diff options
-rw-r--r-- | arch/arm/Kconfig | 1 | ||||
-rw-r--r-- | arch/arm/xen/enlighten.c | 77 | ||||
-rw-r--r-- | arch/x86/include/asm/xen/page.h | 5 | ||||
-rw-r--r-- | arch/x86/xen/grant-table.c | 3 | ||||
-rw-r--r-- | arch/x86/xen/p2m.c | 17 | ||||
-rw-r--r-- | drivers/block/xen-blkback/blkback.c | 15 | ||||
-rw-r--r-- | drivers/xen/gntdev.c | 13 | ||||
-rw-r--r-- | drivers/xen/grant-table.c | 95 | ||||
-rw-r--r-- | drivers/xen/swiotlb-xen.c | 22 | ||||
-rw-r--r-- | drivers/xen/xen-selfballoon.c | 22 | ||||
-rw-r--r-- | include/xen/grant_table.h | 10 |
11 files changed, 197 insertions, 83 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index dc6ef9a2c64..e2541981779 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1905,6 +1905,7 @@ config XEN depends on !GENERIC_ATOMIC64 select ARM_PSCI select SWIOTLB_XEN + select ARCH_DMA_ADDR_T_64BIT help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM. diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 2162172c0dd..b96723e258a 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -23,6 +23,7 @@ #include <linux/of_address.h> #include <linux/cpuidle.h> #include <linux/cpufreq.h> +#include <linux/cpu.h> #include <linux/mm.h> @@ -154,7 +155,7 @@ int xen_unmap_domain_mfn_range(struct vm_area_struct *vma, } EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range); -static void __init xen_percpu_init(void *unused) +static void xen_percpu_init(void) { struct vcpu_register_vcpu_info info; struct vcpu_info *vcpup; @@ -193,6 +194,31 @@ static void xen_power_off(void) BUG(); } +static int xen_cpu_notification(struct notifier_block *self, + unsigned long action, + void *hcpu) +{ + switch (action) { + case CPU_STARTING: + xen_percpu_init(); + break; + default: + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block xen_cpu_notifier = { + .notifier_call = xen_cpu_notification, +}; + +static irqreturn_t xen_arm_callback(int irq, void *arg) +{ + xen_hvm_evtchn_do_upcall(); + return IRQ_HANDLED; +} + /* * see Documentation/devicetree/bindings/arm/xen.txt for the * documentation of the Xen Device Tree format. @@ -208,7 +234,7 @@ static int __init xen_guest_init(void) const char *version = NULL; const char *xen_prefix = "xen,xen-"; struct resource res; - unsigned long grant_frames; + phys_addr_t grant_frames; node = of_find_compatible_node(NULL, NULL, "xen,xen"); if (!node) { @@ -227,8 +253,12 @@ static int __init xen_guest_init(void) return 0; grant_frames = res.start; xen_events_irq = irq_of_parse_and_map(node, 0); - pr_info("Xen %s support found, events_irq=%d gnttab_frame_pfn=%lx\n", - version, xen_events_irq, (grant_frames >> PAGE_SHIFT)); + pr_info("Xen %s support found, events_irq=%d gnttab_frame=%pa\n", + version, xen_events_irq, &grant_frames); + + if (xen_events_irq < 0) + return -ENODEV; + xen_domain_type = XEN_HVM_DOMAIN; xen_setup_features(); @@ -281,9 +311,21 @@ static int __init xen_guest_init(void) disable_cpuidle(); disable_cpufreq(); + xen_init_IRQ(); + + if (request_percpu_irq(xen_events_irq, xen_arm_callback, + "events", &xen_vcpu)) { + pr_err("Error request IRQ %d\n", xen_events_irq); + return -EINVAL; + } + + xen_percpu_init(); + + register_cpu_notifier(&xen_cpu_notifier); + return 0; } -core_initcall(xen_guest_init); +early_initcall(xen_guest_init); static int __init xen_pm_init(void) { @@ -297,31 +339,6 @@ static int __init xen_pm_init(void) } late_initcall(xen_pm_init); -static irqreturn_t xen_arm_callback(int irq, void *arg) -{ - xen_hvm_evtchn_do_upcall(); - return IRQ_HANDLED; -} - -static int __init xen_init_events(void) -{ - if (!xen_domain() || xen_events_irq < 0) - return -ENODEV; - - xen_init_IRQ(); - - if (request_percpu_irq(xen_events_irq, xen_arm_callback, - "events", &xen_vcpu)) { - pr_err("Error requesting IRQ %d\n", xen_events_irq); - return -EINVAL; - } - - on_each_cpu(xen_percpu_init, NULL, 0); - - return 0; -} -postcore_initcall(xen_init_events); - /* In the hypervisor.S file. */ EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op); EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op); diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 3e276eb23d1..787e1bb5aaf 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -52,7 +52,8 @@ extern unsigned long set_phys_range_identity(unsigned long pfn_s, extern int m2p_add_override(unsigned long mfn, struct page *page, struct gnttab_map_grant_ref *kmap_op); extern int m2p_remove_override(struct page *page, - struct gnttab_map_grant_ref *kmap_op); + struct gnttab_map_grant_ref *kmap_op, + unsigned long mfn); extern struct page *m2p_find_override(unsigned long mfn); extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); @@ -121,7 +122,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn) pfn = m2p_find_override_pfn(mfn, ~0); } - /* + /* * pfn is ~0 if there are no entries in the m2p for mfn or if the * entry doesn't map back to the mfn and m2p_override doesn't have a * valid entry for it. diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c index 103c93f874b..c9858358858 100644 --- a/arch/x86/xen/grant-table.c +++ b/arch/x86/xen/grant-table.c @@ -162,14 +162,15 @@ static int __init xlated_setup_gnttab_pages(void) rc = arch_gnttab_map_shared(pfns, nr_grant_frames, nr_grant_frames, &xen_auto_xlat_grant_frames.vaddr); - kfree(pages); if (rc) { pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__, nr_grant_frames, rc); free_xenballooned_pages(nr_grant_frames, pages); + kfree(pages); kfree(pfns); return rc; } + kfree(pages); xen_auto_xlat_grant_frames.pfn = pfns; xen_auto_xlat_grant_frames.count = nr_grant_frames; diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 696c694986d..8009acbe41e 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -899,13 +899,6 @@ int m2p_add_override(unsigned long mfn, struct page *page, "m2p_add_override: pfn %lx not mapped", pfn)) return -EINVAL; } - WARN_ON(PagePrivate(page)); - SetPagePrivate(page); - set_page_private(page, mfn); - page->index = pfn_to_mfn(pfn); - - if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) - return -ENOMEM; if (kmap_op != NULL) { if (!PageHighMem(page)) { @@ -944,19 +937,16 @@ int m2p_add_override(unsigned long mfn, struct page *page, } EXPORT_SYMBOL_GPL(m2p_add_override); int m2p_remove_override(struct page *page, - struct gnttab_map_grant_ref *kmap_op) + struct gnttab_map_grant_ref *kmap_op, + unsigned long mfn) { unsigned long flags; - unsigned long mfn; unsigned long pfn; unsigned long uninitialized_var(address); unsigned level; pte_t *ptep = NULL; pfn = page_to_pfn(page); - mfn = get_phys_to_machine(pfn); - if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) - return -EINVAL; if (!PageHighMem(page)) { address = (unsigned long)__va(pfn << PAGE_SHIFT); @@ -970,10 +960,7 @@ int m2p_remove_override(struct page *page, spin_lock_irqsave(&m2p_override_lock, flags); list_del(&page->lru); spin_unlock_irqrestore(&m2p_override_lock, flags); - WARN_ON(!PagePrivate(page)); - ClearPagePrivate(page); - set_phys_to_machine(pfn, page->index); if (kmap_op != NULL) { if (!PageHighMem(page)) { struct multicall_space mcs; diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 4b97b86da92..da18046d0e0 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -285,8 +285,7 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root, if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST || !rb_next(&persistent_gnt->node)) { - ret = gnttab_unmap_refs(unmap, NULL, pages, - segs_to_unmap); + ret = gnttab_unmap_refs(unmap, pages, segs_to_unmap); BUG_ON(ret); put_free_pages(blkif, pages, segs_to_unmap); segs_to_unmap = 0; @@ -321,8 +320,7 @@ static void unmap_purged_grants(struct work_struct *work) pages[segs_to_unmap] = persistent_gnt->page; if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST) { - ret = gnttab_unmap_refs(unmap, NULL, pages, - segs_to_unmap); + ret = gnttab_unmap_refs(unmap, pages, segs_to_unmap); BUG_ON(ret); put_free_pages(blkif, pages, segs_to_unmap); segs_to_unmap = 0; @@ -330,7 +328,7 @@ static void unmap_purged_grants(struct work_struct *work) kfree(persistent_gnt); } if (segs_to_unmap > 0) { - ret = gnttab_unmap_refs(unmap, NULL, pages, segs_to_unmap); + ret = gnttab_unmap_refs(unmap, pages, segs_to_unmap); BUG_ON(ret); put_free_pages(blkif, pages, segs_to_unmap); } @@ -670,15 +668,14 @@ static void xen_blkbk_unmap(struct xen_blkif *blkif, GNTMAP_host_map, pages[i]->handle); pages[i]->handle = BLKBACK_INVALID_HANDLE; if (++invcount == BLKIF_MAX_SEGMENTS_PER_REQUEST) { - ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, - invcount); + ret = gnttab_unmap_refs(unmap, unmap_pages, invcount); BUG_ON(ret); put_free_pages(blkif, unmap_pages, invcount); invcount = 0; } } if (invcount) { - ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount); + ret = gnttab_unmap_refs(unmap, unmap_pages, invcount); BUG_ON(ret); put_free_pages(blkif, unmap_pages, invcount); } @@ -740,7 +737,7 @@ again: } if (segs_to_map) { - ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map); + ret = gnttab_map_refs(map, pages_to_gnt, segs_to_map); BUG_ON(ret); } diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 073b4a19a8b..34a2704fbc8 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -284,8 +284,10 @@ static int map_grant_pages(struct grant_map *map) } pr_debug("map %d+%d\n", map->index, map->count); - err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, - map->pages, map->count); + err = gnttab_map_refs_userspace(map->map_ops, + use_ptemod ? map->kmap_ops : NULL, + map->pages, + map->count); if (err) return err; @@ -315,9 +317,10 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) } } - err = gnttab_unmap_refs(map->unmap_ops + offset, - use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset, - pages); + err = gnttab_unmap_refs_userspace(map->unmap_ops + offset, + use_ptemod ? map->kmap_ops + offset : NULL, + map->pages + offset, + pages); if (err) return err; diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 1ce1c40331f..8ee13e2e45e 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -837,7 +837,7 @@ unsigned int gnttab_max_grant_frames(void) } EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); -int gnttab_setup_auto_xlat_frames(unsigned long addr) +int gnttab_setup_auto_xlat_frames(phys_addr_t addr) { xen_pfn_t *pfn; unsigned int max_nr_gframes = __max_nr_grant_frames(); @@ -849,8 +849,8 @@ int gnttab_setup_auto_xlat_frames(unsigned long addr) vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes); if (vaddr == NULL) { - pr_warn("Failed to ioremap gnttab share frames (addr=0x%08lx)!\n", - addr); + pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n", + &addr); return -ENOMEM; } pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL); @@ -928,15 +928,17 @@ void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count) } EXPORT_SYMBOL_GPL(gnttab_batch_copy); -int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, +int __gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, struct gnttab_map_grant_ref *kmap_ops, - struct page **pages, unsigned int count) + struct page **pages, unsigned int count, + bool m2p_override) { int i, ret; bool lazy = false; pte_t *pte; - unsigned long mfn; + unsigned long mfn, pfn; + BUG_ON(kmap_ops && !m2p_override); ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); if (ret) return ret; @@ -955,10 +957,12 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT, map_ops[i].dev_bus_addr >> PAGE_SHIFT); } - return ret; + return 0; } - if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { + if (m2p_override && + !in_interrupt() && + paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { arch_enter_lazy_mmu_mode(); lazy = true; } @@ -975,8 +979,20 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, } else { mfn = PFN_DOWN(map_ops[i].dev_bus_addr); } - ret = m2p_add_override(mfn, pages[i], kmap_ops ? - &kmap_ops[i] : NULL); + pfn = page_to_pfn(pages[i]); + + WARN_ON(PagePrivate(pages[i])); + SetPagePrivate(pages[i]); + set_page_private(pages[i], mfn); + + pages[i]->index = pfn_to_mfn(pfn); + if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) { + ret = -ENOMEM; + goto out; + } + if (m2p_override) + ret = m2p_add_override(mfn, pages[i], kmap_ops ? + &kmap_ops[i] : NULL); if (ret) goto out; } @@ -987,15 +1003,32 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, return ret; } + +int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, + struct page **pages, unsigned int count) +{ + return __gnttab_map_refs(map_ops, NULL, pages, count, false); +} EXPORT_SYMBOL_GPL(gnttab_map_refs); -int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, +int gnttab_map_refs_userspace(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count) +{ + return __gnttab_map_refs(map_ops, kmap_ops, pages, count, true); +} +EXPORT_SYMBOL_GPL(gnttab_map_refs_userspace); + +int __gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, struct gnttab_map_grant_ref *kmap_ops, - struct page **pages, unsigned int count) + struct page **pages, unsigned int count, + bool m2p_override) { int i, ret; bool lazy = false; + unsigned long pfn, mfn; + BUG_ON(kmap_ops && !m2p_override); ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); if (ret) return ret; @@ -1006,17 +1039,33 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, INVALID_P2M_ENTRY); } - return ret; + return 0; } - if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { + if (m2p_override && + !in_interrupt() && + paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { arch_enter_lazy_mmu_mode(); lazy = true; } for (i = 0; i < count; i++) { - ret = m2p_remove_override(pages[i], kmap_ops ? - &kmap_ops[i] : NULL); + pfn = page_to_pfn(pages[i]); + mfn = get_phys_to_machine(pfn); + if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) { + ret = -EINVAL; + goto out; + } + + set_page_private(pages[i], INVALID_P2M_ENTRY); + WARN_ON(!PagePrivate(pages[i])); + ClearPagePrivate(pages[i]); + set_phys_to_machine(pfn, pages[i]->index); + if (m2p_override) + ret = m2p_remove_override(pages[i], + kmap_ops ? + &kmap_ops[i] : NULL, + mfn); if (ret) goto out; } @@ -1027,8 +1076,22 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, return ret; } + +int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *map_ops, + struct page **pages, unsigned int count) +{ + return __gnttab_unmap_refs(map_ops, NULL, pages, count, false); +} EXPORT_SYMBOL_GPL(gnttab_unmap_refs); +int gnttab_unmap_refs_userspace(struct gnttab_unmap_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count) +{ + return __gnttab_unmap_refs(map_ops, kmap_ops, pages, count, true); +} +EXPORT_SYMBOL_GPL(gnttab_unmap_refs_userspace); + static unsigned nr_status_frames(unsigned nr_grant_frames) { BUG_ON(grefs_per_grant_frame == 0); diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 1eac0731c34..ebd8f218a78 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -75,14 +75,32 @@ static unsigned long xen_io_tlb_nslabs; static u64 start_dma_addr; +/* + * Both of these functions should avoid PFN_PHYS because phys_addr_t + * can be 32bit when dma_addr_t is 64bit leading to a loss in + * information if the shift is done before casting to 64bit. + */ static inline dma_addr_t xen_phys_to_bus(phys_addr_t paddr) { - return phys_to_machine(XPADDR(paddr)).maddr; + unsigned long mfn = pfn_to_mfn(PFN_DOWN(paddr)); + dma_addr_t dma = (dma_addr_t)mfn << PAGE_SHIFT; + + dma |= paddr & ~PAGE_MASK; + + return dma; } static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr) { - return machine_to_phys(XMADDR(baddr)).paddr; + unsigned long pfn = mfn_to_pfn(PFN_DOWN(baddr)); + dma_addr_t dma = (dma_addr_t)pfn << PAGE_SHIFT; + phys_addr_t paddr = dma; + + BUG_ON(paddr != dma); /* truncation has occurred, should never happen */ + + paddr |= baddr & ~PAGE_MASK; + + return paddr; } static inline dma_addr_t xen_virt_to_bus(void *address) diff --git a/drivers/xen/xen-selfballoon.c b/drivers/xen/xen-selfballoon.c index 21e18c18c7a..745ad79c1d8 100644 --- a/drivers/xen/xen-selfballoon.c +++ b/drivers/xen/xen-selfballoon.c @@ -175,6 +175,7 @@ static void frontswap_selfshrink(void) #endif /* CONFIG_FRONTSWAP */ #define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT)) +#define PAGES2MB(pages) ((pages) >> (20 - PAGE_SHIFT)) /* * Use current balloon size, the goal (vm_committed_as), and hysteresis @@ -525,6 +526,7 @@ EXPORT_SYMBOL(register_xen_selfballooning); int xen_selfballoon_init(bool use_selfballooning, bool use_frontswap_selfshrink) { bool enable = false; + unsigned long reserve_pages; if (!xen_domain()) return -ENODEV; @@ -549,6 +551,26 @@ int xen_selfballoon_init(bool use_selfballooning, bool use_frontswap_selfshrink) if (!enable) return -ENODEV; + /* + * Give selfballoon_reserved_mb a default value(10% of total ram pages) + * to make selfballoon not so aggressive. + * + * There are mainly two reasons: + * 1) The original goal_page didn't consider some pages used by kernel + * space, like slab pages and memory used by device drivers. + * + * 2) The balloon driver may not give back memory to guest OS fast + * enough when the workload suddenly aquries a lot of physical memory. + * + * In both cases, the guest OS will suffer from memory pressure and + * OOM killer may be triggered. + * By reserving extra 10% of total ram pages, we can keep the system + * much more reliably and response faster in some cases. + */ + if (!selfballoon_reserved_mb) { + reserve_pages = totalram_pages / 10; + selfballoon_reserved_mb = PAGES2MB(reserve_pages); + } schedule_delayed_work(&selfballoon_worker, selfballoon_interval * HZ); return 0; diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index 5acb1e4ac0d..7ad033dbc84 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -185,17 +185,21 @@ struct grant_frames { }; extern struct grant_frames xen_auto_xlat_grant_frames; unsigned int gnttab_max_grant_frames(void); -int gnttab_setup_auto_xlat_frames(unsigned long addr); +int gnttab_setup_auto_xlat_frames(phys_addr_t addr); void gnttab_free_auto_xlat_frames(void); #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, - struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count); +int gnttab_map_refs_userspace(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, - struct gnttab_map_grant_ref *kunmap_ops, struct page **pages, unsigned int count); +int gnttab_unmap_refs_userspace(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_map_grant_ref *kunmap_ops, + struct page **pages, unsigned int count); /* Perform a batch of grant map/copy operations. Retry every batch slot * for which the hypervisor returns GNTST_eagain. This is typically due |