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From: Peter Xu <peterx@redhat.com>
To: Igor Mammedov <imammedo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	qemu-devel@nongnu.org, dgilbert@redhat.com
Subject: Re: [PATCH 0/2] kvm: clear dirty bitmaps from all overlapping memslots
Date: Mon, 23 Sep 2019 09:29:46 +0800	[thread overview]
Message-ID: <20190923012946.GJ12858@xz-x1> (raw)
In-Reply-To: <20190920155851.7445cd2a@redhat.com>

On Fri, Sep 20, 2019 at 03:58:51PM +0200, Igor Mammedov wrote:
> On Fri, 20 Sep 2019 20:19:51 +0800
> Peter Xu <peterx@redhat.com> wrote:
> 
> > On Fri, Sep 20, 2019 at 12:21:20PM +0200, Paolo Bonzini wrote:
> > > A single ram_addr (representing a host-virtual address) could be aliased
> > > to multiple guest physical addresses.  Since the KVM dirty page reporting
> > > works on guest physical addresses, we need to clear all of the aliases
> > > when a page is migrated, or there is a risk of losing writes to the
> > > aliases that were not cleared.  
> > 
> > (CCing Igor too so Igor would be aware of these changes that might
> >  conflict with the recent memslot split work)
> > 
> 
> Thanks Peter,
> I'll rebase on top of this series and do some more testing

Igor,

It turns out that this series is probably not required for the current
tree because memory_region_clear_dirty_bitmap() should have handled
the aliasing issue correctly, but then this patchset will be a
pre-requisite of your split series because when we split memory slots
it starts to be possible that log_clear() will be applied to multiple
kvm memslots.

Would you like to pick these two patches directly into your series?
The 1st paragraph in the 2nd patch could probably be inaccurate and
need amending (as mentioned).

Thanks,

-- 
Peter Xu


  reply	other threads:[~2019-09-23  1:31 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-20 10:21 [PATCH 0/2] kvm: clear dirty bitmaps from all overlapping memslots Paolo Bonzini
2019-09-20 10:21 ` [PATCH 1/2] kvm: extract kvm_log_clear_one_slot Paolo Bonzini
2019-09-20 12:11   ` Peter Xu
2019-09-20 10:21 ` [PATCH 2/2] kvm: clear dirty bitmaps from all overlapping memslots Paolo Bonzini
2019-09-20 12:18   ` Peter Xu
2019-09-20 14:03     ` Paolo Bonzini
2019-09-20 12:19 ` [PATCH 0/2] " Peter Xu
2019-09-20 13:58   ` Igor Mammedov
2019-09-23  1:29     ` Peter Xu [this message]
2019-09-23 16:15       ` Igor Mammedov
2019-09-23 16:49         ` Paolo Bonzini
2019-09-24  2:53           ` Peter Xu

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