[RFC PATCH] PPC: KVM: vfio kvm device: support spapr tce
Alex Williamson
alex.williamson at redhat.com
Sat Oct 5 02:05:02 EST 2013
On Fri, 2013-10-04 at 22:24 +1000, Alexey Kardashevskiy wrote:
> This is a very rough change set required for ppc64 to use this KVM device.
>
> vfio_rm.c is a piece of code which is going to be called from the realmode (MMU off),
> and I will put everything spapr-related under #ifdef CONFIG_SPAPR_TCE_IOMMU,
> it is just friday and I have to run :)
>
> This is an RFC but it works.
>
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
> ---
> arch/powerpc/kvm/Kconfig | 1 +
> arch/powerpc/kvm/Makefile | 4 ++++
> include/linux/kvm_host.h | 8 ++++---
> include/linux/vfio.h | 3 +++
> include/uapi/linux/kvm.h | 1 +
> virt/kvm/vfio.c | 46 ++++++++++++++++++++++++++++++++++++++++
> virt/kvm/vfio_rm.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++
> 7 files changed, 114 insertions(+), 3 deletions(-)
> create mode 100644 virt/kvm/vfio_rm.c
>
> diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
> index 61b3535..d1b7f64 100644
> --- a/arch/powerpc/kvm/Kconfig
> +++ b/arch/powerpc/kvm/Kconfig
> @@ -60,6 +60,7 @@ config KVM_BOOK3S_64
> select KVM_BOOK3S_64_HANDLER
> select KVM
> select SPAPR_TCE_IOMMU
> + select KVM_VFIO
> ---help---
> Support running unmodified book3s_64 and book3s_32 guest kernels
> in virtual machines on book3s_64 host processors.
> diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
> index 6646c95..fc2878b 100644
> --- a/arch/powerpc/kvm/Makefile
> +++ b/arch/powerpc/kvm/Makefile
> @@ -55,6 +55,8 @@ kvm-objs-$(CONFIG_KVM_E500MC) := $(kvm-e500mc-objs)
>
> kvm-book3s_64-objs-$(CONFIG_KVM_BOOK3S_64_PR) := \
> $(KVM)/coalesced_mmio.o \
> + $(KVM)/vfio.o \
> + $(KVM)/vfio_rm.o \
> fpu.o \
> book3s_paired_singles.o \
> book3s_pr.o \
> @@ -76,6 +78,7 @@ kvm-book3s_64-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
> kvm-book3s_64-builtin-xics-objs-$(CONFIG_KVM_XICS) := \
> book3s_hv_rm_xics.o
> kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
> + $(KVM)/vfio_rm.o \
> book3s_hv_rmhandlers.o \
> book3s_hv_rm_mmu.o \
> book3s_64_vio_hv.o \
> @@ -89,6 +92,7 @@ kvm-book3s_64-objs-$(CONFIG_KVM_XICS) += \
>
> kvm-book3s_64-module-objs := \
> $(KVM)/kvm_main.o \
> + $(KVM)/vfio.o \
> $(KVM)/eventfd.o \
> powerpc.o \
> emulate.o \
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index ad2b581..43c0290 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -407,6 +407,8 @@ struct kvm {
> #endif
> long tlbs_dirty;
> struct list_head devices;
> +
> + struct kvm_vfio *vfio;
<cringe> can't this be on kvm->arch?
> };
>
> #define kvm_err(fmt, ...) \
> @@ -677,15 +679,15 @@ void kvm_arch_register_noncoherent_dma(struct kvm *kvm);
> void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm);
> bool kvm_arch_has_noncoherent_dma(struct kvm *kvm);
> #else
> -static inline void kvm_arch_register_noncoherent_dma(void)
> +static inline void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
> {
> }
>
> -static inline void kvm_arch_unregister_noncoherent_dma(void)
> +static inline void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
> {
> }
>
> -static inline bool kvm_arch_has_noncoherent_dma(void)
> +static inline bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
> {
> return false;
> }
Will fix in my series.
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 24579a0..681e19b 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -97,4 +97,7 @@ extern struct vfio_group *vfio_group_get_external_user(struct file *filep);
> extern void vfio_group_put_external_user(struct vfio_group *group);
> extern int vfio_external_user_iommu_id(struct vfio_group *group);
>
> +extern struct iommu_group *vfio_find_group_by_liobn(struct kvm *kvm,
> + unsigned long liobn);
> +
Wrong header file.
> #endif /* VFIO_H */
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 7c1a349..a74ad16 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -847,6 +847,7 @@ struct kvm_device_attr {
> #define KVM_DEV_VFIO_GROUP 1
> #define KVM_DEV_VFIO_GROUP_ADD 1
> #define KVM_DEV_VFIO_GROUP_DEL 2
> +#define KVM_DEV_VFIO_SPAPR_TCE_LIOBN 2
>
> /*
> * ioctls for VM fds
> diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
> index 2e336a7..39dea9f 100644
> --- a/virt/kvm/vfio.c
> +++ b/virt/kvm/vfio.c
> @@ -22,6 +22,7 @@
> struct kvm_vfio_group {
> struct list_head node;
> struct vfio_group *vfio_group;
> + uint64_t liobn; /* sPAPR */
Perhaps an arch pointer or at least a union.
> };
>
> struct kvm_vfio {
> @@ -188,12 +189,52 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
> return -ENXIO;
> }
>
> +static int kvm_vfio_set_spapr_tce_liobn(struct kvm_device *dev,
> + long attr, u64 arg)
> +{
> + struct kvm_vfio *kv = dev->private;
> + struct vfio_group *vfio_group;
> + struct kvm_vfio_group *kvg;
> + void __user *argp = (void __user *)arg;
> + struct fd f;
> + int32_t fd;
> + uint64_t liobn = attr;
> +
> + if (get_user(fd, (int32_t __user *)argp))
> + return -EFAULT;
> +
> + f = fdget(fd);
> + if (!f.file)
> + return -EBADF;
> +
> + vfio_group = kvm_vfio_group_get_external_user(f.file);
> + fdput(f);
> +
> + list_for_each_entry(kvg, &kv->group_list, node) {
> + if (kvg->vfio_group == vfio_group) {
> + WARN_ON(kvg->liobn);
Users shouldn't be able to trigger WARN_ON so easily, return -EBUSY,
allow it to be unset and re-set, or just allow the overwrite.
> + kvg->liobn = liobn;
> + kvm_vfio_group_put_external_user(vfio_group);
> + return 0;
> + }
> + }
> +
> + kvm_vfio_group_put_external_user(vfio_group);
> +
> + return -ENXIO;
> +}
> +
> static int kvm_vfio_set_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> switch (attr->group) {
> case KVM_DEV_VFIO_GROUP:
> return kvm_vfio_set_group(dev, attr->attr, attr->addr);
> +#ifdef CONFIG_SPAPR_TCE_IOMMU
> + case KVM_DEV_VFIO_SPAPR_TCE_LIOBN:
> + return kvm_vfio_set_spapr_tce_liobn(dev, attr->attr,
> + attr->addr);
> +#endif
> }
>
> return -ENXIO;
> @@ -211,6 +252,10 @@ static int kvm_vfio_has_attr(struct kvm_device *dev,
> }
>
> break;
> +#ifdef CONFIG_SPAPR_TCE_IOMMU
> + case KVM_DEV_VFIO_SPAPR_TCE_LIOBN:
> + return 0;
> +#endif
> }
>
> return -ENXIO;
> @@ -250,6 +295,7 @@ static int kvm_vfio_create(struct kvm_device *dev, u32 type)
> mutex_init(&kv->lock);
>
> dev->private = kv;
> + dev->kvm->vfio = kv;
>
> return 0;
> }
> diff --git a/virt/kvm/vfio_rm.c b/virt/kvm/vfio_rm.c
> new file mode 100644
> index 0000000..ee9fd96
> --- /dev/null
> +++ b/virt/kvm/vfio_rm.c
> @@ -0,0 +1,54 @@
> +#include <linux/errno.h>
> +#include <linux/file.h>
> +#include <linux/kvm_host.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <linux/vfio.h>
> +
> +struct kvm_vfio_group {
> + struct list_head node;
> + struct vfio_group *vfio_group;
> + uint64_t liobn; /* sPAPR */
> +};
> +
> +struct kvm_vfio {
> + struct list_head group_list;
> + struct mutex lock;
> + bool noncoherent;
> +};
> +
> +struct vfio_group {
> + struct kref kref;
> + int minor;
> + atomic_t container_users;
> + struct iommu_group *iommu_group;
> + struct vfio_container *container;
> + struct list_head device_list;
> + struct mutex device_lock;
> + struct device *dev;
> + struct notifier_block nb;
> + struct list_head vfio_next;
> + struct list_head container_next;
> + atomic_t opened;
> +};
> +
> +struct iommu_group *vfio_find_group_by_liobn(struct kvm *kvm, unsigned long liobn)
> +{
> + struct kvm_vfio_group *kvg;
> +
> + if (!kvm->vfio)
> + return NULL;
> +
> + list_for_each_entry(kvg, &kvm->vfio->group_list, node) {
> + if (kvg->liobn == liobn)
> + return kvg->vfio_group->iommu_group;
> + }
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(vfio_find_group_by_liobn);
> +
> +
You're kidding, right? These are intentionally private data structures
that are blatantly copied so that you can extract what you want. NACK.
The iommu_group is available off struct device, do you even need vfio or
this kvm-vfio device to get from liobn to iommu_group? Thanks,
Alex
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