From: Alexei Starovoitov <ast@xxxxxxxxxx> xen grant table and xenbus ring are not ioremap the way arch specific code is using it, so let's add VM_XEN flag to separate these use cases from VM_IOREMAP users. xen will not and should not be calling ioremap_page_range() on that range. /proc/vmallocinfo will print such regions as "xen" instead of "ioremap". Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> --- arch/x86/xen/grant-table.c | 2 +- drivers/xen/xenbus/xenbus_client.c | 2 +- include/linux/vmalloc.h | 1 + mm/vmalloc.c | 7 +++++-- 4 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c index 1e681bf62561..b816db0349c4 100644 --- a/arch/x86/xen/grant-table.c +++ b/arch/x86/xen/grant-table.c @@ -104,7 +104,7 @@ static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames) area->ptes = kmalloc_array(nr_frames, sizeof(*area->ptes), GFP_KERNEL); if (area->ptes == NULL) return -ENOMEM; - area->area = get_vm_area(PAGE_SIZE * nr_frames, VM_IOREMAP); + area->area = get_vm_area(PAGE_SIZE * nr_frames, VM_XEN); if (!area->area) goto out_free_ptes; if (apply_to_page_range(&init_mm, (unsigned long)area->area->addr, diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index 32835b4b9bc5..b9c81a2d578b 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -758,7 +758,7 @@ static int xenbus_map_ring_pv(struct xenbus_device *dev, bool leaked = false; int err = -ENOMEM; - area = get_vm_area(XEN_PAGE_SIZE * nr_grefs, VM_IOREMAP); + area = get_vm_area(XEN_PAGE_SIZE * nr_grefs, VM_XEN); if (!area) return -ENOMEM; if (apply_to_page_range(&init_mm, (unsigned long)area->addr, diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index c720be70c8dd..71075ece0ed2 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -28,6 +28,7 @@ struct iov_iter; /* in uio.h */ #define VM_FLUSH_RESET_PERMS 0x00000100 /* reset direct map and flush TLB on unmap, can't be freed in atomic context */ #define VM_MAP_PUT_PAGES 0x00000200 /* put pages and free array in vfree */ #define VM_ALLOW_HUGE_VMAP 0x00000400 /* Allow for huge pages on archs with HAVE_ARCH_HUGE_VMALLOC */ +#define VM_XEN 0x00000800 /* xen grant table and xenbus use cases */ #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \ !defined(CONFIG_KASAN_VMALLOC) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index f42f98a127d5..d53ece3f38ee 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3822,9 +3822,9 @@ long vread_iter(struct iov_iter *iter, const char *addr, size_t count) if (flags & VMAP_RAM) copied = vmap_ram_vread_iter(iter, addr, n, flags); - else if (!(vm && (vm->flags & VM_IOREMAP))) + else if (!(vm && (vm->flags & (VM_IOREMAP | VM_XEN)))) copied = aligned_vread_iter(iter, addr, n); - else /* IOREMAP area is treated as memory hole */ + else /* IOREMAP | XEN area is treated as memory hole */ copied = zero_iter(iter, n); addr += copied; @@ -4415,6 +4415,9 @@ static int s_show(struct seq_file *m, void *p) if (v->flags & VM_IOREMAP) seq_puts(m, " ioremap"); + if (v->flags & VM_XEN) + seq_puts(m, " xen"); + if (v->flags & VM_ALLOC) seq_puts(m, " vmalloc"); -- 2.34.1
