From: "Michael S. Tsirkin" <mst@redhat.com>
To: David Hildenbrand <david@redhat.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>,
Nitesh Narayan Lal <nitesh@redhat.com>,
kvm list <kvm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
lcapitulino@redhat.com, pagupta@redhat.com, wei.w.wang@intel.com,
Yang Zhang <yang.zhang.wz@gmail.com>,
Rik van Riel <riel@surriel.com>,
dodgen@google.com, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
dhildenb@redhat.com, Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [RFC][Patch v8 0/7] KVM: Guest Free Page Hinting
Date: Tue, 19 Feb 2019 15:17:40 -0500 [thread overview]
Message-ID: <20190219151552-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <0118482c-e633-3949-6797-94d7deb8a382@redhat.com>
On Tue, Feb 19, 2019 at 09:02:52PM +0100, David Hildenbrand wrote:
> On 19.02.19 20:58, Michael S. Tsirkin wrote:
> > On Tue, Feb 19, 2019 at 10:06:35AM -0800, Alexander Duyck wrote:
> >>> I tend to like an asynchronous reporting approach as discussed in this
> >>> thread, we would have to see if Nitesh could get it implemented.
> >>
> >> I agree it would be great if it could work. However I have concerns
> >> given that work on this patch set dates back to 2017, major issues
> >> such as working around device assignment have yet to be addressed,
> >
> > BTW for device assignment to work, your idea of sending
> > data directly to kvm won't work, will it?
> > You need to update userspace so it can update VFIO right?
> > Another blocker for assignment is ability to make holes
> > an an existing mapping - supported by hardware but
> > not by IOMMU drivers.
>
> I had the exact same thought and then realized that we decided to block
> the balloon in user space until we figured out how to handle this properly.
>
> I wonder if MADV_FREE behaves differently compared to MADV_DONTNEED when
> finding pinned pages, but I doubt it. Most probably we'll have to
> disable hinting for device assignments as well.
OK but let's recognize it as a bug not a feature.
--
MST
next prev parent reply other threads:[~2019-02-19 20:17 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-04 20:18 [RFC][Patch v8 0/7] KVM: Guest Free Page Hinting Nitesh Narayan Lal
2019-02-04 20:18 ` [RFC][Patch v8 1/7] KVM: Support for guest free page hinting Nitesh Narayan Lal
2019-02-05 4:14 ` Michael S. Tsirkin
2019-02-05 13:06 ` Nitesh Narayan Lal
2019-02-05 16:27 ` Michael S. Tsirkin
2019-02-05 16:34 ` Nitesh Narayan Lal
2019-02-04 20:18 ` [RFC][Patch v8 2/7] KVM: Enabling guest free page hinting via static key Nitesh Narayan Lal
2019-02-08 18:07 ` Alexander Duyck
2019-02-08 18:22 ` Nitesh Narayan Lal
2019-02-04 20:18 ` [RFC][Patch v8 3/7] KVM: Guest free page hinting functional skeleton Nitesh Narayan Lal
2019-02-04 20:18 ` [RFC][Patch v8 4/7] KVM: Disabling page poisoning to prevent corruption Nitesh Narayan Lal
2019-02-07 17:23 ` Alexander Duyck
2019-02-07 17:56 ` Nitesh Narayan Lal
2019-02-07 18:24 ` Alexander Duyck
2019-02-07 19:14 ` Michael S. Tsirkin
2019-02-07 21:08 ` Michael S. Tsirkin
2019-02-04 20:18 ` [RFC][Patch v8 5/7] virtio: Enables to add a single descriptor to the host Nitesh Narayan Lal
2019-02-05 20:49 ` Michael S. Tsirkin
2019-02-06 12:56 ` Nitesh Narayan Lal
2019-02-06 13:15 ` Luiz Capitulino
2019-02-06 13:24 ` Nitesh Narayan Lal
2019-02-06 13:29 ` Luiz Capitulino
2019-02-06 14:05 ` Nitesh Narayan Lal
2019-02-06 18:03 ` Michael S. Tsirkin
2019-02-06 18:19 ` Nitesh Narayan Lal
2019-02-04 20:18 ` [RFC][Patch v8 6/7] KVM: Enables the kernel to isolate and report free pages Nitesh Narayan Lal
2019-02-05 20:45 ` Michael S. Tsirkin
2019-02-05 21:54 ` Nitesh Narayan Lal
2019-02-05 21:55 ` Michael S. Tsirkin
2019-02-07 17:43 ` Alexander Duyck
2019-02-07 19:01 ` Michael S. Tsirkin
2019-02-07 20:50 ` Nitesh Narayan Lal
2019-02-08 17:58 ` Alexander Duyck
2019-02-08 20:41 ` Nitesh Narayan Lal
2019-02-08 21:38 ` Michael S. Tsirkin
2019-02-08 22:05 ` Alexander Duyck
2019-02-10 0:38 ` Michael S. Tsirkin
2019-02-11 9:28 ` David Hildenbrand
2019-02-12 5:16 ` Michael S. Tsirkin
2019-02-12 17:10 ` Nitesh Narayan Lal
2019-02-08 21:35 ` Michael S. Tsirkin
2019-02-04 20:18 ` [RFC][Patch v8 7/7] KVM: Adding tracepoints for guest page hinting Nitesh Narayan Lal
2019-02-04 20:20 ` [RFC][QEMU PATCH] KVM: Support for guest free " Nitesh Narayan Lal
2019-02-12 9:03 ` [RFC][Patch v8 0/7] KVM: Guest Free Page Hinting Wang, Wei W
2019-02-12 9:24 ` David Hildenbrand
2019-02-12 17:24 ` Nitesh Narayan Lal
2019-02-12 19:34 ` David Hildenbrand
2019-02-13 8:55 ` Wang, Wei W
2019-02-13 9:19 ` David Hildenbrand
2019-02-13 12:17 ` Nitesh Narayan Lal
2019-02-13 17:09 ` Michael S. Tsirkin
2019-02-13 17:22 ` Nitesh Narayan Lal
[not found] ` <286AC319A985734F985F78AFA26841F73DF6F1C3@shsmsx102.ccr.corp.intel.com>
2019-02-14 9:34 ` David Hildenbrand
2019-02-13 17:16 ` Michael S. Tsirkin
2019-02-13 17:59 ` David Hildenbrand
2019-02-13 19:08 ` Michael S. Tsirkin
2019-02-14 9:08 ` Wang, Wei W
2019-02-14 10:00 ` David Hildenbrand
2019-02-14 10:44 ` David Hildenbrand
2019-02-15 9:15 ` Wang, Wei W
2019-02-15 9:33 ` David Hildenbrand
2019-02-13 9:00 ` Wang, Wei W
2019-02-13 12:06 ` Nitesh Narayan Lal
2019-02-14 8:48 ` Wang, Wei W
2019-02-14 9:42 ` David Hildenbrand
2019-02-15 9:05 ` Wang, Wei W
2019-02-15 9:41 ` David Hildenbrand
2019-02-18 2:36 ` Wei Wang
2019-02-18 2:39 ` Wei Wang
2019-02-15 12:40 ` Nitesh Narayan Lal
2019-02-14 13:00 ` Nitesh Narayan Lal
2019-02-16 9:40 ` David Hildenbrand
2019-02-18 15:50 ` Nitesh Narayan Lal
2019-02-18 16:02 ` David Hildenbrand
2019-02-18 16:49 ` Michael S. Tsirkin
2019-02-18 16:59 ` David Hildenbrand
2019-02-18 17:31 ` Alexander Duyck
2019-02-18 17:41 ` David Hildenbrand
2019-02-18 23:47 ` Alexander Duyck
2019-02-19 2:45 ` Michael S. Tsirkin
2019-02-19 2:46 ` Andrea Arcangeli
2019-02-19 12:52 ` Nitesh Narayan Lal
2019-02-19 16:23 ` Alexander Duyck
2019-02-19 8:06 ` David Hildenbrand
2019-02-19 14:40 ` Michael S. Tsirkin
2019-02-19 14:44 ` David Hildenbrand
2019-02-19 14:45 ` David Hildenbrand
2019-02-18 18:01 ` Michael S. Tsirkin
2019-02-18 17:54 ` Michael S. Tsirkin
2019-02-18 18:29 ` David Hildenbrand
2019-02-18 19:16 ` Michael S. Tsirkin
2019-02-18 19:35 ` David Hildenbrand
2019-02-18 19:47 ` Michael S. Tsirkin
2019-02-18 20:04 ` David Hildenbrand
2019-02-18 20:31 ` Michael S. Tsirkin
2019-02-18 20:40 ` Nitesh Narayan Lal
2019-02-18 21:04 ` David Hildenbrand
2019-02-19 0:01 ` Alexander Duyck
2019-02-19 7:54 ` David Hildenbrand
2019-02-19 18:06 ` Alexander Duyck
2019-02-19 18:31 ` David Hildenbrand
2019-02-19 21:57 ` Alexander Duyck
2019-02-19 22:17 ` Michael S. Tsirkin
2019-02-19 22:36 ` David Hildenbrand
2019-02-19 19:58 ` Michael S. Tsirkin
2019-02-19 20:02 ` David Hildenbrand
2019-02-19 20:17 ` Michael S. Tsirkin [this message]
2019-02-19 20:21 ` David Hildenbrand
2019-02-19 20:35 ` Michael S. Tsirkin
2019-02-19 12:47 ` Nitesh Narayan Lal
2019-02-19 13:03 ` David Hildenbrand
2019-02-19 14:17 ` Nitesh Narayan Lal
2019-02-19 14:21 ` David Hildenbrand
2019-02-18 20:53 ` David Hildenbrand
2019-02-23 0:02 ` Alexander Duyck
2019-02-25 13:01 ` Nitesh Narayan Lal
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