt/1.9.4 (2018-02-28) |
On Fri, Dec 24, 2021 at 12:13:51PM +0800, Chao Peng wrote:
> On Thu, Dec 23, 2021 at 06:06:19PM +0000, Sean Christopherson wrote:
> > On Thu, Dec 23, 2021, Chao Peng wrote:
> > > This new function establishes the mapping in KVM page tables for a
> > > given gfn range. It can be used in the memory fallocate callback for
> > > memfd based memory to establish the mapping for KVM secondary MMU when
> > > the pages are allocated in the memory backend.
> >
> > NAK, under no circumstance should KVM install SPTEs in response to
> > allocating
> > memory in a file. The correct thing to do is to invalidate the gfn range
> > associated with the newly mapped range, i.e. wipe out any shared SPTEs
> > associated
> > with the memslot.
>
> Right, thanks.
BTW, I think the current fallocate() callback is just useless as long as
we don't want to install KVM SPTEs in response to allocating memory in a
file. The invalidation of the shared SPTEs should be notified through
mmu_notifier of the shared memory backend, not memfd_notifier of the
private memory backend.
Thanks,
Chao
[PATCH v3 kvm/queue 09/16] KVM: Split out common memory invalidation code, Chao Peng, 2021/12/23
[PATCH v3 kvm/queue 10/16] KVM: Implement fd-based memory invalidation, Chao Peng, 2021/12/23
[PATCH v3 kvm/queue 11/16] KVM: Add kvm_map_gfn_range, Chao Peng, 2021/12/23
[PATCH v3 kvm/queue 12/16] KVM: Implement fd-based memory fallocation, Chao Peng, 2021/12/23
[PATCH v3 kvm/queue 13/16] KVM: Add KVM_EXIT_MEMORY_ERROR exit, Chao Peng, 2021/12/23
[PATCH v3 kvm/queue 14/16] KVM: Handle page fault for private memory, Chao Peng, 2021/12/23
[PATCH v3 kvm/queue 15/16] KVM: Use kvm_userspace_memory_region_ext, Chao Peng, 2021/12/23
[PATCH v3 kvm/queue 16/16] KVM: Register/unregister private memory slot to memfd, Chao Peng, 2021/12/23