On 16/05/2019 20:40, Alex Williamson wrote:
On Fri, 10 May 2019 10:22:35 +0200
Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
We implement a capability intercafe for VFIO_IOMMU_GET_INFO and add the
first capability: VFIO_IOMMU_INFO_CAPABILITIES.
When calling the ioctl, the user must specify
VFIO_IOMMU_INFO_CAPABILITIES to retrieve the capabilities and must check
in the answer if capabilities are supported.
Older kernel will not check nor set the VFIO_IOMMU_INFO_CAPABILITIES in
the flags of vfio_iommu_type1_info.
The iommu get_attr callback will be called to retrieve the specific
attributes and fill the capabilities, VFIO_IOMMU_INFO_CAP_QFN for the
PCI query function attributes and VFIO_IOMMU_INFO_CAP_QGRP for the
PCI query function group.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
drivers/vfio/vfio_iommu_type1.c | 95 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 94 insertions(+), 1 deletion(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index d0f731c..f7f8120 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1658,6 +1658,70 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
return ret;
}
+int vfio_iommu_type1_caps(struct vfio_iommu *iommu, struct vfio_info_cap *caps,
+ size_t size)
+{
+ struct vfio_domain *d;
+ struct vfio_iommu_type1_info_block *info_fn;
+ struct vfio_iommu_type1_info_block *info_grp;
+ unsigned long total_size, fn_size, grp_size;
+ int ret;
+
+ d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
+ if (!d)
+ return -ENODEV;
+ /* The size of these capabilities are device dependent */
+ fn_size = iommu_domain_get_attr(d->domain,
+ DOMAIN_ATTR_ZPCI_FN_SIZE, NULL);
+ if (fn_size < 0)
+ return fn_size;
What if non-Z archs want to use this? The function is architected
specifically for this one use case, fail if any component is not there
which means it requires a re-write to add further support. If
ZPCI_FN_SIZE isn't support, move on to the next thing.
yes, clear.
+ fn_size += sizeof(struct vfio_info_cap_header);
+ total_size = fn_size;
Here too, total_size should be initialized to zero and each section +=
the size they'd like to add.
thanks, clear too.
+
+ grp_size = iommu_domain_get_attr(d->domain,
+ DOMAIN_ATTR_ZPCI_GRP_SIZE, NULL);
+ if (grp_size < 0)
+ return grp_size;
+ grp_size += sizeof(struct vfio_info_cap_header);
+ total_size += grp_size;
+
+ /* Tell caller to call us with a greater buffer */
+ if (total_size > size) {
+ caps->size = total_size;
+ return 0;
+ }
+
+ info_fn = kzalloc(fn_size, GFP_KERNEL);
+ if (!info_fn)
+ return -ENOMEM;
Maybe fn_size was zero because we're not on Z.
+ ret = iommu_domain_get_attr(d->domain,
+ DOMAIN_ATTR_ZPCI_FN, &info_fn->data);
Kernel internal structures != user api. Thanks,
Alex
Thanks a lot Alex,
I understand the concerns, I was too focussed on Z, I will rework this
as you said:
- definition of the user API and
- take care that another architecture may want to use the interface.
Regards,
Pierre
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
