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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v8 03/15] x86/mm: rewrite virt_to_xen_l*e
From: Wei Liu <wei.liu2@xxxxxxxxxx>
Rewrite those functions to use the new APIs. Modify its callers to unmap
the pointer returned. Since alloc_xen_pagetable_new() is almost never
useful unless accompanied by page clearing and a mapping, introduce a
helper alloc_map_clear_xen_pt() for this sequence.
Note that the change of virt_to_xen_l1e() also requires vmap_to_mfn() to
unmap the page, which requires domain_page.h header in vmap.
Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Signed-off-by: Hongyan Xia <hongyxia@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Changed in v8:
- s/virtual address/linear address/.
- BUG_ON() on NULL return in vmap_to_mfn().
Changed in v7:
- remove a comment.
- use l1e_get_mfn() instead of converting things back and forth.
- add alloc_map_clear_xen_pt().
- unmap before the next mapping to reduce mapcache pressure.
- use normal unmap calls instead of the macro in error paths because
unmap can handle NULL now.
---
xen/arch/x86/domain_page.c | 11 ++++--
xen/arch/x86/mm.c | 96 +++++++++++++++++++++++++++++++++-------------
xen/common/vmap.c | 1 +
xen/include/asm-x86/mm.h | 1 +
xen/include/asm-x86/page.h | 10 ++++-
5 files changed, 88 insertions(+), 31 deletions(-)
diff --git a/xen/arch/x86/domain_page.c b/xen/arch/x86/domain_page.c
index b03728e18e..dc8627c1b5 100644
--- a/xen/arch/x86/domain_page.c
+++ b/xen/arch/x86/domain_page.c
@@ -333,21 +333,24 @@ void unmap_domain_page_global(const void *ptr)
mfn_t domain_page_map_to_mfn(const void *ptr)
{
unsigned long va = (unsigned long)ptr;
- const l1_pgentry_t *pl1e;
+ l1_pgentry_t l1e;
if ( va >= DIRECTMAP_VIRT_START )
return _mfn(virt_to_mfn(ptr));
if ( va >= VMAP_VIRT_START && va < VMAP_VIRT_END )
{
- pl1e = virt_to_xen_l1e(va);
+ const l1_pgentry_t *pl1e = virt_to_xen_l1e(va);
+
BUG_ON(!pl1e);
+ l1e = *pl1e;
+ unmap_domain_page(pl1e);
}
else
{
ASSERT(va >= MAPCACHE_VIRT_START && va < MAPCACHE_VIRT_END);
- pl1e = &__linear_l1_table[l1_linear_offset(va)];
+ l1e = __linear_l1_table[l1_linear_offset(va)];
}
- return l1e_get_mfn(*pl1e);
+ return l1e_get_mfn(l1e);
}
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 7a11d022c9..fd416c0282 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4965,8 +4965,28 @@ void free_xen_pagetable_new(mfn_t mfn)
free_xenheap_page(mfn_to_virt(mfn_x(mfn)));
}
+void *alloc_map_clear_xen_pt(mfn_t *pmfn)
+{
+ mfn_t mfn = alloc_xen_pagetable_new();
+ void *ret;
+
+ if ( mfn_eq(mfn, INVALID_MFN) )
+ return NULL;
+
+ if ( pmfn )
+ *pmfn = mfn;
+ ret = map_domain_page(mfn);
+ clear_page(ret);
+
+ return ret;
+}
+
static DEFINE_SPINLOCK(map_pgdir_lock);
+/*
+ * For virt_to_xen_lXe() functions, they take a linear address and return a
+ * pointer to Xen's LX entry. Caller needs to unmap the pointer.
+ */
static l3_pgentry_t *virt_to_xen_l3e(unsigned long v)
{
l4_pgentry_t *pl4e;
@@ -4975,33 +4995,33 @@ static l3_pgentry_t *virt_to_xen_l3e(unsigned long v)
if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) )
{
bool locking = system_state > SYS_STATE_boot;
- l3_pgentry_t *l3t = alloc_xen_pagetable();
+ mfn_t l3mfn;
+ l3_pgentry_t *l3t = alloc_map_clear_xen_pt(&l3mfn);
if ( !l3t )
return NULL;
- clear_page(l3t);
+ UNMAP_DOMAIN_PAGE(l3t);
if ( locking )
spin_lock(&map_pgdir_lock);
if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) )
{
- l4_pgentry_t l4e = l4e_from_paddr(__pa(l3t), __PAGE_HYPERVISOR);
+ l4_pgentry_t l4e = l4e_from_mfn(l3mfn, __PAGE_HYPERVISOR);
l4e_write(pl4e, l4e);
efi_update_l4_pgtable(l4_table_offset(v), l4e);
- l3t = NULL;
+ l3mfn = INVALID_MFN;
}
if ( locking )
spin_unlock(&map_pgdir_lock);
- if ( l3t )
- free_xen_pagetable(l3t);
+ free_xen_pagetable_new(l3mfn);
}
- return l4e_to_l3e(*pl4e) + l3_table_offset(v);
+ return map_l3t_from_l4e(*pl4e) + l3_table_offset(v);
}
static l2_pgentry_t *virt_to_xen_l2e(unsigned long v)
{
- l3_pgentry_t *pl3e;
+ l3_pgentry_t *pl3e, l3e;
pl3e = virt_to_xen_l3e(v);
if ( !pl3e )
@@ -5010,31 +5030,37 @@ static l2_pgentry_t *virt_to_xen_l2e(unsigned long v)
if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) )
{
bool locking = system_state > SYS_STATE_boot;
- l2_pgentry_t *l2t = alloc_xen_pagetable();
+ mfn_t l2mfn;
+ l2_pgentry_t *l2t = alloc_map_clear_xen_pt(&l2mfn);
if ( !l2t )
+ {
+ unmap_domain_page(pl3e);
return NULL;
- clear_page(l2t);
+ }
+ UNMAP_DOMAIN_PAGE(l2t);
if ( locking )
spin_lock(&map_pgdir_lock);
if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) )
{
- l3e_write(pl3e, l3e_from_paddr(__pa(l2t), __PAGE_HYPERVISOR));
- l2t = NULL;
+ l3e_write(pl3e, l3e_from_mfn(l2mfn, __PAGE_HYPERVISOR));
+ l2mfn = INVALID_MFN;
}
if ( locking )
spin_unlock(&map_pgdir_lock);
- if ( l2t )
- free_xen_pagetable(l2t);
+ free_xen_pagetable_new(l2mfn);
}
BUG_ON(l3e_get_flags(*pl3e) & _PAGE_PSE);
- return l3e_to_l2e(*pl3e) + l2_table_offset(v);
+ l3e = *pl3e;
+ unmap_domain_page(pl3e);
+
+ return map_l2t_from_l3e(l3e) + l2_table_offset(v);
}
l1_pgentry_t *virt_to_xen_l1e(unsigned long v)
{
- l2_pgentry_t *pl2e;
+ l2_pgentry_t *pl2e, l2e;
pl2e = virt_to_xen_l2e(v);
if ( !pl2e )
@@ -5043,26 +5069,32 @@ l1_pgentry_t *virt_to_xen_l1e(unsigned long v)
if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) )
{
bool locking = system_state > SYS_STATE_boot;
- l1_pgentry_t *l1t = alloc_xen_pagetable();
+ mfn_t l1mfn;
+ l1_pgentry_t *l1t = alloc_map_clear_xen_pt(&l1mfn);
if ( !l1t )
+ {
+ unmap_domain_page(pl2e);
return NULL;
- clear_page(l1t);
+ }
+ UNMAP_DOMAIN_PAGE(l1t);
if ( locking )
spin_lock(&map_pgdir_lock);
if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) )
{
- l2e_write(pl2e, l2e_from_paddr(__pa(l1t), __PAGE_HYPERVISOR));
- l1t = NULL;
+ l2e_write(pl2e, l2e_from_mfn(l1mfn, __PAGE_HYPERVISOR));
+ l1mfn = INVALID_MFN;
}
if ( locking )
spin_unlock(&map_pgdir_lock);
- if ( l1t )
- free_xen_pagetable(l1t);
+ free_xen_pagetable_new(l1mfn);
}
BUG_ON(l2e_get_flags(*pl2e) & _PAGE_PSE);
- return l2e_to_l1e(*pl2e) + l1_table_offset(v);
+ l2e = *pl2e;
+ unmap_domain_page(pl2e);
+
+ return map_l1t_from_l2e(l2e) + l1_table_offset(v);
}
/* Convert to from superpage-mapping flags for map_pages_to_xen(). */
@@ -5085,8 +5117,8 @@ int map_pages_to_xen(
unsigned int flags)
{
bool locking = system_state > SYS_STATE_boot;
- l3_pgentry_t *pl3e, ol3e;
- l2_pgentry_t *pl2e, ol2e;
+ l3_pgentry_t *pl3e = NULL, ol3e;
+ l2_pgentry_t *pl2e = NULL, ol2e;
l1_pgentry_t *pl1e, ol1e;
unsigned int i;
int rc = -ENOMEM;
@@ -5107,6 +5139,10 @@ int map_pages_to_xen(
while ( nr_mfns != 0 )
{
+ /* Clean up mappings mapped in the previous iteration. */
+ UNMAP_DOMAIN_PAGE(pl3e);
+ UNMAP_DOMAIN_PAGE(pl2e);
+
pl3e = virt_to_xen_l3e(virt);
if ( !pl3e )
@@ -5275,6 +5311,8 @@ int map_pages_to_xen(
pl1e = virt_to_xen_l1e(virt);
if ( pl1e == NULL )
goto out;
+
+ UNMAP_DOMAIN_PAGE(pl1e);
}
else if ( l2e_get_flags(*pl2e) & _PAGE_PSE )
{
@@ -5451,6 +5489,8 @@ int map_pages_to_xen(
rc = 0;
out:
+ unmap_domain_page(pl2e);
+ unmap_domain_page(pl3e);
return rc;
}
@@ -5474,7 +5514,7 @@ int populate_pt_range(unsigned long virt, unsigned long
nr_mfns)
int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
{
bool locking = system_state > SYS_STATE_boot;
- l3_pgentry_t *pl3e;
+ l3_pgentry_t *pl3e = NULL;
l2_pgentry_t *pl2e;
l1_pgentry_t *pl1e;
unsigned int i;
@@ -5490,6 +5530,9 @@ int modify_xen_mappings(unsigned long s, unsigned long e,
unsigned int nf)
while ( v < e )
{
+ /* Clean up mappings mapped in the previous iteration. */
+ UNMAP_DOMAIN_PAGE(pl3e);
+
pl3e = virt_to_xen_l3e(v);
if ( !pl3e || !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) )
@@ -5718,6 +5761,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e,
unsigned int nf)
rc = 0;
out:
+ unmap_domain_page(pl3e);
return rc;
}
diff --git a/xen/common/vmap.c b/xen/common/vmap.c
index faebc1ddf1..9964ab2096 100644
--- a/xen/common/vmap.c
+++ b/xen/common/vmap.c
@@ -1,6 +1,7 @@
#ifdef VMAP_VIRT_START
#include <xen/bitmap.h>
#include <xen/cache.h>
+#include <xen/domain_page.h>
#include <xen/init.h>
#include <xen/mm.h>
#include <xen/pfn.h>
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 7e74996053..5b76308948 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -586,6 +586,7 @@ void *alloc_xen_pagetable(void);
void free_xen_pagetable(void *v);
mfn_t alloc_xen_pagetable_new(void);
void free_xen_pagetable_new(mfn_t mfn);
+void *alloc_map_clear_xen_pt(mfn_t *pmfn);
l1_pgentry_t *virt_to_xen_l1e(unsigned long v);
diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h
index f632affaef..608a048c28 100644
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -291,7 +291,15 @@ void copy_page_sse2(void *, const void *);
#define pfn_to_paddr(pfn) __pfn_to_paddr(pfn)
#define paddr_to_pfn(pa) __paddr_to_pfn(pa)
#define paddr_to_pdx(pa) pfn_to_pdx(paddr_to_pfn(pa))
-#define vmap_to_mfn(va) _mfn(l1e_get_pfn(*virt_to_xen_l1e((unsigned
long)(va))))
+
+#define vmap_to_mfn(va) ({ \
+ const l1_pgentry_t *pl1e_ = virt_to_xen_l1e((unsigned long)(va)); \
+ mfn_t mfn_; \
+ BUG_ON(!pl1e_); \
+ mfn_ = l1e_get_mfn(*pl1e_); \
+ unmap_domain_page(pl1e_); \
+ mfn_; })
+
#define vmap_to_page(va) mfn_to_page(vmap_to_mfn(va))
#endif /* !defined(__ASSEMBLY__) */
--
2.16.6
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