2020-04-01 11:44:19

by Bharat Bhushan

Subject: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by endpoint

Different endpoint can support different page size, probe
endpoint if it supports specific page size otherwise use
global page sizes.

Signed-off-by: Bharat Bhushan <[email protected]>
---
drivers/iommu/virtio-iommu.c | 33 +++++++++++++++++++++++++++----
include/uapi/linux/virtio_iommu.h | 7 +++++++
2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index cce329d71fba..c794cb5b7b3e 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -78,6 +78,7 @@ struct viommu_endpoint {
struct viommu_dev *viommu;
struct viommu_domain *vdomain;
struct list_head resv_regions;
+ u64 pgsize_bitmap;
};

struct viommu_request {
@@ -415,6 +416,20 @@ static int viommu_replay_mappings(struct viommu_domain *vdomain)
return ret;
}

+static int viommu_set_pgsize_bitmap(struct viommu_endpoint *vdev,
+ struct virtio_iommu_probe_pgsize_mask *mask,
+ size_t len)
+
+{
+ u64 pgsize_bitmap = le64_to_cpu(mask->pgsize_bitmap);
+
+ if (len < sizeof(*mask))
+ return -EINVAL;
+
+ vdev->pgsize_bitmap = pgsize_bitmap;
+ return 0;
+}
+
static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
struct virtio_iommu_probe_resv_mem *mem,
size_t len)
@@ -494,11 +509,13 @@ static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev)
while (type != VIRTIO_IOMMU_PROBE_T_NONE &&
cur < viommu->probe_size) {
len = le16_to_cpu(prop->length) + sizeof(*prop);
-
switch (type) {
case VIRTIO_IOMMU_PROBE_T_RESV_MEM:
ret = viommu_add_resv_mem(vdev, (void *)prop, len);
break;
+ case VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK:
+ ret = viommu_set_pgsize_bitmap(vdev, (void *)prop, len);
+ break;
default:
dev_err(dev, "unknown viommu prop 0x%x\n", type);
}
@@ -607,16 +624,23 @@ static struct iommu_domain *viommu_domain_alloc(unsigned type)
return &vdomain->domain;
}

-static int viommu_domain_finalise(struct viommu_dev *viommu,
+static int viommu_domain_finalise(struct viommu_endpoint *vdev,
struct iommu_domain *domain)
{
int ret;
struct viommu_domain *vdomain = to_viommu_domain(domain);
+ struct viommu_dev *viommu = vdev->viommu;

vdomain->viommu = viommu;
vdomain->map_flags = viommu->map_flags;

- domain->pgsize_bitmap = viommu->pgsize_bitmap;
+ /* Devices in same domain must support same size pages */
+ if ((domain->pgsize_bitmap != viommu->pgsize_bitmap) &&
+ (domain->pgsize_bitmap != vdev->pgsize_bitmap))
+ return -EINVAL;
+
+ domain->pgsize_bitmap = vdev->pgsize_bitmap;
+
domain->geometry = viommu->geometry;

ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
@@ -657,7 +681,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
* Properly initialize the domain now that we know which viommu
* owns it.
*/
- ret = viommu_domain_finalise(vdev->viommu, domain);
+ ret = viommu_domain_finalise(vdev, domain);
} else if (vdomain->viommu != vdev->viommu) {
dev_err(dev, "cannot attach to foreign vIOMMU\n");
ret = -EXDEV;
@@ -875,6 +899,7 @@ static int viommu_add_device(struct device *dev)

vdev->dev = dev;
vdev->viommu = viommu;
+ vdev->pgsize_bitmap = viommu->pgsize_bitmap;
INIT_LIST_HEAD(&vdev->resv_regions);
fwspec->iommu_priv = vdev;

diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h
index 237e36a280cb..dc9d3f40bcd8 100644
--- a/include/uapi/linux/virtio_iommu.h
+++ b/include/uapi/linux/virtio_iommu.h
@@ -111,6 +111,7 @@ struct virtio_iommu_req_unmap {

#define VIRTIO_IOMMU_PROBE_T_NONE 0
#define VIRTIO_IOMMU_PROBE_T_RESV_MEM 1
+#define VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK 2

#define VIRTIO_IOMMU_PROBE_T_MASK 0xfff

@@ -119,6 +120,12 @@ struct virtio_iommu_probe_property {
__le16 length;
};

+struct virtio_iommu_probe_pgsize_mask {
+ struct virtio_iommu_probe_property head;
+ __u8 reserved[4];
+ __u64 pgsize_bitmap;
+};
+
#define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0
#define VIRTIO_IOMMU_RESV_MEM_T_MSI 1

--
2.17.1

2020-04-01 13:01:01

by Robin Murphy

Subject: Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by endpoint

On 2020-04-01 12:38 pm, Bharat Bhushan wrote:
> Different endpoint can support different page size, probe
> endpoint if it supports specific page size otherwise use
> global page sizes.
>
> Signed-off-by: Bharat Bhushan <[email protected]>
> ---
> drivers/iommu/virtio-iommu.c | 33 +++++++++++++++++++++++++++----
> include/uapi/linux/virtio_iommu.h | 7 +++++++
> 2 files changed, 36 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> index cce329d71fba..c794cb5b7b3e 100644
> --- a/drivers/iommu/virtio-iommu.c
> +++ b/drivers/iommu/virtio-iommu.c
> @@ -78,6 +78,7 @@ struct viommu_endpoint {
> struct viommu_dev *viommu;
> struct viommu_domain *vdomain;
> struct list_head resv_regions;
> + u64 pgsize_bitmap;
> };
>
> struct viommu_request {
> @@ -415,6 +416,20 @@ static int viommu_replay_mappings(struct viommu_domain *vdomain)
> return ret;
> }
>
> +static int viommu_set_pgsize_bitmap(struct viommu_endpoint *vdev,
> + struct virtio_iommu_probe_pgsize_mask *mask,
> + size_t len)
> +
> +{
> + u64 pgsize_bitmap = le64_to_cpu(mask->pgsize_bitmap);
> +
> + if (len < sizeof(*mask))
> + return -EINVAL;
> +
> + vdev->pgsize_bitmap = pgsize_bitmap;
> + return 0;
> +}
> +
> static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
> struct virtio_iommu_probe_resv_mem *mem,
> size_t len)
> @@ -494,11 +509,13 @@ static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev)
> while (type != VIRTIO_IOMMU_PROBE_T_NONE &&
> cur < viommu->probe_size) {
> len = le16_to_cpu(prop->length) + sizeof(*prop);
> -
> switch (type) {
> case VIRTIO_IOMMU_PROBE_T_RESV_MEM:
> ret = viommu_add_resv_mem(vdev, (void *)prop, len);
> break;
> + case VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK:
> + ret = viommu_set_pgsize_bitmap(vdev, (void *)prop, len);
> + break;
> default:
> dev_err(dev, "unknown viommu prop 0x%x\n", type);
> }
> @@ -607,16 +624,23 @@ static struct iommu_domain *viommu_domain_alloc(unsigned type)
> return &vdomain->domain;
> }
>
> -static int viommu_domain_finalise(struct viommu_dev *viommu,
> +static int viommu_domain_finalise(struct viommu_endpoint *vdev,
> struct iommu_domain *domain)
> {
> int ret;
> struct viommu_domain *vdomain = to_viommu_domain(domain);
> + struct viommu_dev *viommu = vdev->viommu;
>
> vdomain->viommu = viommu;
> vdomain->map_flags = viommu->map_flags;
>
> - domain->pgsize_bitmap = viommu->pgsize_bitmap;
> + /* Devices in same domain must support same size pages */

AFAICS what the code appears to do is enforce that the first endpoint
attached to any domain has the same pgsize_bitmap as the most recently
probed viommu_dev instance, then ignore any subsequent endpoints
attached to the same domain. Thus I'm not sure that comment is accurate.

Robin.

> + if ((domain->pgsize_bitmap != viommu->pgsize_bitmap) &&
> + (domain->pgsize_bitmap != vdev->pgsize_bitmap))
> + return -EINVAL;
> +
> + domain->pgsize_bitmap = vdev->pgsize_bitmap;
> +
> domain->geometry = viommu->geometry;
>
> ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
> @@ -657,7 +681,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
> * Properly initialize the domain now that we know which viommu
> * owns it.
> */
> - ret = viommu_domain_finalise(vdev->viommu, domain);
> + ret = viommu_domain_finalise(vdev, domain);
> } else if (vdomain->viommu != vdev->viommu) {
> dev_err(dev, "cannot attach to foreign vIOMMU\n");
> ret = -EXDEV;
> @@ -875,6 +899,7 @@ static int viommu_add_device(struct device *dev)
>
> vdev->dev = dev;
> vdev->viommu = viommu;
> + vdev->pgsize_bitmap = viommu->pgsize_bitmap;
> INIT_LIST_HEAD(&vdev->resv_regions);
> fwspec->iommu_priv = vdev;
>
> diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h
> index 237e36a280cb..dc9d3f40bcd8 100644
> --- a/include/uapi/linux/virtio_iommu.h
> +++ b/include/uapi/linux/virtio_iommu.h
> @@ -111,6 +111,7 @@ struct virtio_iommu_req_unmap {
>
> #define VIRTIO_IOMMU_PROBE_T_NONE 0
> #define VIRTIO_IOMMU_PROBE_T_RESV_MEM 1
> +#define VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK 2
>
> #define VIRTIO_IOMMU_PROBE_T_MASK 0xfff
>
> @@ -119,6 +120,12 @@ struct virtio_iommu_probe_property {
> __le16 length;
> };
>
> +struct virtio_iommu_probe_pgsize_mask {
> + struct virtio_iommu_probe_property head;
> + __u8 reserved[4];
> + __u64 pgsize_bitmap;
> +};
> +
> #define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0
> #define VIRTIO_IOMMU_RESV_MEM_T_MSI 1
>
>

2020-04-01 15:50:51

by Jean-Philippe Brucker

Subject: Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by endpoint

On Wed, Apr 01, 2020 at 02:00:13PM +0100, Robin Murphy wrote:
> On 2020-04-01 12:38 pm, Bharat Bhushan wrote:
> > Different endpoint can support different page size, probe
> > endpoint if it supports specific page size otherwise use
> > global page sizes.
> >
> > Signed-off-by: Bharat Bhushan <[email protected]>
> > ---
> > drivers/iommu/virtio-iommu.c | 33 +++++++++++++++++++++++++++----
> > include/uapi/linux/virtio_iommu.h | 7 +++++++
> > 2 files changed, 36 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> > index cce329d71fba..c794cb5b7b3e 100644
> > --- a/drivers/iommu/virtio-iommu.c
> > +++ b/drivers/iommu/virtio-iommu.c
> > @@ -78,6 +78,7 @@ struct viommu_endpoint {
> > struct viommu_dev *viommu;
> > struct viommu_domain *vdomain;
> > struct list_head resv_regions;
> > + u64 pgsize_bitmap;
> > };
> > struct viommu_request {
> > @@ -415,6 +416,20 @@ static int viommu_replay_mappings(struct viommu_domain *vdomain)
> > return ret;
> > }
> > +static int viommu_set_pgsize_bitmap(struct viommu_endpoint *vdev,
> > + struct virtio_iommu_probe_pgsize_mask *mask,
> > + size_t len)
> > +
> > +{
> > + u64 pgsize_bitmap = le64_to_cpu(mask->pgsize_bitmap);
> > +
> > + if (len < sizeof(*mask))
> > + return -EINVAL;
> > +
> > + vdev->pgsize_bitmap = pgsize_bitmap;
> > + return 0;
> > +}
> > +
> > static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
> > struct virtio_iommu_probe_resv_mem *mem,
> > size_t len)
> > @@ -494,11 +509,13 @@ static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev)
> > while (type != VIRTIO_IOMMU_PROBE_T_NONE &&
> > cur < viommu->probe_size) {
> > len = le16_to_cpu(prop->length) + sizeof(*prop);
> > -

Whitespace change

> > switch (type) {
> > case VIRTIO_IOMMU_PROBE_T_RESV_MEM:
> > ret = viommu_add_resv_mem(vdev, (void *)prop, len);
> > break;
> > + case VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK:
> > + ret = viommu_set_pgsize_bitmap(vdev, (void *)prop, len);
> > + break;
> > default:
> > dev_err(dev, "unknown viommu prop 0x%x\n", type);
> > }
> > @@ -607,16 +624,23 @@ static struct iommu_domain *viommu_domain_alloc(unsigned type)
> > return &vdomain->domain;
> > }
> > -static int viommu_domain_finalise(struct viommu_dev *viommu,
> > +static int viommu_domain_finalise(struct viommu_endpoint *vdev,
> > struct iommu_domain *domain)
> > {
> > int ret;
> > struct viommu_domain *vdomain = to_viommu_domain(domain);
> > + struct viommu_dev *viommu = vdev->viommu;
> > vdomain->viommu = viommu;
> > vdomain->map_flags = viommu->map_flags;
> > - domain->pgsize_bitmap = viommu->pgsize_bitmap;
> > + /* Devices in same domain must support same size pages */
>
> AFAICS what the code appears to do is enforce that the first endpoint
> attached to any domain has the same pgsize_bitmap as the most recently
> probed viommu_dev instance, then ignore any subsequent endpoints attached to
> the same domain. Thus I'm not sure that comment is accurate.
>

Yes viommu_domain_finalise() is only called once. What I had in mind is
something like:

---- 8< ----
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 750f69c49b95..8303b7b513ff 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -639,6 +639,29 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev,
return 0;
}

+/*
+ * Check whether the endpoint's capabilities are compatible with other endpoints
+ * in the domain. Report any inconsistency.
+ */
+static bool viommu_endpoint_is_compatible(struct viommu_endpoint *vdev,
+ struct viommu_domain *vdomain)
+{
+ struct device *dev = vdev->dev;
+
+ if (vdomain->viommu != vdev->viommu) {
+ dev_err(dev, "cannot attach to foreign vIOMMU\n");
+ return false;
+ }
+
+ if (vdomain->domain.pgsize_bitmap != vdev->pgsize_bitmap) {
+ dev_err(dev, "incompatible domain bitmap 0x%lx != 0x%lx\n",
+ vdomain->domain.pgsize_bitmap, vdev->pgsize_bitmap);
+ return false;
+ }
+
+ return true;
+}
+
static void viommu_domain_free(struct iommu_domain *domain)
{
struct viommu_domain *vdomain = to_viommu_domain(domain);
@@ -670,9 +693,8 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
* owns it.
*/
ret = viommu_domain_finalise(vdev, domain);
- } else if (vdomain->viommu != vdev->viommu) {
- dev_err(dev, "cannot attach to foreign vIOMMU\n");
- ret = -EXDEV;
+ } else if (!viommu_endpoint_is_compatible(vdev, vdomain)) {
+ ret = -EINVAL;
}
mutex_unlock(&vdomain->mutex);
---- >8 ----

>
> > + if ((domain->pgsize_bitmap != viommu->pgsize_bitmap) &&
> > + (domain->pgsize_bitmap != vdev->pgsize_bitmap))
> > + return -EINVAL;
> > +
> > + domain->pgsize_bitmap = vdev->pgsize_bitmap;
> > +
> > domain->geometry = viommu->geometry;
> > ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
> > @@ -657,7 +681,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
> > * Properly initialize the domain now that we know which viommu
> > * owns it.
> > */
> > - ret = viommu_domain_finalise(vdev->viommu, domain);
> > + ret = viommu_domain_finalise(vdev, domain);
> > } else if (vdomain->viommu != vdev->viommu) {
> > dev_err(dev, "cannot attach to foreign vIOMMU\n");
> > ret = -EXDEV;
> > @@ -875,6 +899,7 @@ static int viommu_add_device(struct device *dev)
> > vdev->dev = dev;
> > vdev->viommu = viommu;
> > + vdev->pgsize_bitmap = viommu->pgsize_bitmap;
> > INIT_LIST_HEAD(&vdev->resv_regions);
> > fwspec->iommu_priv = vdev;
> > diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h
> > index 237e36a280cb..dc9d3f40bcd8 100644
> > --- a/include/uapi/linux/virtio_iommu.h
> > +++ b/include/uapi/linux/virtio_iommu.h
> > @@ -111,6 +111,7 @@ struct virtio_iommu_req_unmap {
> > #define VIRTIO_IOMMU_PROBE_T_NONE 0
> > #define VIRTIO_IOMMU_PROBE_T_RESV_MEM 1
> > +#define VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK 2
> > #define VIRTIO_IOMMU_PROBE_T_MASK 0xfff
> > @@ -119,6 +120,12 @@ struct virtio_iommu_probe_property {
> > __le16 length;
> > };
> > +struct virtio_iommu_probe_pgsize_mask {
> > + struct virtio_iommu_probe_property head;
> > + __u8 reserved[4];
> > + __u64 pgsize_bitmap;

Should be __le64

Thanks,
Jean

> > +};
> > +
> > #define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0
> > #define VIRTIO_IOMMU_RESV_MEM_T_MSI 1
> >

2020-04-02 03:54:31

by Bharat Bhushan

Subject: RE: [EXT] Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by endpoint

> -----Original Message-----
> From: Jean-Philippe Brucker <[email protected]>
> Sent: Wednesday, April 1, 2020 9:20 PM
> To: Robin Murphy <[email protected]>
> Cc: Bharat Bhushan <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected]
> foundation.org; [email protected]; [email protected];
> [email protected]; [email protected]
> Subject: [EXT] Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by
> endpoint
>
> External Email
>
> ----------------------------------------------------------------------
> On Wed, Apr 01, 2020 at 02:00:13PM +0100, Robin Murphy wrote:
> > On 2020-04-01 12:38 pm, Bharat Bhushan wrote:
> > > Different endpoint can support different page size, probe endpoint
> > > if it supports specific page size otherwise use global page sizes.
> > >
> > > Signed-off-by: Bharat Bhushan <[email protected]>
> > > ---
> > > drivers/iommu/virtio-iommu.c | 33 +++++++++++++++++++++++++++----
> > > include/uapi/linux/virtio_iommu.h | 7 +++++++
> > > 2 files changed, 36 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/iommu/virtio-iommu.c
> > > b/drivers/iommu/virtio-iommu.c index cce329d71fba..c794cb5b7b3e
> > > 100644
> > > --- a/drivers/iommu/virtio-iommu.c
> > > +++ b/drivers/iommu/virtio-iommu.c
> > > @@ -78,6 +78,7 @@ struct viommu_endpoint {
> > > struct viommu_dev *viommu;
> > > struct viommu_domain *vdomain;
> > > struct list_head resv_regions;
> > > + u64 pgsize_bitmap;
> > > };
> > > struct viommu_request {
> > > @@ -415,6 +416,20 @@ static int viommu_replay_mappings(struct
> viommu_domain *vdomain)
> > > return ret;
> > > }
> > > +static int viommu_set_pgsize_bitmap(struct viommu_endpoint *vdev,
> > > + struct virtio_iommu_probe_pgsize_mask *mask,
> > > + size_t len)
> > > +
> > > +{
> > > + u64 pgsize_bitmap = le64_to_cpu(mask->pgsize_bitmap);
> > > +
> > > + if (len < sizeof(*mask))
> > > + return -EINVAL;
> > > +
> > > + vdev->pgsize_bitmap = pgsize_bitmap;
> > > + return 0;
> > > +}
> > > +
> > > static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
> > > struct virtio_iommu_probe_resv_mem *mem,
> > > size_t len)
> > > @@ -494,11 +509,13 @@ static int viommu_probe_endpoint(struct
> viommu_dev *viommu, struct device *dev)
> > > while (type != VIRTIO_IOMMU_PROBE_T_NONE &&
> > > cur < viommu->probe_size) {
> > > len = le16_to_cpu(prop->length) + sizeof(*prop);
> > > -
>
> Whitespace change
>
> > > switch (type) {
> > > case VIRTIO_IOMMU_PROBE_T_RESV_MEM:
> > > ret = viommu_add_resv_mem(vdev, (void *)prop, len);
> > > break;
> > > + case VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK:
> > > + ret = viommu_set_pgsize_bitmap(vdev, (void *)prop, len);
> > > + break;
> > > default:
> > > dev_err(dev, "unknown viommu prop 0x%x\n", type);
> > > }
> > > @@ -607,16 +624,23 @@ static struct iommu_domain
> *viommu_domain_alloc(unsigned type)
> > > return &vdomain->domain;
> > > }
> > > -static int viommu_domain_finalise(struct viommu_dev *viommu,
> > > +static int viommu_domain_finalise(struct viommu_endpoint *vdev,
> > > struct iommu_domain *domain)
> > > {
> > > int ret;
> > > struct viommu_domain *vdomain = to_viommu_domain(domain);
> > > + struct viommu_dev *viommu = vdev->viommu;
> > > vdomain->viommu = viommu;
> > > vdomain->map_flags = viommu->map_flags;
> > > - domain->pgsize_bitmap = viommu->pgsize_bitmap;
> > > + /* Devices in same domain must support same size pages */
> >
> > AFAICS what the code appears to do is enforce that the first endpoint
> > attached to any domain has the same pgsize_bitmap as the most recently
> > probed viommu_dev instance, then ignore any subsequent endpoints
> > attached to the same domain. Thus I'm not sure that comment is accurate.
> >
>
> Yes viommu_domain_finalise() is only called once. What I had in mind is
> something like:

Ohh, I did not realized that viommu_domain_finalise().
I have included below suggested changes

>
> ---- 8< ----
> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index
> 750f69c49b95..8303b7b513ff 100644
> --- a/drivers/iommu/virtio-iommu.c
> +++ b/drivers/iommu/virtio-iommu.c
> @@ -639,6 +639,29 @@ static int viommu_domain_finalise(struct
> viommu_endpoint *vdev,
> return 0;
> }
>
> +/*
> + * Check whether the endpoint's capabilities are compatible with other
> +endpoints
> + * in the domain. Report any inconsistency.
> + */
> +static bool viommu_endpoint_is_compatible(struct viommu_endpoint *vdev,
> + struct viommu_domain *vdomain)
> +{
> + struct device *dev = vdev->dev;
> +
> + if (vdomain->viommu != vdev->viommu) {
> + dev_err(dev, "cannot attach to foreign vIOMMU\n");
> + return false;
> + }
> +
> + if (vdomain->domain.pgsize_bitmap != vdev->pgsize_bitmap) {
> + dev_err(dev, "incompatible domain bitmap 0x%lx != 0x%lx\n",
> + vdomain->domain.pgsize_bitmap, vdev->pgsize_bitmap);
> + return false;
> + }
> +
> + return true;
> +}
> +
> static void viommu_domain_free(struct iommu_domain *domain) {
> struct viommu_domain *vdomain = to_viommu_domain(domain); @@ -
> 670,9 +693,8 @@ static int viommu_attach_dev(struct iommu_domain *domain,
> struct device *dev)
> * owns it.
> */
> ret = viommu_domain_finalise(vdev, domain);
> - } else if (vdomain->viommu != vdev->viommu) {
> - dev_err(dev, "cannot attach to foreign vIOMMU\n");
> - ret = -EXDEV;
> + } else if (!viommu_endpoint_is_compatible(vdev, vdomain)) {
> + ret = -EINVAL;
> }
> mutex_unlock(&vdomain->mutex);
> ---- >8 ----
>
> >
> > > + if ((domain->pgsize_bitmap != viommu->pgsize_bitmap) &&
> > > + (domain->pgsize_bitmap != vdev->pgsize_bitmap))
> > > + return -EINVAL;
> > > +
> > > + domain->pgsize_bitmap = vdev->pgsize_bitmap;
> > > +
> > > domain->geometry = viommu->geometry;
> > > ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
> > > @@ -657,7 +681,7 @@ static int viommu_attach_dev(struct iommu_domain
> *domain, struct device *dev)
> > > * Properly initialize the domain now that we know which viommu
> > > * owns it.
> > > */
> > > - ret = viommu_domain_finalise(vdev->viommu, domain);
> > > + ret = viommu_domain_finalise(vdev, domain);
> > > } else if (vdomain->viommu != vdev->viommu) {
> > > dev_err(dev, "cannot attach to foreign vIOMMU\n");
> > > ret = -EXDEV;
> > > @@ -875,6 +899,7 @@ static int viommu_add_device(struct device *dev)
> > > vdev->dev = dev;
> > > vdev->viommu = viommu;
> > > + vdev->pgsize_bitmap = viommu->pgsize_bitmap;
> > > INIT_LIST_HEAD(&vdev->resv_regions);
> > > fwspec->iommu_priv = vdev;
> > > diff --git a/include/uapi/linux/virtio_iommu.h
> > > b/include/uapi/linux/virtio_iommu.h
> > > index 237e36a280cb..dc9d3f40bcd8 100644
> > > --- a/include/uapi/linux/virtio_iommu.h
> > > +++ b/include/uapi/linux/virtio_iommu.h
> > > @@ -111,6 +111,7 @@ struct virtio_iommu_req_unmap {
> > > #define VIRTIO_IOMMU_PROBE_T_NONE 0
> > > #define VIRTIO_IOMMU_PROBE_T_RESV_MEM 1
> > > +#define VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK 2
> > > #define VIRTIO_IOMMU_PROBE_T_MASK 0xfff
> > > @@ -119,6 +120,12 @@ struct virtio_iommu_probe_property {
> > > __le16 length;
> > > };
> > > +struct virtio_iommu_probe_pgsize_mask {
> > > + struct virtio_iommu_probe_property head;
> > > + __u8 reserved[4];
> > > + __u64 pgsize_bitmap;
>
> Should be __le64

Based on" iommu/virtio: Fix sparse warning" patch https://www.spinics.net/lists/linux-virtualization/msg41944.html changed to __u64 (not __le64)

Will keep __le64.

Thanks
-Bharat

>
> Thanks,
> Jean
>
> > > +};
> > > +
> > > #define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0
> > > #define VIRTIO_IOMMU_RESV_MEM_T_MSI 1
> > >

2020-04-02 09:52:49

by Jean-Philippe Brucker

Subject: Re: [EXT] Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by endpoint

On Thu, Apr 02, 2020 at 03:53:40AM +0000, Bharat Bhushan wrote:
> > > > +struct virtio_iommu_probe_pgsize_mask {
> > > > + struct virtio_iommu_probe_property head;
> > > > + __u8 reserved[4];
> > > > + __u64 pgsize_bitmap;
> >
> > Should be __le64
>
> Based on" iommu/virtio: Fix sparse warning" patch https://www.spinics.net/lists/linux-virtualization/msg41944.html changed to __u64 (not __le64)

Yes that one was only for the virtio config struct, to play nice with
other devices. We should still use __le for the other structures,
including probe properties.

Thanks,
Jean

>
> Will keep __le64.
>
> Thanks
> -Bharat
>
> >
> > Thanks,
> > Jean
> >
> > > > +};
> > > > +
> > > > #define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0
> > > > #define VIRTIO_IOMMU_RESV_MEM_T_MSI 1
> > > >