# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1257252028 0
# Node ID 7a206c6f216aeb6cb7b7e4deb90f2f84ce1e2ed8
# Parent 450f2ddd2dc6688bb3c5be3636944b33b3b1bb9c
x86: improve reporting through XENMEM_machine_memory_map
Since Dom0 derives machine address ranges usable for assigning PCI
device resources from the output of this sub-hypercall, Xen should
make
sure it properly reports all ranges not suitable for this (as either
reserved or unusable):
- RAM regions excluded via command line option
- memory regions used by Xen itself (LAPIC, IOAPICs)
While the latter should generally already be excluded by the BIOS
provided E820 table, this apparently isn't always the case at least
for IOAPICs, and with Linux having got changed to account for this it
seems to make sense to also do so in Xen.
Generally the HPET range should also be excluded here, but since it
isn't being reflected in Dom0's iomem_caps (and can't be, as it's a
sub-page range) I wasn't sure whether adding explicit code for doing
so would be reasonable.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
xen/arch/x86/e820.c | 8 +++-
xen/arch/x86/mm.c | 82 ++++++++++++++++++++++++++++++++++++++-------
xen/common/rangeset.c | 18 +++++++++
xen/include/xen/rangeset.h | 3 +
4 files changed, 99 insertions(+), 12 deletions(-)
diff -r 450f2ddd2dc6 -r 7a206c6f216a xen/arch/x86/e820.c
--- a/xen/arch/x86/e820.c Tue Nov 03 09:33:22 2009 +0000
+++ b/xen/arch/x86/e820.c Tue Nov 03 12:40:28 2009 +0000
@@ -373,7 +373,13 @@ static void __init clip_to_limit(uint64_
((e820.map[i].addr + e820.map[i].size) <= limit) )
continue;
old_limit = e820.map[i].addr + e820.map[i].size;
- if ( e820.map[i].addr < limit )
+ if ( e820_change_range_type(&e820, max(e820.map[i].addr, limit),
+ old_limit, E820_RAM, E820_UNUSABLE) )
+ {
+ /* Start again now e820 map must have changed. */
+ i = 0;
+ }
+ else if ( e820.map[i].addr < limit )
{
e820.map[i].size = limit - e820.map[i].addr;
}
diff -r 450f2ddd2dc6 -r 7a206c6f216a xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Tue Nov 03 09:33:22 2009 +0000
+++ b/xen/arch/x86/mm.c Tue Nov 03 12:40:28 2009 +0000
@@ -3962,6 +3962,37 @@ typedef struct e820entry e820entry_t;
typedef struct e820entry e820entry_t;
DEFINE_XEN_GUEST_HANDLE(e820entry_t);
+struct memory_map_context
+{
+ unsigned int n;
+ unsigned long s;
+ struct xen_memory_map map;
+};
+
+static int handle_iomem_range(unsigned long s, unsigned long e, void *p)
+{
+ struct memory_map_context *ctxt = p;
+
+ if ( s > ctxt->s )
+ {
+ e820entry_t ent;
+ XEN_GUEST_HANDLE(e820entry_t) buffer;
+
+ if ( ctxt->n + 1 >= ctxt->map.nr_entries )
+ return -EINVAL;
+ ent.addr = (uint64_t)ctxt->s << PAGE_SHIFT;
+ ent.size = (uint64_t)(s - ctxt->s) << PAGE_SHIFT;
+ ent.type = E820_RESERVED;
+ buffer = guest_handle_cast(ctxt->map.buffer, e820entry_t);
+ if ( __copy_to_guest_offset(buffer, ctxt->n, &ent, 1) < 0 )
+ return -EFAULT;
+ ctxt->n++;
+ }
+ ctxt->s = e + 1;
+
+ return 0;
+}
+
long arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
{
struct page_info *page = NULL;
@@ -4123,9 +4154,9 @@ long arch_memory_op(int op, XEN_GUEST_HA
case XENMEM_machine_memory_map:
{
- struct xen_memory_map memmap;
+ struct memory_map_context ctxt;
XEN_GUEST_HANDLE(e820entry_t) buffer;
- int count;
+ unsigned int i;
int rc;
if ( !IS_PRIV(current->domain) )
@@ -4135,20 +4166,49 @@ long arch_memory_op(int op, XEN_GUEST_HA
if ( rc )
return rc;
- if ( copy_from_guest(&memmap, arg, 1) )
+ if ( copy_from_guest(&ctxt.map, arg, 1) )
return -EFAULT;
- if ( memmap.nr_entries < e820.nr_map + 1 )
+ if ( ctxt.map.nr_entries < e820.nr_map + 1 )
return -EINVAL;
- buffer = guest_handle_cast(memmap.buffer, e820entry_t);
-
- count = min((unsigned int)e820.nr_map, memmap.nr_entries);
- if ( copy_to_guest(buffer, e820.map, count) < 0 )
+ buffer = guest_handle_cast(ctxt.map.buffer, e820entry_t);
+ if ( !guest_handle_okay(buffer, ctxt.map.nr_entries) )
return -EFAULT;
- memmap.nr_entries = count;
-
- if ( copy_to_guest(arg, &memmap, 1) )
+ for ( i = 0, ctxt.n = 0, ctxt.s = 0; i < e820.nr_map; ++i, ++ctxt.n )
+ {
+ unsigned long s = PFN_DOWN(e820.map[i].addr);
+
+ if ( s )
+ {
+ rc = rangeset_report_ranges(current->domain->iomem_caps,
+ ctxt.s, s - 1,
+ handle_iomem_range, &ctxt);
+ if ( !rc )
+ rc = handle_iomem_range(s, s, &ctxt);
+ if ( rc )
+ return rc;
+ }
+ if ( ctxt.map.nr_entries <= ctxt.n + (e820.nr_map - i) )
+ return -EINVAL;
+ if ( __copy_to_guest_offset(buffer, ctxt.n, e820.map + i, 1) < 0 )
+ return -EFAULT;
+ ctxt.s = PFN_UP(e820.map[i].addr + e820.map[i].size);
+ }
+
+ if ( ctxt.s )
+ {
+ rc = rangeset_report_ranges(current->domain->iomem_caps, ctxt.s,
+ ~0UL, handle_iomem_range, &ctxt);
+ if ( !rc && ctxt.s )
+ rc = handle_iomem_range(~0UL, ~0UL, &ctxt);
+ if ( rc )
+ return rc;
+ }
+
+ ctxt.map.nr_entries = ctxt.n;
+
+ if ( copy_to_guest(arg, &ctxt.map, 1) )
return -EFAULT;
return 0;
diff -r 450f2ddd2dc6 -r 7a206c6f216a xen/common/rangeset.c
--- a/xen/common/rangeset.c Tue Nov 03 09:33:22 2009 +0000
+++ b/xen/common/rangeset.c Tue Nov 03 12:40:28 2009 +0000
@@ -251,6 +251,24 @@ int rangeset_contains_range(
return contains;
}
+int rangeset_report_ranges(
+ struct rangeset *r, unsigned long s, unsigned long e,
+ int (*cb)(unsigned long s, unsigned long e, void *), void *ctxt)
+{
+ struct range *x;
+ int rc = 0;
+
+ spin_lock(&r->lock);
+
+ for ( x = find_range(r, s); x && (x->s <= e) && !rc; x = next_range(r, x) )
+ if ( x->e >= s )
+ rc = cb(max(x->s, s), min(x->e, e), ctxt);
+
+ spin_unlock(&r->lock);
+
+ return rc;
+}
+
int rangeset_add_singleton(
struct rangeset *r, unsigned long s)
{
diff -r 450f2ddd2dc6 -r 7a206c6f216a xen/include/xen/rangeset.h
--- a/xen/include/xen/rangeset.h Tue Nov 03 09:33:22 2009 +0000
+++ b/xen/include/xen/rangeset.h Tue Nov 03 12:40:28 2009 +0000
@@ -53,6 +53,9 @@ int __must_check rangeset_remove_range(
struct rangeset *r, unsigned long s, unsigned long e);
int __must_check rangeset_contains_range(
struct rangeset *r, unsigned long s, unsigned long e);
+int rangeset_report_ranges(
+ struct rangeset *r, unsigned long s, unsigned long e,
+ int (*cb)(unsigned long s, unsigned long e, void *), void *ctxt);
/* Add/remove/query a single number. */
int __must_check rangeset_add_singleton(
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