diff mbox

[v3,08/12] hw/pci: introduce pci_device_notify_iommu()

Message ID 1519900415-30314-9-git-send-email-yi.l.liu@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Liu, Yi L March 1, 2018, 10:33 a.m. UTC
This patch adds pci_device_notify_iommu() for notify virtual IOMMU
emulator when assigned device is added. And adds a new notify_func
in PCIBus. vIOMMU emulator provides the instance of this notify_func.

Reason:
When virtual IOMMU is exposed to guest, vIOMMU emulator needs to
programm host IOMMU to setup DMA mapping for assigned devices. This
is a per-device operation, to be efficient, vIOMMU emulator needs
to record the assigned devices.

Example: devices assigned thru vfio, vfio_realize would call
pci_device_notify_iommu() to notify vIOMMU emulator to record necessary
info for assigned device.

Signed-off-by: Liu, Yi L <yi.l.liu@linux.intel.com>
---
 hw/alpha/typhoon.c       |  2 +-
 hw/hppa/dino.c           |  2 +-
 hw/i386/amd_iommu.c      |  2 +-
 hw/i386/intel_iommu.c    | 22 +++++++++++++++++++++-
 hw/pci-host/ppce500.c    |  2 +-
 hw/pci-host/prep.c       |  2 +-
 hw/pci-host/sabre.c      |  2 +-
 hw/pci/pci.c             | 25 +++++++++++++++++++++++--
 hw/ppc/spapr_pci.c       |  2 +-
 hw/s390x/s390-pci-bus.c  |  4 ++--
 hw/vfio/pci.c            |  3 +++
 include/hw/pci/pci.h     | 12 +++++++++++-
 include/hw/pci/pci_bus.h |  1 +
 13 files changed, 68 insertions(+), 13 deletions(-)

Comments

Paolo Bonzini March 2, 2018, 3:12 p.m. UTC | #1
On 01/03/2018 11:33, Liu, Yi L wrote:
> This patch adds pci_device_notify_iommu() for notify virtual IOMMU
> emulator when assigned device is added. And adds a new notify_func
> in PCIBus. vIOMMU emulator provides the instance of this notify_func.
> 
> Reason:
> When virtual IOMMU is exposed to guest, vIOMMU emulator needs to
> programm host IOMMU to setup DMA mapping for assigned devices. This
> is a per-device operation, to be efficient, vIOMMU emulator needs
> to record the assigned devices.
> 
> Example: devices assigned thru vfio, vfio_realize would call
> pci_device_notify_iommu() to notify vIOMMU emulator to record necessary
> info for assigned device.

I think the notification should not be left to the individual device.
Instead, the add notification should be done in pci_setup_sva_ops, and
the delete notification should be done in pci_qdev_unrealize, before
calling pc->exit, and only if dev->sva_ops is not NULL.

In general I think it's better to change your names from "assigned_dev"
to "sva_dev", because the point of the list is to only iterate over
devices that might be interested in using SVA.

Paolo
Paolo Bonzini March 2, 2018, 4:06 p.m. UTC | #2
On 01/03/2018 11:33, Liu, Yi L wrote:
> +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_ADD);
> +
>      pci_setup_sva_ops(pdev, &vfio_pci_sva_ops);
>  
>      return;
> @@ -3134,6 +3136,7 @@ static void vfio_exitfn(PCIDevice *pdev)
>  {
>      VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
>  
> +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_DEL);

Please make the names longer: PCI_IOMMU_NOTIFY_DEVICE_ADDED and
PCI_IOMMU_NOTIFY_DEVICE_REMOVED.  (This is independent of my other
remark, about doing this in generic PCI code for all devices that
register SVA ops).

Thanks,

Paolo
Peter Xu March 5, 2018, 8:27 a.m. UTC | #3
On Thu, Mar 01, 2018 at 06:33:31PM +0800, Liu, Yi L wrote:

[...]

> -void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque)
> +void pci_device_notify_iommu(PCIDevice *dev, PCIDevNotifyType type)
>  {
> -    bus->iommu_fn = fn;
> +    PCIBus *bus = PCI_BUS(pci_get_bus(dev));
> +    PCIBus *iommu_bus = bus;
> +
> +    while (iommu_bus && !iommu_bus->iommu_fn && iommu_bus->parent_dev) {
> +        iommu_bus = PCI_BUS(pci_get_bus(iommu_bus->parent_dev));
> +    }
> +    if (iommu_bus && iommu_bus->notify_fn) {
> +        iommu_bus->notify_fn(bus,
> +                             iommu_bus->iommu_opaque,
> +                             dev->devfn,
> +                             type);

We didn't really check the return code for notify function.  What if
it failed?  If we care, we'd better handle the failure; or we can just
define the notify_fn() to return void (now it's int).

> +    }
> +    return;

I saw many places in the series that you added explicit return for
"void" return-typed functions.  IMHO all of them can be dropped.

> +}

Thanks,
Liu, Yi L March 5, 2018, 8:42 a.m. UTC | #4
On Fri, Mar 02, 2018 at 04:12:01PM +0100, Paolo Bonzini wrote:
> On 01/03/2018 11:33, Liu, Yi L wrote:
> > This patch adds pci_device_notify_iommu() for notify virtual IOMMU
> > emulator when assigned device is added. And adds a new notify_func
> > in PCIBus. vIOMMU emulator provides the instance of this notify_func.
> > 
> > Reason:
> > When virtual IOMMU is exposed to guest, vIOMMU emulator needs to
> > programm host IOMMU to setup DMA mapping for assigned devices. This
> > is a per-device operation, to be efficient, vIOMMU emulator needs
> > to record the assigned devices.
> > 
> > Example: devices assigned thru vfio, vfio_realize would call
> > pci_device_notify_iommu() to notify vIOMMU emulator to record necessary
> > info for assigned device.
> 
> I think the notification should not be left to the individual device.
> Instead, the add notification should be done in pci_setup_sva_ops, and
> the delete notification should be done in pci_qdev_unrealize, before
> calling pc->exit, and only if dev->sva_ops is not NULL.

Agreed. I think it works together with your comments against
"[PATCH v3 05/12] hw/pci: introduce PCISVAOps to PCIDevice". Would apply
it in next version.
 
> In general I think it's better to change your names from "assigned_dev"
> to "sva_dev", because the point of the list is to only iterate over
> devices that might be interested in using SVA.

For "assigned_dev", my purpose is to distinguish "assigned devices" from
emulated devices. Only the SVA usage on "assigned devices" is cared here.
But it is true only SVA capable device is interested. So I may need to
rename it as "assigned_sva_dev". How about your opinion?

Thanks,
Yi Liu
Liu, Yi L March 5, 2018, 8:43 a.m. UTC | #5
On Fri, Mar 02, 2018 at 05:06:56PM +0100, Paolo Bonzini wrote:
> On 01/03/2018 11:33, Liu, Yi L wrote:
> > +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_ADD);
> > +
> >      pci_setup_sva_ops(pdev, &vfio_pci_sva_ops);
> >  
> >      return;
> > @@ -3134,6 +3136,7 @@ static void vfio_exitfn(PCIDevice *pdev)
> >  {
> >      VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> >  
> > +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_DEL);
> 
> Please make the names longer: PCI_IOMMU_NOTIFY_DEVICE_ADDED and
> PCI_IOMMU_NOTIFY_DEVICE_REMOVED.  (This is independent of my other
> remark, about doing this in generic PCI code for all devices that
> register SVA ops).

Thanks for the suggestion, will appply.

Regards,
Yi Liu
Liu, Yi L March 5, 2018, 8:46 a.m. UTC | #6
On Mon, Mar 05, 2018 at 04:27:43PM +0800, Peter Xu wrote:
> On Thu, Mar 01, 2018 at 06:33:31PM +0800, Liu, Yi L wrote:
> 
> [...]
> 
> > -void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque)
> > +void pci_device_notify_iommu(PCIDevice *dev, PCIDevNotifyType type)
> >  {
> > -    bus->iommu_fn = fn;
> > +    PCIBus *bus = PCI_BUS(pci_get_bus(dev));
> > +    PCIBus *iommu_bus = bus;
> > +
> > +    while (iommu_bus && !iommu_bus->iommu_fn && iommu_bus->parent_dev) {
> > +        iommu_bus = PCI_BUS(pci_get_bus(iommu_bus->parent_dev));
> > +    }
> > +    if (iommu_bus && iommu_bus->notify_fn) {
> > +        iommu_bus->notify_fn(bus,
> > +                             iommu_bus->iommu_opaque,
> > +                             dev->devfn,
> > +                             type);
> 
> We didn't really check the return code for notify function.  What if
> it failed?  If we care, we'd better handle the failure; or we can just
> define the notify_fn() to return void (now it's int).

Good catch. I think we need to handle failure. User should be aware of
it. I'll try to add accordingly in next version.
 
> > +    }
> > +    return;
> 
> I saw many places in the series that you added explicit return for
> "void" return-typed functions.  IMHO all of them can be dropped.

Thanks for spotting it, would fix them in next version.

Regards,
Yi Liu
Peter Xu March 5, 2018, 10:43 a.m. UTC | #7
On Mon, Mar 05, 2018 at 04:43:09PM +0800, Liu, Yi L wrote:
> On Fri, Mar 02, 2018 at 05:06:56PM +0100, Paolo Bonzini wrote:
> > On 01/03/2018 11:33, Liu, Yi L wrote:
> > > +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_ADD);
> > > +
> > >      pci_setup_sva_ops(pdev, &vfio_pci_sva_ops);
> > >  
> > >      return;
> > > @@ -3134,6 +3136,7 @@ static void vfio_exitfn(PCIDevice *pdev)
> > >  {
> > >      VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> > >  
> > > +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_DEL);
> > 
> > Please make the names longer: PCI_IOMMU_NOTIFY_DEVICE_ADDED and
> > PCI_IOMMU_NOTIFY_DEVICE_REMOVED.  (This is independent of my other
> > remark, about doing this in generic PCI code for all devices that
> > register SVA ops).
> 
> Thanks for the suggestion, will appply.

Isn't the name too generic if it's tailored for VFIO only? Would
something like PCI_IOMMU_NOTIFY_VFIO_ADD be a bit better?
Paolo Bonzini March 6, 2018, 10:18 a.m. UTC | #8
On 05/03/2018 09:42, Liu, Yi L wrote:
>> In general I think it's better to change your names from "assigned_dev"
>> to "sva_dev", because the point of the list is to only iterate over
>> devices that might be interested in using SVA.
>
> For "assigned_dev", my purpose is to distinguish "assigned devices" from
> emulated devices. Only the SVA usage on "assigned devices" is cared here.
> But it is true only SVA capable device is interested. So I may need to
> rename it as "assigned_sva_dev". How about your opinion?

What you care about is not whether the device assigned, but rather
whether it called or not pci_setup_sva_ops.  Currently only VFIO does
this, but that's not a requirement.  Hence my suggestion of calling it
sva_dev.

Paolo
Paolo Bonzini March 6, 2018, 10:19 a.m. UTC | #9
On 05/03/2018 11:43, Peter Xu wrote:
> On Mon, Mar 05, 2018 at 04:43:09PM +0800, Liu, Yi L wrote:
>> On Fri, Mar 02, 2018 at 05:06:56PM +0100, Paolo Bonzini wrote:
>>> On 01/03/2018 11:33, Liu, Yi L wrote:
>>>> +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_ADD);
>>>> +
>>>>      pci_setup_sva_ops(pdev, &vfio_pci_sva_ops);
>>>>  
>>>>      return;
>>>> @@ -3134,6 +3136,7 @@ static void vfio_exitfn(PCIDevice *pdev)
>>>>  {
>>>>      VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
>>>>  
>>>> +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_DEL);
>>>
>>> Please make the names longer: PCI_IOMMU_NOTIFY_DEVICE_ADDED and
>>> PCI_IOMMU_NOTIFY_DEVICE_REMOVED.  (This is independent of my other
>>> remark, about doing this in generic PCI code for all devices that
>>> register SVA ops).
>>
>> Thanks for the suggestion, will appply.
> 
> Isn't the name too generic if it's tailored for VFIO only? Would
> something like PCI_IOMMU_NOTIFY_VFIO_ADD be a bit better?

I don't think it's for VFIO only.  It's just that VFIO is the only
caller of pci_setup_sva_ops.

Paolo
Peter Xu March 6, 2018, 10:47 a.m. UTC | #10
On Tue, Mar 06, 2018 at 11:19:13AM +0100, Paolo Bonzini wrote:
> On 05/03/2018 11:43, Peter Xu wrote:
> > On Mon, Mar 05, 2018 at 04:43:09PM +0800, Liu, Yi L wrote:
> >> On Fri, Mar 02, 2018 at 05:06:56PM +0100, Paolo Bonzini wrote:
> >>> On 01/03/2018 11:33, Liu, Yi L wrote:
> >>>> +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_ADD);
> >>>> +
> >>>>      pci_setup_sva_ops(pdev, &vfio_pci_sva_ops);
> >>>>  
> >>>>      return;
> >>>> @@ -3134,6 +3136,7 @@ static void vfio_exitfn(PCIDevice *pdev)
> >>>>  {
> >>>>      VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> >>>>  
> >>>> +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_DEL);
> >>>
> >>> Please make the names longer: PCI_IOMMU_NOTIFY_DEVICE_ADDED and
> >>> PCI_IOMMU_NOTIFY_DEVICE_REMOVED.  (This is independent of my other
> >>> remark, about doing this in generic PCI code for all devices that
> >>> register SVA ops).
> >>
> >> Thanks for the suggestion, will appply.
> > 
> > Isn't the name too generic if it's tailored for VFIO only? Would
> > something like PCI_IOMMU_NOTIFY_VFIO_ADD be a bit better?
> 
> I don't think it's for VFIO only.  It's just that VFIO is the only
> caller of pci_setup_sva_ops.

Indeed.  E.g., we can have emulated devices that also want to provide
the SVA ops.
Liu, Yi L March 6, 2018, 11:03 a.m. UTC | #11
On Tue, Mar 06, 2018 at 11:18:43AM +0100, Paolo Bonzini wrote:
> On 05/03/2018 09:42, Liu, Yi L wrote:
> >> In general I think it's better to change your names from "assigned_dev"
> >> to "sva_dev", because the point of the list is to only iterate over
> >> devices that might be interested in using SVA.
> >
> > For "assigned_dev", my purpose is to distinguish "assigned devices" from
> > emulated devices. Only the SVA usage on "assigned devices" is cared here.
> > But it is true only SVA capable device is interested. So I may need to
> > rename it as "assigned_sva_dev". How about your opinion?
> 
> What you care about is not whether the device assigned, but rather
> whether it called or not pci_setup_sva_ops.  Currently only VFIO does
> this, but that's not a requirement.  Hence my suggestion of calling it
> sva_dev.

Yes, only VFIO calls pci_setup_sva_ops so far, but it should not limited to.
I'll apply in next version.

Thanks,
Yi Liu
Liu, Yi L March 6, 2018, 11:06 a.m. UTC | #12
On Tue, Mar 06, 2018 at 06:47:27PM +0800, Peter Xu wrote:
> On Tue, Mar 06, 2018 at 11:19:13AM +0100, Paolo Bonzini wrote:
> > On 05/03/2018 11:43, Peter Xu wrote:
> > > On Mon, Mar 05, 2018 at 04:43:09PM +0800, Liu, Yi L wrote:
> > >> On Fri, Mar 02, 2018 at 05:06:56PM +0100, Paolo Bonzini wrote:
> > >>> On 01/03/2018 11:33, Liu, Yi L wrote:
> > >>>> +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_ADD);
> > >>>> +
> > >>>>      pci_setup_sva_ops(pdev, &vfio_pci_sva_ops);
> > >>>>  
> > >>>>      return;
> > >>>> @@ -3134,6 +3136,7 @@ static void vfio_exitfn(PCIDevice *pdev)
> > >>>>  {
> > >>>>      VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> > >>>>  
> > >>>> +    pci_device_notify_iommu(pdev, PCI_NTY_DEV_DEL);
> > >>>
> > >>> Please make the names longer: PCI_IOMMU_NOTIFY_DEVICE_ADDED and
> > >>> PCI_IOMMU_NOTIFY_DEVICE_REMOVED.  (This is independent of my other
> > >>> remark, about doing this in generic PCI code for all devices that
> > >>> register SVA ops).
> > >>
> > >> Thanks for the suggestion, will appply.
> > > 
> > > Isn't the name too generic if it's tailored for VFIO only? Would
> > > something like PCI_IOMMU_NOTIFY_VFIO_ADD be a bit better?
> > 
> > I don't think it's for VFIO only.  It's just that VFIO is the only
> > caller of pci_setup_sva_ops.
> 
> Indeed.  E.g., we can have emulated devices that also want to provide
> the SVA ops.

Excatly as Paolo commented. ^_^

Thanks,
Yi Liu
Paolo Bonzini March 6, 2018, 11:22 a.m. UTC | #13
On 06/03/2018 12:03, Liu, Yi L wrote:
> On Tue, Mar 06, 2018 at 11:18:43AM +0100, Paolo Bonzini wrote:
>> On 05/03/2018 09:42, Liu, Yi L wrote:
>>>> In general I think it's better to change your names from "assigned_dev"
>>>> to "sva_dev", because the point of the list is to only iterate over
>>>> devices that might be interested in using SVA.
>>>
>>> For "assigned_dev", my purpose is to distinguish "assigned devices" from
>>> emulated devices. Only the SVA usage on "assigned devices" is cared here.
>>> But it is true only SVA capable device is interested. So I may need to
>>> rename it as "assigned_sva_dev". How about your opinion?
>>
>> What you care about is not whether the device assigned, but rather
>> whether it called or not pci_setup_sva_ops.  Currently only VFIO does
>> this, but that's not a requirement.  Hence my suggestion of calling it
>> sva_dev.
> 
> Yes, only VFIO calls pci_setup_sva_ops so far, but it should not limited to.
> I'll apply in next version.

For what it's worth, I agree with David's suggestion for naming (so
pci_setup_pasid_ops, pasid_dev, etc.)

Paolo
Yi Liu March 6, 2018, 11:27 a.m. UTC | #14
> From: Paolo Bonzini [mailto:pbonzini@redhat.com]

> Sent: Tuesday, March 6, 2018 7:22 PM

> Subject: Re: [Qemu-devel] [PATCH v3 08/12] hw/pci: introduce

> pci_device_notify_iommu()

> 

> On 06/03/2018 12:03, Liu, Yi L wrote:

> > On Tue, Mar 06, 2018 at 11:18:43AM +0100, Paolo Bonzini wrote:

> >> On 05/03/2018 09:42, Liu, Yi L wrote:

> >>>> In general I think it's better to change your names from "assigned_dev"

> >>>> to "sva_dev", because the point of the list is to only iterate over

> >>>> devices that might be interested in using SVA.

> >>>

> >>> For "assigned_dev", my purpose is to distinguish "assigned devices"

> >>> from emulated devices. Only the SVA usage on "assigned devices" is cared here.

> >>> But it is true only SVA capable device is interested. So I may need

> >>> to rename it as "assigned_sva_dev". How about your opinion?

> >>

> >> What you care about is not whether the device assigned, but rather

> >> whether it called or not pci_setup_sva_ops.  Currently only VFIO does

> >> this, but that's not a requirement.  Hence my suggestion of calling

> >> it sva_dev.

> >

> > Yes, only VFIO calls pci_setup_sva_ops so far, but it should not limited to.

> > I'll apply in next version.

> 

> For what it's worth, I agree with David's suggestion for naming (so

> pci_setup_pasid_ops, pasid_dev, etc.)


Thanks, Paolo. I would follow suggestions from you two.

Regards,
Yi Liu
diff mbox

Patch

diff --git a/hw/alpha/typhoon.c b/hw/alpha/typhoon.c
index 6a40869..a7b02cd 100644
--- a/hw/alpha/typhoon.c
+++ b/hw/alpha/typhoon.c
@@ -894,7 +894,7 @@  PCIBus *typhoon_init(ram_addr_t ram_size, ISABus **isa_bus,
                              "iommu-typhoon", UINT64_MAX);
     address_space_init(&s->pchip.iommu_as, MEMORY_REGION(&s->pchip.iommu),
                        "pchip0-pci");
-    pci_setup_iommu(b, typhoon_pci_dma_iommu, s);
+    pci_setup_iommu(b, typhoon_pci_dma_iommu, NULL, s);
 
     /* Pchip0 PCI special/interrupt acknowledge, 0x801.F800.0000, 64MB.  */
     memory_region_init_io(&s->pchip.reg_iack, OBJECT(s), &alpha_pci_iack_ops,
diff --git a/hw/hppa/dino.c b/hw/hppa/dino.c
index 15aefde..7867b46 100644
--- a/hw/hppa/dino.c
+++ b/hw/hppa/dino.c
@@ -481,7 +481,7 @@  PCIBus *dino_init(MemoryRegion *addr_space,
                                 0xf0000000 + DINO_MEM_CHUNK_SIZE,
                                 &s->bm_pci_alias);
     address_space_init(&s->bm_as, &s->bm, "pci-bm");
-    pci_setup_iommu(b, dino_pcihost_set_iommu, s);
+    pci_setup_iommu(b, dino_pcihost_set_iommu, NULL, s);
 
     *p_rtc_irq = qemu_allocate_irq(dino_set_timer_irq, s, 0);
     *p_ser_irq = qemu_allocate_irq(dino_set_serial_irq, s, 0);
diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index 7bfde37..341a14d 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -1178,7 +1178,7 @@  static void amdvi_realize(DeviceState *dev, Error **err)
 
     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->mmio);
     sysbus_mmio_map(SYS_BUS_DEVICE(s), 0, AMDVI_BASE_ADDR);
-    pci_setup_iommu(bus, amdvi_host_dma_iommu, s);
+    pci_setup_iommu(bus, amdvi_host_dma_iommu, NULL, s);
     s->devid = object_property_get_int(OBJECT(&s->pci), "addr", err);
     msi_init(&s->pci.dev, 0, 1, true, false, err);
     amdvi_init(s);
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 9edf392..2fd0a6d 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3005,6 +3005,26 @@  static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
     return &vtd_as->as;
 }
 
+static int vtd_device_notify(PCIBus *bus,
+                             void *opaque,
+                             int devfn,
+                             PCIDevNotifyType type)
+{
+    IntelIOMMUState *s = opaque;
+    VTDAddressSpace *vtd_as;
+
+    assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
+
+    vtd_as = vtd_find_add_as(s, bus, devfn);
+
+    if (vtd_as == NULL) {
+        return -1;
+    }
+
+    /* TODO: record assigned device in IOMMU Emulator */
+    return 0;
+}
+
 static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
 {
     X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
@@ -3075,7 +3095,7 @@  static void vtd_realize(DeviceState *dev, Error **errp)
                                               g_free, g_free);
     vtd_init(s);
     sysbus_mmio_map(SYS_BUS_DEVICE(s), 0, Q35_HOST_BRIDGE_IOMMU_ADDR);
-    pci_setup_iommu(bus, vtd_host_dma_iommu, dev);
+    pci_setup_iommu(bus, vtd_host_dma_iommu, vtd_device_notify, dev);
     /* Pseudo address space under root PCI bus. */
     pcms->ioapic_as = vtd_host_dma_iommu(bus, s, Q35_PSEUDO_DEVFN_IOAPIC);
 }
diff --git a/hw/pci-host/ppce500.c b/hw/pci-host/ppce500.c
index eb75e08..8175df5 100644
--- a/hw/pci-host/ppce500.c
+++ b/hw/pci-host/ppce500.c
@@ -469,7 +469,7 @@  static int e500_pcihost_initfn(SysBusDevice *dev)
     memory_region_init(&s->bm, OBJECT(s), "bm-e500", UINT64_MAX);
     memory_region_add_subregion(&s->bm, 0x0, &s->busmem);
     address_space_init(&s->bm_as, &s->bm, "pci-bm");
-    pci_setup_iommu(b, e500_pcihost_set_iommu, s);
+    pci_setup_iommu(b, e500_pcihost_set_iommu, NULL, s);
 
     pci_create_simple(b, 0, "e500-host-bridge");
 
diff --git a/hw/pci-host/prep.c b/hw/pci-host/prep.c
index 01f67f9..b4d02cf 100644
--- a/hw/pci-host/prep.c
+++ b/hw/pci-host/prep.c
@@ -282,7 +282,7 @@  static void raven_pcihost_initfn(Object *obj)
     memory_region_add_subregion(&s->bm, 0         , &s->bm_pci_memory_alias);
     memory_region_add_subregion(&s->bm, 0x80000000, &s->bm_ram_alias);
     address_space_init(&s->bm_as, &s->bm, "raven-bm");
-    pci_setup_iommu(&s->pci_bus, raven_pcihost_set_iommu, s);
+    pci_setup_iommu(&s->pci_bus, raven_pcihost_set_iommu, NULL, s);
 
     h->bus = &s->pci_bus;
 
diff --git a/hw/pci-host/sabre.c b/hw/pci-host/sabre.c
index e2f4ee4..e119753 100644
--- a/hw/pci-host/sabre.c
+++ b/hw/pci-host/sabre.c
@@ -399,7 +399,7 @@  static void sabre_realize(DeviceState *dev, Error **errp)
     /* IOMMU */
     memory_region_add_subregion_overlap(&s->sabre_config, 0x200,
                     sysbus_mmio_get_region(SYS_BUS_DEVICE(s->iommu), 0), 1);
-    pci_setup_iommu(phb->bus, sabre_pci_dma_iommu, s->iommu);
+    pci_setup_iommu(phb->bus, sabre_pci_dma_iommu, NULL, s->iommu);
 
     /* APB secondary busses */
     pci_dev = pci_create_multifunction(phb->bus, PCI_DEVFN(1, 0), true,
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 157fe21..0f2db02 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2567,9 +2567,30 @@  AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
     return &address_space_memory;
 }
 
-void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque)
+void pci_device_notify_iommu(PCIDevice *dev, PCIDevNotifyType type)
 {
-    bus->iommu_fn = fn;
+    PCIBus *bus = PCI_BUS(pci_get_bus(dev));
+    PCIBus *iommu_bus = bus;
+
+    while (iommu_bus && !iommu_bus->iommu_fn && iommu_bus->parent_dev) {
+        iommu_bus = PCI_BUS(pci_get_bus(iommu_bus->parent_dev));
+    }
+    if (iommu_bus && iommu_bus->notify_fn) {
+        iommu_bus->notify_fn(bus,
+                             iommu_bus->iommu_opaque,
+                             dev->devfn,
+                             type);
+    }
+    return;
+}
+
+void pci_setup_iommu(PCIBus *bus,
+                     PCIIOMMUFunc iommu_fn,
+                     PCIIOMMUNotifyFunc notify_fn,
+                     void *opaque)
+{
+    bus->iommu_fn = iommu_fn;
+    bus->notify_fn = notify_fn;
     bus->iommu_opaque = opaque;
 }
 
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 39a1498..2be0a0f 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -1687,7 +1687,7 @@  static void spapr_phb_realize(DeviceState *dev, Error **errp)
     memory_region_add_subregion(&sphb->iommu_root, SPAPR_PCI_MSI_WINDOW,
                                 &sphb->msiwindow);
 
-    pci_setup_iommu(bus, spapr_pci_dma_iommu, sphb);
+    pci_setup_iommu(bus, spapr_pci_dma_iommu, NULL, sphb);
 
     pci_bus_set_route_irq_fn(bus, spapr_route_intx_pin_to_irq);
 
diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
index 1bad7ab..cc650c4 100644
--- a/hw/s390x/s390-pci-bus.c
+++ b/hw/s390x/s390-pci-bus.c
@@ -705,7 +705,7 @@  static int s390_pcihost_init(SysBusDevice *dev)
                               s390_pci_set_irq, s390_pci_map_irq, NULL,
                               get_system_memory(), get_system_io(), 0, 64,
                               TYPE_PCI_BUS);
-    pci_setup_iommu(b, s390_pci_dma_iommu, s);
+    pci_setup_iommu(b, s390_pci_dma_iommu, NULL, s);
 
     bus = BUS(b);
     qbus_set_hotplug_handler(bus, DEVICE(dev), NULL);
@@ -817,7 +817,7 @@  static void s390_pcihost_hot_plug(HotplugHandler *hotplug_dev,
         PCIDevice *pdev = PCI_DEVICE(dev);
 
         pci_bridge_map_irq(pb, dev->id, s390_pci_map_irq);
-        pci_setup_iommu(&pb->sec_bus, s390_pci_dma_iommu, s);
+        pci_setup_iommu(&pb->sec_bus, s390_pci_dma_iommu, NULL, s);
 
         bus = BUS(&pb->sec_bus);
         qbus_set_hotplug_handler(bus, DEVICE(s), errp);
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index b7297cc..a9c0898 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3098,6 +3098,8 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     vfio_register_req_notifier(vdev);
     vfio_setup_resetfn_quirk(vdev);
 
+    pci_device_notify_iommu(pdev, PCI_NTY_DEV_ADD);
+
     pci_setup_sva_ops(pdev, &vfio_pci_sva_ops);
 
     return;
@@ -3134,6 +3136,7 @@  static void vfio_exitfn(PCIDevice *pdev)
 {
     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
 
+    pci_device_notify_iommu(pdev, PCI_NTY_DEV_DEL);
     vfio_unregister_req_notifier(vdev);
     vfio_unregister_err_notifier(vdev);
     pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 32889a4..964be2b 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -485,10 +485,20 @@  void pci_bus_get_w64_range(PCIBus *bus, Range *range);
 
 void pci_device_deassert_intx(PCIDevice *dev);
 
+enum PCIDevNotifyType {
+    PCI_NTY_DEV_ADD = 0,
+    PCI_NTY_DEV_DEL,
+};
+typedef enum PCIDevNotifyType PCIDevNotifyType;
 typedef AddressSpace *(*PCIIOMMUFunc)(PCIBus *, void *, int);
+typedef int (*PCIIOMMUNotifyFunc)(PCIBus *, void *, int, PCIDevNotifyType);
 
 AddressSpace *pci_device_iommu_address_space(PCIDevice *dev);
-void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque);
+void pci_device_notify_iommu(PCIDevice *dev, PCIDevNotifyType type);
+void pci_setup_iommu(PCIBus *bus,
+                     PCIIOMMUFunc iommu_fn,
+                     PCIIOMMUNotifyFunc notify_fn,
+                     void *opaque);
 
 void pci_setup_sva_ops(PCIDevice *dev, PCISVAOps *ops);
 void pci_device_sva_bind_pasid_table(PCIBus *bus, int32_t devfn,
diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
index b7da8f5..54a0c8e 100644
--- a/include/hw/pci/pci_bus.h
+++ b/include/hw/pci/pci_bus.h
@@ -21,6 +21,7 @@  typedef struct PCIBusClass {
 struct PCIBus {
     BusState qbus;
     PCIIOMMUFunc iommu_fn;
+    PCIIOMMUNotifyFunc notify_fn;
     void *iommu_opaque;
     uint8_t devfn_min;
     uint32_t slot_reserved_mask;