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authorJuergen Gross <jgross@suse.com>2015-09-04 14:05:51 +0200
committerDavid Vrabel <david.vrabel@citrix.com>2015-09-08 16:28:06 +0100
commit626d7508664c4bc8e67f496da4387ecd0c410b8c (patch)
treeaa6f8868b6e18950a16dd8225c7e95a429a0dca9
parentcb9e444b5aaa900bb4310da411315b6947c53e37 (diff)
xen: switch extra memory accounting to use pfns
Instead of using physical addresses for accounting of extra memory areas available for ballooning switch to pfns as this is much less error prone regarding partial pages. Reported-by: Roger Pau Monné <roger.pau@citrix.com> Tested-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
-rw-r--r--arch/x86/xen/setup.c80
-rw-r--r--drivers/xen/balloon.c6
-rw-r--r--include/xen/page.h4
3 files changed, 49 insertions, 41 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 70de4c8b8f27..f5ef6746d47a 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -90,62 +90,69 @@ static void __init xen_parse_512gb(void)
xen_512gb_limit = val;
}
-static void __init xen_add_extra_mem(phys_addr_t start, phys_addr_t size)
+static void __init xen_add_extra_mem(unsigned long start_pfn,
+ unsigned long n_pfns)
{
int i;
+ /*
+ * No need to check for zero size, should happen rarely and will only
+ * write a new entry regarded to be unused due to zero size.
+ */
for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
/* Add new region. */
- if (xen_extra_mem[i].size == 0) {
- xen_extra_mem[i].start = start;
- xen_extra_mem[i].size = size;
+ if (xen_extra_mem[i].n_pfns == 0) {
+ xen_extra_mem[i].start_pfn = start_pfn;
+ xen_extra_mem[i].n_pfns = n_pfns;
break;
}
/* Append to existing region. */
- if (xen_extra_mem[i].start + xen_extra_mem[i].size == start) {
- xen_extra_mem[i].size += size;
+ if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
+ start_pfn) {
+ xen_extra_mem[i].n_pfns += n_pfns;
break;
}
}
if (i == XEN_EXTRA_MEM_MAX_REGIONS)
printk(KERN_WARNING "Warning: not enough extra memory regions\n");
- memblock_reserve(start, size);
+ memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
}
-static void __init xen_del_extra_mem(phys_addr_t start, phys_addr_t size)
+static void __init xen_del_extra_mem(unsigned long start_pfn,
+ unsigned long n_pfns)
{
int i;
- phys_addr_t start_r, size_r;
+ unsigned long start_r, size_r;
for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
- start_r = xen_extra_mem[i].start;
- size_r = xen_extra_mem[i].size;
+ start_r = xen_extra_mem[i].start_pfn;
+ size_r = xen_extra_mem[i].n_pfns;
/* Start of region. */
- if (start_r == start) {
- BUG_ON(size > size_r);
- xen_extra_mem[i].start += size;
- xen_extra_mem[i].size -= size;
+ if (start_r == start_pfn) {
+ BUG_ON(n_pfns > size_r);
+ xen_extra_mem[i].start_pfn += n_pfns;
+ xen_extra_mem[i].n_pfns -= n_pfns;
break;
}
/* End of region. */
- if (start_r + size_r == start + size) {
- BUG_ON(size > size_r);
- xen_extra_mem[i].size -= size;
+ if (start_r + size_r == start_pfn + n_pfns) {
+ BUG_ON(n_pfns > size_r);
+ xen_extra_mem[i].n_pfns -= n_pfns;
break;
}
/* Mid of region. */
- if (start > start_r && start < start_r + size_r) {
- BUG_ON(start + size > start_r + size_r);
- xen_extra_mem[i].size = start - start_r;
+ if (start_pfn > start_r && start_pfn < start_r + size_r) {
+ BUG_ON(start_pfn + n_pfns > start_r + size_r);
+ xen_extra_mem[i].n_pfns = start_pfn - start_r;
/* Calling memblock_reserve() again is okay. */
- xen_add_extra_mem(start + size, start_r + size_r -
- (start + size));
+ xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
+ (start_pfn + n_pfns));
break;
}
}
- memblock_free(start, size);
+ memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
}
/*
@@ -156,11 +163,10 @@ static void __init xen_del_extra_mem(phys_addr_t start, phys_addr_t size)
unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
{
int i;
- phys_addr_t addr = PFN_PHYS(pfn);
for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
- if (addr >= xen_extra_mem[i].start &&
- addr < xen_extra_mem[i].start + xen_extra_mem[i].size)
+ if (pfn >= xen_extra_mem[i].start_pfn &&
+ pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
return INVALID_P2M_ENTRY;
}
@@ -176,10 +182,10 @@ void __init xen_inv_extra_mem(void)
int i;
for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
- if (!xen_extra_mem[i].size)
+ if (!xen_extra_mem[i].n_pfns)
continue;
- pfn_s = PFN_DOWN(xen_extra_mem[i].start);
- pfn_e = PFN_UP(xen_extra_mem[i].start + xen_extra_mem[i].size);
+ pfn_s = xen_extra_mem[i].start_pfn;
+ pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
for (pfn = pfn_s; pfn < pfn_e; pfn++)
set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
@@ -507,7 +513,7 @@ void __init xen_remap_memory(void)
} else if (pfn_s + len == xen_remap_buf.target_pfn) {
len += xen_remap_buf.size;
} else {
- xen_del_extra_mem(PFN_PHYS(pfn_s), PFN_PHYS(len));
+ xen_del_extra_mem(pfn_s, len);
pfn_s = xen_remap_buf.target_pfn;
len = xen_remap_buf.size;
}
@@ -517,7 +523,7 @@ void __init xen_remap_memory(void)
}
if (pfn_s != ~0UL && len)
- xen_del_extra_mem(PFN_PHYS(pfn_s), PFN_PHYS(len));
+ xen_del_extra_mem(pfn_s, len);
set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
@@ -744,7 +750,7 @@ static void __init xen_reserve_xen_mfnlist(void)
**/
char * __init xen_memory_setup(void)
{
- unsigned long max_pfn;
+ unsigned long max_pfn, pfn_s, n_pfns;
phys_addr_t mem_end, addr, size, chunk_size;
u32 type;
int rc;
@@ -831,9 +837,11 @@ char * __init xen_memory_setup(void)
chunk_size = min(size, mem_end - addr);
} else if (extra_pages) {
chunk_size = min(size, PFN_PHYS(extra_pages));
- extra_pages -= PFN_DOWN(chunk_size);
- xen_add_extra_mem(addr, chunk_size);
- xen_max_p2m_pfn = PFN_DOWN(addr + chunk_size);
+ pfn_s = PFN_UP(addr);
+ n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
+ extra_pages -= n_pfns;
+ xen_add_extra_mem(pfn_s, n_pfns);
+ xen_max_p2m_pfn = pfn_s + n_pfns;
} else
type = E820_UNUSABLE;
}
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index bf4a23c7c591..1fa633b2d556 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -638,9 +638,9 @@ static int __init balloon_init(void)
* regions (see arch/x86/xen/setup.c).
*/
for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++)
- if (xen_extra_mem[i].size)
- balloon_add_region(PFN_UP(xen_extra_mem[i].start),
- PFN_DOWN(xen_extra_mem[i].size));
+ if (xen_extra_mem[i].n_pfns)
+ balloon_add_region(xen_extra_mem[i].start_pfn,
+ xen_extra_mem[i].n_pfns);
return 0;
}
diff --git a/include/xen/page.h b/include/xen/page.h
index c5ed20bb3fe9..a5983da2f5cd 100644
--- a/include/xen/page.h
+++ b/include/xen/page.h
@@ -9,8 +9,8 @@ static inline unsigned long page_to_mfn(struct page *page)
}
struct xen_memory_region {
- phys_addr_t start;
- phys_addr_t size;
+ unsigned long start_pfn;
+ unsigned long n_pfns;
};
#define XEN_EXTRA_MEM_MAX_REGIONS 128 /* == E820MAX */