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In-Reply-To: <17068236.8b8.18ea1d8622f.Coremail.w_angrong@163.com>
From: Jason Wang <jasowang@redhat.com>
Date: Mon, 8 Apr 2024 14:37:40 +0800
Message-ID: <CACGkMEtYPwhkDJFxiZZHUtVy3NTY_f3DWG7K_5ZJ7Yknu_y8cw@mail.gmail.com>
Subject: Re: Re: [PATCH v3] vhost/vdpa: Add MSI translation tables to iommu
 for software-managed MSI
To: tab <w_angrong@163.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>, kvm@vger.kernel.org, virtualization@lists.linux.dev, 
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org, 
	Cindy Lu <lulu@redhat.com>
Content-Type: text/plain; charset="UTF-8"
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On Wed, Apr 3, 2024 at 10:47=E2=80=AFAM tab <w_angrong@163.com> wrote:
>
> > >
> > > On Fri, Mar 29, 2024 at 11:55:50AM +0800, Jason Wang wrote:
> > > > On Wed, Mar 27, 2024 at 5:08=E2=80=AFPM Jason Wang <jasowang@redhat=
com> wrote:
> > > > >
> > > > > On Thu, Mar 21, 2024 at 3:00=E2=80=AFPM Michael S. Tsirkin <mst@r=
edhat.com> wrote:
> > > > > >
> > > > > > On Wed, Mar 20, 2024 at 06:19:12PM +0800, Wang Rong wrote:
> > > > > > > From: Rong Wang <w_angrong@163.com>
> > > > > > >
> > > > > > > Once enable iommu domain for one device, the MSI
> > > > > > > translation tables have to be there for software-managed MSI.
> > > > > > > Otherwise, platform with software-managed MSI without an
> > > > > > > irq bypass function, can not get a correct memory write event
> > > > > > > from pcie, will not get irqs.
> > > > > > > The solution is to obtain the MSI phy base address from
> > > > > > > iommu reserved region, and set it to iommu MSI cookie,
> > > > > > > then translation tables will be created while request irq.
> > > > > > >
> > > > > > > Change log
> > > > > > > ----------
> > > > > > >
> > > > > > > v1->v2:
> > > > > > > - add resv iotlb to avoid overlap mapping.
> > > > > > > v2->v3:
> > > > > > > - there is no need to export the iommu symbol anymore.
> > > > > > >
> > > > > > > Signed-off-by: Rong Wang <w_angrong@163.com>
> > > > > >
> > > > > > There's in interest to keep extending vhost iotlb -
> > > > > > we should just switch over to iommufd which supports
> > > > > > this already.
> > > > >
> > > > > IOMMUFD is good but VFIO supports this before IOMMUFD. This patch
> > > > > makes vDPA run without a backporting of full IOMMUFD in the produ=
ction
> > > > > environment. I think it's worth.
> > > > >
> > > > > If you worry about the extension, we can just use the vhost iotlb
> > > > > existing facility to do this.
> > > > >
> > > > > Thanks
> > > >
> > > > Btw, Wang Rong,
> > > >
> > > > It looks that Cindy does have the bandwidth in working for IOMMUFD =
support.
> > >
> > > I think you mean she does not.
> >
> > Yes, you are right.
> >
> > Thanks
>
> I need to discuss internally, and there may be someone else will do that.
>
> Thanks.

Ok, please let us know if you have a conclusion.

Thanks

>
> >
> > >
> > > > Do you have the will to do that?
> > > >
> > > > Thanks
> > >
>
>
>
>
> --
> =E5=8F=91=E8=87=AA=E6=88=91=E7=9A=84=E7=BD=91=E6=98=93=E9=82=AE=E7=AE=B1=
=E5=B9=B3=E6=9D=BF=E9=80=82=E9=85=8D=E7=89=88
> <br/><br/><br/>
>
>
> ----- Original Message -----
> From: "Jason Wang" <jasowang@redhat.com>
> To: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: "Wang Rong" <w_angrong@163.com>, kvm@vger.kernel.org, virtualization@=
lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Cin=
dy Lu" <lulu@redhat.com>
> Sent: Fri, 29 Mar 2024 18:39:54 +0800
> Subject: Re: [PATCH v3] vhost/vdpa: Add MSI translation tables to iommu f=
or software-managed MSI
>
> On Fri, Mar 29, 2024 at 5:13=E2=80=AFPM Michael S. Tsirkin <mst@redhat.co=
m> wrote:
> >
> > On Fri, Mar 29, 2024 at 11:55:50AM +0800, Jason Wang wrote:
> > > On Wed, Mar 27, 2024 at 5:08=E2=80=AFPM Jason Wang <jasowang@redhat.c=
om> wrote:
> > > >
> > > > On Thu, Mar 21, 2024 at 3:00=E2=80=AFPM Michael S. Tsirkin <mst@red=
hat.com> wrote:
> > > > >
> > > > > On Wed, Mar 20, 2024 at 06:19:12PM +0800, Wang Rong wrote:
> > > > > > From: Rong Wang <w_angrong@163.com>
> > > > > >
> > > > > > Once enable iommu domain for one device, the MSI
> > > > > > translation tables have to be there for software-managed MSI.
> > > > > > Otherwise, platform with software-managed MSI without an
> > > > > > irq bypass function, can not get a correct memory write event
> > > > > > from pcie, will not get irqs.
> > > > > > The solution is to obtain the MSI phy base address from
> > > > > > iommu reserved region, and set it to iommu MSI cookie,
> > > > > > then translation tables will be created while request irq.
> > > > > >
> > > > > > Change log
> > > > > > ----------
> > > > > >
> > > > > > v1->v2:
> > > > > > - add resv iotlb to avoid overlap mapping.
> > > > > > v2->v3:
> > > > > > - there is no need to export the iommu symbol anymore.
> > > > > >
> > > > > > Signed-off-by: Rong Wang <w_angrong@163.com>
> > > > >
> > > > > There's in interest to keep extending vhost iotlb -
> > > > > we should just switch over to iommufd which supports
> > > > > this already.
> > > >
> > > > IOMMUFD is good but VFIO supports this before IOMMUFD. This patch
> > > > makes vDPA run without a backporting of full IOMMUFD in the product=
ion
> > > > environment. I think it's worth.
> > > >
> > > > If you worry about the extension, we can just use the vhost iotlb
> > > > existing facility to do this.
> > > >
> > > > Thanks
> > >
> > > Btw, Wang Rong,
> > >
> > > It looks that Cindy does have the bandwidth in working for IOMMUFD su=
pport.
> >
> > I think you mean she does not.
>
> Yes, you are right.
>
> Thanks
>
> >
> > > Do you have the will to do that?
> > >
> > > Thanks
> >