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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 7/9] xen: arm: handle variable p2m levels in apply_p2m_changes
As with previous changes this involves conversion from a linear series of
lookups into a loop over the levels.
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Cc: Arianna Avanzini <avanzini.arianna@xxxxxxxxx>
---
v2:
- Rebase, in particular over 4b25423aee13 "arch/arm: unmap partially-mapped
memory regions" which had some interesting interactions (which I hope I've
gotten right!)
- Spell previous and concatenate correctly.
- ASSERT rather than BUG_ON for concatenated level zero root.
---
xen/arch/arm/p2m.c | 172 ++++++++++++++++++++++++----------------------------
1 file changed, 78 insertions(+), 94 deletions(-)
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index ea5e342..8e330c7 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -15,7 +15,6 @@
/* First level P2M is 2 consecutive pages */
#define P2M_ROOT_ORDER 1
-#define P2M_ROOT_ENTRIES (LPAE_ENTRIES<<P2M_ROOT_ORDER)
#define P2M_ROOT_PAGES (1<<P2M_ROOT_ORDER)
static bool_t p2m_valid(lpae_t pte)
@@ -119,31 +118,6 @@ void flush_tlb_domain(struct domain *d)
p2m_load_VTTBR(current->domain);
}
-static int p2m_first_level_index(paddr_t addr)
-{
- /*
- * 1st pages are concatenated so zeroeth offset gives us the
- * index of the 1st page
- */
- return zeroeth_table_offset(addr);
-}
-
-/*
- * Map whichever of the first pages contain addr. The caller should
- * then use first_table_offset as an index.
- */
-static lpae_t *p2m_map_first(struct p2m_domain *p2m, paddr_t addr)
-{
- struct page_info *page;
-
- if ( first_linear_offset(addr) >= P2M_ROOT_ENTRIES )
- return NULL;
-
- page = p2m->root + p2m_first_level_index(addr);
-
- return __map_domain_page(page);
-}
-
/*
* Lookup the MFN corresponding to a domain's PFN.
*
@@ -733,13 +707,12 @@ static int apply_p2m_changes(struct domain *d,
{
int rc, ret;
struct p2m_domain *p2m = &d->arch.p2m;
- lpae_t *first = NULL, *second = NULL, *third = NULL;
+ lpae_t *mappings[4] = { NULL, };
paddr_t addr, orig_maddr = maddr;
unsigned int level = 0;
- unsigned long cur_first_page = ~0,
- cur_first_offset = ~0,
- cur_second_offset = ~0;
- unsigned long count = 0;
+ unsigned int cur_root_table = ~0;
+ unsigned int cur_offset[4] = { ~0, };
+ unsigned int count = 0;
bool_t flush = false;
bool_t flush_pt;
@@ -751,9 +724,21 @@ static int apply_p2m_changes(struct domain *d,
spin_lock(&p2m->lock);
+ /* Static mapping. P2M_ROOT_PAGES > 1 are handled below */
+ if ( P2M_ROOT_PAGES == 1 )
+ mappings[P2M_ROOT_LEVEL] = __map_domain_page(p2m->root);
+
addr = start_gpaddr;
while ( addr < end_gpaddr )
{
+ int root_table;
+ const unsigned int offsets[4] = {
+ zeroeth_table_offset(addr),
+ first_table_offset(addr),
+ second_table_offset(addr),
+ third_table_offset(addr)
+ };
+
/*
* Arbitrarily, preempt every 512 operations or 8192 nops.
* 512*P2M_ONE_PROGRESS == 8192*P2M_ONE_PROGRESS_NOP == 0x2000
@@ -773,76 +758,72 @@ static int apply_p2m_changes(struct domain *d,
count = 0;
}
- if ( cur_first_page != p2m_first_level_index(addr) )
+ if ( P2M_ROOT_PAGES > 1 )
{
- if ( first ) unmap_domain_page(first);
- first = p2m_map_first(p2m, addr);
- if ( !first )
+ int i;
+ /*
+ * Concatenated root-level tables. The table number will be the
+ * offset at the previous level. It is not possible to concatenate
+ * a level-0 root.
+ */
+ ASSERT(P2M_ROOT_LEVEL > 0);
+ root_table = offsets[P2M_ROOT_LEVEL - 1];
+ if ( root_table >= P2M_ROOT_PAGES )
{
rc = -EINVAL;
goto out;
}
- cur_first_page = p2m_first_level_index(addr);
- /* Any mapping further down is now invalid */
- cur_first_offset = cur_second_offset = ~0;
- }
-
- /* We only use a 3 level p2m at the moment, so no level 0,
- * current hardware doesn't support super page mappings at
- * level 0 anyway */
-
- level = 1;
- ret = apply_one_level(d, &first[first_table_offset(addr)],
- level, flush_pt, op,
- start_gpaddr, end_gpaddr,
- &addr, &maddr, &flush,
- mattr, t);
- if ( ret < 0 ) { rc = ret ; goto out; }
- count += ret;
- if ( ret != P2M_ONE_DESCEND ) continue;
-
- BUG_ON(!p2m_valid(first[first_table_offset(addr)]));
- if ( cur_first_offset != first_table_offset(addr) )
- {
- if (second) unmap_domain_page(second);
- second = map_domain_page(first[first_table_offset(addr)].p2m.base);
- cur_first_offset = first_table_offset(addr);
- /* Any mapping further down is now invalid */
- cur_second_offset = ~0;
+ if ( cur_root_table != root_table )
+ {
+ if ( mappings[P2M_ROOT_LEVEL] )
+ unmap_domain_page(mappings[P2M_ROOT_LEVEL]);
+ mappings[P2M_ROOT_LEVEL] =
+ __map_domain_page(p2m->root + root_table);
+ if ( !mappings[P2M_ROOT_LEVEL] )
+ {
+ rc = -EINVAL;
+ goto out;
+ }
+ cur_root_table = root_table;
+ /* Any mapping further down is now invalid */
+ for ( i = P2M_ROOT_LEVEL; i < 4; i++ )
+ cur_offset[i] = ~0;
+ }
}
- /* else: second already valid */
-
- level = 2;
- ret = apply_one_level(d,&second[second_table_offset(addr)],
- level, flush_pt, op,
- start_gpaddr, end_gpaddr,
- &addr, &maddr, &flush,
- mattr, t);
- if ( ret < 0 ) { rc = ret ; goto out; }
- count += ret;
- if ( ret != P2M_ONE_DESCEND ) continue;
- BUG_ON(!p2m_valid(second[second_table_offset(addr)]));
-
- if ( cur_second_offset != second_table_offset(addr) )
+ for ( level = P2M_ROOT_LEVEL; level < 4; level++ )
{
- /* map third level */
- if (third) unmap_domain_page(third);
- third =
map_domain_page(second[second_table_offset(addr)].p2m.base);
- cur_second_offset = second_table_offset(addr);
+ unsigned offset = offsets[level];
+ lpae_t *entry = &mappings[level][offset];
+
+ ret = apply_one_level(d, entry,
+ level, flush_pt, op,
+ start_gpaddr, end_gpaddr,
+ &addr, &maddr, &flush,
+ mattr, t);
+ if ( ret < 0 ) { rc = ret ; goto out; }
+ count += ret;
+ /* L3 had better have done something! We cannot descend any
further */
+ BUG_ON(level == 3 && ret == P2M_ONE_DESCEND);
+ if ( ret != P2M_ONE_DESCEND ) break;
+
+ BUG_ON(!p2m_valid(*entry));
+
+ if ( cur_offset[level] != offset )
+ {
+ /* Update mapping for next level */
+ int i;
+ if ( mappings[level+1] )
+ unmap_domain_page(mappings[level+1]);
+ mappings[level+1] = map_domain_page(entry->p2m.base);
+ cur_offset[level] = offset;
+ /* Any mapping further down is now invalid */
+ for ( i = level+1; i < 4; i++ )
+ cur_offset[i] = ~0;
+ }
+ /* else: next level already valid */
}
-
- level = 3;
- ret = apply_one_level(d, &third[third_table_offset(addr)],
- level, flush_pt, op,
- start_gpaddr, end_gpaddr,
- &addr, &maddr, &flush,
- mattr, t);
- if ( ret < 0 ) { rc = ret ; goto out; }
- /* L3 had better have done something! We cannot descend any further */
- BUG_ON(ret == P2M_ONE_DESCEND);
- count += ret;
}
if ( flush )
@@ -866,9 +847,6 @@ static int apply_p2m_changes(struct domain *d,
rc = 0;
out:
- if (third) unmap_domain_page(third);
- if (second) unmap_domain_page(second);
- if (first) unmap_domain_page(first);
if ( rc < 0 && ( op == INSERT || op == ALLOCATE ) &&
addr != start_gpaddr )
{
@@ -884,6 +862,12 @@ out:
mattr, p2m_invalid);
}
+ for ( level = P2M_ROOT_LEVEL; level < 4; level ++ )
+ {
+ if ( mappings[level] )
+ unmap_domain_page(mappings[level]);
+ }
+
spin_unlock(&p2m->lock);
return rc;
--
1.7.10.4
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