From: Paolo Bonzini <pbonzini@redhat.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Igor Mammedov <imammedo@redhat.com>
Cc: qemu-devel@nongnu.org, maxime.coquelin@redhat.com,
groug@kaod.org, mst@redhat.com
Subject: Re: [Qemu-devel] [PATCH v4 4/6] vhost: add regions to temporary list
Date: Fri, 15 Dec 2017 15:50:29 +0100 [thread overview]
Message-ID: <3b22f588-f7be-d1e2-9b72-072308fe8218@redhat.com> (raw)
In-Reply-To: <20171215133022.GD14126@work-vm>
On 15/12/2017 14:30, Dr. David Alan Gilbert wrote:
>> Also it seems that we have a race in current code where
>> region_del() unrefs memory region first and then by the
>> commit time memory region could be gone since old flatview
>> is unreffed before commit callback is called, but guest still
>> uses old memory map until vhost_set_mem_table() is complete.
>> We probably should unref deleted(old) sections after
>> guest gets new memmap.
>
> Will they really get cleaned up before the commit() returns?
> There's no rcu like thing guarding it?
The memory subsystem only keeps them alive until before commmit() is
invoked.
Paolo
next prev parent reply other threads:[~2017-12-15 14:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-13 18:08 [Qemu-devel] [PATCH v4 0/6] Rework vhost memory region updates Dr. David Alan Gilbert (git)
2017-12-13 18:08 ` [Qemu-devel] [PATCH v4 1/6] vhost: Move log_dirty check Dr. David Alan Gilbert (git)
2017-12-14 14:30 ` Igor Mammedov
2017-12-14 15:20 ` Dr. David Alan Gilbert
2017-12-15 10:01 ` Igor Mammedov
2017-12-27 12:10 ` Igor Mammedov
2018-01-09 18:42 ` Dr. David Alan Gilbert
2017-12-13 18:08 ` [Qemu-devel] [PATCH v4 2/6] vhost: Simplify ring verification checks Dr. David Alan Gilbert (git)
2017-12-14 14:07 ` Igor Mammedov
2017-12-15 12:24 ` Dr. David Alan Gilbert
2017-12-13 18:08 ` [Qemu-devel] [PATCH v4 3/6] vhost: Add temporary memory structure Dr. David Alan Gilbert (git)
2017-12-14 15:15 ` Igor Mammedov
2017-12-15 13:15 ` Dr. David Alan Gilbert
2017-12-13 18:08 ` [Qemu-devel] [PATCH v4 4/6] vhost: add regions to temporary list Dr. David Alan Gilbert (git)
2017-12-13 21:31 ` Paolo Bonzini
2017-12-14 15:53 ` Dr. David Alan Gilbert
2017-12-14 15:27 ` Igor Mammedov
2017-12-14 18:43 ` Michael S. Tsirkin
2017-12-18 20:29 ` Dr. David Alan Gilbert
2017-12-15 13:30 ` Dr. David Alan Gilbert
2017-12-15 14:50 ` Paolo Bonzini [this message]
2017-12-15 16:11 ` Dr. David Alan Gilbert
2017-12-13 18:08 ` [Qemu-devel] [PATCH v4 5/6] vhost: compare and flip in new memory region list Dr. David Alan Gilbert (git)
2017-12-13 18:08 ` [Qemu-devel] [PATCH v4 6/6] vhost: Clean out old vhost_set_memory and friends Dr. David Alan Gilbert (git)
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