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Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to
From: |
Peter Xu |
Subject: |
Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM |
Date: |
Mon, 1 Apr 2019 18:25:15 +0800 |
User-agent: |
Mutt/1.10.1 (2018-07-13) |
On Mon, Apr 01, 2019 at 09:12:38AM +0000, Elijah Shakkour wrote:
>
>
> > -----Original Message-----
> > From: Peter Xu <address@hidden>
> > Sent: Monday, April 1, 2019 5:47 AM
> > To: Elijah Shakkour <address@hidden>
> > Cc: Knut Omang <address@hidden>; Michael S. Tsirkin
> > <address@hidden>; Alex Williamson <address@hidden>;
> > Marcel Apfelbaum <address@hidden>; Stefan Hajnoczi
> > <address@hidden>; address@hidden
> > Subject: Re: QEMU and vIOMMU support for emulated VF passthrough to
> > nested (L2) VM
> >
> > On Sun, Mar 31, 2019 at 11:15:00AM +0000, Elijah Shakkour wrote:
> >
> > [...]
> >
> > > I didn't have DMA nor MMIO read/write working with my old command
> > line.
> > > But, when I removed all CPU flags and only provided "-cpu host", I see
> > > that
> > MMIO works.
> > > Still, DMA read/write from emulated device doesn't work for VF. For
> > example:
> > > Driver provides me a buffer pointer through MMIO write, this address
> > (pointer) is GPA of L2, and when I try to call pci_dma_read() with this
> > address
> > I get:
> > > "
> > > Unassigned mem read 0000000000000000
> > > "
> >
> > I don't know where this error log was dumped but if it's during DMA then I
> > agree it can probably be related to vIOMMU.
> >
>
> This log is dumped from:
> memory.c: unassigned_mem_read()
>
> > > As I said, my problem now is in translation of L2 GPA provided by driver,
> > when I call DMA read/write for this address from VF.
> > > Any insights?
> >
> > I just noticed that you were using QEMU 2.12 [1]. If that's the case,
> > please
> > rebase to the latest QEMU, at least >=3.0 because there's major refactor of
> > the shadow logic during 3.0 devel cycle AFAICT.
> >
>
> Rebased to QEMU 3.1
> Now I see the address I'm trying to read from in log but still same error:
> "
> Unassigned mem read 00000000f0481000
> "
> What do you suggest?
Would you please answer the questions that Knut asked? Is it working
for L1 guest? How about PF?
You can also try to enable VT-d device log by appending:
-trace enable="vtd_*"
In case it dumps anything useful for you.
--
Peter Xu
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Elijah Shakkour, 2019/04/01
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM,
Peter Xu <=
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Elijah Shakkour, 2019/04/01
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Knut Omang, 2019/04/01
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Elijah Shakkour, 2019/04/02
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Peter Xu, 2019/04/02
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Elijah Shakkour, 2019/04/03
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Elijah Shakkour, 2019/04/03
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Peter Xu, 2019/04/04
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Tian, Kevin, 2019/04/04
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Elijah Shakkour, 2019/04/07
- Re: [Qemu-devel] QEMU and vIOMMU support for emulated VF passthrough to nested (L2) VM, Tian, Kevin, 2019/04/07