On 1/14/22 21:31, Matthew Rosato wrote:
Introduce support for VFIO_DEVICE_FEATURE_ZPCI_AIF, which is a new
VFIO_DEVICE_FEATURE ioctl. This interface is used to indicate that an
s390x vfio-pci device wishes to enable/disable zPCI adapter interrupt
forwarding, which allows underlying firmware to deliver interrupts
directly to the associated kvm guest.
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
---
arch/s390/include/asm/kvm_pci.h | 2 +
drivers/vfio/pci/vfio_pci_core.c | 2 +
drivers/vfio/pci/vfio_pci_zdev.c | 98 +++++++++++++++++++++++++++++++-
include/linux/vfio_pci_core.h | 10 ++++
include/uapi/linux/vfio.h | 7 +++
include/uapi/linux/vfio_zdev.h | 20 +++++++
6 files changed, 138 insertions(+), 1 deletion(-)
diff --git a/arch/s390/include/asm/kvm_pci.h b/arch/s390/include/asm/kvm_pci.h
index dc00c3f27a00..dbab349a4a75 100644
--- a/arch/s390/include/asm/kvm_pci.h
+++ b/arch/s390/include/asm/kvm_pci.h
@@ -36,6 +36,8 @@ struct kvm_zdev {
struct zpci_fib fib;
struct notifier_block nb;
bool interp;
+ bool aif;
+ bool fhost;
Can we please have a comment on these booleans?
Can we have explicit naming to be able to follow their usage more easily?
May be aif_float and aif_host to match with the VFIO feature?
};
int kvm_s390_pci_dev_open(struct zpci_dev *zdev);
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 2b2d64a2190c..01658de660bd 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1174,6 +1174,8 @@ long vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd,
return 0;
case VFIO_DEVICE_FEATURE_ZPCI_INTERP:
return vfio_pci_zdev_feat_interp(vdev, feature, arg);
+ case VFIO_DEVICE_FEATURE_ZPCI_AIF:
+ return vfio_pci_zdev_feat_aif(vdev, feature, arg);
default:
return -ENOTTY;
}
diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c
index 4339f48b98bc..891cfa016d63 100644
--- a/drivers/vfio/pci/vfio_pci_zdev.c
+++ b/drivers/vfio/pci/vfio_pci_zdev.c
@@ -13,6 +13,7 @@
#include <linux/vfio_zdev.h>
#include <asm/pci_clp.h>
#include <asm/pci_io.h>
+#include <asm/pci_insn.h>
#include <asm/kvm_pci.h>
#include <linux/vfio_pci_core.h>
@@ -208,6 +209,99 @@ int vfio_pci_zdev_feat_interp(struct vfio_pci_core_device *vdev,
return rc;
}
+int vfio_pci_zdev_feat_aif(struct vfio_pci_core_device *vdev,
+ struct vfio_device_feature feature,
+ unsigned long arg)
+{
+ struct zpci_dev *zdev = to_zpci(vdev->pdev);
+ struct vfio_device_zpci_aif *data;
+ struct vfio_device_feature *feat;
+ unsigned long minsz;
+ int size, rc = 0;
+
+ if (!zdev || !zdev->kzdev)
+ return -EINVAL;
+
+ /* If PROBE specified, return probe results immediately */
+ if (feature.flags & VFIO_DEVICE_FEATURE_PROBE)
+ return kvm_s390_pci_aif_probe(zdev);
+
+ /* GET and SET are mutually exclusive */
+ if ((feature.flags & VFIO_DEVICE_FEATURE_GET) &&
+ (feature.flags & VFIO_DEVICE_FEATURE_SET))
+ return -EINVAL;
+
+ size = sizeof(*feat) + sizeof(*data);
+ feat = kzalloc(size, GFP_KERNEL);
+ if (!feat)
+ return -ENOMEM;
+
+ data = (struct vfio_device_zpci_aif *)&feat->data;
+ minsz = offsetofend(struct vfio_device_feature, flags);
+
+ if (feature.argsz < minsz + sizeof(*data))
+ return -EINVAL;
+
+ /* Get the rest of the payload for GET/SET */
+ rc = copy_from_user(data, (void __user *)(arg + minsz),
+ sizeof(*data));
+ if (rc)
+ rc = -EINVAL;
+
+ if (feature.flags & VFIO_DEVICE_FEATURE_GET) {
+ if (zdev->kzdev->aif)
+ data->flags = VFIO_DEVICE_ZPCI_FLAG_AIF_FLOAT;
+ if (zdev->kzdev->fhost)
+ data->flags |= VFIO_DEVICE_ZPCI_FLAG_AIF_HOST;
+
+ if (copy_to_user((void __user *)arg, feat, size))
+ rc = -EFAULT;
+ } else if (feature.flags & VFIO_DEVICE_FEATURE_SET) {
+ if (data->flags & VFIO_DEVICE_ZPCI_FLAG_AIF_FLOAT) {
+ /* create a guest fib */
+ struct zpci_fib fib;
+
+ fib.fmt0.aibv = data->ibv;
+ fib.fmt0.isc = data->isc;
+ fib.fmt0.noi = data->noi;
+ if (data->sb != 0) {
+ fib.fmt0.aisb = data->sb;
+ fib.fmt0.aisbo = data->sbo;
+ fib.fmt0.sum = 1;
+ } else {
+ fib.fmt0.aisb = 0;
+ fib.fmt0.aisbo = 0;
+ fib.fmt0.sum = 0;
+ }
+ if (data->flags & VFIO_DEVICE_ZPCI_FLAG_AIF_HOST) {
+ rc = kvm_s390_pci_aif_enable(zdev, &fib, false);
+ if (!rc) {
+ zdev->kzdev->aif = true;
+ zdev->kzdev->fhost = true;
+ }
+ } else {
+ rc = kvm_s390_pci_aif_enable(zdev, &fib, true);
+ if (!rc)
+ zdev->kzdev->aif = true;
+ }
+ } else if (data->flags == 0) {
+ rc = kvm_s390_pci_aif_disable(zdev);
+ if (!rc) {
+ zdev->kzdev->aif = false;
+ zdev->kzdev->fhost = false;
+ }
+ } else {
+ rc = -EINVAL;
+ }
+ } else {
+ /* Neither GET nor SET were specified */
+ rc = -EINVAL;
+ }
+
+ kfree(feat);
+ return rc;
+}
+
static int vfio_pci_zdev_group_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
@@ -255,8 +349,10 @@ void vfio_pci_zdev_release(struct vfio_pci_core_device *vdev)
* If the device was using interpretation, don't trust that userspace
* did the appropriate cleanup
*/
- if (zdev->gd != 0)
+ if (zdev->gd != 0) {
+ kvm_s390_pci_aif_disable(zdev);
kvm_s390_pci_interp_disable(zdev);
+ }
kvm_s390_pci_dev_release(zdev);
}
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 0db2b1051931..7ec5e82e7933 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -201,6 +201,9 @@ extern int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
int vfio_pci_zdev_feat_interp(struct vfio_pci_core_device *vdev,
struct vfio_device_feature feature,
unsigned long arg);
+int vfio_pci_zdev_feat_aif(struct vfio_pci_core_device *vdev,
+ struct vfio_device_feature feature,
+ unsigned long arg);
void vfio_pci_zdev_open(struct vfio_pci_core_device *vdev);
void vfio_pci_zdev_release(struct vfio_pci_core_device *vdev);
#else
@@ -217,6 +220,13 @@ static inline int vfio_pci_zdev_feat_interp(struct vfio_pci_core_device *vdev,
return -ENOTTY;
}
+static inline int vfio_pci_zdev_feat_aif(struct vfio_pci_core_device *vdev,
+ struct vfio_device_feature feature,
+ unsigned long arg)
+{
+ return -ENOTTY;
+}
+
static inline void vfio_pci_zdev_open(struct vfio_pci_core_device *vdev)
{
}
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index b9a75485b8e7..fe3bfd99bf50 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -1009,6 +1009,13 @@ struct vfio_device_feature {
*/
#define VFIO_DEVICE_FEATURE_ZPCI_INTERP (1)
+/*
+ * Provide support for enbaling adapter interruption forwarding for zPCI
+ * devices. This feature is only valid for s390x PCI devices. Data provided
+ * when setting and getting this feature is further described in vfio_zdev.h
+ */
+#define VFIO_DEVICE_FEATURE_ZPCI_AIF (2)
+
/* -------- API for Type1 VFIO IOMMU -------- */
/**
diff --git a/include/uapi/linux/vfio_zdev.h b/include/uapi/linux/vfio_zdev.h
index 575f0410dc66..c574e23f9385 100644
--- a/include/uapi/linux/vfio_zdev.h
+++ b/include/uapi/linux/vfio_zdev.h
@@ -90,4 +90,24 @@ struct vfio_device_zpci_interp {
__u32 fh; /* Host device function handle */
};
+/**
+ * VFIO_DEVICE_FEATURE_ZPCI_AIF
+ *
+ * This feature is used for enabling forwarding of adapter interrupts directly
+ * from firmware to the guest. When setting this feature, the flags indicate
+ * whether to enable/disable the feature and the structure defined below is
+ * used to setup the forwarding structures. When getting this feature, only
+ * the flags are used to indicate the current state.
+ */
+struct vfio_device_zpci_aif {
+ __u64 flags;
+#define VFIO_DEVICE_ZPCI_FLAG_AIF_FLOAT 1
+#define VFIO_DEVICE_ZPCI_FLAG_AIF_HOST 2
I think we need more information on these flags.
What does AIF_FLOAT and what does AIF_HOST ?
+ __u64 ibv; /* Address of guest interrupt bit vector */
+ __u64 sb; /* Address of guest summary bit */
+ __u32 noi; /* Number of interrupts */
+ __u8 isc; /* Guest interrupt subclass */
+ __u8 sbo; /* Offset of guest summary bit vector */
+};
+
#endif
--
Pierre Morel
IBM Lab Boeblingen
