# HG changeset patch
# User yamahata@xxxxxxxxxxxxx
# Date 1185762640 -32400
# Node ID fb5043d15cae94f0686f5ad009d67ff97d0a1c3c
# Parent 4492a0285bae734ee18f6acbb6b3f9c80f153be7
remove xencomm page size limit.
Currently xencomm has page size limit so that a domain with many memory
(e.g. 100GB+) can't be created.
This patch allows that the address array of struct xencomm_desc to cross
page boundary so that the size of struct xencomm_desc can exceed page size.
Note that struct xencomm_desc itself can't page boundary.
PATCHNAME: remove_xencomm_page_size_limit_xen_side
Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
diff -r 4492a0285bae -r fb5043d15cae xen/arch/ia64/xen/xencomm.c
--- a/xen/arch/ia64/xen/xencomm.c Fri Jul 27 08:15:16 2007 -0600
+++ b/xen/arch/ia64/xen/xencomm.c Mon Jul 30 11:30:40 2007 +0900
@@ -34,6 +34,15 @@ static int xencomm_debug = 1; /* extreme
#else
#define xencomm_debug 0
#endif
+
+static int
+xencomm_desc_cross_page_boundary(unsigned long paddr)
+{
+ unsigned long offset = paddr & ~PAGE_MASK;
+ if (offset > PAGE_SIZE - sizeof(struct xencomm_desc))
+ return 1;
+ return 0;
+}
static int
xencomm_copy_chunk_from(
@@ -85,15 +94,18 @@ xencomm_copy_from_guest(
unsigned int n,
unsigned int skip)
{
+ unsigned long from_ulong = (unsigned long)from;
struct xencomm_desc *desc;
unsigned long desc_addr;
+ struct xencomm_desc *desc_paddr;
+ unsigned long *address;
unsigned int from_pos = 0;
unsigned int to_pos = 0;
unsigned int i = 0;
if (xencomm_debug)
printk("xencomm_copy_from_guest: from=%lx+%u n=%u\n",
- (unsigned long)from, skip, n);
+ from_ulong, skip, n);
if (XENCOMM_IS_INLINE(from)) {
unsigned long src_paddr = XENCOMM_INLINE_ADDR(from);
@@ -121,8 +133,11 @@ xencomm_copy_from_guest(
return 0;
}
+ /* check if struct desc doesn't cross page boundry */
+ if (xencomm_desc_cross_page_boundary(from_ulong))
+ return -EINVAL;
/* first we need to access the descriptor */
- desc_addr = xencomm_paddr_to_maddr((unsigned long)from);
+ desc_addr = xencomm_paddr_to_maddr(from_ulong);
if (desc_addr == 0)
return -EFAULT;
@@ -132,18 +147,26 @@ xencomm_copy_from_guest(
__func__, desc, desc->magic);
return -EFAULT;
}
+ desc_paddr = (struct xencomm_desc *)from;
+ address = &desc->address[i];
/* iterate through the descriptor, copying up to a page at a time */
while ((to_pos < n) && (i < desc->nr_addrs)) {
- unsigned long src_paddr = desc->address[i];
+ unsigned long src_paddr;
unsigned int pgoffset;
unsigned int chunksz;
unsigned int chunk_skip;
- if (src_paddr == XENCOMM_INVALID) {
- i++;
- continue;
- }
+ /* When crossing page boundary, machine address must be calculated. */
+ if (((unsigned long)address & ~PAGE_MASK) == 0) {
+ address = (unsigned long*)xencomm_paddr_to_maddr(
+ (unsigned long)&desc_paddr->address[i]);
+ if (address == NULL)
+ return -EFAULT;
+ }
+ src_paddr = *address;
+ if (src_paddr == XENCOMM_INVALID)
+ goto skip_to_next;
pgoffset = src_paddr % PAGE_SIZE;
chunksz = PAGE_SIZE - pgoffset;
@@ -170,7 +193,9 @@ xencomm_copy_from_guest(
to_pos += bytes;
}
+ skip_to_next:
i++;
+ address++;
}
return n - to_pos;
@@ -226,15 +251,18 @@ xencomm_copy_to_guest(
unsigned int n,
unsigned int skip)
{
+ unsigned long to_ulong = (unsigned long)to;
struct xencomm_desc *desc;
unsigned long desc_addr;
+ struct xencomm_desc *desc_paddr;
+ unsigned long *address;
unsigned int from_pos = 0;
unsigned int to_pos = 0;
unsigned int i = 0;
if (xencomm_debug)
printk ("xencomm_copy_to_guest: to=%lx+%u n=%u\n",
- (unsigned long)to, skip, n);
+ to_ulong, skip, n);
if (XENCOMM_IS_INLINE(to)) {
unsigned long dest_paddr = XENCOMM_INLINE_ADDR(to);
@@ -263,8 +291,11 @@ xencomm_copy_to_guest(
return 0;
}
+ /* check if struct desc doesn't cross page boundry */
+ if (xencomm_desc_cross_page_boundary(to_ulong))
+ return -EINVAL;
/* first we need to access the descriptor */
- desc_addr = xencomm_paddr_to_maddr((unsigned long)to);
+ desc_addr = xencomm_paddr_to_maddr(to_ulong);
if (desc_addr == 0)
return -EFAULT;
@@ -273,18 +304,26 @@ xencomm_copy_to_guest(
printk("%s error: %p magic was 0x%x\n", __func__, desc, desc->magic);
return -EFAULT;
}
+ desc_paddr = (struct xencomm_desc*)to;
+ address = &desc->address[i];
/* iterate through the descriptor, copying up to a page at a time */
while ((from_pos < n) && (i < desc->nr_addrs)) {
- unsigned long dest_paddr = desc->address[i];
+ unsigned long dest_paddr;
unsigned int pgoffset;
unsigned int chunksz;
unsigned int chunk_skip;
- if (dest_paddr == XENCOMM_INVALID) {
- i++;
- continue;
- }
+ /* When crossing page boundary, machine address must be calculated. */
+ if (((unsigned long)address & ~PAGE_MASK) == 0) {
+ address = (unsigned long*)xencomm_paddr_to_maddr(
+ (unsigned long)&desc_paddr->address[i]);
+ if (address == NULL)
+ return -EFAULT;
+ }
+ dest_paddr = *address;
+ if (dest_paddr == XENCOMM_INVALID)
+ goto skip_to_next;
pgoffset = dest_paddr % PAGE_SIZE;
chunksz = PAGE_SIZE - pgoffset;
@@ -308,7 +347,9 @@ xencomm_copy_to_guest(
to_pos += bytes;
}
+ skip_to_next:
i++;
+ address++;
}
return n - from_pos;
}
@@ -320,15 +361,21 @@ xencomm_add_offset(
void *handle,
unsigned int bytes)
{
+ unsigned long handle_ulong = (unsigned long)handle;
struct xencomm_desc *desc;
unsigned long desc_addr;
+ struct xencomm_desc *desc_paddr;
+ unsigned long *address;
int i = 0;
if (XENCOMM_IS_INLINE(handle))
return (void *)((unsigned long)handle + bytes);
+ /* check if struct desc doesn't cross page boundry */
+ if (xencomm_desc_cross_page_boundary(handle_ulong))
+ return NULL;
/* first we need to access the descriptor */
- desc_addr = xencomm_paddr_to_maddr((unsigned long)handle);
+ desc_addr = xencomm_paddr_to_maddr(handle_ulong);
if (desc_addr == 0)
return NULL;
@@ -337,18 +384,26 @@ xencomm_add_offset(
printk("%s error: %p magic was 0x%x\n", __func__, desc, desc->magic);
return NULL;
}
+ desc_paddr = (struct xencomm_desc*)handle;
+ address = &desc->address[i];
/* iterate through the descriptor incrementing addresses */
while ((bytes > 0) && (i < desc->nr_addrs)) {
- unsigned long dest_paddr = desc->address[i];
+ unsigned long dest_paddr;
unsigned int pgoffset;
unsigned int chunksz;
unsigned int chunk_skip;
- if (dest_paddr == XENCOMM_INVALID) {
- i++;
- continue;
- }
+ /* When crossing page boundary, machine address must be calculated. */
+ if (((unsigned long)address & ~PAGE_MASK) == 0) {
+ address = (unsigned long*)xencomm_paddr_to_maddr(
+ (unsigned long)&desc_paddr->address[i]);
+ if (address == NULL)
+ return NULL;
+ }
+ dest_paddr = *address;
+ if (dest_paddr == XENCOMM_INVALID)
+ goto skip_to_next;
pgoffset = dest_paddr % PAGE_SIZE;
chunksz = PAGE_SIZE - pgoffset;
@@ -356,13 +411,15 @@ xencomm_add_offset(
chunk_skip = min(chunksz, bytes);
if (chunk_skip == chunksz) {
/* exhausted this page */
- desc->address[i] = XENCOMM_INVALID;
+ *address = XENCOMM_INVALID;
} else {
- desc->address[i] += chunk_skip;
+ *address += chunk_skip;
}
bytes -= chunk_skip;
-
- i++;
+
+ skip_to_next:
+ i++;
+ address++;
}
return handle;
}
--
yamahata
15660_fb5043d15cae_remove_xencomm_page_size_limit_xen_side.patch
Description: Text Data
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