Re: [PATCH 13/32] KVM: s390: pci: add basic kvm_zdev structure

Eric Farman
2021-12-10T19:05:06Z

On Tue, 2021-12-07 at 15:57 -0500, Matthew Rosato wrote:
> This structure will be used to carry kvm passthrough information
> related to
> zPCI devices.
>
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>

Reviewed-by: Eric Farman <farman@linux.ibm.com>

> ---
> arch/s390/include/asm/kvm_pci.h | 29 +++++++++++++++++
> arch/s390/include/asm/pci.h | 3 ++
> arch/s390/kvm/Makefile | 2 +-
> arch/s390/kvm/pci.c | 57
> +++++++++++++++++++++++++++++++++
> 4 files changed, 90 insertions(+), 1 deletion(-)
> create mode 100644 arch/s390/include/asm/kvm_pci.h
> create mode 100644 arch/s390/kvm/pci.c
>
> diff --git a/arch/s390/include/asm/kvm_pci.h
> b/arch/s390/include/asm/kvm_pci.h
> new file mode 100644
> index 000000000000..3e491a39704c
> --- /dev/null
> +++ b/arch/s390/include/asm/kvm_pci.h
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * KVM PCI Passthrough for virtual machines on s390
> + *
> + * Copyright IBM Corp. 2021
> + *
> + * Author(s): Matthew Rosato <mjrosato@linux.ibm.com>
> + */
> +
> +
> +#ifndef ASM_KVM_PCI_H
> +#define ASM_KVM_PCI_H
> +
> +#include <linux/types.h>
> +#include <linux/kvm_types.h>
> +#include <linux/kvm_host.h>
> +#include <linux/kvm.h>
> +#include <linux/pci.h>
> +
> +struct kvm_zdev {
> + struct zpci_dev *zdev;
> + struct kvm *kvm;
> +};
> +
> +extern int kvm_s390_pci_dev_open(struct zpci_dev *zdev);
> +extern void kvm_s390_pci_dev_release(struct zpci_dev *zdev);
> +extern int kvm_s390_pci_attach_kvm(struct zpci_dev *zdev, struct kvm
> *kvm);
> +
> +#endif /* ASM_KVM_PCI_H */
> diff --git a/arch/s390/include/asm/pci.h
> b/arch/s390/include/asm/pci.h
> index 86f43644756d..32810e1ed308 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 {
> @@ -190,6 +191,8 @@ struct zpci_dev {
> struct dentry *debugfs_dev;
>
> struct s390_domain *s390_domain; /* s390 IOMMU domain data */
> +
> + struct kvm_zdev *kzdev; /* passthrough data */
> };
>
> static inline bool zdev_enabled(struct zpci_dev *zdev)
> diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> index b3aaadc60ead..95ea865e5d29 100644
> --- a/arch/s390/kvm/Makefile
> +++ b/arch/s390/kvm/Makefile
> @@ -10,6 +10,6 @@ common-objs = $(KVM)/kvm_main.o
> $(KVM)/eventfd.o $(KVM)/async_pf.o \
> ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
>
> kvm-objs := $(common-objs) kvm-s390.o intercept.o interrupt.o priv.o
> sigp.o
> -kvm-objs += diag.o gaccess.o guestdbg.o vsie.o pv.o
> +kvm-objs += diag.o gaccess.o guestdbg.o vsie.o pv.o pci.o
>
> obj-$(CONFIG_KVM) += kvm.o
> diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
> new file mode 100644
> index 000000000000..ecfc458a5b39
> --- /dev/null
> +++ b/arch/s390/kvm/pci.c
> @@ -0,0 +1,57 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * s390 kvm PCI passthrough support
> + *
> + * Copyright IBM Corp. 2021
> + *
> + * Author(s): Matthew Rosato <mjrosato@linux.ibm.com>
> + */
> +
> +#include <linux/kvm_host.h>
> +#include <linux/pci.h>
> +#include <asm/kvm_pci.h>
> +
> +int kvm_s390_pci_dev_open(struct zpci_dev *zdev)
> +{
> + struct kvm_zdev *kzdev;
> +
> + if (zdev == NULL)
> + return -ENODEV;
> +
> + kzdev = kzalloc(sizeof(struct kvm_zdev), GFP_KERNEL);
> + if (!kzdev)
> + return -ENOMEM;
> +
> + kzdev->zdev = zdev;
> + zdev->kzdev = kzdev;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(kvm_s390_pci_dev_open);
> +
> +void kvm_s390_pci_dev_release(struct zpci_dev *zdev)
> +{
> + struct kvm_zdev *kzdev;
> +
> + if (!zdev || !zdev->kzdev)
> + return;
> +
> + kzdev = zdev->kzdev;
> + WARN_ON(kzdev->zdev != zdev);
> + zdev->kzdev = 0;
> + kfree(kzdev);
> +
> +}
> +EXPORT_SYMBOL_GPL(kvm_s390_pci_dev_release);
> +
> +int kvm_s390_pci_attach_kvm(struct zpci_dev *zdev, struct kvm *kvm)
> +{
> + struct kvm_zdev *kzdev = zdev->kzdev;
> +
> + if (!kzdev)
> + return -ENODEV;
> +
> + kzdev->kvm = kvm;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(kvm_s390_pci_attach_kvm);