[PATCH v7 11/22] KVM: s390: pci: add basic kvm_zdev structure

Matthew Rosato
2022-05-13T19:17:02Z

This structure will be used to carry kvm passthrough information related to
zPCI devices.

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
---
arch/s390/include/asm/pci.h | 3 +++
arch/s390/kvm/Makefile | 1 +
arch/s390/kvm/pci.c | 36 ++++++++++++++++++++++++++++++++++++
arch/s390/kvm/pci.h | 21 +++++++++++++++++++++
4 files changed, 61 insertions(+)
create mode 100644 arch/s390/kvm/pci.c
create mode 100644 arch/s390/kvm/pci.h

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 4c5b8fbc2079..50f1851edfbe 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -97,6 +97,7 @@ struct zpci_bar_struct {
};

struct s390_domain;
+struct kvm_zdev;

#define ZPCI_FUNCTIONS_PER_BUS 256
struct zpci_bus {
@@ -189,7 +190,9 @@ struct zpci_dev {

struct dentry *debugfs_dev;

+ /* IOMMU and passthrough */
struct s390_domain *s390_domain; /* s390 IOMMU domain data */
+ struct kvm_zdev *kzdev;
};

static inline bool zdev_enabled(struct zpci_dev *zdev)
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index 26f4a74e5ce4..02217fb4ae10 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -10,4 +10,5 @@ ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
kvm-y += kvm-s390.o intercept.o interrupt.o priv.o sigp.o
kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o

+kvm-$(CONFIG_VFIO_PCI_ZDEV_KVM) += pci.o
obj-$(CONFIG_KVM) += kvm.o
diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
new file mode 100644
index 000000000000..21c2be5c2713
--- /dev/null
+++ b/arch/s390/kvm/pci.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * s390 kvm PCI passthrough support
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Author(s): Matthew Rosato <mjrosato@linux.ibm.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/pci.h>
+#include "pci.h"
+
+static int kvm_s390_pci_dev_open(struct zpci_dev *zdev)
+{
+ struct kvm_zdev *kzdev;
+
+ kzdev = kzalloc(sizeof(struct kvm_zdev), GFP_KERNEL);
+ if (!kzdev)
+ return -ENOMEM;
+
+ kzdev->zdev = zdev;
+ zdev->kzdev = kzdev;
+
+ return 0;
+}
+
+static void kvm_s390_pci_dev_release(struct zpci_dev *zdev)
+{
+ struct kvm_zdev *kzdev;
+
+ kzdev = zdev->kzdev;
+ WARN_ON(kzdev->zdev != zdev);
+ zdev->kzdev = 0;
+ kfree(kzdev);
+}
diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h
new file mode 100644
index 000000000000..ce93978e8913
--- /dev/null
+++ b/arch/s390/kvm/pci.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * s390 kvm PCI passthrough support
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Author(s): Matthew Rosato <mjrosato@linux.ibm.com>
+ */
+
+#ifndef __KVM_S390_PCI_H
+#define __KVM_S390_PCI_H
+
+#include <linux/kvm_host.h>
+#include <linux/pci.h>
+
+struct kvm_zdev {
+ struct zpci_dev *zdev;
+ struct kvm *kvm;
+};
+
+#endif /* __KVM_S390_PCI_H */
--
2.27.0