From c10c21efa4bccab486c2e6a047c13dfa6cf7426c Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Wed, 19 Dec 2018 19:52:15 +1100 Subject: [PATCH] powerpc/vfio/iommu/kvm: Do not pin device memory This new memory does not have page structs as it is not plugged to the host so gup() will fail anyway. This adds 2 helpers: - mm_iommu_newdev() to preregister the "memory device" memory so the rest of API can still be used; - mm_iommu_is_devmem() to know if the physical address is one of thise new regions which we must avoid unpinning of. This adds @mm to tce_page_is_contained() and iommu_tce_xchg() to test if the memory is device memory to avoid pfn_to_page(). This adds a check for device memory in mm_iommu_ua_mark_dirty_rm() which does delayed pages dirtying. Signed-off-by: Alexey Kardashevskiy Reviewed-by: Paul Mackerras Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/iommu.h | 5 +- arch/powerpc/include/asm/mmu_context.h | 11 +++ arch/powerpc/kernel/iommu.c | 11 ++- arch/powerpc/kvm/book3s_64_vio.c | 18 ++--- arch/powerpc/mm/mmu_context_iommu.c | 93 +++++++++++++++++++++++--- drivers/vfio/vfio_iommu_spapr_tce.c | 29 +++++--- 6 files changed, 135 insertions(+), 32 deletions(-) diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h index 35db0cbc9222..a8aeac0db01c 100644 --- a/arch/powerpc/include/asm/iommu.h +++ b/arch/powerpc/include/asm/iommu.h @@ -218,8 +218,9 @@ extern void iommu_register_group(struct iommu_table_group *table_group, extern int iommu_add_device(struct device *dev); extern void iommu_del_device(struct device *dev); extern int __init tce_iommu_bus_notifier_init(void); -extern long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry, - unsigned long *hpa, enum dma_data_direction *direction); +extern long iommu_tce_xchg(struct mm_struct *mm, struct iommu_table *tbl, + unsigned long entry, unsigned long *hpa, + enum dma_data_direction *direction); #else static inline void iommu_register_group(struct iommu_table_group *table_group, int pci_domain_number, diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 424899a7fac8..6ee8195a2ffb 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -24,6 +24,9 @@ extern bool mm_iommu_preregistered(struct mm_struct *mm); extern long mm_iommu_new(struct mm_struct *mm, unsigned long ua, unsigned long entries, struct mm_iommu_table_group_mem_t **pmem); +extern long mm_iommu_newdev(struct mm_struct *mm, unsigned long ua, + unsigned long entries, unsigned long dev_hpa, + struct mm_iommu_table_group_mem_t **pmem); extern long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem); extern void mm_iommu_init(struct mm_struct *mm); @@ -39,8 +42,16 @@ extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, extern long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem, unsigned long ua, unsigned int pageshift, unsigned long *hpa); extern void mm_iommu_ua_mark_dirty_rm(struct mm_struct *mm, unsigned long ua); +extern bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa, + unsigned int pageshift, unsigned long *size); extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem); extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem); +#else +static inline bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa, + unsigned int pageshift, unsigned long *size) +{ + return false; +} #endif extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm); extern void set_context(unsigned long id, pgd_t *pgd); diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index f0dc680e659a..cbcc6152b7f5 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -47,6 +47,7 @@ #include #include #include +#include #define DBG(...) @@ -993,15 +994,19 @@ int iommu_tce_check_gpa(unsigned long page_shift, unsigned long gpa) } EXPORT_SYMBOL_GPL(iommu_tce_check_gpa); -long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry, - unsigned long *hpa, enum dma_data_direction *direction) +long iommu_tce_xchg(struct mm_struct *mm, struct iommu_table *tbl, + unsigned long entry, unsigned long *hpa, + enum dma_data_direction *direction) { long ret; + unsigned long size = 0; ret = tbl->it_ops->exchange(tbl, entry, hpa, direction); if (!ret && ((*direction == DMA_FROM_DEVICE) || - (*direction == DMA_BIDIRECTIONAL))) + (*direction == DMA_BIDIRECTIONAL)) && + !mm_iommu_is_devmem(mm, *hpa, tbl->it_page_shift, + &size)) SetPageDirty(pfn_to_page(*hpa >> PAGE_SHIFT)); /* if (unlikely(ret)) diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index 62a8d03ba7e9..532ab79734c7 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -397,12 +397,13 @@ static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, return H_SUCCESS; } -static void kvmppc_clear_tce(struct iommu_table *tbl, unsigned long entry) +static void kvmppc_clear_tce(struct mm_struct *mm, struct iommu_table *tbl, + unsigned long entry) { unsigned long hpa = 0; enum dma_data_direction dir = DMA_NONE; - iommu_tce_xchg(tbl, entry, &hpa, &dir); + iommu_tce_xchg(mm, tbl, entry, &hpa, &dir); } static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm, @@ -433,7 +434,7 @@ static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm, unsigned long hpa = 0; long ret; - if (WARN_ON_ONCE(iommu_tce_xchg(tbl, entry, &hpa, &dir))) + if (WARN_ON_ONCE(iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir))) return H_TOO_HARD; if (dir == DMA_NONE) @@ -441,7 +442,7 @@ static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm, ret = kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry); if (ret != H_SUCCESS) - iommu_tce_xchg(tbl, entry, &hpa, &dir); + iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir); return ret; } @@ -487,7 +488,7 @@ long kvmppc_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl, if (mm_iommu_mapped_inc(mem)) return H_TOO_HARD; - ret = iommu_tce_xchg(tbl, entry, &hpa, &dir); + ret = iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir); if (WARN_ON_ONCE(ret)) { mm_iommu_mapped_dec(mem); return H_TOO_HARD; @@ -566,7 +567,7 @@ long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, entry, ua, dir); if (ret != H_SUCCESS) { - kvmppc_clear_tce(stit->tbl, entry); + kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry); goto unlock_exit; } } @@ -655,7 +656,8 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu, iommu_tce_direction(tce)); if (ret != H_SUCCESS) { - kvmppc_clear_tce(stit->tbl, entry); + kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, + entry); goto unlock_exit; } } @@ -704,7 +706,7 @@ long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu, return ret; WARN_ON_ONCE(1); - kvmppc_clear_tce(stit->tbl, entry); + kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry); } } diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c index ce8cc69f7901..a712a650a8b6 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -36,6 +36,8 @@ struct mm_iommu_table_group_mem_t { u64 ua; /* userspace address */ u64 entries; /* number of entries in hpas[] */ u64 *hpas; /* vmalloc'ed */ +#define MM_IOMMU_TABLE_INVALID_HPA ((uint64_t)-1) + u64 dev_hpa; /* Device memory base address */ }; static long mm_iommu_adjust_locked_vm(struct mm_struct *mm, @@ -126,7 +128,8 @@ static int mm_iommu_move_page_from_cma(struct page *page) return 0; } -long mm_iommu_new(struct mm_struct *mm, unsigned long ua, unsigned long entries, +static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, + unsigned long entries, unsigned long dev_hpa, struct mm_iommu_table_group_mem_t **pmem) { struct mm_iommu_table_group_mem_t *mem; @@ -150,11 +153,13 @@ long mm_iommu_new(struct mm_struct *mm, unsigned long ua, unsigned long entries, } - ret = mm_iommu_adjust_locked_vm(mm, entries, true); - if (ret) - goto unlock_exit; + if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) { + ret = mm_iommu_adjust_locked_vm(mm, entries, true); + if (ret) + goto unlock_exit; - locked_entries = entries; + locked_entries = entries; + } mem = kzalloc(sizeof(*mem), GFP_KERNEL); if (!mem) { @@ -162,6 +167,13 @@ long mm_iommu_new(struct mm_struct *mm, unsigned long ua, unsigned long entries, goto unlock_exit; } + if (dev_hpa != MM_IOMMU_TABLE_INVALID_HPA) { + mem->pageshift = __ffs(dev_hpa | (entries << PAGE_SHIFT)); + mem->dev_hpa = dev_hpa; + goto good_exit; + } + mem->dev_hpa = MM_IOMMU_TABLE_INVALID_HPA; + /* * For a starting point for a maximum page size calculation * we use @ua and @entries natural alignment to allow IOMMU pages @@ -230,6 +242,7 @@ populate: mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT; } +good_exit: atomic64_set(&mem->mapped, 1); mem->used = 1; mem->ua = ua; @@ -246,13 +259,31 @@ unlock_exit: return ret; } + +long mm_iommu_new(struct mm_struct *mm, unsigned long ua, unsigned long entries, + struct mm_iommu_table_group_mem_t **pmem) +{ + return mm_iommu_do_alloc(mm, ua, entries, MM_IOMMU_TABLE_INVALID_HPA, + pmem); +} EXPORT_SYMBOL_GPL(mm_iommu_new); +long mm_iommu_newdev(struct mm_struct *mm, unsigned long ua, + unsigned long entries, unsigned long dev_hpa, + struct mm_iommu_table_group_mem_t **pmem) +{ + return mm_iommu_do_alloc(mm, ua, entries, dev_hpa, pmem); +} +EXPORT_SYMBOL_GPL(mm_iommu_newdev); + static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem) { long i; struct page *page = NULL; + if (!mem->hpas) + return; + for (i = 0; i < mem->entries; ++i) { if (!mem->hpas[i]) continue; @@ -294,6 +325,7 @@ static void mm_iommu_release(struct mm_iommu_table_group_mem_t *mem) long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem) { long ret = 0; + unsigned long entries, dev_hpa; mutex_lock(&mem_list_mutex); @@ -315,9 +347,12 @@ long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem) } /* @mapped became 0 so now mappings are disabled, release the region */ + entries = mem->entries; + dev_hpa = mem->dev_hpa; mm_iommu_release(mem); - mm_iommu_adjust_locked_vm(mm, mem->entries, false); + if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) + mm_iommu_adjust_locked_vm(mm, entries, false); unlock_exit: mutex_unlock(&mem_list_mutex); @@ -387,7 +422,7 @@ long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, unsigned long ua, unsigned int pageshift, unsigned long *hpa) { const long entry = (ua - mem->ua) >> PAGE_SHIFT; - u64 *va = &mem->hpas[entry]; + u64 *va; if (entry >= mem->entries) return -EFAULT; @@ -395,6 +430,12 @@ long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, if (pageshift > mem->pageshift) return -EFAULT; + if (!mem->hpas) { + *hpa = mem->dev_hpa + (ua - mem->ua); + return 0; + } + + va = &mem->hpas[entry]; *hpa = (*va & MM_IOMMU_TABLE_GROUP_PAGE_MASK) | (ua & ~PAGE_MASK); return 0; @@ -405,7 +446,6 @@ long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem, unsigned long ua, unsigned int pageshift, unsigned long *hpa) { const long entry = (ua - mem->ua) >> PAGE_SHIFT; - void *va = &mem->hpas[entry]; unsigned long *pa; if (entry >= mem->entries) @@ -414,7 +454,12 @@ long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem, if (pageshift > mem->pageshift) return -EFAULT; - pa = (void *) vmalloc_to_phys(va); + if (!mem->hpas) { + *hpa = mem->dev_hpa + (ua - mem->ua); + return 0; + } + + pa = (void *) vmalloc_to_phys(&mem->hpas[entry]); if (!pa) return -EFAULT; @@ -434,6 +479,9 @@ extern void mm_iommu_ua_mark_dirty_rm(struct mm_struct *mm, unsigned long ua) if (!mem) return; + if (mem->dev_hpa != MM_IOMMU_TABLE_INVALID_HPA) + return; + entry = (ua - mem->ua) >> PAGE_SHIFT; va = &mem->hpas[entry]; @@ -444,6 +492,33 @@ extern void mm_iommu_ua_mark_dirty_rm(struct mm_struct *mm, unsigned long ua) *pa |= MM_IOMMU_TABLE_GROUP_PAGE_DIRTY; } +bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa, + unsigned int pageshift, unsigned long *size) +{ + struct mm_iommu_table_group_mem_t *mem; + unsigned long end; + + list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) { + if (mem->dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) + continue; + + end = mem->dev_hpa + (mem->entries << PAGE_SHIFT); + if ((mem->dev_hpa <= hpa) && (hpa < end)) { + /* + * Since the IOMMU page size might be bigger than + * PAGE_SIZE, the amount of preregistered memory + * starting from @hpa might be smaller than 1<mapped)) diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 1d8b88928329..c424913324e3 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -222,8 +222,16 @@ put_exit: return ret; } -static bool tce_page_is_contained(struct page *page, unsigned page_shift) +static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa, + unsigned int page_shift) { + struct page *page; + unsigned long size = 0; + + if (mm_iommu_is_devmem(mm, hpa, page_shift, &size)) + return size == (1UL << page_shift); + + page = pfn_to_page(hpa >> PAGE_SHIFT); /* * Check that the TCE table granularity is not bigger than the size of * a page we just found. Otherwise the hardware can get access to @@ -499,7 +507,8 @@ static int tce_iommu_clear(struct tce_container *container, direction = DMA_NONE; oldhpa = 0; - ret = iommu_tce_xchg(tbl, entry, &oldhpa, &direction); + ret = iommu_tce_xchg(container->mm, tbl, entry, &oldhpa, + &direction); if (ret) continue; @@ -537,7 +546,6 @@ static long tce_iommu_build(struct tce_container *container, enum dma_data_direction direction) { long i, ret = 0; - struct page *page; unsigned long hpa; enum dma_data_direction dirtmp; @@ -548,15 +556,16 @@ static long tce_iommu_build(struct tce_container *container, if (ret) break; - page = pfn_to_page(hpa >> PAGE_SHIFT); - if (!tce_page_is_contained(page, tbl->it_page_shift)) { + if (!tce_page_is_contained(container->mm, hpa, + tbl->it_page_shift)) { ret = -EPERM; break; } hpa |= offset; dirtmp = direction; - ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp); + ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa, + &dirtmp); if (ret) { tce_iommu_unuse_page(container, hpa); pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n", @@ -583,7 +592,6 @@ static long tce_iommu_build_v2(struct tce_container *container, enum dma_data_direction direction) { long i, ret = 0; - struct page *page; unsigned long hpa; enum dma_data_direction dirtmp; @@ -596,8 +604,8 @@ static long tce_iommu_build_v2(struct tce_container *container, if (ret) break; - page = pfn_to_page(hpa >> PAGE_SHIFT); - if (!tce_page_is_contained(page, tbl->it_page_shift)) { + if (!tce_page_is_contained(container->mm, hpa, + tbl->it_page_shift)) { ret = -EPERM; break; } @@ -610,7 +618,8 @@ static long tce_iommu_build_v2(struct tce_container *container, if (mm_iommu_mapped_inc(mem)) break; - ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp); + ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa, + &dirtmp); if (ret) { /* dirtmp cannot be DMA_NONE here */ tce_iommu_unuse_page_v2(container, tbl, entry + i); -- 2.30.2