* RE: [RESEND PATCH v3 kernel 0/7] Extend virtio-balloon for fast (de)inflating & fast live migration
From: Li, Liang Z @ 2016-10-23 11:29 UTC (permalink / raw)
To: Michael S. Tsirkin, Hansen, Dave
Cc: virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org,
amit.shah@redhat.com, qemu-devel@nongnu.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
pbonzini@redhat.com, virtualization@lists.linux-foundation.org,
dgilbert@redhat.com
In-Reply-To: <20161021224428-mutt-send-email-mst@kernel.org>
> On Fri, Oct 21, 2016 at 10:25:21AM -0700, Dave Hansen wrote:
> > On 10/20/2016 11:24 PM, Liang Li wrote:
> > > Dave Hansen suggested a new scheme to encode the data structure,
> > > because of additional complexity, it's not implemented in v3.
> >
> > So, what do you want done with this patch set? Do you want it applied
> > as-is so that we can introduce a new host/guest ABI that we must
> > support until the end of time? Then, we go back in a year or two and
> > add the newer format that addresses the deficiencies that this ABI has
> > with a third version?
> >
>
> Exactly my questions.
Hi Dave & Michael,
In the V2, both of you thought that the memory I allocated for the bitmap is too large, and gave some
suggestions about the solution, so I changed the implementation and used scattered pages for the bitmap
instead of a large physical continued memory. I didn't get the comments about the changes, so I am not
sure whether that is OK or not, that's the why I resend the V3, I just want your opinions about that part.
I will implement the new schema as Dave suggested in V4. Before that, could you take a look at this version and
give some comments?
Thanks!
Liang
^ permalink raw reply
* Re: [PATCH 2/5] stop_machine: yield CPU during stop machine
From: Nicholas Piggin @ 2016-10-22 0:06 UTC (permalink / raw)
To: Peter Zijlstra
Cc: linux-arch, linux-s390, kvm, xen-devel-request, Heiko Carstens,
linux-kernel, virtualization, Noam Camus, Martin Schwidefsky,
linuxppc-dev
In-Reply-To: <20161021120536.GC3142@twins.programming.kicks-ass.net>
On Fri, 21 Oct 2016 14:05:36 +0200
Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Oct 21, 2016 at 01:58:55PM +0200, Christian Borntraeger wrote:
> > stop_machine can take a very long time if the hypervisor does
> > overcommitment for guest CPUs. When waiting for "the one", lets
> > give up our CPU by using the new cpu_relax_yield.
>
> This seems something that would apply to most other virt stuff. Lets Cc
> a few more lists for that.
>
> > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > ---
> > kernel/stop_machine.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
> > index ec9ab2f..1eb8266 100644
> > --- a/kernel/stop_machine.c
> > +++ b/kernel/stop_machine.c
> > @@ -194,7 +194,7 @@ static int multi_cpu_stop(void *data)
> > /* Simple state machine */
> > do {
> > /* Chill out and ensure we re-read multi_stop_state. */
> > - cpu_relax();
> > + cpu_relax_yield();
> > if (msdata->state != curstate) {
> > curstate = msdata->state;
> > switch (curstate) {
> > --
> > 2.5.5
> >
This is the only caller of cpu_relax_yield()?
As a step to removing cpu_yield_lowlatency this series is nice so I
have no objection. But "general" kernel coders still have basically
no chance of using this properly.
I wonder what can be done about that. I've got that spin_do/while
series I'll rebase on top of this, but a spin_yield variant of them
is of no more help to the caller.
What makes this unique? Long latency and not performance critical?
Most places where we spin and maybe yield have been moved to arch
code, but I wonder whether we can make an easier to use architecture
independent API?
Thanks,
Nick
^ permalink raw reply
* Re: [RESEND PATCH v3 kernel 0/7] Extend virtio-balloon for fast (de)inflating & fast live migration
From: Michael S. Tsirkin @ 2016-10-21 19:44 UTC (permalink / raw)
To: Dave Hansen
Cc: virtio-dev, kvm, qemu-devel, amit.shah, Liang Li, linux-kernel,
virtualization, linux-mm, pbonzini, dgilbert
In-Reply-To: <580A4F81.60201@intel.com>
On Fri, Oct 21, 2016 at 10:25:21AM -0700, Dave Hansen wrote:
> On 10/20/2016 11:24 PM, Liang Li wrote:
> > Dave Hansen suggested a new scheme to encode the data structure,
> > because of additional complexity, it's not implemented in v3.
>
> So, what do you want done with this patch set? Do you want it applied
> as-is so that we can introduce a new host/guest ABI that we must support
> until the end of time? Then, we go back in a year or two and add the
> newer format that addresses the deficiencies that this ABI has with a
> third version?
>
Exactly my questions.
^ permalink raw reply
* Re: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check
From: rkrcmar @ 2016-10-21 18:39 UTC (permalink / raw)
To: David Laight
Cc: kernellwp@gmail.com, linux-s390@vger.kernel.org, jgross@suse.com,
kvm@vger.kernel.org, peterz@infradead.org, 'Pan Xinhui',
boqun.feng@gmail.com, will.deacon@arm.com,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org, mingo@redhat.com,
paulus@samba.org, xen-devel-request@lists.xenproject.org,
pbonzini@redhat.com, paulmck@linux.vnet.ibm.com,
linuxppc-dev@lists.ozlabs.org
In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6DB0207B44@AcuExch.aculab.com>
2016-10-21 11:27+0000, David Laight:
> From: Pan Xinhui
>> Sent: 20 October 2016 22:28
>> Commit ("x86, kvm: support vcpu preempted check") add one field "__u8
>> preempted" into struct kvm_steal_time. This field tells if one vcpu is
>> running or not.
>>
>> It is zero if 1) some old KVM deos not support this filed. 2) the vcpu is
>> preempted. Other values means the vcpu has been preempted.
>>
>> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
>> ---
>> Documentation/virtual/kvm/msr.txt | 8 +++++++-
>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt
>> index 2a71c8f..3376f13 100644
>> --- a/Documentation/virtual/kvm/msr.txt
>> +++ b/Documentation/virtual/kvm/msr.txt
>> @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03
>> __u64 steal;
>> __u32 version;
>> __u32 flags;
>> - __u32 pad[12];
>> + __u8 preempted;
>> + __u32 pad[11];
>> }
>
> I think I'd be explicit about the 3 pad bytes you've left.
Seconded.
With that change are all KVM bits
Acked-by: Radim Krčmář <rkrcmar@redhat.com>
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply
* Re: [RESEND PATCH v3 kernel 0/7] Extend virtio-balloon for fast (de)inflating & fast live migration
From: Dave Hansen @ 2016-10-21 17:25 UTC (permalink / raw)
To: Liang Li, mst
Cc: virtio-dev, kvm, amit.shah, qemu-devel, linux-kernel, linux-mm,
pbonzini, virtualization, dgilbert
In-Reply-To: <1477031080-12616-1-git-send-email-liang.z.li@intel.com>
On 10/20/2016 11:24 PM, Liang Li wrote:
> Dave Hansen suggested a new scheme to encode the data structure,
> because of additional complexity, it's not implemented in v3.
So, what do you want done with this patch set? Do you want it applied
as-is so that we can introduce a new host/guest ABI that we must support
until the end of time? Then, we go back in a year or two and add the
newer format that addresses the deficiencies that this ABI has with a
third version?
^ permalink raw reply
* Re: [PATCH/RFC 0/5] cpu_relax: introduce yield, remove lowlatency
From: David Miller @ 2016-10-21 15:12 UTC (permalink / raw)
To: borntraeger
Cc: linux-arch, linux-s390, kvm, peterz, heiko.carstens, linux-kernel,
npiggin, virtualization, noamc, schwidefsky, xen-devel,
linuxppc-dev
In-Reply-To: <2cf23cb7-05c5-0a2d-2ed5-aa90d582f802@de.ibm.com>
From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Fri, 21 Oct 2016 17:08:54 +0200
> On 10/21/2016 04:57 PM, David Miller wrote:
>> From: Christian Borntraeger <borntraeger@de.ibm.com>
>> Date: Fri, 21 Oct 2016 13:58:53 +0200
>>
>>> For spinning loops people did often use barrier() or cpu_relax().
>>> For most architectures cpu_relax and barrier are the same, but on
>>> some architectures cpu_relax can add some latency. For example on s390
>>> cpu_relax gives up the time slice to the hypervisor. On power cpu_relax
>>> tries to give some of the CPU to the neighbor threads. To reduce the
>>> latency another variant cpu_relax_lowlatency was introduced. Before this
>>> is used in more and more places, lets revert the logic of provide a new
>>> function cpu_relax_yield that can spend some time and for s390 yields
>>> the guest CPU.
>>
>> Sparc64, fwiw, behaves similarly to powerpc.
>
> As sparc currently defines cpu_relax_lowlatency to cpu_relax, this patch set
> should be a no-op then for sparc, correct?
>
> My intend was that cpu_relax should not add a huge latency but can certainly
> push some cpu power to hardware threads of the same core. This seems to be
> the case for sparc/power and some arc variants.
Agreed.
^ permalink raw reply
* Re: [PATCH/RFC 0/5] cpu_relax: introduce yield, remove lowlatency
From: Christian Borntraeger @ 2016-10-21 15:08 UTC (permalink / raw)
To: David Miller
Cc: linux-arch, linux-s390, KVM list, peterz, heiko.carstens,
linux-kernel, npiggin, virtualization, noamc, schwidefsky,
xen-devel, linuxppc-dev
In-Reply-To: <20161021.105727.140184460493941551.davem@davemloft.net>
On 10/21/2016 04:57 PM, David Miller wrote:
> From: Christian Borntraeger <borntraeger@de.ibm.com>
> Date: Fri, 21 Oct 2016 13:58:53 +0200
>
>> For spinning loops people did often use barrier() or cpu_relax().
>> For most architectures cpu_relax and barrier are the same, but on
>> some architectures cpu_relax can add some latency. For example on s390
>> cpu_relax gives up the time slice to the hypervisor. On power cpu_relax
>> tries to give some of the CPU to the neighbor threads. To reduce the
>> latency another variant cpu_relax_lowlatency was introduced. Before this
>> is used in more and more places, lets revert the logic of provide a new
>> function cpu_relax_yield that can spend some time and for s390 yields
>> the guest CPU.
>
> Sparc64, fwiw, behaves similarly to powerpc.
As sparc currently defines cpu_relax_lowlatency to cpu_relax, this patch set
should be a no-op then for sparc, correct?
My intend was that cpu_relax should not add a huge latency but can certainly
push some cpu power to hardware threads of the same core. This seems to be
the case for sparc/power and some arc variants.
Christian
^ permalink raw reply
* Re: [PATCH] drm/virtio: kconfig: Fixup white space.
From: Sean Paul via Virtualization @ 2016-10-21 14:53 UTC (permalink / raw)
To: Peter Griffin
Cc: kernel, Dave Airlie, Linux Kernel Mailing List, dri-devel,
virtualization, Lee Jones, Linux ARM Kernel
In-Reply-To: <1475913318-12275-1-git-send-email-peter.griffin@linaro.org>
On Sat, Oct 8, 2016 at 3:55 AM, Peter Griffin <peter.griffin@linaro.org> wrote:
> Use tabs instead of spaces.
>
> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
> Acked-by: Lee Jones <lee.jones@linaro.org>
Applied to drm-misc, thanks
> ---
> drivers/gpu/drm/virtio/Kconfig | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/virtio/Kconfig b/drivers/gpu/drm/virtio/Kconfig
> index e1afc3d..81d1807 100644
> --- a/drivers/gpu/drm/virtio/Kconfig
> +++ b/drivers/gpu/drm/virtio/Kconfig
> @@ -1,10 +1,10 @@
> config DRM_VIRTIO_GPU
> tristate "Virtio GPU driver"
> depends on DRM && VIRTIO
> - select DRM_KMS_HELPER
> - select DRM_TTM
> + select DRM_KMS_HELPER
> + select DRM_TTM
> help
> This is the virtual GPU driver for virtio. It can be used with
> - QEMU based VMMs (like KVM or Xen).
> + QEMU based VMMs (like KVM or Xen).
>
> If unsure say M.
> --
> 1.9.1
>
^ permalink raw reply
* Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers
From: Aaron Conole @ 2016-10-21 13:24 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Jarod Wilson, David Kershner, Wei Liu, VMware, Inc., netdev,
Haiyang Zhang, linux-kernel, virtualization, Paul Durrant,
Shrikrishna Khare
In-Reply-To: <20161021063505-mutt-send-email-mst@kernel.org>
"Michael S. Tsirkin" <mst@redhat.com> writes:
> On Thu, Oct 20, 2016 at 10:37:20PM -0400, Jarod Wilson wrote:
>> On Thu, Oct 20, 2016 at 11:23:54PM +0300, Michael S. Tsirkin wrote:
>> > On Thu, Oct 20, 2016 at 01:55:21PM -0400, Jarod Wilson wrote:
>> ...
>> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> > > index fad84f3..720809f 100644
>> > > --- a/drivers/net/virtio_net.c
>> > > +++ b/drivers/net/virtio_net.c
>> > > @@ -1419,17 +1419,6 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
>> > > .set_settings = virtnet_set_settings,
>> > > };
>> > >
>> > > -#define MIN_MTU 68
>> > > -#define MAX_MTU 65535
>> > > -
>> > > -static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
>> > > -{
>> > > - if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
>> > > - return -EINVAL;
>> > > - dev->mtu = new_mtu;
>> > > - return 0;
>> > > -}
>> > > -
>> > > static const struct net_device_ops virtnet_netdev = {
>> > > .ndo_open = virtnet_open,
>> > > .ndo_stop = virtnet_close,
>> > > @@ -1437,7 +1426,6 @@ static const struct net_device_ops virtnet_netdev = {
>> > > .ndo_validate_addr = eth_validate_addr,
>> > > .ndo_set_mac_address = virtnet_set_mac_address,
>> > > .ndo_set_rx_mode = virtnet_set_rx_mode,
>> > > - .ndo_change_mtu = virtnet_change_mtu,
>> > > .ndo_get_stats64 = virtnet_stats,
>> > > .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
>> > > .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
>> > > @@ -1748,6 +1736,9 @@ static bool virtnet_validate_features(struct virtio_device *vdev)
>> > > return true;
>> > > }
>> > >
>> > > +#define MIN_MTU ETH_MIN_MTU
>> > > +#define MAX_MTU ETH_MAX_MTU
>> > > +
>> >
>> > Can we drop these btw?
>>
>> Bah. Yeah. Should have just used them directly. I didn't add ETH_MAX_MTU
>> until after doing the virtio_net changes, so I missed that.
>>
>> > > static int virtnet_probe(struct virtio_device *vdev)
>> > > {
>> > > int i, err;
>> > > @@ -1821,6 +1812,10 @@ static int virtnet_probe(struct virtio_device *vdev)
>> > >
>> > > dev->vlan_features = dev->features;
>> > >
>> > > + /* MTU range: 68 - 65535 */
>> > > + dev->min_mtu = MIN_MTU;
>> > > + dev->max_mtu = MAX_MTU;
>> > > +
>> > > /* Configuration may specify what MAC to use. Otherwise random. */
>> > > if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
>> > > virtio_cread_bytes(vdev,
>> > > @@ -1875,8 +1870,10 @@ static int virtnet_probe(struct virtio_device *vdev)
>> > > mtu = virtio_cread16(vdev,
>> > > offsetof(struct virtio_net_config,
>> > > mtu));
>> > > - if (virtnet_change_mtu(dev, mtu))
>> > > + if (mtu < dev->min_mtu || mtu > dev->max_mtu)
>> >
>> > In fact the > max_mtu branch does not make sense since a 16 bit
>> > value can't exceed MAX_MTU.
>>
>> Hm. mtu is declared as an int, not sure if there's any sort of type
>> promotion to be worried about (not an area I know much/anything about).
>
> Not by design, that's for sure.
If you're really worried, we could declare it as a u16. The value
returned from virtio_cread16 is type u16, and there are no type
promotion rules I'm aware of that would do the wrong thing there.
>> Certainly something that could be looked into as a minor optimization,
>> though it's only in a probe path and shouldn't hurt anything, so ... meh?
>
> Right. Aaron said he's working on a patch that essentially does
> dev->max_mtu = mtu after validation, so this part will look
> a bit silly there.
Agreed, but I can do that in my patch if you don't want the extra churn.
-Aaron
^ permalink raw reply
* Re: [PATCH 2/5] stop_machine: yield CPU during stop machine
From: Juergen Gross @ 2016-10-21 12:41 UTC (permalink / raw)
To: Peter Zijlstra, Christian Borntraeger
Cc: linux-arch, linux-s390, kvm, Heiko Carstens, linux-kernel,
Nicholas Piggin, virtualization, Noam Camus, Martin Schwidefsky,
xen-devel, linuxppc-dev
In-Reply-To: <20161021120536.GC3142@twins.programming.kicks-ass.net>
On 21/10/16 14:05, Peter Zijlstra wrote:
> On Fri, Oct 21, 2016 at 01:58:55PM +0200, Christian Borntraeger wrote:
>> stop_machine can take a very long time if the hypervisor does
>> overcommitment for guest CPUs. When waiting for "the one", lets
>> give up our CPU by using the new cpu_relax_yield.
>
> This seems something that would apply to most other virt stuff. Lets Cc
> a few more lists for that.
Corrected xen-devel mail address.
Juergen
>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> ---
>> kernel/stop_machine.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
>> index ec9ab2f..1eb8266 100644
>> --- a/kernel/stop_machine.c
>> +++ b/kernel/stop_machine.c
>> @@ -194,7 +194,7 @@ static int multi_cpu_stop(void *data)
>> /* Simple state machine */
>> do {
>> /* Chill out and ensure we re-read multi_stop_state. */
>> - cpu_relax();
>> + cpu_relax_yield();
>> if (msdata->state != curstate) {
>> curstate = msdata->state;
>> switch (curstate) {
>> --
>> 2.5.5
>>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization
>
^ permalink raw reply
* Re: [PATCH 2/5] stop_machine: yield CPU during stop machine
From: Peter Zijlstra @ 2016-10-21 12:05 UTC (permalink / raw)
To: Christian Borntraeger
Cc: linux-arch, linux-s390, kvm, xen-devel-request, Heiko Carstens,
linux-kernel, Nicholas Piggin, virtualization, Noam Camus,
Martin Schwidefsky, linuxppc-dev
In-Reply-To: <1477051138-1610-3-git-send-email-borntraeger@de.ibm.com>
On Fri, Oct 21, 2016 at 01:58:55PM +0200, Christian Borntraeger wrote:
> stop_machine can take a very long time if the hypervisor does
> overcommitment for guest CPUs. When waiting for "the one", lets
> give up our CPU by using the new cpu_relax_yield.
This seems something that would apply to most other virt stuff. Lets Cc
a few more lists for that.
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
> kernel/stop_machine.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
> index ec9ab2f..1eb8266 100644
> --- a/kernel/stop_machine.c
> +++ b/kernel/stop_machine.c
> @@ -194,7 +194,7 @@ static int multi_cpu_stop(void *data)
> /* Simple state machine */
> do {
> /* Chill out and ensure we re-read multi_stop_state. */
> - cpu_relax();
> + cpu_relax_yield();
> if (msdata->state != curstate) {
> curstate = msdata->state;
> switch (curstate) {
> --
> 2.5.5
>
^ permalink raw reply
* RE: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check
From: David Laight @ 2016-10-21 11:27 UTC (permalink / raw)
To: 'Pan Xinhui', linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org,
virtualization@lists.linux-foundation.org,
linux-s390@vger.kernel.org,
xen-devel-request@lists.xenproject.org, kvm@vger.kernel.org
Cc: kernellwp@gmail.com, jgross@suse.com, rkrcmar@redhat.com,
peterz@infradead.org, boqun.feng@gmail.com, will.deacon@arm.com,
mingo@redhat.com, paulus@samba.org, pbonzini@redhat.com,
paulmck@linux.vnet.ibm.com
In-Reply-To: <1476998874-2089-10-git-send-email-xinhui.pan@linux.vnet.ibm.com>
From: Pan Xinhui
> Sent: 20 October 2016 22:28
> Commit ("x86, kvm: support vcpu preempted check") add one field "__u8
> preempted" into struct kvm_steal_time. This field tells if one vcpu is
> running or not.
>
> It is zero if 1) some old KVM deos not support this filed. 2) the vcpu is
> preempted. Other values means the vcpu has been preempted.
>
> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
> ---
> Documentation/virtual/kvm/msr.txt | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt
> index 2a71c8f..3376f13 100644
> --- a/Documentation/virtual/kvm/msr.txt
> +++ b/Documentation/virtual/kvm/msr.txt
> @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03
> __u64 steal;
> __u32 version;
> __u32 flags;
> - __u32 pad[12];
> + __u8 preempted;
> + __u32 pad[11];
> }
I think I'd be explicit about the 3 pad bytes you've left.
David
^ permalink raw reply
* Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers
From: Wei Liu @ 2016-10-21 10:09 UTC (permalink / raw)
To: Jarod Wilson
Cc: David Kershner, Wei Liu, Michael S. Tsirkin, VMware, Inc., netdev,
Haiyang Zhang, linux-kernel, virtualization, Paul Durrant,
Shrikrishna Khare
In-Reply-To: <20161020175524.6184-7-jarod@redhat.com>
On Thu, Oct 20, 2016 at 01:55:21PM -0400, Jarod Wilson wrote:
> hyperv_net:
> - set min/max_mtu, per Haiyang, after rndis_filter_device_add
>
> virtio_net:
> - set min/max_mtu
> - remove virtnet_change_mtu
>
> vmxnet3:
> - set min/max_mtu
>
> xen-netback:
> - min_mtu = 0, max_mtu = 65517
>
> xen-netfront:
> - min_mtu = 0, max_mtu = 65535
>
> unisys/visor:
> - clean up defines a little to not clash with network core or add
> redundat definitions
>
> CC: netdev@vger.kernel.org
> CC: virtualization@lists.linux-foundation.org
> CC: "K. Y. Srinivasan" <kys@microsoft.com>
> CC: Haiyang Zhang <haiyangz@microsoft.com>
> CC: "Michael S. Tsirkin" <mst@redhat.com>
> CC: Shrikrishna Khare <skhare@vmware.com>
> CC: "VMware, Inc." <pv-drivers@vmware.com>
> CC: Wei Liu <wei.liu2@citrix.com>
> CC: Paul Durrant <paul.durrant@citrix.com>
> CC: David Kershner <david.kershner@unisys.com>
> Signed-off-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
^ permalink raw reply
* [RESEND PATCH v3 kernel 7/7] virtio-balloon: tell host vm's unused page info
From: Liang Li @ 2016-10-21 6:24 UTC (permalink / raw)
To: mst
Cc: virtio-dev, kvm, amit.shah, Liang Li, dave.hansen, qemu-devel,
linux-kernel, linux-mm, pbonzini, virtualization, dgilbert
In-Reply-To: <1477031080-12616-1-git-send-email-liang.z.li@intel.com>
Support the request for vm's unused page information, response with
a page bitmap. QEMU can make use of this bitmap and the dirty page
logging mechanism to skip the transportation of these unused pages,
this is very helpful to speed up the live migration process.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Amit Shah <amit.shah@redhat.com>
---
drivers/virtio/virtio_balloon.c | 143 +++++++++++++++++++++++++++++++++++++---
1 file changed, 134 insertions(+), 9 deletions(-)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index c31839c..f10bb8b 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -56,7 +56,7 @@
struct virtio_balloon {
struct virtio_device *vdev;
- struct virtqueue *inflate_vq, *deflate_vq, *stats_vq;
+ struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *misc_vq;
/* The balloon servicing is delegated to a freezable workqueue. */
struct work_struct update_balloon_stats_work;
@@ -78,6 +78,8 @@ struct virtio_balloon {
unsigned int nr_page_bmap;
/* Used to record the processed pfn range */
unsigned long min_pfn, max_pfn, start_pfn, end_pfn;
+ /* Request header */
+ struct balloon_req_hdr req_hdr;
/*
* The pages we've told the Host we're not using are enqueued
* at vb_dev_info->pages list.
@@ -423,6 +425,78 @@ static void update_balloon_stats(struct virtio_balloon *vb)
pages_to_bytes(available));
}
+static void send_unused_pages_info(struct virtio_balloon *vb,
+ unsigned long req_id)
+{
+ struct scatterlist sg_in, sg_out[BALLOON_BMAP_COUNT + 1];
+ unsigned long pfn = 0, bmap_len, pfn_limit, last_pfn, nr_pfn;
+ struct virtqueue *vq = vb->misc_vq;
+ struct balloon_bmap_hdr *hdr = vb->bmap_hdr;
+ int ret = 1, nr_buf, used_nr_bmap = 0, i;
+
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP) &&
+ vb->nr_page_bmap == 1)
+ extend_page_bitmap(vb);
+
+ pfn_limit = PFNS_PER_BMAP * vb->nr_page_bmap;
+ mutex_lock(&vb->balloon_lock);
+ last_pfn = get_max_pfn();
+
+ while (ret) {
+ clear_page_bitmap(vb);
+ ret = get_unused_pages(pfn, pfn + pfn_limit, vb->page_bitmap,
+ PFNS_PER_BMAP, vb->nr_page_bmap);
+ if (ret < 0)
+ break;
+ hdr->cmd = cpu_to_virtio16(vb->vdev, BALLOON_GET_UNUSED_PAGES);
+ hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT);
+ hdr->req_id = cpu_to_virtio64(vb->vdev, req_id);
+ hdr->start_pfn = cpu_to_virtio64(vb->vdev, pfn);
+ bmap_len = BALLOON_BMAP_SIZE * vb->nr_page_bmap;
+
+ if (!ret) {
+ hdr->flag = cpu_to_virtio16(vb->vdev,
+ BALLOON_FLAG_DONE);
+ nr_pfn = last_pfn - pfn;
+ used_nr_bmap = nr_pfn / PFNS_PER_BMAP;
+ if (nr_pfn % PFNS_PER_BMAP)
+ used_nr_bmap++;
+ bmap_len = nr_pfn / BITS_PER_BYTE;
+ } else {
+ hdr->flag = cpu_to_virtio16(vb->vdev,
+ BALLOON_FLAG_CONT);
+ used_nr_bmap = vb->nr_page_bmap;
+ }
+ hdr->bmap_len = cpu_to_virtio64(vb->vdev, bmap_len);
+ nr_buf = used_nr_bmap + 1;
+ sg_init_table(sg_out, nr_buf);
+ sg_set_buf(&sg_out[0], hdr, sizeof(struct balloon_bmap_hdr));
+ for (i = 0; i < used_nr_bmap; i++) {
+ unsigned int buf_len = BALLOON_BMAP_SIZE;
+
+ if (i + 1 == used_nr_bmap)
+ buf_len = bmap_len - BALLOON_BMAP_SIZE * i;
+ sg_set_buf(&sg_out[i + 1], vb->page_bitmap[i], buf_len);
+ }
+
+ while (vq->num_free < nr_buf)
+ msleep(2);
+ if (virtqueue_add_outbuf(vq, sg_out, nr_buf, vb,
+ GFP_KERNEL) == 0) {
+ virtqueue_kick(vq);
+ while (!virtqueue_get_buf(vq, &i)
+ && !virtqueue_is_broken(vq))
+ cpu_relax();
+ }
+ pfn += pfn_limit;
+ }
+
+ mutex_unlock(&vb->balloon_lock);
+ sg_init_one(&sg_in, &vb->req_hdr, sizeof(vb->req_hdr));
+ virtqueue_add_inbuf(vq, &sg_in, 1, &vb->req_hdr, GFP_KERNEL);
+ virtqueue_kick(vq);
+}
+
/*
* While most virtqueues communicate guest-initiated requests to the hypervisor,
* the stats queue operates in reverse. The driver initializes the virtqueue
@@ -563,18 +637,56 @@ static void update_balloon_size_func(struct work_struct *work)
queue_work(system_freezable_wq, work);
}
+static void misc_handle_rq(struct virtio_balloon *vb)
+{
+ struct balloon_req_hdr *ptr_hdr;
+ unsigned int len;
+
+ ptr_hdr = virtqueue_get_buf(vb->misc_vq, &len);
+ if (!ptr_hdr || len != sizeof(vb->req_hdr))
+ return;
+
+ switch (ptr_hdr->cmd) {
+ case BALLOON_GET_UNUSED_PAGES:
+ send_unused_pages_info(vb, ptr_hdr->param);
+ break;
+ default:
+ break;
+ }
+}
+
+static void misc_request(struct virtqueue *vq)
+{
+ struct virtio_balloon *vb = vq->vdev->priv;
+
+ misc_handle_rq(vb);
+}
+
static int init_vqs(struct virtio_balloon *vb)
{
- struct virtqueue *vqs[3];
- vq_callback_t *callbacks[] = { balloon_ack, balloon_ack, stats_request };
- static const char * const names[] = { "inflate", "deflate", "stats" };
+ struct virtqueue *vqs[4];
+ vq_callback_t *callbacks[] = { balloon_ack, balloon_ack,
+ stats_request, misc_request };
+ static const char * const names[] = { "inflate", "deflate", "stats",
+ "misc" };
int err, nvqs;
/*
* We expect two virtqueues: inflate and deflate, and
* optionally stat.
*/
- nvqs = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ) ? 3 : 2;
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_MISC_VQ))
+ nvqs = 4;
+ else if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ))
+ nvqs = 3;
+ else
+ nvqs = 2;
+
+ if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
+ __virtio_clear_bit(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP);
+ __virtio_clear_bit(vb->vdev, VIRTIO_BALLOON_F_MISC_VQ);
+ }
+
err = vb->vdev->config->find_vqs(vb->vdev, nvqs, vqs, callbacks, names);
if (err)
return err;
@@ -595,6 +707,16 @@ static int init_vqs(struct virtio_balloon *vb)
BUG();
virtqueue_kick(vb->stats_vq);
}
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_MISC_VQ)) {
+ struct scatterlist sg_in;
+
+ vb->misc_vq = vqs[3];
+ sg_init_one(&sg_in, &vb->req_hdr, sizeof(vb->req_hdr));
+ if (virtqueue_add_inbuf(vb->misc_vq, &sg_in, 1,
+ &vb->req_hdr, GFP_KERNEL) < 0)
+ BUG();
+ virtqueue_kick(vb->misc_vq);
+ }
return 0;
}
@@ -703,13 +825,15 @@ static int virtballoon_probe(struct virtio_device *vdev)
vb->num_pages = 0;
vb->bmap_hdr = kzalloc(sizeof(struct balloon_bmap_hdr), GFP_KERNEL);
/* Clear the feature bit if memory allocation fails */
- if (!vb->bmap_hdr)
+ if (!vb->bmap_hdr) {
__virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_BITMAP);
- else {
+ __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_MISC_VQ);
+ } else {
vb->page_bitmap[0] = kmalloc(BALLOON_BMAP_SIZE, GFP_KERNEL);
- if (!vb->page_bitmap[0])
+ if (!vb->page_bitmap[0]) {
__virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_BITMAP);
- else
+ __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_MISC_VQ);
+ } else
vb->nr_page_bmap = 1;
}
mutex_init(&vb->balloon_lock);
@@ -832,6 +956,7 @@ static int virtballoon_restore(struct virtio_device *vdev)
VIRTIO_BALLOON_F_STATS_VQ,
VIRTIO_BALLOON_F_DEFLATE_ON_OOM,
VIRTIO_BALLOON_F_PAGE_BITMAP,
+ VIRTIO_BALLOON_F_MISC_VQ,
};
static struct virtio_driver virtio_balloon_driver = {
--
1.8.3.1
^ permalink raw reply related
* [RESEND PATCH v3 kernel 6/7] virtio-balloon: define feature bit and head for misc virt queue
From: Liang Li @ 2016-10-21 6:24 UTC (permalink / raw)
To: mst
Cc: virtio-dev, kvm, amit.shah, Liang Li, dave.hansen, qemu-devel,
linux-kernel, linux-mm, pbonzini, virtualization, dgilbert
In-Reply-To: <1477031080-12616-1-git-send-email-liang.z.li@intel.com>
Define a new feature bit which supports a new virtual queue. This
new virtual qeuque is for information exchange between hypervisor
and guest. The VMM hypervisor can make use of this virtual queue
to request the guest do some operations, e.g. drop page cache,
synchronize file system, etc. And the VMM hypervisor can get some
of guest's runtime information through this virtual queue, e.g. the
guest's unused page information, which can be used for live migration
optimization.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Amit Shah <amit.shah@redhat.com>
---
include/uapi/linux/virtio_balloon.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index d3b182a..3a9d633 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h
@@ -35,6 +35,7 @@
#define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */
#define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
#define VIRTIO_BALLOON_F_PAGE_BITMAP 3 /* Send page info with bitmap */
+#define VIRTIO_BALLOON_F_MISC_VQ 4 /* Misc info virtqueue */
/* Size of a PFN in the balloon interface. */
#define VIRTIO_BALLOON_PFN_SHIFT 12
@@ -101,4 +102,25 @@ struct balloon_bmap_hdr {
__virtio64 bmap_len;
};
+enum balloon_req_id {
+ /* Get unused pages information */
+ BALLOON_GET_UNUSED_PAGES,
+};
+
+enum balloon_flag {
+ /* Have more data for a request */
+ BALLOON_FLAG_CONT,
+ /* No more data for a request */
+ BALLOON_FLAG_DONE,
+};
+
+struct balloon_req_hdr {
+ /* Used to distinguish different request */
+ __virtio16 cmd;
+ /* Reserved */
+ __virtio16 reserved[3];
+ /* Request parameter */
+ __virtio64 param;
+};
+
#endif /* _LINUX_VIRTIO_BALLOON_H */
--
1.8.3.1
^ permalink raw reply related
* [RESEND PATCH v3 kernel 5/7] mm: add the related functions to get unused page
From: Liang Li @ 2016-10-21 6:24 UTC (permalink / raw)
To: mst
Cc: virtio-dev, kvm, amit.shah, Liang Li, dave.hansen, qemu-devel,
linux-kernel, linux-mm, pbonzini, Andrew Morton, virtualization,
Mel Gorman, dgilbert
In-Reply-To: <1477031080-12616-1-git-send-email-liang.z.li@intel.com>
Save the unused page info into page bitmap. The virtio balloon
driver call this new API to get the unused page bitmap and send
the bitmap to hypervisor(QEMU) for speeding up live migration.
During sending the bitmap, some the pages may be modified and are
no free anymore, this inaccuracy can be corrected by the dirty
page logging mechanism.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Amit Shah <amit.shah@redhat.com>
---
include/linux/mm.h | 2 ++
mm/page_alloc.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 86 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2a89da0e..84f56ec 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1777,6 +1777,8 @@ extern void free_area_init_node(int nid, unsigned long * zones_size,
unsigned long zone_start_pfn, unsigned long *zholes_size);
extern void free_initmem(void);
extern unsigned long get_max_pfn(void);
+extern int get_unused_pages(unsigned long start_pfn, unsigned long end_pfn,
+ unsigned long *bitmap[], unsigned long len, unsigned int nr_bmap);
/*
* Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e5f63a9..848bb85 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4436,6 +4436,90 @@ unsigned long get_max_pfn(void)
}
EXPORT_SYMBOL(get_max_pfn);
+static void mark_unused_pages_bitmap(struct zone *zone,
+ unsigned long start_pfn, unsigned long end_pfn,
+ unsigned long *bitmap[], unsigned long bits,
+ unsigned int nr_bmap)
+{
+ unsigned long pfn, flags, nr_pg, pos, *bmap;
+ unsigned int order, i, t, bmap_idx;
+ struct list_head *curr;
+
+ if (zone_is_empty(zone))
+ return;
+
+ end_pfn = min(start_pfn + nr_bmap * bits, end_pfn);
+ spin_lock_irqsave(&zone->lock, flags);
+
+ for_each_migratetype_order(order, t) {
+ list_for_each(curr, &zone->free_area[order].free_list[t]) {
+ pfn = page_to_pfn(list_entry(curr, struct page, lru));
+ if (pfn < start_pfn || pfn >= end_pfn)
+ continue;
+ nr_pg = 1UL << order;
+ if (pfn + nr_pg > end_pfn)
+ nr_pg = end_pfn - pfn;
+ bmap_idx = (pfn - start_pfn) / bits;
+ if (bmap_idx == (pfn + nr_pg - start_pfn) / bits) {
+ bmap = bitmap[bmap_idx];
+ pos = (pfn - start_pfn) % bits;
+ bitmap_set(bmap, pos, nr_pg);
+ } else
+ for (i = 0; i < nr_pg; i++) {
+ bmap_idx = pos / bits;
+ bmap = bitmap[bmap_idx];
+ pos = pos % bits;
+ bitmap_set(bmap, pos, 1);
+ }
+ }
+ }
+
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+/*
+ * During live migration, page is always discardable unless it's
+ * content is needed by the system.
+ * get_unused_pages provides an API to get the unused pages, these
+ * unused pages can be discarded if there is no modification since
+ * the request. Some other mechanism, like the dirty page logging
+ * can be used to track the modification.
+ *
+ * This function scans the free page list to get the unused pages
+ * whose pfn are range from start_pfn to end_pfn, and set the
+ * corresponding bit in the bitmap if an unused page is found.
+ *
+ * Allocating a large bitmap may fail because of fragmentation,
+ * instead of using a single bitmap, we use a scatter/gather bitmap.
+ * The 'bitmap' is the start address of an array which contains
+ * 'nr_bmap' separate small bitmaps, each bitmap contains 'bits' bits.
+ *
+ * return -1 if parameters are invalid
+ * return 0 when end_pfn >= max_pfn
+ * return 1 when end_pfn < max_pfn
+ */
+int get_unused_pages(unsigned long start_pfn, unsigned long end_pfn,
+ unsigned long *bitmap[], unsigned long bits, unsigned int nr_bmap)
+{
+ struct zone *zone;
+ int ret = 0;
+
+ if (bitmap == NULL || *bitmap == NULL || nr_bmap == 0 ||
+ bits == 0 || start_pfn > end_pfn)
+ return -1;
+ if (end_pfn < max_pfn)
+ ret = 1;
+ if (end_pfn >= max_pfn)
+ ret = 0;
+
+ for_each_populated_zone(zone)
+ mark_unused_pages_bitmap(zone, start_pfn, end_pfn, bitmap,
+ bits, nr_bmap);
+
+ return ret;
+}
+EXPORT_SYMBOL(get_unused_pages);
+
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
zoneref->zone = zone;
--
1.8.3.1
^ permalink raw reply related
* [RESEND PATCH v3 kernel 4/7] virtio-balloon: speed up inflate/deflate process
From: Liang Li @ 2016-10-21 6:24 UTC (permalink / raw)
To: mst
Cc: virtio-dev, kvm, amit.shah, Liang Li, dave.hansen, qemu-devel,
linux-kernel, linux-mm, pbonzini, virtualization, dgilbert
In-Reply-To: <1477031080-12616-1-git-send-email-liang.z.li@intel.com>
The implementation of the current virtio-balloon is not very
efficient, the time spends on different stages of inflating
the balloon to 7GB of a 8GB idle guest:
a. allocating pages (6.5%)
b. sending PFNs to host (68.3%)
c. address translation (6.1%)
d. madvise (19%)
It takes about 4126ms for the inflating process to complete.
Debugging shows that the bottle neck are the stage b and stage d.
If using a bitmap to send the page info instead of the PFNs, we
can reduce the overhead in stage b quite a lot. Furthermore, we
can do the address translation and call madvise() with a bulk of
RAM pages, instead of the current page per page way, the overhead
of stage c and stage d can also be reduced a lot.
This patch is the kernel side implementation which is intended to
speed up the inflating & deflating process by adding a new feature
to the virtio-balloon device. With this new feature, inflating the
balloon to 7GB of a 8GB idle guest only takes 590ms, the
performance improvement is about 85%.
TODO: optimize stage a by allocating/freeing a chunk of pages
instead of a single page at a time.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Amit Shah <amit.shah@redhat.com>
---
drivers/virtio/virtio_balloon.c | 233 +++++++++++++++++++++++++++++++++++-----
1 file changed, 209 insertions(+), 24 deletions(-)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 59ffe5a..c31839c 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -42,6 +42,10 @@
#define OOM_VBALLOON_DEFAULT_PAGES 256
#define VIRTBALLOON_OOM_NOTIFY_PRIORITY 80
+#define BALLOON_BMAP_SIZE (8 * PAGE_SIZE)
+#define PFNS_PER_BMAP (BALLOON_BMAP_SIZE * BITS_PER_BYTE)
+#define BALLOON_BMAP_COUNT 32
+
static int oom_pages = OOM_VBALLOON_DEFAULT_PAGES;
module_param(oom_pages, int, S_IRUSR | S_IWUSR);
MODULE_PARM_DESC(oom_pages, "pages to free on OOM");
@@ -67,6 +71,13 @@ struct virtio_balloon {
/* Number of balloon pages we've told the Host we're not using. */
unsigned int num_pages;
+ /* Pointer of the bitmap header. */
+ void *bmap_hdr;
+ /* Bitmap and bitmap count used to tell the host the pages */
+ unsigned long *page_bitmap[BALLOON_BMAP_COUNT];
+ unsigned int nr_page_bmap;
+ /* Used to record the processed pfn range */
+ unsigned long min_pfn, max_pfn, start_pfn, end_pfn;
/*
* The pages we've told the Host we're not using are enqueued
* at vb_dev_info->pages list.
@@ -110,16 +121,66 @@ static void balloon_ack(struct virtqueue *vq)
wake_up(&vb->acked);
}
+static inline void init_pfn_range(struct virtio_balloon *vb)
+{
+ vb->min_pfn = ULONG_MAX;
+ vb->max_pfn = 0;
+}
+
+static inline void update_pfn_range(struct virtio_balloon *vb,
+ struct page *page)
+{
+ unsigned long balloon_pfn = page_to_balloon_pfn(page);
+
+ if (balloon_pfn < vb->min_pfn)
+ vb->min_pfn = balloon_pfn;
+ if (balloon_pfn > vb->max_pfn)
+ vb->max_pfn = balloon_pfn;
+}
+
static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)
{
- struct scatterlist sg;
- unsigned int len;
+ struct scatterlist sg, sg2[BALLOON_BMAP_COUNT + 1];
+ unsigned int len, i;
+
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP)) {
+ struct balloon_bmap_hdr *hdr = vb->bmap_hdr;
+ unsigned long bmap_len;
+ int nr_pfn, nr_used_bmap, nr_buf;
+
+ nr_pfn = vb->end_pfn - vb->start_pfn + 1;
+ nr_pfn = roundup(nr_pfn, BITS_PER_LONG);
+ nr_used_bmap = nr_pfn / PFNS_PER_BMAP;
+ bmap_len = nr_pfn / BITS_PER_BYTE;
+ nr_buf = nr_used_bmap + 1;
+
+ /* cmd, reserved and req_id are init to 0, unused here */
+ hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT);
+ hdr->start_pfn = cpu_to_virtio64(vb->vdev, vb->start_pfn);
+ hdr->bmap_len = cpu_to_virtio64(vb->vdev, bmap_len);
+ sg_init_table(sg2, nr_buf);
+ sg_set_buf(&sg2[0], hdr, sizeof(struct balloon_bmap_hdr));
+ for (i = 0; i < nr_used_bmap; i++) {
+ unsigned int buf_len = BALLOON_BMAP_SIZE;
+
+ if (i + 1 == nr_used_bmap)
+ buf_len = bmap_len - BALLOON_BMAP_SIZE * i;
+ sg_set_buf(&sg2[i + 1], vb->page_bitmap[i], buf_len);
+ }
- sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns);
+ while (vq->num_free < nr_buf)
+ msleep(2);
+ if (virtqueue_add_outbuf(vq, sg2, nr_buf, vb, GFP_KERNEL) == 0)
+ virtqueue_kick(vq);
- /* We should always be able to add one buffer to an empty queue. */
- virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL);
- virtqueue_kick(vq);
+ } else {
+ sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns);
+
+ /* We should always be able to add one buffer to an empty
+ * queue. */
+ virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL);
+ virtqueue_kick(vq);
+ }
/* When host has read buffer, this completes via balloon_ack */
wait_event(vb->acked, virtqueue_get_buf(vq, &len));
@@ -138,13 +199,93 @@ static void set_page_pfns(struct virtio_balloon *vb,
page_to_balloon_pfn(page) + i);
}
-static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
+static void extend_page_bitmap(struct virtio_balloon *vb)
+{
+ int i;
+ unsigned long bmap_len, bmap_count;
+
+ bmap_len = ALIGN(get_max_pfn(), BITS_PER_LONG) / BITS_PER_BYTE;
+ bmap_count = bmap_len / BALLOON_BMAP_SIZE;
+ if (bmap_len % BALLOON_BMAP_SIZE)
+ bmap_count++;
+ if (bmap_count > BALLOON_BMAP_COUNT)
+ bmap_count = BALLOON_BMAP_COUNT;
+
+ for (i = 1; i < bmap_count; i++) {
+ vb->page_bitmap[i] = kmalloc(BALLOON_BMAP_SIZE, GFP_ATOMIC);
+ if (vb->page_bitmap[i])
+ vb->nr_page_bmap++;
+ else
+ break;
+ }
+}
+
+static void kfree_page_bitmap(struct virtio_balloon *vb)
+{
+ int i;
+
+ for (i = 0; i < vb->nr_page_bmap; i++)
+ kfree(vb->page_bitmap[i]);
+}
+
+static void clear_page_bitmap(struct virtio_balloon *vb)
+{
+ int i;
+
+ for (i = 0; i < vb->nr_page_bmap; i++)
+ memset(vb->page_bitmap[i], 0, BALLOON_BMAP_SIZE);
+}
+
+static void set_page_bitmap(struct virtio_balloon *vb,
+ struct list_head *pages, struct virtqueue *vq)
+{
+ unsigned long pfn, pfn_limit;
+ struct page *page;
+ bool found;
+ int bmap_idx;
+
+ vb->min_pfn = rounddown(vb->min_pfn, BITS_PER_LONG);
+ vb->max_pfn = roundup(vb->max_pfn, BITS_PER_LONG);
+ pfn_limit = PFNS_PER_BMAP * vb->nr_page_bmap;
+
+ for (pfn = vb->min_pfn; pfn < vb->max_pfn; pfn += pfn_limit) {
+ unsigned long end_pfn;
+
+ clear_page_bitmap(vb);
+ vb->start_pfn = pfn;
+ end_pfn = pfn;
+ found = false;
+ list_for_each_entry(page, pages, lru) {
+ unsigned long pos, balloon_pfn;
+
+ balloon_pfn = page_to_balloon_pfn(page);
+ if (balloon_pfn < pfn || balloon_pfn >= pfn + pfn_limit)
+ continue;
+ bmap_idx = (balloon_pfn - pfn) / PFNS_PER_BMAP;
+ pos = (balloon_pfn - pfn) % PFNS_PER_BMAP;
+ set_bit(pos, vb->page_bitmap[bmap_idx]);
+ if (balloon_pfn > end_pfn)
+ end_pfn = balloon_pfn;
+ found = true;
+ }
+ if (found) {
+ vb->end_pfn = end_pfn;
+ tell_host(vb, vq);
+ }
+ }
+}
+
+static unsigned int fill_balloon(struct virtio_balloon *vb, size_t num,
+ bool use_bmap)
{
struct balloon_dev_info *vb_dev_info = &vb->vb_dev_info;
- unsigned num_allocated_pages;
+ unsigned int num_allocated_pages;
- /* We can only do one array worth at a time. */
- num = min(num, ARRAY_SIZE(vb->pfns));
+ if (use_bmap)
+ init_pfn_range(vb);
+ else
+ /* We can only do one array worth at a time. */
+ num = min(num, ARRAY_SIZE(vb->pfns));
mutex_lock(&vb->balloon_lock);
for (vb->num_pfns = 0; vb->num_pfns < num;
@@ -159,7 +300,10 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
msleep(200);
break;
}
- set_page_pfns(vb, vb->pfns + vb->num_pfns, page);
+ if (use_bmap)
+ update_pfn_range(vb, page);
+ else
+ set_page_pfns(vb, vb->pfns + vb->num_pfns, page);
vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE;
if (!virtio_has_feature(vb->vdev,
VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
@@ -168,8 +312,13 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
num_allocated_pages = vb->num_pfns;
/* Did we get any? */
- if (vb->num_pfns != 0)
- tell_host(vb, vb->inflate_vq);
+ if (vb->num_pfns != 0) {
+ if (use_bmap)
+ set_page_bitmap(vb, &vb_dev_info->pages,
+ vb->inflate_vq);
+ else
+ tell_host(vb, vb->inflate_vq);
+ }
mutex_unlock(&vb->balloon_lock);
return num_allocated_pages;
@@ -189,15 +338,19 @@ static void release_pages_balloon(struct virtio_balloon *vb,
}
}
-static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
+static unsigned int leak_balloon(struct virtio_balloon *vb, size_t num,
+ bool use_bmap)
{
- unsigned num_freed_pages;
+ unsigned int num_freed_pages;
struct page *page;
struct balloon_dev_info *vb_dev_info = &vb->vb_dev_info;
LIST_HEAD(pages);
- /* We can only do one array worth at a time. */
- num = min(num, ARRAY_SIZE(vb->pfns));
+ if (use_bmap)
+ init_pfn_range(vb);
+ else
+ /* We can only do one array worth at a time. */
+ num = min(num, ARRAY_SIZE(vb->pfns));
mutex_lock(&vb->balloon_lock);
/* We can't release more pages than taken */
@@ -207,7 +360,10 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
page = balloon_page_dequeue(vb_dev_info);
if (!page)
break;
- set_page_pfns(vb, vb->pfns + vb->num_pfns, page);
+ if (use_bmap)
+ update_pfn_range(vb, page);
+ else
+ set_page_pfns(vb, vb->pfns + vb->num_pfns, page);
list_add(&page->lru, &pages);
vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE;
}
@@ -218,8 +374,14 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
* virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST);
* is true, we *have* to do it in this order
*/
- if (vb->num_pfns != 0)
- tell_host(vb, vb->deflate_vq);
+ if (vb->num_pfns != 0) {
+ if (use_bmap)
+ set_page_bitmap(vb, &pages, vb->deflate_vq);
+ else
+ tell_host(vb, vb->deflate_vq);
+
+ release_pages_balloon(vb, &pages);
+ }
release_pages_balloon(vb, &pages);
mutex_unlock(&vb->balloon_lock);
return num_freed_pages;
@@ -354,13 +516,15 @@ static int virtballoon_oom_notify(struct notifier_block *self,
struct virtio_balloon *vb;
unsigned long *freed;
unsigned num_freed_pages;
+ bool use_bmap;
vb = container_of(self, struct virtio_balloon, nb);
if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
return NOTIFY_OK;
freed = parm;
- num_freed_pages = leak_balloon(vb, oom_pages);
+ use_bmap = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP);
+ num_freed_pages = leak_balloon(vb, oom_pages, use_bmap);
update_balloon_size(vb);
*freed += num_freed_pages;
@@ -380,15 +544,19 @@ static void update_balloon_size_func(struct work_struct *work)
{
struct virtio_balloon *vb;
s64 diff;
+ bool use_bmap;
vb = container_of(work, struct virtio_balloon,
update_balloon_size_work);
diff = towards_target(vb);
+ use_bmap = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP);
+ if (use_bmap && diff && vb->nr_page_bmap == 1)
+ extend_page_bitmap(vb);
if (diff > 0)
- diff -= fill_balloon(vb, diff);
+ diff -= fill_balloon(vb, diff, use_bmap);
else if (diff < 0)
- diff += leak_balloon(vb, -diff);
+ diff += leak_balloon(vb, -diff, use_bmap);
update_balloon_size(vb);
if (diff)
@@ -533,6 +701,17 @@ static int virtballoon_probe(struct virtio_device *vdev)
spin_lock_init(&vb->stop_update_lock);
vb->stop_update = false;
vb->num_pages = 0;
+ vb->bmap_hdr = kzalloc(sizeof(struct balloon_bmap_hdr), GFP_KERNEL);
+ /* Clear the feature bit if memory allocation fails */
+ if (!vb->bmap_hdr)
+ __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_BITMAP);
+ else {
+ vb->page_bitmap[0] = kmalloc(BALLOON_BMAP_SIZE, GFP_KERNEL);
+ if (!vb->page_bitmap[0])
+ __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_BITMAP);
+ else
+ vb->nr_page_bmap = 1;
+ }
mutex_init(&vb->balloon_lock);
init_waitqueue_head(&vb->acked);
vb->vdev = vdev;
@@ -583,9 +762,12 @@ static int virtballoon_probe(struct virtio_device *vdev)
static void remove_common(struct virtio_balloon *vb)
{
+ bool use_bmap;
+
+ use_bmap = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP);
/* There might be pages left in the balloon: free them. */
while (vb->num_pages)
- leak_balloon(vb, vb->num_pages);
+ leak_balloon(vb, vb->num_pages, use_bmap);
update_balloon_size(vb);
/* Now we reset the device so we can clean up the queues. */
@@ -609,6 +791,8 @@ static void virtballoon_remove(struct virtio_device *vdev)
remove_common(vb);
if (vb->vb_dev_info.inode)
iput(vb->vb_dev_info.inode);
+ kfree_page_bitmap(vb);
+ kfree(vb->bmap_hdr);
kfree(vb);
}
@@ -647,6 +831,7 @@ static int virtballoon_restore(struct virtio_device *vdev)
VIRTIO_BALLOON_F_MUST_TELL_HOST,
VIRTIO_BALLOON_F_STATS_VQ,
VIRTIO_BALLOON_F_DEFLATE_ON_OOM,
+ VIRTIO_BALLOON_F_PAGE_BITMAP,
};
static struct virtio_driver virtio_balloon_driver = {
--
1.8.3.1
^ permalink raw reply related
* [RESEND PATCH v3 kernel 3/7] mm: add a function to get the max pfn
From: Liang Li @ 2016-10-21 6:24 UTC (permalink / raw)
To: mst
Cc: virtio-dev, kvm, amit.shah, Liang Li, dave.hansen, qemu-devel,
linux-kernel, linux-mm, pbonzini, Andrew Morton, virtualization,
Mel Gorman, dgilbert
In-Reply-To: <1477031080-12616-1-git-send-email-liang.z.li@intel.com>
Expose the function to get the max pfn, so it can be used in the
virtio-balloon device driver. Simply include the 'linux/bootmem.h'
is not enough, if the device driver is built to a module, directly
refer the max_pfn lead to build failed.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Amit Shah <amit.shah@redhat.com>
---
include/linux/mm.h | 1 +
mm/page_alloc.c | 10 ++++++++++
2 files changed, 11 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ffbd729..2a89da0e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1776,6 +1776,7 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
extern void free_area_init_node(int nid, unsigned long * zones_size,
unsigned long zone_start_pfn, unsigned long *zholes_size);
extern void free_initmem(void);
+extern unsigned long get_max_pfn(void);
/*
* Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2b3bf67..e5f63a9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4426,6 +4426,16 @@ void show_free_areas(unsigned int filter)
show_swap_cache_info();
}
+/*
+ * The max_pfn can change because of memory hot plug, so it's only good
+ * as a hint. e.g. for sizing data structures.
+ */
+unsigned long get_max_pfn(void)
+{
+ return max_pfn;
+}
+EXPORT_SYMBOL(get_max_pfn);
+
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
zoneref->zone = zone;
--
1.8.3.1
^ permalink raw reply related
* [RESEND PATCH v3 kernel 2/7] virtio-balloon: define new feature bit and page bitmap head
From: Liang Li @ 2016-10-21 6:24 UTC (permalink / raw)
To: mst
Cc: virtio-dev, kvm, amit.shah, Liang Li, dave.hansen, qemu-devel,
linux-kernel, linux-mm, pbonzini, virtualization, dgilbert
In-Reply-To: <1477031080-12616-1-git-send-email-liang.z.li@intel.com>
Add a new feature which supports sending the page information with
a bitmap. The current implementation uses PFNs array, which is not
very efficient. Using bitmap can improve the performance of
inflating/deflating significantly
The page bitmap header will used to tell the host some information
about the page bitmap. e.g. the page size, page bitmap length and
start pfn.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Amit Shah <amit.shah@redhat.com>
---
include/uapi/linux/virtio_balloon.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index 343d7dd..d3b182a 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h
@@ -34,6 +34,7 @@
#define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */
#define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */
#define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
+#define VIRTIO_BALLOON_F_PAGE_BITMAP 3 /* Send page info with bitmap */
/* Size of a PFN in the balloon interface. */
#define VIRTIO_BALLOON_PFN_SHIFT 12
@@ -82,4 +83,22 @@ struct virtio_balloon_stat {
__virtio64 val;
} __attribute__((packed));
+/* Page bitmap header structure */
+struct balloon_bmap_hdr {
+ /* Used to distinguish different request */
+ __virtio16 cmd;
+ /* Shift width of page in the bitmap */
+ __virtio16 page_shift;
+ /* flag used to identify different status */
+ __virtio16 flag;
+ /* Reserved */
+ __virtio16 reserved;
+ /* ID of the request */
+ __virtio64 req_id;
+ /* The pfn of 0 bit in the bitmap */
+ __virtio64 start_pfn;
+ /* The length of the bitmap, in bytes */
+ __virtio64 bmap_len;
+};
+
#endif /* _LINUX_VIRTIO_BALLOON_H */
--
1.8.3.1
^ permalink raw reply related
* [RESEND PATCH v3 kernel 1/7] virtio-balloon: rework deflate to add page to a list
From: Liang Li @ 2016-10-21 6:24 UTC (permalink / raw)
To: mst
Cc: virtio-dev, kvm, amit.shah, Liang Li, dave.hansen, qemu-devel,
linux-kernel, linux-mm, pbonzini, virtualization, dgilbert
In-Reply-To: <1477031080-12616-1-git-send-email-liang.z.li@intel.com>
Will allow faster notifications using a bitmap down the road.
balloon_pfn_to_page() can be removed because it's useless.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Amit Shah <amit.shah@redhat.com>
---
drivers/virtio/virtio_balloon.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 4e7003d..59ffe5a 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -103,12 +103,6 @@ static u32 page_to_balloon_pfn(struct page *page)
return pfn * VIRTIO_BALLOON_PAGES_PER_PAGE;
}
-static struct page *balloon_pfn_to_page(u32 pfn)
-{
- BUG_ON(pfn % VIRTIO_BALLOON_PAGES_PER_PAGE);
- return pfn_to_page(pfn / VIRTIO_BALLOON_PAGES_PER_PAGE);
-}
-
static void balloon_ack(struct virtqueue *vq)
{
struct virtio_balloon *vb = vq->vdev->priv;
@@ -181,18 +175,16 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
return num_allocated_pages;
}
-static void release_pages_balloon(struct virtio_balloon *vb)
+static void release_pages_balloon(struct virtio_balloon *vb,
+ struct list_head *pages)
{
- unsigned int i;
- struct page *page;
+ struct page *page, *next;
- /* Find pfns pointing at start of each page, get pages and free them. */
- for (i = 0; i < vb->num_pfns; i += VIRTIO_BALLOON_PAGES_PER_PAGE) {
- page = balloon_pfn_to_page(virtio32_to_cpu(vb->vdev,
- vb->pfns[i]));
+ list_for_each_entry_safe(page, next, pages, lru) {
if (!virtio_has_feature(vb->vdev,
VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
adjust_managed_page_count(page, 1);
+ list_del(&page->lru);
put_page(page); /* balloon reference */
}
}
@@ -202,6 +194,7 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
unsigned num_freed_pages;
struct page *page;
struct balloon_dev_info *vb_dev_info = &vb->vb_dev_info;
+ LIST_HEAD(pages);
/* We can only do one array worth at a time. */
num = min(num, ARRAY_SIZE(vb->pfns));
@@ -215,6 +208,7 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
if (!page)
break;
set_page_pfns(vb, vb->pfns + vb->num_pfns, page);
+ list_add(&page->lru, &pages);
vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE;
}
@@ -226,7 +220,7 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
*/
if (vb->num_pfns != 0)
tell_host(vb, vb->deflate_vq);
- release_pages_balloon(vb);
+ release_pages_balloon(vb, &pages);
mutex_unlock(&vb->balloon_lock);
return num_freed_pages;
}
--
1.8.3.1
^ permalink raw reply related
* [RESEND PATCH v3 kernel 0/7] Extend virtio-balloon for fast (de)inflating & fast live migration
From: Liang Li @ 2016-10-21 6:24 UTC (permalink / raw)
To: mst
Cc: virtio-dev, kvm, amit.shah, Liang Li, dave.hansen, qemu-devel,
linux-kernel, linux-mm, pbonzini, virtualization, dgilbert
This patch set contains two parts of changes to the virtio-balloon.
One is the change for speeding up the inflating & deflating process,
the main idea of this optimization is to use bitmap to send the page
information to host instead of the PFNs, to reduce the overhead of
virtio data transmission, address translation and madvise(). This can
help to improve the performance by about 85%.
Another change is for speeding up live migration. By skipping process
guest's free pages in the first round of data copy, to reduce needless
data processing, this can help to save quite a lot of CPU cycles and
network bandwidth. We put guest's free page information in bitmap and
send it to host with the virt queue of virtio-balloon. For an idle 8GB
guest, this can help to shorten the total live migration time from 2Sec
to about 500ms in the 10Gbps network environment.
Dave Hansen suggested a new scheme to encode the data structure,
because of additional complexity, it's not implemented in v3.
Changes from v2 to v3:
* Change the name of 'free page' to 'unused page'.
* Use the scatter & gather bitmap instead of a 1MB page bitmap.
* Fix overwriting the page bitmap after kicking.
* Some of MST's comments for v2.
Changes from v1 to v2:
* Abandon the patch for dropping page cache.
* Put some structures to uapi head file.
* Use a new way to determine the page bitmap size.
* Use a unified way to send the free page information with the bitmap
* Address the issues referred in MST's comments
Liang Li (7):
virtio-balloon: rework deflate to add page to a list
virtio-balloon: define new feature bit and page bitmap head
mm: add a function to get the max pfn
virtio-balloon: speed up inflate/deflate process
mm: add the related functions to get unused page
virtio-balloon: define feature bit and head for misc virt queue
virtio-balloon: tell host vm's unused page info
drivers/virtio/virtio_balloon.c | 390 ++++++++++++++++++++++++++++++++----
include/linux/mm.h | 3 +
include/uapi/linux/virtio_balloon.h | 41 ++++
mm/page_alloc.c | 94 +++++++++
4 files changed, 485 insertions(+), 43 deletions(-)
--
1.8.3.1
^ permalink raw reply
* Re: [PATCH v5 0/9] implement vcpu preempted check
From: Peter Zijlstra @ 2016-10-21 5:40 UTC (permalink / raw)
To: Pan Xinhui
Cc: kernellwp, linux-s390, jgross, kvm, rkrcmar, xen-devel-request,
will.deacon, linux-kernel, virtualization, mingo, paulus, mpe,
benh, pbonzini, paulmck, linuxppc-dev, boqun.feng
In-Reply-To: <1476998874-2089-1-git-send-email-xinhui.pan@linux.vnet.ibm.com>
On Thu, Oct 20, 2016 at 05:27:45PM -0400, Pan Xinhui wrote:
>
> This patch set aims to fix lock holder preemption issues.
Thanks, this looks very good. I'll wait for ACKs from at least the KVM
people, since that was I think the most contentious patch.
^ permalink raw reply
* Re: [PATCH v5 7/9] x86, xen: support vcpu preempted check
From: Juergen Gross @ 2016-10-21 5:08 UTC (permalink / raw)
To: Pan Xinhui, linux-kernel, linuxppc-dev, virtualization,
linux-s390, xen-devel, kvm
Cc: kernellwp, rkrcmar, peterz, benh, will.deacon, mingo, paulus,
David Vrabel, mpe, pbonzini, Boris Ostrovsky, paulmck, boqun.feng
In-Reply-To: <1476998874-2089-8-git-send-email-xinhui.pan@linux.vnet.ibm.com>
Corrected xen-devel mailing list address, added other Xen maintainers
On 20/10/16 23:27, Pan Xinhui wrote:
> From: Juergen Gross <jgross@suse.com>
>
> Support the vcpu_is_preempted() functionality under Xen. This will
> enhance lock performance on overcommitted hosts (more runnable vcpus
> than physical cpus in the system) as doing busy waits for preempted
> vcpus will hurt system performance far worse than early yielding.
>
> A quick test (4 vcpus on 1 physical cpu doing a parallel build job
> with "make -j 8") reduced system time by about 5% with this patch.
>
> Signed-off-by: Juergen Gross <jgross@suse.com>
> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
> ---
> arch/x86/xen/spinlock.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
> index 3d6e006..74756bb 100644
> --- a/arch/x86/xen/spinlock.c
> +++ b/arch/x86/xen/spinlock.c
> @@ -114,7 +114,6 @@ void xen_uninit_lock_cpu(int cpu)
> per_cpu(irq_name, cpu) = NULL;
> }
>
> -
> /*
> * Our init of PV spinlocks is split in two init functions due to us
> * using paravirt patching and jump labels patching and having to do
> @@ -137,6 +136,8 @@ void __init xen_init_spinlocks(void)
> pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock);
> pv_lock_ops.wait = xen_qlock_wait;
> pv_lock_ops.kick = xen_qlock_kick;
> +
> + pv_lock_ops.vcpu_is_preempted = xen_vcpu_stolen;
> }
>
> /*
>
^ permalink raw reply
* Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers
From: Michael S. Tsirkin @ 2016-10-21 3:36 UTC (permalink / raw)
To: Jarod Wilson
Cc: Aaron Conole, David Kershner, Wei Liu, VMware, Inc., netdev,
Haiyang Zhang, linux-kernel, virtualization, Paul Durrant,
Shrikrishna Khare
In-Reply-To: <20161021023720.GA11396@redhat.com>
On Thu, Oct 20, 2016 at 10:37:20PM -0400, Jarod Wilson wrote:
> On Thu, Oct 20, 2016 at 11:23:54PM +0300, Michael S. Tsirkin wrote:
> > On Thu, Oct 20, 2016 at 01:55:21PM -0400, Jarod Wilson wrote:
> ...
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index fad84f3..720809f 100644
> > > --- a/drivers/net/virtio_net.c
> > > +++ b/drivers/net/virtio_net.c
> > > @@ -1419,17 +1419,6 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
> > > .set_settings = virtnet_set_settings,
> > > };
> > >
> > > -#define MIN_MTU 68
> > > -#define MAX_MTU 65535
> > > -
> > > -static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
> > > -{
> > > - if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
> > > - return -EINVAL;
> > > - dev->mtu = new_mtu;
> > > - return 0;
> > > -}
> > > -
> > > static const struct net_device_ops virtnet_netdev = {
> > > .ndo_open = virtnet_open,
> > > .ndo_stop = virtnet_close,
> > > @@ -1437,7 +1426,6 @@ static const struct net_device_ops virtnet_netdev = {
> > > .ndo_validate_addr = eth_validate_addr,
> > > .ndo_set_mac_address = virtnet_set_mac_address,
> > > .ndo_set_rx_mode = virtnet_set_rx_mode,
> > > - .ndo_change_mtu = virtnet_change_mtu,
> > > .ndo_get_stats64 = virtnet_stats,
> > > .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
> > > .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
> > > @@ -1748,6 +1736,9 @@ static bool virtnet_validate_features(struct virtio_device *vdev)
> > > return true;
> > > }
> > >
> > > +#define MIN_MTU ETH_MIN_MTU
> > > +#define MAX_MTU ETH_MAX_MTU
> > > +
> >
> > Can we drop these btw?
>
> Bah. Yeah. Should have just used them directly. I didn't add ETH_MAX_MTU
> until after doing the virtio_net changes, so I missed that.
>
> > > static int virtnet_probe(struct virtio_device *vdev)
> > > {
> > > int i, err;
> > > @@ -1821,6 +1812,10 @@ static int virtnet_probe(struct virtio_device *vdev)
> > >
> > > dev->vlan_features = dev->features;
> > >
> > > + /* MTU range: 68 - 65535 */
> > > + dev->min_mtu = MIN_MTU;
> > > + dev->max_mtu = MAX_MTU;
> > > +
> > > /* Configuration may specify what MAC to use. Otherwise random. */
> > > if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
> > > virtio_cread_bytes(vdev,
> > > @@ -1875,8 +1870,10 @@ static int virtnet_probe(struct virtio_device *vdev)
> > > mtu = virtio_cread16(vdev,
> > > offsetof(struct virtio_net_config,
> > > mtu));
> > > - if (virtnet_change_mtu(dev, mtu))
> > > + if (mtu < dev->min_mtu || mtu > dev->max_mtu)
> >
> > In fact the > max_mtu branch does not make sense since a 16 bit
> > value can't exceed MAX_MTU.
>
> Hm. mtu is declared as an int, not sure if there's any sort of type
> promotion to be worried about (not an area I know much/anything about).
Not by design, that's for sure.
> Certainly something that could be looked into as a minor optimization,
> though it's only in a probe path and shouldn't hurt anything, so ... meh?
Right. Aaron said he's working on a patch that essentially does
dev->max_mtu = mtu after validation, so this part will look
a bit silly there.
> --
> Jarod Wilson
> jarod@redhat.com
^ permalink raw reply
* Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers
From: Jarod Wilson @ 2016-10-21 2:37 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Aaron Conole, David Kershner, Wei Liu, VMware, Inc., netdev,
Haiyang Zhang, linux-kernel, virtualization, Paul Durrant,
Shrikrishna Khare
In-Reply-To: <20161020231559-mutt-send-email-mst@kernel.org>
On Thu, Oct 20, 2016 at 11:23:54PM +0300, Michael S. Tsirkin wrote:
> On Thu, Oct 20, 2016 at 01:55:21PM -0400, Jarod Wilson wrote:
...
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index fad84f3..720809f 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -1419,17 +1419,6 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
> > .set_settings = virtnet_set_settings,
> > };
> >
> > -#define MIN_MTU 68
> > -#define MAX_MTU 65535
> > -
> > -static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
> > -{
> > - if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
> > - return -EINVAL;
> > - dev->mtu = new_mtu;
> > - return 0;
> > -}
> > -
> > static const struct net_device_ops virtnet_netdev = {
> > .ndo_open = virtnet_open,
> > .ndo_stop = virtnet_close,
> > @@ -1437,7 +1426,6 @@ static const struct net_device_ops virtnet_netdev = {
> > .ndo_validate_addr = eth_validate_addr,
> > .ndo_set_mac_address = virtnet_set_mac_address,
> > .ndo_set_rx_mode = virtnet_set_rx_mode,
> > - .ndo_change_mtu = virtnet_change_mtu,
> > .ndo_get_stats64 = virtnet_stats,
> > .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
> > .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
> > @@ -1748,6 +1736,9 @@ static bool virtnet_validate_features(struct virtio_device *vdev)
> > return true;
> > }
> >
> > +#define MIN_MTU ETH_MIN_MTU
> > +#define MAX_MTU ETH_MAX_MTU
> > +
>
> Can we drop these btw?
Bah. Yeah. Should have just used them directly. I didn't add ETH_MAX_MTU
until after doing the virtio_net changes, so I missed that.
> > static int virtnet_probe(struct virtio_device *vdev)
> > {
> > int i, err;
> > @@ -1821,6 +1812,10 @@ static int virtnet_probe(struct virtio_device *vdev)
> >
> > dev->vlan_features = dev->features;
> >
> > + /* MTU range: 68 - 65535 */
> > + dev->min_mtu = MIN_MTU;
> > + dev->max_mtu = MAX_MTU;
> > +
> > /* Configuration may specify what MAC to use. Otherwise random. */
> > if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
> > virtio_cread_bytes(vdev,
> > @@ -1875,8 +1870,10 @@ static int virtnet_probe(struct virtio_device *vdev)
> > mtu = virtio_cread16(vdev,
> > offsetof(struct virtio_net_config,
> > mtu));
> > - if (virtnet_change_mtu(dev, mtu))
> > + if (mtu < dev->min_mtu || mtu > dev->max_mtu)
>
> In fact the > max_mtu branch does not make sense since a 16 bit
> value can't exceed MAX_MTU.
Hm. mtu is declared as an int, not sure if there's any sort of type
promotion to be worried about (not an area I know much/anything about).
Certainly something that could be looked into as a minor optimization,
though it's only in a probe path and shouldn't hurt anything, so ... meh?
--
Jarod Wilson
jarod@redhat.com
^ permalink raw reply
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