diff options
| -rw-r--r-- | arch/x86/include/asm/xen/page.h | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/xen/swiotlb-xen.h | 14 | ||||
| -rw-r--r-- | arch/x86/kernel/pci-dma.c | 7 | ||||
| -rw-r--r-- | arch/x86/xen/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten.c | 4 | ||||
| -rw-r--r-- | arch/x86/xen/mmu.c | 293 | ||||
| -rw-r--r-- | arch/x86/xen/pci-swiotlb-xen.c | 58 | ||||
| -rw-r--r-- | drivers/xen/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/xen/Makefile | 1 | ||||
| -rw-r--r-- | drivers/xen/balloon.c | 15 | ||||
| -rw-r--r-- | drivers/xen/swiotlb-xen.c | 515 | ||||
| -rw-r--r-- | include/linux/vmalloc.h | 2 | ||||
| -rw-r--r-- | include/xen/interface/memory.h | 50 | ||||
| -rw-r--r-- | include/xen/swiotlb-xen.h | 65 | ||||
| -rw-r--r-- | include/xen/xen-ops.h | 6 | ||||
| -rw-r--r-- | mm/vmalloc.c | 4 |
16 files changed, 1024 insertions, 24 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 018a0a4..bf5f7d3 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -112,13 +112,9 @@ static inline xpaddr_t machine_to_phys(xmaddr_t machine) */ static inline unsigned long mfn_to_local_pfn(unsigned long mfn) { - extern unsigned long max_mapnr; unsigned long pfn = mfn_to_pfn(mfn); - if ((pfn < max_mapnr) - && !xen_feature(XENFEAT_auto_translated_physmap) - && (get_phys_to_machine(pfn) != mfn)) - return max_mapnr; /* force !pfn_valid() */ - /* XXX fixme; not true with sparsemem */ + if (get_phys_to_machine(pfn) != mfn) + return -1; /* force !pfn_valid() */ return pfn; } diff --git a/arch/x86/include/asm/xen/swiotlb-xen.h b/arch/x86/include/asm/xen/swiotlb-xen.h new file mode 100644 index 0000000..1be1ab7 --- /dev/null +++ b/arch/x86/include/asm/xen/swiotlb-xen.h @@ -0,0 +1,14 @@ +#ifndef _ASM_X86_SWIOTLB_XEN_H +#define _ASM_X86_SWIOTLB_XEN_H + +#ifdef CONFIG_SWIOTLB_XEN +extern int xen_swiotlb; +extern int __init pci_xen_swiotlb_detect(void); +extern void __init pci_xen_swiotlb_init(void); +#else +#define xen_swiotlb (0) +static inline int __init pci_xen_swiotlb_detect(void) { return 0; } +static inline void __init pci_xen_swiotlb_init(void) { } +#endif + +#endif /* _ASM_X86_SWIOTLB_XEN_H */ diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 4b7e3d8..9f07cfc 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -13,6 +13,7 @@ #include <asm/calgary.h> #include <asm/amd_iommu.h> #include <asm/x86_init.h> +#include <asm/xen/swiotlb-xen.h> static int forbid_dac __read_mostly; @@ -132,7 +133,7 @@ void __init pci_iommu_alloc(void) /* free the range so iommu could get some range less than 4G */ dma32_free_bootmem(); - if (pci_swiotlb_detect()) + if (pci_xen_swiotlb_detect() || pci_swiotlb_detect()) goto out; gart_iommu_hole_init(); @@ -144,6 +145,8 @@ void __init pci_iommu_alloc(void) /* needs to be called after gart_iommu_hole_init */ amd_iommu_detect(); out: + pci_xen_swiotlb_init(); + pci_swiotlb_init(); } @@ -296,7 +299,7 @@ static int __init pci_iommu_init(void) #endif x86_init.iommu.iommu_init(); - if (swiotlb) { + if (swiotlb || xen_swiotlb) { printk(KERN_INFO "PCI-DMA: " "Using software bounce buffering for IO (SWIOTLB)\n"); swiotlb_print_info(); diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index 9309546..7793851 100644 --- a/arch/x86/xen/Makefile +++ b/arch/x86/xen/Makefile @@ -18,3 +18,4 @@ obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o obj-$(CONFIG_XEN_DEBUG_FS) += debugfs.o +obj-$(CONFIG_SWIOTLB_XEN) += pci-swiotlb-xen.o diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index d4ff5e8..7d46c84 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1172,6 +1172,10 @@ asmlinkage void __init xen_start_kernel(void) pgd = (pgd_t *)xen_start_info->pt_base; + if (!xen_initial_domain()) + __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); + + __supported_pte_mask |= _PAGE_IOMAP; /* Don't do the full vcpu_info placement stuff until we have a possible map and a non-dummy shared_info. */ per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0]; diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 413b19b..42086ac 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -42,6 +42,7 @@ #include <linux/highmem.h> #include <linux/debugfs.h> #include <linux/bug.h> +#include <linux/vmalloc.h> #include <linux/module.h> #include <linux/gfp.h> @@ -51,15 +52,19 @@ #include <asm/mmu_context.h> #include <asm/setup.h> #include <asm/paravirt.h> +#include <asm/e820.h> #include <asm/linkage.h> +#include <asm/page.h> #include <asm/xen/hypercall.h> #include <asm/xen/hypervisor.h> +#include <xen/xen.h> #include <xen/page.h> #include <xen/interface/xen.h> #include <xen/interface/hvm/hvm_op.h> #include <xen/interface/version.h> +#include <xen/interface/memory.h> #include <xen/hvc-console.h> #include "multicalls.h" @@ -68,6 +73,13 @@ #define MMU_UPDATE_HISTO 30 +/* + * Protects atomic reservation decrease/increase against concurrent increases. + * Also protects non-atomic updates of current_pages and driver_pages, and + * balloon lists. + */ +DEFINE_SPINLOCK(xen_reservation_lock); + #ifdef CONFIG_XEN_DEBUG_FS static struct { @@ -378,6 +390,28 @@ static bool xen_page_pinned(void *ptr) return PagePinned(page); } +static bool xen_iomap_pte(pte_t pte) +{ + return pte_flags(pte) & _PAGE_IOMAP; +} + +static void xen_set_iomap_pte(pte_t *ptep, pte_t pteval) +{ + struct multicall_space mcs; + struct mmu_update *u; + + mcs = xen_mc_entry(sizeof(*u)); + u = mcs.args; + + /* ptep might be kmapped when using 32-bit HIGHPTE */ + u->ptr = arbitrary_virt_to_machine(ptep).maddr; + u->val = pte_val_ma(pteval); + + MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_IO); + + xen_mc_issue(PARAVIRT_LAZY_MMU); +} + static void xen_extend_mmu_update(const struct mmu_update *update) { struct multicall_space mcs; @@ -454,6 +488,11 @@ void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags) void xen_set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval) { + if (xen_iomap_pte(pteval)) { + xen_set_iomap_pte(ptep, pteval); + goto out; + } + ADD_STATS(set_pte_at, 1); // ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep)); ADD_STATS(set_pte_at_current, mm == current->mm); @@ -524,8 +563,25 @@ static pteval_t pte_pfn_to_mfn(pteval_t val) return val; } +static pteval_t iomap_pte(pteval_t val) +{ + if (val & _PAGE_PRESENT) { + unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT; + pteval_t flags = val & PTE_FLAGS_MASK; + + /* We assume the pte frame number is a MFN, so + just use it as-is. */ + val = ((pteval_t)pfn << PAGE_SHIFT) | flags; + } + + return val; +} + pteval_t xen_pte_val(pte_t pte) { + if (xen_initial_domain() && (pte.pte & _PAGE_IOMAP)) + return pte.pte; + return pte_mfn_to_pfn(pte.pte); } PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val); @@ -538,7 +594,22 @@ PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val); pte_t xen_make_pte(pteval_t pte) { - pte = pte_pfn_to_mfn(pte); + phys_addr_t addr = (pte & PTE_PFN_MASK); + + /* + * Unprivileged domains are allowed to do IOMAPpings for + * PCI passthrough, but not map ISA space. The ISA + * mappings are just dummy local mappings to keep other + * parts of the kernel happy. + */ + if (unlikely(pte & _PAGE_IOMAP) && + (xen_initial_domain() || addr >= ISA_END_ADDRESS)) { + pte = iomap_pte(pte); + } else { + pte &= ~_PAGE_IOMAP; + pte = pte_pfn_to_mfn(pte); + } + return native_make_pte(pte); } PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte); @@ -594,6 +665,11 @@ void xen_set_pud(pud_t *ptr, pud_t val) void xen_set_pte(pte_t *ptep, pte_t pte) { + if (xen_iomap_pte(pte)) { + xen_set_iomap_pte(ptep, pte); + return; + } + ADD_STATS(pte_update, 1); // ADD_STATS(pte_update_pinned, xen_page_pinned(ptep)); ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU); @@ -610,6 +686,11 @@ void xen_set_pte(pte_t *ptep, pte_t pte) #ifdef CONFIG_X86_PAE void xen_set_pte_atomic(pte_t *ptep, pte_t pte) { + if (xen_iomap_pte(pte)) { + xen_set_iomap_pte(ptep, pte); + return; + } + set_64bit((u64 *)ptep, native_pte_val(pte)); } @@ -936,8 +1017,6 @@ static int xen_pin_page(struct mm_struct *mm, struct page *page, read-only, and can be pinned. */ static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd) { - vm_unmap_aliases(); - xen_mc_batch(); if (__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT)) { @@ -1501,7 +1580,6 @@ static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned l if (PagePinned(virt_to_page(mm->pgd))) { SetPagePinned(page); - vm_unmap_aliases(); if (!PageHighMem(page)) { make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn))); if (level == PT_PTE && USE_SPLIT_PTLOCKS) @@ -1812,9 +1890,16 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) pte = pfn_pte(phys, prot); break; - default: + case FIX_PARAVIRT_BOOTMAP: + /* This is an MFN, but it isn't an IO mapping from the + IO domain */ pte = mfn_pte(phys, prot); break; + + default: + /* By default, set_fixmap is used for hardware mappings */ + pte = mfn_pte(phys, __pgprot(pgprot_val(prot) | _PAGE_IOMAP)); + break; } __native_set_fixmap(idx, pte); @@ -1940,7 +2025,205 @@ void __init xen_init_mmu_ops(void) x86_init.paging.pagetable_setup_start = xen_pagetable_setup_start; x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done; pv_mmu_ops = xen_mmu_ops; + + vmap_lazy_unmap = false; +} + +/* Protected by xen_reservation_lock. */ +#define MAX_CONTIG_ORDER 9 /* 2MB */ +static unsigned long discontig_frames[1<<MAX_CONTIG_ORDER]; + +#define VOID_PTE (mfn_pte(0, __pgprot(0))) +static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order, + unsigned long *in_frames, + unsigned long *out_frames) +{ + int i; + struct multicall_space mcs; + + xen_mc_batch(); + for (i = 0; i < (1UL<<order); i++, vaddr += PAGE_SIZE) { + mcs = __xen_mc_entry(0); + + if (in_frames) + in_frames[i] = virt_to_mfn(vaddr); + + MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0); + set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY); + + if (out_frames) + out_frames[i] = virt_to_pfn(vaddr); + } + xen_mc_issue(0); +} + +/* + * Update the pfn-to-mfn mappings for a virtual address range, either to + * point to an array of mfns, or contiguously from a single starting + * mfn. + */ +static void xen_remap_exchanged_ptes(unsigned long vaddr, int order, + unsigned long *mfns, + unsigned long first_mfn) +{ + unsigned i, limit; + unsigned long mfn; + + xen_mc_batch(); + + limit = 1u << order; + for (i = 0; i < limit; i++, vaddr += PAGE_SIZE) { + struct multicall_space mcs; + unsigned flags; + + mcs = __xen_mc_entry(0); + if (mfns) + mfn = mfns[i]; + else + mfn = first_mfn + i; + + if (i < (limit - 1)) + flags = 0; + else { + if (order == 0) + flags = UVMF_INVLPG | UVMF_ALL; + else + flags = UVMF_TLB_FLUSH | UVMF_ALL; + } + + MULTI_update_va_mapping(mcs.mc, vaddr, + mfn_pte(mfn, PAGE_KERNEL), flags); + + set_phys_to_machine(virt_to_pfn(vaddr), mfn); + } + + xen_mc_issue(0); +} + +/* + * Perform the hypercall to exchange a region of our pfns to point to + * memory with the required contiguous alignment. Takes the pfns as + * input, and populates mfns as output. + * + * Returns a success code indicating whether the hypervisor was able to + * satisfy the request or not. + */ +static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in, + unsigned long *pfns_in, + unsigned long extents_out, + unsigned int order_out, + unsigned long *mfns_out, + unsigned int address_bits) +{ + long rc; + int success; + + struct xen_memory_exchange exchange = { + .in = { + .nr_extents = extents_in, + .extent_order = order_in, + .extent_start = pfns_in, + .domid = DOMID_SELF + }, + .out = { + .nr_extents = extents_out, + .extent_order = order_out, + .extent_start = mfns_out, + .address_bits = address_bits, + .domid = DOMID_SELF + } + }; + + BUG_ON(extents_in << order_in != extents_out << order_out); + + rc = HYPERVISOR_memory_op(XENMEM_exchange, &exchange); + success = (exchange.nr_exchanged == extents_in); + + BUG_ON(!success && ((exchange.nr_exchanged != 0) || (rc == 0))); + BUG_ON(success && (rc != 0)); + + return success; +} + +int xen_create_contiguous_region(unsigned long vstart, unsigned int order, + unsigned int address_bits) +{ + unsigned long *in_frames = discontig_frames, out_frame; + unsigned long flags; + int success; + + /* + * Currently an auto-translated guest will not perform I/O, nor will + * it require PAE page directories below 4GB. Therefore any calls to + * this function are redundant and can be ignored. + */ + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return 0; + + if (unlikely(order > MAX_CONTIG_ORDER)) + return -ENOMEM; + + memset((void *) vstart, 0, PAGE_SIZE << order); + + spin_lock_irqsave(&xen_reservation_lock, flags); + + /* 1. Zap current PTEs, remembering MFNs. */ + xen_zap_pfn_range(vstart, order, in_frames, NULL); + + /* 2. Get a new contiguous memory extent. */ + out_frame = virt_to_pfn(vstart); + success = xen_exchange_memory(1UL << order, 0, in_frames, + 1, order, &out_frame, + address_bits); + + /* 3. Map the new extent in place of old pages. */ + if (success) + xen_remap_exchanged_ptes(vstart, order, NULL, out_frame); + else + xen_remap_exchanged_ptes(vstart, order, in_frames, 0); + + spin_unlock_irqrestore(&xen_reservation_lock, flags); + + return success ? 0 : -ENOMEM; +} +EXPORT_SYMBOL_GPL(xen_create_contiguous_region); + +void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) +{ + unsigned long *out_frames = discontig_frames, in_frame; + unsigned long flags; + int success; + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return; + + if (unlikely(order > MAX_CONTIG_ORDER)) + return; + + memset((void *) vstart, 0, PAGE_SIZE << order); + + spin_lock_irqsave(&xen_reservation_lock, flags); + + /* 1. Find start MFN of contiguous extent. */ + in_frame = virt_to_mfn(vstart); + + /* 2. Zap current PTEs. */ + xen_zap_pfn_range(vstart, order, NULL, out_frames); + + /* 3. Do the exchange for non-contiguous MFNs. */ + success = xen_exchange_memory(1, order, &in_frame, 1UL << order, + 0, out_frames, 0); + + /* 4. Map new pages in place of old pages. */ + if (success) + xen_remap_exchanged_ptes(vstart, order, out_frames, 0); + else + xen_remap_exchanged_ptes(vstart, order, NULL, in_frame); + + spin_unlock_irqrestore(&xen_reservation_lock, flags); } +EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region); #ifdef CONFIG_XEN_PVHVM static void xen_hvm_exit_mmap(struct mm_struct *mm) diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c new file mode 100644 index 0000000..a013ec9 --- /dev/null +++ b/arch/x86/xen/pci-swiotlb-xen.c @@ -0,0 +1,58 @@ +/* Glue code to lib/swiotlb-xen.c */ + +#include <linux/dma-mapping.h> +#include <xen/swiotlb-xen.h> + +#include <asm/xen/hypervisor.h> +#include <xen/xen.h> + +int xen_swiotlb __read_mostly; + +static struct dma_map_ops xen_swiotlb_dma_ops = { + .mapping_error = xen_swiotlb_dma_mapping_error, + .alloc_coherent = xen_swiotlb_alloc_coherent, + .free_coherent = xen_swiotlb_free_coherent, + .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu, + .sync_single_for_device = xen_swiotlb_sync_single_for_device, + .sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = xen_swiotlb_sync_sg_for_device, + .map_sg = xen_swiotlb_map_sg_attrs, + .unmap_sg = xen_swiotlb_unmap_sg_attrs, + .map_page = xen_swiotlb_map_page, + .unmap_page = xen_swiotlb_unmap_page, + .dma_supported = xen_swiotlb_dma_supported, +}; + +/* + * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary + * + * This returns non-zero if we are forced to use xen_swiotlb (by the boot + * option). + */ +int __init pci_xen_swiotlb_detect(void) +{ + + /* If running as PV guest, either iommu=soft, or swiotlb=force will + * activate this IOMMU. If running as PV privileged, activate it + * irregardlesss. + */ + if ((xen_initial_domain() || swiotlb || swiotlb_force) && + (xen_pv_domain())) + xen_swiotlb = 1; + + /* If we are running under Xen, we MUST disable the native SWIOTLB. + * Don't worry about swiotlb_force flag activating the native, as + * the 'swiotlb' flag is the only one turning it on. */ + if (xen_pv_domain()) + swiotlb = 0; + + return xen_swiotlb; +} + +void __init pci_xen_swiotlb_init(void) +{ + if (xen_swiotlb) { + xen_swiotlb_init(1); + dma_ops = &xen_swiotlb_dma_ops; + } +} diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 0a88269..60d71e9 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -71,4 +71,9 @@ config XEN_PLATFORM_PCI initializing xenbus and grant_table when running in a Xen HVM domain. As a consequence this driver is required to run any Xen PV frontend on Xen HVM. + +config SWIOTLB_XEN + def_bool y + depends on SWIOTLB + endmenu diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index e392fb7..fcaf838 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -11,3 +11,4 @@ obj-$(CONFIG_XEN_DEV_EVTCHN) += evtchn.o obj-$(CONFIG_XENFS) += xenfs/ obj-$(CONFIG_XEN_SYS_HYPERVISOR) += sys-hypervisor.o obj-$(CONFIG_XEN_PLATFORM_PCI) += platform-pci.o +obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 1a0d8c2..500290b 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -85,13 +85,6 @@ static struct sys_device balloon_sysdev; static int register_balloon(struct sys_device *sysdev); -/* - * Protects atomic reservation decrease/increase against concurrent increases. - * Also protects non-atomic updates of current_pages and driver_pages, and - * balloon lists. - */ -static DEFINE_SPINLOCK(balloon_lock); - static struct balloon_stats balloon_stats; /* We increase/decrease in batches which fit in a page */ @@ -210,7 +203,7 @@ static int increase_reservation(unsigned long nr_pages) if (nr_pages > ARRAY_SIZE(frame_list)) nr_pages = ARRAY_SIZE(frame_list); - spin_lock_irqsave(&balloon_lock, flags); + spin_lock_irqsave(&xen_reservation_lock, flags); page = balloon_first_page(); for (i = 0; i < nr_pages; i++) { @@ -254,7 +247,7 @@ static int increase_reservation(unsigned long nr_pages) balloon_stats.current_pages += rc; out: - spin_unlock_irqrestore(&balloon_lock, flags); + spin_unlock_irqrestore(&xen_reservation_lock, flags); return rc < 0 ? rc : rc != nr_pages; } @@ -299,7 +292,7 @@ static int decrease_reservation(unsigned long nr_pages) kmap_flush_unused(); flush_tlb_all(); - spin_lock_irqsave(&balloon_lock, flags); + spin_lock_irqsave(&xen_reservation_lock, flags); /* No more mappings: invalidate P2M and add to balloon. */ for (i = 0; i < nr_pages; i++) { @@ -315,7 +308,7 @@ static int decrease_reservation(unsigned long nr_pages) balloon_stats.current_pages -= nr_pages; - spin_unlock_irqrestore(&balloon_lock, flags); + spin_unlock_irqrestore(&xen_reservation_lock, flags); return need_sleep; } diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c new file mode 100644 index 0000000..54469c3 --- /dev/null +++ b/drivers/xen/swiotlb-xen.c @@ -0,0 +1,515 @@ +/* + * Copyright 2010 + * by Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> + * + * This code provides a IOMMU for Xen PV guests with PCI passthrough. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License v2.0 as published by + * the Free Software Foundation + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * PV guests under Xen are running in an non-contiguous memory architecture. + * + * When PCI pass-through is utilized, this necessitates an IOMMU for + * translating bus (DMA) to virtual and vice-versa and also providing a + * mechanism to have contiguous pages for device drivers operations (say DMA + * operations). + * + * Specifically, under Xen the Linux idea of pages is an illusion. It + * assumes that pages start at zero and go up to the available memory. To + * help with that, the Linux Xen MMU provides a lookup mechanism to + * translate the page frame numbers (PFN) to machine frame numbers (MFN) + * and vice-versa. The MFN are the "real" frame numbers. Furthermore + * memory is not contiguous. Xen hypervisor stitches memory for guests + * from different pools, which means there is no guarantee that PFN==MFN + * and PFN+1==MFN+1. Lastly with Xen 4.0, pages (in debug mode) are + * allocated in descending order (high to low), meaning the guest might + * never get any MFN's under the 4GB mark. + * + */ + +#include <linux/bootmem.h> +#include <linux/dma-mapping.h> +#include <xen/swiotlb-xen.h> +#include <xen/page.h> +#include <xen/xen-ops.h> +/* + * Used to do a quick range check in swiotlb_tbl_unmap_single and + * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this + * API. + */ + +static char *xen_io_tlb_start, *xen_io_tlb_end; +static unsigned long xen_io_tlb_nslabs; +/* + * Quick lookup value of the bus address of the IOTLB. + */ + +u64 start_dma_addr; + +static dma_addr_t xen_phys_to_bus(phys_addr_t paddr) +{ + return phys_to_machine(XPADDR(paddr)).maddr;; +} + +static phys_addr_t xen_bus_to_phys(dma_addr_t baddr) +{ + return machine_to_phys(XMADDR(baddr)).paddr; +} + +static dma_addr_t xen_virt_to_bus(void *address) +{ + return xen_phys_to_bus(virt_to_phys(address)); +} + +static int check_pages_physically_contiguous(unsigned long pfn, + unsigned int offset, + size_t length) +{ + unsigned long next_mfn; + int i; + int nr_pages; + + next_mfn = pfn_to_mfn(pfn); + nr_pages = (offset + length + PAGE_SIZE-1) >> PAGE_SHIFT; + + for (i = 1; i < nr_pages; i++) { + if (pfn_to_mfn(++pfn) != ++next_mfn) + return 0; + } + return 1; +} + +static int range_straddles_page_boundary(phys_addr_t p, size_t size) +{ + unsigned long pfn = PFN_DOWN(p); + unsigned int offset = p & ~PAGE_MASK; + + if (offset + size <= PAGE_SIZE) + return 0; + if (check_pages_physically_contiguous(pfn, offset, size)) + return 0; + return 1; +} + +static int is_xen_swiotlb_buffer(dma_addr_t dma_addr) +{ + unsigned long mfn = PFN_DOWN(dma_addr); + unsigned long pfn = mfn_to_local_pfn(mfn); + phys_addr_t paddr; + + /* If the address is outside our domain, it CAN + * have the same virtual address as another address + * in our domain. Therefore _only_ check address within our domain. + */ + if (pfn_valid(pfn)) { + paddr = PFN_PHYS(pfn); + return paddr >= virt_to_phys(xen_io_tlb_start) && + paddr < virt_to_phys(xen_io_tlb_end); + } + return 0; +} + +static int max_dma_bits = 32; + +static int +xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) +{ + int i, rc; + int dma_bits; + + dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT; + + i = 0; + do { + int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE); + + do { + rc = xen_create_contiguous_region( + (unsigned long)buf + (i << IO_TLB_SHIFT), + get_order(slabs << IO_TLB_SHIFT), + dma_bits); + } while (rc && dma_bits++ < max_dma_bits); + if (rc) + return rc; + + i += slabs; + } while (i < nslabs); + return 0; +} + +void __init xen_swiotlb_init(int verbose) +{ + unsigned long bytes; + int rc; + + xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT); + xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE); + + bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT; + + /* + * Get IO TLB memory from any location. + */ + xen_io_tlb_start = alloc_bootmem(bytes); + if (!xen_io_tlb_start) + panic("Cannot allocate SWIOTLB buffer"); + + xen_io_tlb_end = xen_io_tlb_start + bytes; + /* + * And replace that memory with pages under 4GB. + */ + rc = xen_swiotlb_fixup(xen_io_tlb_start, + bytes, + xen_io_tlb_nslabs); + if (rc) + goto error; + + start_dma_addr = xen_virt_to_bus(xen_io_tlb_start); + swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose); + + return; +error: + panic("DMA(%d): Failed to exchange pages allocated for DMA with Xen! "\ + "We either don't have the permission or you do not have enough"\ + "free memory under 4GB!\n", rc); +} + +void * +xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, + dma_addr_t *dma_handle, gfp_t flags) +{ + void *ret; + int order = get_order(size); + u64 dma_mask = DMA_BIT_MASK(32); + unsigned long vstart; + + /* + * Ignore region specifiers - the kernel's ideas of + * pseudo-phys memory layout has nothing to do with the + * machine physical layout. We can't allocate highmem + * because we can't return a pointer to it. + */ + flags &= ~(__GFP_DMA | __GFP_HIGHMEM); + + if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret)) + return ret; + + vstart = __get_free_pages(flags, order); + ret = (void *)vstart; + + if (hwdev && hwdev->coherent_dma_mask) + dma_mask = dma_alloc_coherent_mask(hwdev, flags); + + if (ret) { + if (xen_create_contiguous_region(vstart, order, + fls64(dma_mask)) != 0) { + free_pages(vstart, order); + return NULL; + } + memset(ret, 0, size); + *dma_handle = virt_to_machine(ret).maddr; + } + return ret; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_alloc_coherent); + +void +xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, + dma_addr_t dev_addr) +{ + int order = get_order(size); + + if (dma_release_from_coherent(hwdev, order, vaddr)) + return; + + xen_destroy_contiguous_region((unsigned long)vaddr, order); + free_pages((unsigned long)vaddr, order); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent); + + +/* + * Map a single buffer of the indicated size for DMA in streaming mode. The + * physical address to use is returned. + * + * Once the device is given the dma address, the device owns this memory until + * either xen_swiotlb_unmap_page or xen_swiotlb_dma_sync_single is performed. + */ +dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + phys_addr_t phys = page_to_phys(page) + offset; + dma_addr_t dev_addr = xen_phys_to_bus(phys); + void *map; + + BUG_ON(dir == DMA_NONE); + /* + * If the address happens to be in the device's DMA window, + * we can safely return the device addr and not worry about bounce + * buffering it. + */ + if (dma_capable(dev, dev_addr, size) && + !range_straddles_page_boundary(phys, size) && !swiotlb_force) + return dev_addr; + + /* + * Oh well, have to allocate and map a bounce buffer. + */ + map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir); + if (!map) + return DMA_ERROR_CODE; + + dev_addr = xen_virt_to_bus(map); + + /* + * Ensure that the address returned is DMA'ble + */ + if (!dma_capable(dev, dev_addr, size)) + panic("map_single: bounce buffer is not DMA'ble"); + + return dev_addr; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_map_page); + +/* + * Unmap a single streaming mode DMA translation. The dma_addr and size must + * match what was provided for in a previous xen_swiotlb_map_page call. All + * other usages are undefined. + * + * After this call, reads by the cpu to the buffer are guaranteed to see + * whatever the device wrote there. + */ +static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir) +{ + phys_addr_t paddr = xen_bus_to_phys(dev_addr); + + BUG_ON(dir == DMA_NONE); + + /* NOTE: We use dev_addr here, not paddr! */ + if (is_xen_swiotlb_buffer(dev_addr)) { + swiotlb_tbl_unmap_single(hwdev, phys_to_virt(paddr), size, dir); + return; + } + + if (dir != DMA_FROM_DEVICE) + return; + + /* + * phys_to_virt doesn't work with hihgmem page but we could + * call dma_mark_clean() with hihgmem page here. However, we + * are fine since dma_mark_clean() is null on POWERPC. We can + * make dma_mark_clean() take a physical address if necessary. + */ + dma_mark_clean(phys_to_virt(paddr), size); +} + +void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + xen_unmap_single(hwdev, dev_addr, size, dir); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page); + +/* + * Make physical memory consistent for a single streaming mode DMA translation + * after a transfer. + * + * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer + * using the cpu, yet do not wish to teardown the dma mapping, you must + * call this function before doing so. At the next point you give the dma + * address back to the card, you must first perform a + * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer + */ +static void +xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir, + enum dma_sync_target target) +{ + phys_addr_t paddr = xen_bus_to_phys(dev_addr); + + BUG_ON(dir == DMA_NONE); + + /* NOTE: We use dev_addr here, not paddr! */ + if (is_xen_swiotlb_buffer(dev_addr)) { + swiotlb_tbl_sync_single(hwdev, phys_to_virt(paddr), size, dir, + target); + return; + } + + if (dir != DMA_FROM_DEVICE) + return; + + dma_mark_clean(phys_to_virt(paddr), size); +} + +void +xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir) +{ + xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_cpu); + +void +xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir) +{ + xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_device); + +/* + * Map a set of buffers described by scatterlist in streaming mode for DMA. + * This is the scatter-gather version of the above xen_swiotlb_map_page + * interface. Here the scatter gather list elements are each tagged with the + * appropriate dma address and length. They are obtained via + * sg_dma_{address,length}(SG). + * + * NOTE: An implementation may be able to use a smaller number of + * DMA address/length pairs than there are SG table elements. + * (for example via virtual mapping capabilities) + * The routine returns the number of addr/length pairs actually + * used, at most nents. + * + * Device ownership issues as mentioned above for xen_swiotlb_map_page are the + * same here. + */ +int +xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + BUG_ON(dir == DMA_NONE); + + for_each_sg(sgl, sg, nelems, i) { + phys_addr_t paddr = sg_phys(sg); + dma_addr_t dev_addr = xen_phys_to_bus(paddr); + + if (swiotlb_force || + !dma_capable(hwdev, dev_addr, sg->length) || + range_straddles_page_boundary(paddr, sg->length)) { + void *map = swiotlb_tbl_map_single(hwdev, + start_dma_addr, + sg_phys(sg), + sg->length, dir); + if (!map) { + /* Don't panic here, we expect map_sg users + to do proper error handling. */ + xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, + attrs); + sgl[0].dma_length = 0; + return DMA_ERROR_CODE; + } + sg->dma_address = xen_virt_to_bus(map); + } else + sg->dma_address = dev_addr; + sg->dma_length = sg->length; + } + return nelems; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg_attrs); + +int +xen_swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, + enum dma_data_direction dir) +{ + return xen_swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg); + +/* + * Unmap a set of streaming mode DMA translations. Again, cpu read rules + * concerning calls here are the same as for swiotlb_unmap_page() above. + */ +void +xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + BUG_ON(dir == DMA_NONE); + + for_each_sg(sgl, sg, nelems, i) + xen_unmap_single(hwdev, sg->dma_address, sg->dma_length, dir); + +} +EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs); + +void +xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, + enum dma_data_direction dir) +{ + return xen_swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg); + +/* + * Make physical memory consistent for a set of streaming mode DMA translations + * after a transfer. + * + * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules + * and usage. + */ +static void +xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + enum dma_sync_target target) +{ + struct scatterlist *sg; + int i; + + for_each_sg(sgl, sg, nelems, i) + xen_swiotlb_sync_single(hwdev, sg->dma_address, + sg->dma_length, dir, target); +} + +void +xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, + int nelems, enum dma_data_direction dir) +{ + xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_cpu); + +void +xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, + int nelems, enum dma_data_direction dir) +{ + xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device); + +int +xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) +{ + return !dma_addr; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error); + +/* + * Return whether the given device DMA address mask can be supported + * properly. For example, if your device can only drive the low 24-bits + * during bus mastering, then you would pass 0x00ffffff as the mask to + * this function. + */ +int +xen_swiotlb_dma_supported(struct device *hwdev, u64 mask) +{ + return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_dma_supported); diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index de05e96..01c2145 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -7,6 +7,8 @@ struct vm_area_struct; /* vma defining user mapping in mm_types.h */ +extern bool vmap_lazy_unmap; + /* bits in flags of vmalloc's vm_struct below */ #define VM_IOREMAP 0x00000001 /* ioremap() and friends */ #define VM_ALLOC 0x00000002 /* vmalloc() */ diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h index af36ead..d3938d3 100644 --- a/include/xen/interface/memory.h +++ b/include/xen/interface/memory.h @@ -9,6 +9,8 @@ #ifndef __XEN_PUBLIC_MEMORY_H__ #define __XEN_PUBLIC_MEMORY_H__ +#include <linux/spinlock.h> + /* * Increase or decrease the specified domain's memory reservation. Returns a * -ve errcode on failure, or the # extents successfully allocated or freed. @@ -53,6 +55,48 @@ struct xen_memory_reservation { DEFINE_GUEST_HANDLE_STRUCT(xen_memory_reservation); /* + * An atomic exchange of memory pages. If return code is zero then + * @out.extent_list provides GMFNs of the newly-allocated memory. + * Returns zero on complete success, otherwise a negative error code. + * On complete success then always @nr_exchanged == @in.nr_extents. + * On partial success @nr_exchanged indicates how much work was done. + */ +#define XENMEM_exchange 11 +struct xen_memory_exchange { + /* + * [IN] Details of memory extents to be exchanged (GMFN bases). + * Note that @in.address_bits is ignored and unused. + */ + struct xen_memory_reservation in; + + /* + * [IN/OUT] Details of new memory extents. + * We require that: + * 1. @in.domid == @out.domid + * 2. @in.nr_extents << @in.extent_order == + * @out.nr_extents << @out.extent_order + * 3. @in.extent_start and @out.extent_start lists must not overlap + * 4. @out.extent_start lists GPFN bases to be populated + * 5. @out.extent_start is overwritten with allocated GMFN bases + */ + struct xen_memory_reservation out; + + /* + * [OUT] Number of input extents that were successfully exchanged: + * 1. The first @nr_exchanged input extents were successfully + * deallocated. + * 2. The corresponding first entries in the output extent list correctly + * indicate the GMFNs that were successfully exchanged. + * 3. All other input and output extents are untouched. + * 4. If not all input exents are exchanged then the return code of this + * command will be non-zero. + * 5. THIS FIELD MUST BE INITIALISED TO ZERO BY THE CALLER! + */ + unsigned long nr_exchanged; +}; + +DEFINE_GUEST_HANDLE_STRUCT(xen_memory_exchange); +/* * Returns the maximum machine frame number of mapped RAM in this system. * This command always succeeds (it never returns an error code). * arg == NULL. @@ -142,4 +186,10 @@ struct xen_translate_gpfn_list { }; DEFINE_GUEST_HANDLE_STRUCT(xen_translate_gpfn_list); + +/* + * Prevent the balloon driver from changing the memory reservation + * during a driver critical region. + */ +extern spinlock_t xen_reservation_lock; #endif /* __XEN_PUBLIC_MEMORY_H__ */ diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h new file mode 100644 index 0000000..2ea2fdc --- /dev/null +++ b/include/xen/swiotlb-xen.h @@ -0,0 +1,65 @@ +#ifndef __LINUX_SWIOTLB_XEN_H +#define __LINUX_SWIOTLB_XEN_H + +#include <linux/swiotlb.h> + +extern void xen_swiotlb_init(int verbose); + +extern void +*xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, + dma_addr_t *dma_handle, gfp_t flags); + +extern void +xen_swiotlb_free_coherent(struct device *hwdev, size_t size, + void *vaddr, dma_addr_t dma_handle); + +extern dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs); + +extern void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs); +/* +extern int +xen_swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nents, + enum dma_data_direction dir); + +extern void +xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nents, + enum dma_data_direction dir); +*/ +extern int +xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + struct dma_attrs *attrs); + +extern void +xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + struct dma_attrs *attrs); + +extern void +xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir); + +extern void +xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, + int nelems, enum dma_data_direction dir); + +extern void +xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir); + +extern void +xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, + int nelems, enum dma_data_direction dir); + +extern int +xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr); + +extern int +xen_swiotlb_dma_supported(struct device *hwdev, u64 mask); + +#endif /* __LINUX_SWIOTLB_XEN_H */ diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index 46bc81e..351f405 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -17,4 +17,10 @@ void xen_arch_resume(void); int xen_setup_shutdown_event(void); +extern unsigned long *xen_contiguous_bitmap; +int xen_create_contiguous_region(unsigned long vstart, unsigned int order, + unsigned int address_bits); + +void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order); + #endif /* INCLUDE_XEN_OPS_H */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 918c513..6b8889d 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -31,6 +31,7 @@ #include <asm/tlbflush.h> #include <asm/shmparam.h> +bool vmap_lazy_unmap __read_mostly = true; /*** Page table manipulation functions ***/ @@ -502,6 +503,9 @@ static unsigned long lazy_max_pages(void) { unsigned int log; + if (!vmap_lazy_unmap) + return 0; + log = fls(num_online_cpus()); return log * (32UL * 1024 * 1024 / PAGE_SIZE); |
