Re: [PATCH v2 14/30] KVM: s390: pci: add basic kvm_zdev structure

[Pierre Morel]

On 1/14/22 21:31, Matthew Rosato wrote:
> This structure will be used to carry kvm passthrough information related to
> zPCI devices.
>
> Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> ---
>   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             | 46 +++++++++++++++++++++++++++++++++
>   4 files changed, 79 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..aafee2976929
> --- /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@xxxxxxxxxxxxx>
> + */
> +
> +

One blank line too much.

Otherwise, look good to me.

Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>

> +#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;
> +};
> +
> +int kvm_s390_pci_dev_open(struct zpci_dev *zdev);
> +void kvm_s390_pci_dev_release(struct zpci_dev *zdev);
> +void 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 f3cd2da8128c..9b6c657d8d31 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..a26f4fe7b680 100644
> --- a/arch/s390/kvm/Makefile
> +++ b/arch/s390/kvm/Makefile
> @@ -11,5 +11,5 @@ ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
>   
>   kvm-objs := $(common-objs) kvm-s390.o intercept.o interrupt.o priv.o sigp.o
>   kvm-objs += diag.o gaccess.o guestdbg.o vsie.o pv.o
> -
> +kvm-$(CONFIG_PCI) += 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..1c33bc7bf2bd
> --- /dev/null
> +++ b/arch/s390/kvm/pci.c
> @@ -0,0 +1,46 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * s390 kvm PCI passthrough support
> + *
> + * Copyright IBM Corp. 2021
> + *
> + *    Author(s): Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> + */
> +
> +#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;
> +
> +	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;
> +
> +	kzdev = zdev->kzdev;
> +	WARN_ON(kzdev->zdev != zdev);
> +	zdev->kzdev = 0;
> +	kfree(kzdev);
> +}
> +EXPORT_SYMBOL_GPL(kvm_s390_pci_dev_release);
> +
> +void kvm_s390_pci_attach_kvm(struct zpci_dev *zdev, struct kvm *kvm)
> +{
> +	struct kvm_zdev *kzdev = zdev->kzdev;
> +
> +	kzdev->kvm = kvm;
> +}
> +EXPORT_SYMBOL_GPL(kvm_s390_pci_attach_kvm);

--
Pierre Morel
IBM Lab Boeblingen