Hi Eric,
> -Original Message-
> From: Auger Eric [mailto:eric.au...@redhat.com]
> Sent: 16 April 2020 08:45
> To: Zhangfei Gao ; eric.auger@gmail.com;
> iommu@lists.linux-foundation.org; linux-ker...@vger.kernel.org;
> k...@vger.kernel.org; kvm...@lists.cs.columbia.edu; w...@kernel.org
The Type-1 hypervisor we are dealing with does not allow for MMIO transport.
[1] summarizes some of the problems we have in making virtio work on such
hypervisors. This patch proposes a solution for transport problem viz how we can
do config space IO on such a hypervisor. Hypervisor specific metho
Some hypervisors may not support MMIO transport i.e trap config
space access and have it be handled by backend driver. They may
allow other ways to interact with backend such as message-queue
or doorbell API. This patch allows for hypervisor specific
methods for config space IO.
Signed-off-by: Sri
On Thu, Apr 30, 2020 at 03:32:55PM +0530, Srivatsa Vaddagiri wrote:
> The Type-1 hypervisor we are dealing with does not allow for MMIO transport.
How about PCI then?
--
MST
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On Thu, Apr 30, 2020 at 03:32:55PM +0530, Srivatsa Vaddagiri wrote:
> The Type-1 hypervisor we are dealing with does not allow for MMIO transport.
> [1] summarizes some of the problems we have in making virtio work on such
> hypervisors. This patch proposes a solution for transport problem viz how
On Thu, Apr 30, 2020 at 03:32:56PM +0530, Srivatsa Vaddagiri wrote:
> Some hypervisors may not support MMIO transport i.e trap config
> space access and have it be handled by backend driver. They may
> allow other ways to interact with backend such as message-queue
> or doorbell API. This patch all
* Will Deacon [2020-04-30 11:08:22]:
> > This patch is meant to seek comments. If its considered to be in right
> > direction, will work on making it more complete and send the next version!
>
> What's stopping you from implementing the trapping support in the
> hypervisor? Unlike the other patc
* Will Deacon [2020-04-30 11:14:32]:
> > +#ifdef CONFIG_VIRTIO_MMIO_OPS
> >
> > +static struct virtio_mmio_ops *mmio_ops;
> > +
> > +#define virtio_readb(a)mmio_ops->mmio_readl((a))
> > +#define virtio_readw(a)mmio_ops->mmio_readl((a))
> > +#define virtio_readl(a)
Hi Vatsa,
On Thu, Apr 30, 2020 at 03:59:39PM +0530, Srivatsa Vaddagiri wrote:
> * Will Deacon [2020-04-30 11:08:22]:
>
> > > This patch is meant to seek comments. If its considered to be in right
> > > direction, will work on making it more complete and send the next version!
> >
> > What's sto
* Michael S. Tsirkin [2020-04-30 06:07:56]:
> On Thu, Apr 30, 2020 at 03:32:55PM +0530, Srivatsa Vaddagiri wrote:
> > The Type-1 hypervisor we are dealing with does not allow for MMIO
> > transport.
>
> How about PCI then?
Correct me if I am wrong, but basically virtio_pci uses the same low-l
On Thu, Apr 30, 2020 at 04:04:46PM +0530, Srivatsa Vaddagiri wrote:
> * Will Deacon [2020-04-30 11:14:32]:
>
> > > +#ifdef CONFIG_VIRTIO_MMIO_OPS
> > >
> > > +static struct virtio_mmio_ops *mmio_ops;
> > > +
> > > +#define virtio_readb(a) mmio_ops->mmio_readl((a))
> > > +#define virtio
On 2020/4/30 下午6:07, Michael S. Tsirkin wrote:
On Thu, Apr 30, 2020 at 03:32:55PM +0530, Srivatsa Vaddagiri wrote:
The Type-1 hypervisor we are dealing with does not allow for MMIO transport.
How about PCI then?
Or maybe you can use virtio-vdpa.
Thanks
___
* Will Deacon [2020-04-30 11:39:19]:
> Hi Vatsa,
>
> On Thu, Apr 30, 2020 at 03:59:39PM +0530, Srivatsa Vaddagiri wrote:
> > > What's stopping you from implementing the trapping support in the
> > > hypervisor? Unlike the other patches you sent out, where the guest memory
> > > is not accessible
* Will Deacon [2020-04-30 11:41:50]:
> On Thu, Apr 30, 2020 at 04:04:46PM +0530, Srivatsa Vaddagiri wrote:
> > If CONFIG_VIRTIO_MMIO_OPS is defined, then I expect this to be
> > unconditionally
> > set to 'magic_qcom_ops' that uses hypervisor-supported interface for IO (for
> > example: message_
In commit a7ba5c3d008d ("drivers/iommu: Export core IOMMU API symbols to
permit modular drivers") a bunch of iommu symbols were exported, all
with _GPL markings except iommu_group_get_for_dev(). That export should
also be _GPL like the others.
Cc: Will Deacon
Cc: Joerg Roedel
Cc: John Garry
Fi
On Thu, Apr 30, 2020 at 02:01:20PM +0200, Greg Kroah-Hartman wrote:
> In commit a7ba5c3d008d ("drivers/iommu: Export core IOMMU API symbols to
> permit modular drivers") a bunch of iommu symbols were exported, all
> with _GPL markings except iommu_group_get_for_dev(). That export should
> also be
On Thu, Apr 30, 2020 at 01:17:53PM +0100, Will Deacon wrote:
> Thanks, not sure how I managed to screw this up in the original patch!
>
> Acked-by: Will Deacon
>
> Joerg -- can you pick this one up please?
Yes, will send it as a fix for 5.7, but note that this function will be
unexported in 5.8
On 30.04.20 13:11, Srivatsa Vaddagiri wrote:
* Will Deacon [2020-04-30 11:41:50]:
On Thu, Apr 30, 2020 at 04:04:46PM +0530, Srivatsa Vaddagiri wrote:
If CONFIG_VIRTIO_MMIO_OPS is defined, then I expect this to be unconditionally
set to 'magic_qcom_ops' that uses hypervisor-supported interface
* Jan Kiszka [2020-04-30 14:59:50]:
> >I believe ivshmem2_virtio requires hypervisor to support PCI device emulation
> >(for life-cycle management of VMs), which our hypervisor may not support. A
> >simple shared memory and doorbell or message-queue based transport will work
> >for
> >us.
>
> A
Hi
On 28.04.2020 16:27, Tvrtko Ursulin wrote:
>
> On 28/04/2020 14:19, Marek Szyprowski wrote:
>> The Documentation/DMA-API-HOWTO.txt states that dma_map_sg returns the
>> numer of the created entries in the DMA address space. However the
>> subsequent calls to dma_sync_sg_for_{device,cpu} and dma
Shared Virtual Addressing (SVA) allows to share process page tables with
devices using the IOMMU, PASIDs and I/O page faults. Add SVA support to
the Arm SMMUv3 driver.
Since v5 [1]:
* Added patches 1-3. Patch 1 adds a PASID field to mm_struct as
discussed in [1] and [2]. This is also needed for
Let IOMMU drivers allocate a single PASID per mm. Store the mm in the
IOASID set to allow refcounting and searching mm by PASID, when handling
an I/O page fault.
Signed-off-by: Jean-Philippe Brucker
---
drivers/iommu/Kconfig | 5 +++
drivers/iommu/Makefile| 1 +
drivers/iommu/iommu-sva
If the SMMU supports it and the kernel was built with HTTU support, enable
hardware update of access and dirty flags. This is essential for shared
page tables, to reduce the number of access faults on the fault queue.
We can enable HTTU even if CPUs don't support it, because the kernel
always chec
Add a macro to check if an ASID is from the current generation, since a
subsequent patch will introduce a third user for this test.
Signed-off-by: Jean-Philippe Brucker
---
arch/arm64/mm/context.c | 8 +---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/mm/context.c
On ARM systems, some platform devices behind an IOMMU may support stall,
which is the ability to recover from page faults. Let the firmware tell us
when a device supports stall.
Reviewed-by: Rob Herring
Signed-off-by: Jean-Philippe Brucker
---
.../devicetree/bindings/iommu/iommu.txt| 18
The invalidate_range() notifier is called for any change to the address
space. Perform the required ATC invalidations.
Signed-off-by: Jean-Philippe Brucker
---
drivers/iommu/arm-smmu-v3.c | 56 ++---
1 file changed, 46 insertions(+), 10 deletions(-)
diff --git a/
The SMMUv3 driver uses pci_{enable,disable}_pri() and related
functions. Export those functions to allow the driver to be built as a
module.
Acked-by: Bjorn Helgaas
Reviewed-by: Kuppuswamy Sathyanarayanan
Signed-off-by: Jean-Philippe Brucker
---
drivers/pci/ats.c | 4
1 file changed, 4 i
In preparation for sharing some ASIDs with the CPU, use a global xarray to
store ASIDs and their context. ASID#0 is now reserved, and the ASID
space is global.
Signed-off-by: Jean-Philippe Brucker
---
drivers/iommu/arm-smmu-v3.c | 27 ++-
1 file changed, 18 insertions(+),
When handling faults from the event or PRI queue, we need to find the
struct device associated to a SID. Add a rb_tree to keep track of SIDs.
Signed-off-by: Jean-Philippe Brucker
---
drivers/iommu/arm-smmu-v3.c | 175 +---
1 file changed, 145 insertions(+), 30 del
With Shared Virtual Addressing (SVA), we need to mirror CPU TTBR, TCR,
MAIR and ASIDs in SMMU contexts. Each SMMU has a single ASID space split
into two sets, shared and private. Shared ASIDs correspond to those
obtained from the arch ASID allocator, and private ASIDs are used for
"classic" map/unm
Let IOASID users take references to existing ioasids with ioasid_get().
ioasid_free() drops a reference and only frees the ioasid when its
reference number is zero. It returns whether the ioasid was freed.
Signed-off-by: Jean-Philippe Brucker
---
include/linux/ioasid.h | 10 --
drivers/i
The SMMUv3 driver would like to read the MMFR0 PARANGE field in order to
share CPU page tables with devices. Allow the driver to be built as
module by exporting the read_sanitized_ftr_reg() cpufeature symbol.
Cc: Suzuki K Poulose
Signed-off-by: Jean-Philippe Brucker
---
arch/arm64/kernel/cpufea
The SMMUv3 can handle invalidation targeted at TLB entries with shared
ASIDs. If the implementation supports broadcast TLB maintenance, enable it
and keep track of it in a feature bit. The SMMU will then be affected by
inner-shareable TLB invalidations from other agents.
A major side-effect of thi
For PCI devices that support it, enable the PRI capability and handle PRI
Page Requests with the generic fault handler. It is enabled on demand by
iommu_sva_device_init().
Signed-off-by: Jean-Philippe Brucker
---
drivers/iommu/arm-smmu-v3.c | 286 +---
1 file chan
Some devices can tag their DMA requests with a 20-bit Process Address
Space ID (PASID), allowing them to access multiple address spaces. In
combination with recoverable I/O page faults (for example PCIe PRI),
PASID allows the IOMMU to share page tables with the MMU.
To make sure that a single PASI
The sva_bind() function allows devices to access process address spaces
using a PASID (aka SSID).
(1) bind() allocates or gets an existing MMU notifier tied to the
(domain, mm) pair. Each mm gets one PASID.
(2) Any change to the address space calls invalidate_range() which sends
ATC inval
ARMv8.1 extensions added Virtualization Host Extensions (VHE), which allow
to run a host kernel at EL2. When using normal DMA, Device and CPU address
spaces are dissociated, and do not need to implement the same
capabilities, so VHE hasn't been used in the SMMU until now.
With shared address space
The SMMU provides a Stall model for handling page faults in platform
devices. It is similar to PCI PRI, but doesn't require devices to have
their own translation cache. Instead, faulting transactions are parked
and the OS is given a chance to fix the page tables and retry the
transaction.
Enable s
The SMMU has a single ASID space, the union of shared and private ASID
sets. This means that the SMMU driver competes with the arch allocator
for ASIDs. Shared ASIDs are those of Linux processes, allocated by the
arch, and contribute in broadcast TLB maintenance. Private ASIDs are
allocated by the
To enable address space sharing with the IOMMU, introduce mm_context_get()
and mm_context_put(), that pin down a context and ensure that it will keep
its ASID after a rollover. Export the symbols to let the modular SMMUv3
driver use them.
Pinning is necessary because a device constantly needs a va
Some systems allow devices to handle I/O Page Faults in the core mm. For
example systems implementing the PCIe PRI extension or Arm SMMU stall
model. Infrastructure for reporting these recoverable page faults was
added to the IOMMU core by commit 0c830e6b3282 ("iommu: Introduce device
fault report
Implement the IOMMU device feature callbacks to support the SVA feature.
At the moment dev_has_feat() returns false since I/O Page Faults isn't
yet implemented.
Signed-off-by: Jean-Philippe Brucker
---
drivers/iommu/arm-smmu-v3.c | 125
1 file changed, 125 in
When a recoverable page fault is handled by the fault workqueue, find the
associated mm and call handle_mm_fault.
Signed-off-by: Jean-Philippe Brucker
---
v5->v6: select CONFIG_IOMMU_SVA
---
drivers/iommu/Kconfig | 1 +
drivers/iommu/io-pgfault.c | 79 +-
Extract some of the most generic TCR defines, so they can be reused by
the page table sharing code.
Signed-off-by: Jean-Philippe Brucker
---
v5->v6: Update MAINTAINERS
---
drivers/iommu/io-pgtable-arm.h | 30 ++
drivers/iommu/io-pgtable-arm.c | 27 ++--
Aggregate all sanity-checks for sharing CPU page tables with the SMMU
under a single ARM_SMMU_FEAT_SVA bit. For PCIe SVA, users also need to
check FEAT_ATS and FEAT_PRI. For platform SVA, they will most likely have
to check FEAT_STALLS.
Cc: Suzuki K Poulose
Signed-off-by: Jean-Philippe Brucker
-
The SMMUv3 driver, which can be built without CONFIG_PCI, will soon gain
support for PRI. Partially revert commit c6e9aefbf9db ("PCI/ATS: Remove
unused PRI and PASID stubs") to re-introduce the PRI stubs, and avoid
adding more #ifdefs to the SMMU driver.
Acked-by: Bjorn Helgaas
Reviewed-by: Kupp
On 04/30/2020 03:34 PM, Jean-Philippe Brucker wrote:
The SMMUv3 driver would like to read the MMFR0 PARANGE field in order to
share CPU page tables with devices. Allow the driver to be built as
module by exporting the read_sanitized_ftr_reg() cpufeature symbol.
Cc: Suzuki K Poulose
Signed-off-b
On Wed, Apr 29, 2020 at 06:20:48AM -0400, Michael S. Tsirkin wrote:
> On Wed, Apr 29, 2020 at 03:39:53PM +0530, Srivatsa Vaddagiri wrote:
> > That would still not work I think where swiotlb is used for pass-thr devices
> > (when private memory is fine) as well as virtio devices (when shared memory
On 04/30/2020 03:34 PM, Jean-Philippe Brucker wrote:
With Shared Virtual Addressing (SVA), we need to mirror CPU TTBR, TCR,
MAIR and ASIDs in SMMU contexts. Each SMMU has a single ASID space split
into two sets, shared and private. Shared ASIDs correspond to those
obtained from the arch ASID allo
On Thu, 30 Apr 2020 16:34:01 +0200
Jean-Philippe Brucker wrote:
> Let IOASID users take references to existing ioasids with
> ioasid_get(). ioasid_free() drops a reference and only frees the
> ioasid when its reference number is zero. It returns whether the
> ioasid was freed.
>
Looks good to me
On Thu, Apr 30, 2020 at 07:03:21PM +0530, Srivatsa Vaddagiri wrote:
> * Jan Kiszka [2020-04-30 14:59:50]:
>
> > >I believe ivshmem2_virtio requires hypervisor to support PCI device
> > >emulation
> > >(for life-cycle management of VMs), which our hypervisor may not support.
PCI is mostly just 2
On Thu, 30 Apr 2020 11:39:31 -0700
Jacob Pan wrote:
> > -void ioasid_free(ioasid_t ioasid)
> > +bool ioasid_free(ioasid_t ioasid)
> > {
Sorry I missed this in the last reply.
I think free needs to be unconditional since there is not a good way to
fail it.
Also can we have more symmetric APIs,
Hi Jean,
A couple question on how SMMU handles CD.v and translation disable.
On Thu, 30 Apr 2020 16:34:16 +0200
Jean-Philippe Brucker wrote:
> The sva_bind() function allows devices to access process address
> spaces using a PASID (aka SSID).
>
> (1) bind() allocates or gets an existing MMU no
On Thu, 30 Apr 2020 16:33:59 +0200
Jean-Philippe Brucker wrote:
> Shared Virtual Addressing (SVA) allows to share process page tables
> with devices using the IOMMU, PASIDs and I/O page faults. Add SVA
> support to the Arm SMMUv3 driver.
>
> Since v5 [1]:
>
> * Added patches 1-3. Patch 1 adds a
>> On Tue, Apr 14, 2020 at 03:13:40PM +0200, Christoph Hellwig wrote:
>> > The pgprot argument to __vmalloc is always PROT_KERNEL now, so remove
>> > it.
Greetings;
I recently noticed this change via the linux-next tree.
It may not be possible to edit at this late date, but the change
descriptio
Greetings;
I recently noticed this change via the linux-next tree.
It may not be possible to edit at this late date, but the change
description refers to PROT_KERNEL, which is a symbol which does not appear
to exist; perhaps PAGE_KERNEL was meant? The mismatch caused me and a
couple other folks s
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