[GIT PULL 17/42] vfio-pci/zdev: add open/close device hooks

Claudio Imbrenda
2022-07-21T16:14:32Z

From: Matthew Rosato <mjrosato@linux.ibm.com>

During vfio-pci open_device, pass the KVM associated with the vfio group
(if one exists). This is needed in order to pass a special indicator
(GISA) to firmware to allow zPCI interpretation facilities to be used
for only the specific KVM associated with the vfio-pci device. During
vfio-pci close_device, unregister the notifier.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-18-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
drivers/vfio/pci/vfio_pci_core.c | 10 +++++++++-
drivers/vfio/pci/vfio_pci_zdev.c | 24 ++++++++++++++++++++++++
include/linux/vfio_pci_core.h | 10 ++++++++++
3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index a0d69ddaf90d..b1e5cfbadf38 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -316,10 +316,14 @@ int vfio_pci_core_enable(struct vfio_pci_core_device *vdev)
pci_write_config_word(pdev, PCI_COMMAND, cmd);
}

- ret = vfio_config_init(vdev);
+ ret = vfio_pci_zdev_open_device(vdev);
if (ret)
goto out_free_state;

+ ret = vfio_config_init(vdev);
+ if (ret)
+ goto out_free_zdev;
+
msix_pos = pdev->msix_cap;
if (msix_pos) {
u16 flags;
@@ -340,6 +344,8 @@ int vfio_pci_core_enable(struct vfio_pci_core_device *vdev)

return 0;

+out_free_zdev:
+ vfio_pci_zdev_close_device(vdev);
out_free_state:
kfree(vdev->pci_saved_state);
vdev->pci_saved_state = NULL;
@@ -418,6 +424,8 @@ void vfio_pci_core_disable(struct vfio_pci_core_device *vdev)

vdev->needs_reset = true;

+ vfio_pci_zdev_close_device(vdev);
+
/*
* If we have saved state, restore it. If we can reset the device,
* even better. Resetting with current state seems better than
diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c
index ea4c0d2b0663..686f2e75e392 100644
--- a/drivers/vfio/pci/vfio_pci_zdev.c
+++ b/drivers/vfio/pci/vfio_pci_zdev.c
@@ -11,6 +11,7 @@
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include <linux/vfio_zdev.h>
+#include <linux/kvm_host.h>
#include <asm/pci_clp.h>
#include <asm/pci_io.h>

@@ -136,3 +137,26 @@ int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,

return ret;
}
+
+int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev)
+{
+ struct zpci_dev *zdev = to_zpci(vdev->pdev);
+
+ if (!zdev)
+ return -ENODEV;
+
+ if (!vdev->vdev.kvm)
+ return 0;
+
+ return kvm_s390_pci_register_kvm(zdev, vdev->vdev.kvm);
+}
+
+void vfio_pci_zdev_close_device(struct vfio_pci_core_device *vdev)
+{
+ struct zpci_dev *zdev = to_zpci(vdev->pdev);
+
+ if (!zdev || !vdev->vdev.kvm)
+ return;
+
+ kvm_s390_pci_unregister_kvm(zdev);
+}
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 63af2897939c..d5d9e17f0156 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -209,12 +209,22 @@ static inline int vfio_pci_igd_init(struct vfio_pci_core_device *vdev)
#ifdef CONFIG_VFIO_PCI_ZDEV_KVM
extern int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
struct vfio_info_cap *caps);
+int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev);
+void vfio_pci_zdev_close_device(struct vfio_pci_core_device *vdev);
#else
static inline int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
struct vfio_info_cap *caps)
{
return -ENODEV;
}
+
+static inline int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev)
+{
+ return 0;
+}
+
+static inline void vfio_pci_zdev_close_device(struct vfio_pci_core_device *vdev)
+{}
#endif

/* Will be exported for vfio pci drivers usage */
--
2.36.1