[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v5 2/3] xen: introduce arch_grant_(un)map_page_identity
Introduce two arch specific functions to create a new p2m mapping of granted pages at pfn == mfn. We don't an x86 implementation as these functions should never be compiled on x86 (they are called from an if (0) statement). Base the implementation of arm_smmu_(un)map_page on arch_grant_(un)map_page_identity. Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Acked-by: Julien Grall <julien.grall@xxxxxxxxxx> --- Changes in v5: - actually define arch_grant_(un)map_page_identity as extern without implementation on x86. Changes in v4: - declare the x86 implementations as extern; - add ASSERTs to ARM implementations. Changes in v3: - fix commit title; - use p2m_iommu types; - call arch_grant_(un)map_page_identity functions from arm_smmu_(un)map_page. --- xen/arch/arm/p2m.c | 26 ++++++++++++++++++++++++++ xen/drivers/passthrough/arm/smmu.c | 13 ++----------- xen/include/asm-arm/p2m.h | 4 ++++ xen/include/asm-x86/p2m.h | 4 ++++ 4 files changed, 36 insertions(+), 11 deletions(-) diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 9960e17..c2634fc 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -555,6 +555,32 @@ void guest_physmap_remove_page(struct domain *d, pfn_to_paddr(mfn), MATTR_MEM, p2m_invalid); } +int arch_grant_map_page_identity(struct domain *d, unsigned long frame, + bool_t writeable) +{ + p2m_type_t t; + + ASSERT(is_domain_direct_mapped(d)); + + /* This is not an IOMMU mapping but it is not a regular RAM p2m type + * either. We are using IOMMU p2m types here to prevent the pages + * from being used as grants. */ + if ( writeable ) + t = p2m_iommu_map_rw; + else + t = p2m_iommu_map_ro; + + return guest_physmap_add_entry(d, frame, frame, 0, t); +} + +int arch_grant_unmap_page_identity(struct domain *d, unsigned long frame) +{ + ASSERT(is_domain_direct_mapped(d)); + + guest_physmap_remove_page(d, frame, frame, 0); + return 0; +} + int p2m_alloc_table(struct domain *d) { struct p2m_domain *p2m = &d->arch.p2m; diff --git a/xen/drivers/passthrough/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c index f4eb2a2..fb0c694 100644 --- a/xen/drivers/passthrough/arm/smmu.c +++ b/xen/drivers/passthrough/arm/smmu.c @@ -1539,8 +1539,6 @@ static void arm_smmu_iommu_domain_teardown(struct domain *d) static int arm_smmu_map_page(struct domain *d, unsigned long gfn, unsigned long mfn, unsigned int flags) { - p2m_type_t t; - /* Grant mappings can be used for DMA requests. The dev_bus_addr returned by * the hypercall is the MFN (not the IPA). For device protected by * an IOMMU, Xen needs to add a 1:1 mapping in the domain p2m to @@ -1555,12 +1553,7 @@ static int arm_smmu_map_page(struct domain *d, unsigned long gfn, if ( !(flags & (IOMMUF_readable | IOMMUF_writable)) ) return -EINVAL; - t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : p2m_iommu_map_ro; - - /* The function guest_physmap_add_entry replaces the current mapping - * if there is already one... - */ - return guest_physmap_add_entry(d, gfn, mfn, 0, t); + return arch_grant_map_page_identity(d, mfn, flags & IOMMUF_writable); } static int arm_smmu_unmap_page(struct domain *d, unsigned long gfn) @@ -1571,9 +1564,7 @@ static int arm_smmu_unmap_page(struct domain *d, unsigned long gfn) if ( !is_domain_direct_mapped(d) ) return -EINVAL; - guest_physmap_remove_page(d, gfn, gfn, 0); - - return 0; + return arch_grant_unmap_page_identity(d, gfn); } static const struct iommu_ops arm_smmu_iommu_ops = { diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h index 911d32d..b682f51 100644 --- a/xen/include/asm-arm/p2m.h +++ b/xen/include/asm-arm/p2m.h @@ -181,6 +181,10 @@ static inline int get_page_and_type(struct page_info *page, return rc; } +int arch_grant_map_page_identity(struct domain *d, unsigned long frame, + bool_t writeable); +int arch_grant_unmap_page_identity(struct domain *d, unsigned long frame); + #endif /* _XEN_P2M_H */ /* diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h index 0ddbadb..010e488 100644 --- a/xen/include/asm-x86/p2m.h +++ b/xen/include/asm-x86/p2m.h @@ -717,6 +717,10 @@ static inline unsigned int p2m_get_iommu_flags(p2m_type_t p2mt) return flags; } + +extern int arch_grant_map_page_identity(struct domain *d, unsigned long frame, + bool_t writeable); +extern int arch_grant_unmap_page_identity(struct domain *d, unsigned long frame); #endif /* _XEN_P2M_H */ -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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