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Re: [Qemu-devel] [RFC PATCH 1/8] iommu: Introduce bind_pasid_table API f
From: |
Alex Williamson |
Subject: |
Re: [Qemu-devel] [RFC PATCH 1/8] iommu: Introduce bind_pasid_table API function |
Date: |
Fri, 12 May 2017 15:59:14 -0600 |
On Wed, 26 Apr 2017 18:11:58 +0800
"Liu, Yi L" <address@hidden> wrote:
> From: Jacob Pan <address@hidden>
>
> Virtual IOMMU was proposed to support Shared Virtual Memory (SVM) use
> case in the guest:
> https://lists.gnu.org/archive/html/qemu-devel/2016-11/msg05311.html
>
> As part of the proposed architecture, when a SVM capable PCI
> device is assigned to a guest, nested mode is turned on. Guest owns the
> first level page tables (request with PASID) and performs GVA->GPA
> translation. Second level page tables are owned by the host for GPA->HPA
> translation for both request with and without PASID.
>
> A new IOMMU driver interface is therefore needed to perform tasks as
> follows:
> * Enable nested translation and appropriate translation type
> * Assign guest PASID table pointer (in GPA) and size to host IOMMU
>
> This patch introduces new functions called iommu_(un)bind_pasid_table()
> to IOMMU APIs. Architecture specific IOMMU function can be added later
> to perform the specific steps for binding pasid table of assigned devices.
>
> This patch also adds model definition in iommu.h. It would be used to
> check if the bind request is from a compatible entity. e.g. a bind
> request from an intel_iommu emulator may not be supported by an ARM SMMU
> driver.
>
> Signed-off-by: Jacob Pan <address@hidden>
> Signed-off-by: Liu, Yi L <address@hidden>
> ---
> drivers/iommu/iommu.c | 19 +++++++++++++++++++
> include/linux/iommu.h | 31 +++++++++++++++++++++++++++++++
> 2 files changed, 50 insertions(+)
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index dbe7f65..f2da636 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -1134,6 +1134,25 @@ int iommu_attach_device(struct iommu_domain *domain,
> struct device *dev)
> }
> EXPORT_SYMBOL_GPL(iommu_attach_device);
>
> +int iommu_bind_pasid_table(struct iommu_domain *domain, struct device *dev,
> + struct pasid_table_info *pasidt_binfo)
> +{
> + if (unlikely(!domain->ops->bind_pasid_table))
> + return -EINVAL;
> +
> + return domain->ops->bind_pasid_table(domain, dev, pasidt_binfo);
> +}
> +EXPORT_SYMBOL_GPL(iommu_bind_pasid_table);
> +
> +int iommu_unbind_pasid_table(struct iommu_domain *domain, struct device *dev)
> +{
> + if (unlikely(!domain->ops->unbind_pasid_table))
> + return -EINVAL;
> +
> + return domain->ops->unbind_pasid_table(domain, dev);
> +}
> +EXPORT_SYMBOL_GPL(iommu_unbind_pasid_table);
> +
> static void __iommu_detach_device(struct iommu_domain *domain,
> struct device *dev)
> {
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 0ff5111..491a011 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -131,6 +131,15 @@ struct iommu_dm_region {
> int prot;
> };
>
> +struct pasid_table_info {
> + __u64 ptr; /* PASID table ptr */
> + __u64 size; /* PASID table size*/
> + __u32 model; /* magic number */
> +#define INTEL_IOMMU (1 << 0)
> +#define ARM_SMMU (1 << 1)
> + __u8 opaque[];/* IOMMU-specific details */
> +};
This needs to be in uapi since you're expecting a user to pass it
> +
> #ifdef CONFIG_IOMMU_API
>
> /**
> @@ -159,6 +168,8 @@ struct iommu_dm_region {
> * @domain_get_windows: Return the number of windows for a domain
> * @of_xlate: add OF master IDs to iommu grouping
> * @pgsize_bitmap: bitmap of all possible supported page sizes
> + * @bind_pasid_table: bind pasid table pointer for guest SVM
> + * @unbind_pasid_table: unbind pasid table pointer and restore defaults
> */
> struct iommu_ops {
> bool (*capable)(enum iommu_cap);
> @@ -200,6 +211,10 @@ struct iommu_ops {
> u32 (*domain_get_windows)(struct iommu_domain *domain);
>
> int (*of_xlate)(struct device *dev, struct of_phandle_args *args);
> + int (*bind_pasid_table)(struct iommu_domain *domain, struct device *dev,
> + struct pasid_table_info *pasidt_binfo);
> + int (*unbind_pasid_table)(struct iommu_domain *domain,
> + struct device *dev);
>
> unsigned long pgsize_bitmap;
> };
> @@ -221,6 +236,10 @@ extern int iommu_attach_device(struct iommu_domain
> *domain,
> struct device *dev);
> extern void iommu_detach_device(struct iommu_domain *domain,
> struct device *dev);
> +extern int iommu_bind_pasid_table(struct iommu_domain *domain,
> + struct device *dev, struct pasid_table_info *pasidt_binfo);
> +extern int iommu_unbind_pasid_table(struct iommu_domain *domain,
> + struct device *dev);
> extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
> extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
> phys_addr_t paddr, size_t size, int prot);
> @@ -595,6 +614,18 @@ const struct iommu_ops *iommu_get_instance(struct
> fwnode_handle *fwnode)
> return NULL;
> }
>
> +static inline
> +int iommu_bind_pasid_table(struct iommu_domain *domain, struct device *dev,
> + struct pasid_table_info *pasidt_binfo)
> +{
> + return -EINVAL;
> +}
> +static inline
> +int iommu_unbind_pasid_table(struct iommu_domain *domain, struct device *dev)
> +{
> + return -EINVAL;
> +}
> +
> #endif /* CONFIG_IOMMU_API */
>
> #endif /* __LINUX_IOMMU_H */
- Re: [Qemu-devel] [RFC PATCH 1/8] iommu: Introduce bind_pasid_table API function,
Alex Williamson <=