* [PATCH 1 of 2] Small changes to blktap: free memory on release, invalidate p2m entry when unmapping grants, check for alloc failure of idx_map, added DONTCOPY flag
2007-05-22 14:17 [PATCH 0 of 2] RFC blktap: Small changes to blktap + added a hook to clear ptes on implicit releases of VMAs Geoffrey Lefebvre
@ 2007-05-22 14:17 ` Geoffrey Lefebvre
2007-05-22 14:17 ` [PATCH 2 of 2] Added a hook for clearing ptes when a vma is freed by the kernel. Adapted from gntdev Geoffrey Lefebvre
1 sibling, 0 replies; 5+ messages in thread
From: Geoffrey Lefebvre @ 2007-05-22 14:17 UTC (permalink / raw)
To: xen-devel; +Cc: andrew.warfield, @xensource.com
# HG changeset patch
# User Geoffrey Lefebvre <geoffrey@cs.ubc.ca>
# Date 1179788512 25200
# Node ID f5218394705702c1aaa02520be2ba5a9f2648f37
# Parent 9cf9027ec568929946a1ee9094821fdec1eb68ff
Small changes to blktap: free memory on release, invalidate p2m entry when unmapping grants, check for alloc failure of idx_map, added DONTCOPY flag.
diff -r 9cf9027ec568 -r f52183947057 linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c Sat May 19 16:41:48 2007 -0700
+++ b/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c Mon May 21 16:01:52 2007 -0700
@@ -477,6 +477,11 @@ static int blktap_open(struct inode *ino
info->idx_map = kmalloc(sizeof(unsigned long) * MAX_PENDING_REQS,
GFP_KERNEL);
+ if (info->idx_map == NULL) {
+ goto fail_nomem;
+ }
+
+
if (idx > 0) {
init_waitqueue_head(&info->wait);
for (i = 0; i < MAX_PENDING_REQS; i++)
@@ -510,16 +515,24 @@ static int blktap_release(struct inode *
zap_page_range(
info->vma, info->vma->vm_start,
info->vma->vm_end - info->vma->vm_start, NULL);
+
+ kfree(info->vma->vm_private_data);
+
info->vma = NULL;
}
-
+
+ if (info->idx_map) {
+ kfree(info->idx_map);
+ info->idx_map = NULL;
+ }
+
if ( (info->status != CLEANSHUTDOWN) && (info->blkif != NULL) ) {
if (info->blkif->xenblkd != NULL) {
kthread_stop(info->blkif->xenblkd);
info->blkif->xenblkd = NULL;
}
info->status = CLEANSHUTDOWN;
- }
+ }
return 0;
}
@@ -590,6 +603,7 @@ static int blktap_mmap(struct file *filp
vma->vm_private_data = map;
vma->vm_flags |= VM_FOREIGN;
+ vma->vm_flags |= VM_DONTCOPY;
info->vma = vma;
info->ring_ok = 1;
@@ -885,6 +899,10 @@ static void fast_flush_area(pending_req_
idx_to_kaddr(mmap_idx, k_idx, i),
GNTMAP_host_map, khandle->kernel);
invcount++;
+
+ set_phys_to_machine(
+ __pa(idx_to_kaddr(mmap_idx, k_idx, i))
+ >> PAGE_SHIFT, INVALID_P2M_ENTRY);
}
if (khandle->user != INVALID_GRANT_HANDLE) {
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH 2 of 2] Added a hook for clearing ptes when a vma is freed by the kernel. Adapted from gntdev
2007-05-22 14:17 [PATCH 0 of 2] RFC blktap: Small changes to blktap + added a hook to clear ptes on implicit releases of VMAs Geoffrey Lefebvre
2007-05-22 14:17 ` [PATCH 1 of 2] Small changes to blktap: free memory on release, invalidate p2m entry when unmapping grants, check for alloc failure of idx_map, added DONTCOPY flag Geoffrey Lefebvre
@ 2007-05-22 14:17 ` Geoffrey Lefebvre
2007-05-23 10:44 ` Isaku Yamahata
1 sibling, 1 reply; 5+ messages in thread
From: Geoffrey Lefebvre @ 2007-05-22 14:17 UTC (permalink / raw)
To: xen-devel; +Cc: andrew.warfield, @xensource.com
# HG changeset patch
# User Geoffrey Lefebvre <geoffrey@cs.ubc.ca>
# Date 1179788664 25200
# Node ID 236647990e986bca16f150c2fca87c0ed1ebd729
# Parent f5218394705702c1aaa02520be2ba5a9f2648f37
Added a hook for clearing ptes when a vma is freed by the kernel. Adapted from gntdev.
diff -r f52183947057 -r 236647990e98 linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c Mon May 21 16:01:52 2007 -0700
+++ b/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c Mon May 21 16:04:24 2007 -0700
@@ -269,6 +269,16 @@ static inline int GET_NEXT_REQ(unsigned
return INVALID_REQ;
}
+static inline int OFFSET_TO_USR_IDX(int offset)
+{
+ return offset / BLKIF_MAX_SEGMENTS_PER_REQUEST;
+}
+
+static inline int OFFSET_TO_SEG(int offset)
+{
+ return offset % BLKIF_MAX_SEGMENTS_PER_REQUEST;
+}
+
#define BLKTAP_INVALID_HANDLE(_g) \
(((_g->kernel) == INVALID_GRANT_HANDLE) && \
@@ -295,8 +305,94 @@ static struct page *blktap_nopage(struct
return NOPAGE_SIGBUS;
}
+static pte_t blktap_clear_pte(struct vm_area_struct *vma,
+ unsigned long uvaddr,
+ pte_t *ptep, int is_fullmm)
+{
+ pte_t copy = *ptep;
+ tap_blkif_t *info;
+ int offset, seg, usr_idx, pending_idx, mmap_idx;
+ unsigned long uvstart = vma->vm_start + (RING_PAGES << PAGE_SHIFT);
+ unsigned long kvaddr;
+ struct page **map;
+ struct page *pg;
+ struct grant_handle_pair *khandle;
+ struct gnttab_unmap_grant_ref unmap[2];
+ int count = 0;
+ static int print_warning = 1;
+
+ /*print a warning message once, if the hook gets called*/
+ if (print_warning) {
+ WPRINTK("Clear pte hook called!\n");
+ print_warning = 0;
+ }
+
+ /* If the address is before the start of the grant mapped region
+ * or if vm_file is NULL (meaning mmap failed and we have nothing to do)
+ */
+ if (uvaddr < uvstart || vma->vm_file == NULL)
+ return copy;
+
+ info = vma->vm_file->private_data;
+ map = vma->vm_private_data;
+
+ /* TODO Should these be changed to if statements? */
+ BUG_ON(!info);
+ BUG_ON(!info->idx_map);
+ BUG_ON(!map);
+
+ offset = (int) ((uvaddr - uvstart) >> PAGE_SHIFT);
+ usr_idx = OFFSET_TO_USR_IDX(offset);
+ seg = OFFSET_TO_SEG(offset);
+
+ pending_idx = MASK_PEND_IDX(ID_TO_IDX(info->idx_map[usr_idx]));
+ mmap_idx = ID_TO_MIDX(info->idx_map[usr_idx]);
+
+ kvaddr = idx_to_kaddr(mmap_idx, pending_idx, seg);
+ pg = pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT);
+ ClearPageReserved(pg);
+ map[offset] = NULL;
+
+ khandle = &pending_handle(mmap_idx, pending_idx, seg);
+
+ if (khandle->kernel != INVALID_GRANT_HANDLE) {
+
+ gnttab_set_unmap_op(&unmap[count], kvaddr,
+ GNTMAP_host_map, khandle->kernel);
+ count++;
+
+ set_phys_to_machine(__pa(kvaddr) >> PAGE_SHIFT,
+ INVALID_P2M_ENTRY);
+ }
+
+ if (khandle->user != INVALID_GRANT_HANDLE) {
+
+ BUG_ON(xen_feature(XENFEAT_auto_translated_physmap));
+
+ gnttab_set_unmap_op(&unmap[count], virt_to_machine(ptep),
+ GNTMAP_host_map
+ | GNTMAP_application_map
+ | GNTMAP_contains_pte,
+ khandle->user);
+ count++;
+ }
+
+ if (count) {
+ int ret;
+
+ BLKTAP_INVALIDATE_HANDLE(khandle);
+
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+ unmap, count);
+ BUG_ON(ret);
+ }
+
+ return copy;
+}
+
struct vm_operations_struct blktap_vm_ops = {
nopage: blktap_nopage,
+ zap_pte: blktap_clear_pte,
};
/******************************************************************
@@ -604,6 +700,10 @@ static int blktap_mmap(struct file *filp
vma->vm_private_data = map;
vma->vm_flags |= VM_FOREIGN;
vma->vm_flags |= VM_DONTCOPY;
+
+#ifdef CONFIG_X86
+ vma->vm_mm->context.has_foreign_mappings = 1;
+#endif
info->vma = vma;
info->ring_ok = 1;
^ permalink raw reply [flat|nested] 5+ messages in thread