On 12/8/21 4:44 AM, Niklas Schnelle wrote:
On Tue, 2021-12-07 at 15:57 -0500, Matthew Rosato wrote:
These routines will be wired into the vfio_pci_zdev ioctl handlers to
respond to requests to enable / disable a device for zPCI Load/Store
interpretation.
The first time such a request is received, enable the necessary facilities
for the guest.
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
---
arch/s390/include/asm/kvm_pci.h | 4 ++
arch/s390/kvm/pci.c | 91 +++++++++++++++++++++++++++++++++
arch/s390/pci/pci.c | 3 ++
3 files changed, 98 insertions(+)
diff --git a/arch/s390/include/asm/kvm_pci.h b/arch/s390/include/asm/kvm_pci.h
index 3e491a39704c..5d6283acb54c 100644
--- a/arch/s390/include/asm/kvm_pci.h
---8<---
return rc;
+ }
+
+ /*
+ * Store information about the identity of the kvm guest allowed to
+ * access this device via interpretation to be used by host CLP
+ */
+ zdev->gd = gd;
+
+ rc = zpci_enable_device(zdev);
+ if (rc)
+ goto err;
+
+ /* Re-register the IOMMU that was already created */
+ rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
+ (u64)zdev->dma_table);
The zdev->dma_table is a virtual address but we need an absolute
address in the MPCIFC so the above should use
virt_to_phys(zdev->dma_table) to be compatible with future V != R
kernel memory. As of now since virtual and absolute kernel addresses
are the same this is not a bug and we've had this (wrong) pattern in
the rest of the code but let's get it righht here from the start.
See also my commit "s390/pci: use physical addresses in DMA tables"
that is currently in the s390 feature branch.
You're right of course -- I saw those changes happening as I prepared
this series but I didn't want to delay getting comments any longer, what
with the holidays approaching. Of course, I didn't realize they were
already out on the feature branch.
I suspect there is some more of this also in the code related to
handling RPCIT. AEN setup too.
+ if (rc)
+ goto err;
+
+ return rc;
+
+err:
+ zdev->gd = 0;
+ return rc;
+}
+EXPORT_SYMBOL_GPL(kvm_s390_pci_interp_enable);
+
+int kvm_s390_pci_interp_disable(struct zpci_dev *zdev)
+{
+ int rc;
+
+ if (zdev->gd == 0)
+ return -EINVAL;
+
+ /* Remove the host CLP guest designation */
+ zdev->gd = 0;
+
+ if (zdev_enabled(zdev)) {
+ rc = zpci_disable_device(zdev);
+ if (rc)
+ return rc;
+ }
+
+ rc = zpci_enable_device(zdev);
+ if (rc)
+ return rc;
+
+ /* Re-register the IOMMU that was already created */
+ rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
+ (u64)zdev->dma_table);
Same as above
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(kvm_s390_pci_interp_disable);
+
---8<---
