On Fri, Feb 23, 2024 at 03:57:27PM -0800, Alexei Starovoitov wrote: > 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 them from VM_IOREMAP users. > xen will not and should not be calling ioremap_page_range() on that range. > /proc/vmallocinfo will print such region as "xen" instead of "ioremap" as well. > > 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..223e51c243bc 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 use cases */ > > #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \ > !defined(CONFIG_KASAN_VMALLOC) There's also VM_DEFER_KMEMLEAK a line below: #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \ !defined(CONFIG_KASAN_VMALLOC) #define VM_DEFER_KMEMLEAK 0x00000801 /* defer kmemleak object creation */ #else #define VM_DEFER_KMEMLEAK 0 #endif It should be adjusted as well. I think it makes sense to use an enumeration for vm_flags, just like as Suren did for GFP (https://lore.kernel.org/linux-mm/20240224015800.2569851-1-surenb@xxxxxxxxxx/) -- Sincerely yours, Mike.
