# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Date 1180518344 -3600
# Node ID 1f7a6456c330272a3cec13b31fc1ba9b4db898ec
# Parent 152dc0d812b21f6738635e2fb503b663172f34be
[XEN] gnttab: Add new op unmap_and_replace
The operation unmap_and_replace is an extension of unmap_grant_ref.
A new argument in the form of a virtual address (for PV) is given.
Instead of modifying the PTE for the mapped grant table entry to
null, we change it to the PTE for the new address. In turn we
point the new address to null.
As it stands grant table entries once mapped cannot be
remapped by the guest OS (it can however perform a new
mapping on the same entry but that is within our control).
Therefore it's safe to manipulate the mapped PTE entry to
redirect it to a normal page where we've copied the contents.
It's intended to be used as follows:
1) map_grant_ref to v1
2) ...
3) alloc page at v2
4) copy the page at v1 to v2
5) unmap_and_replace v1 with v2
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Added compat integration (PAE-on-64).
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
linux-2.6-xen-sparse/include/xen/gnttab.h | 15 +++++
xen/arch/ia64/xen/mm.c | 17 +++---
xen/arch/powerpc/mm.c | 13 +++-
xen/arch/x86/mm.c | 58 +++++++++++++++++---
xen/common/compat/grant_table.c | 8 ++
xen/common/grant_table.c | 85 ++++++++++++++++++++++++++++--
xen/include/asm-ia64/grant_table.h | 7 ++
xen/include/asm-powerpc/grant_table.h | 9 ++-
xen/include/asm-x86/grant_table.h | 9 ++-
xen/include/public/grant_table.h | 23 ++++++++
xen/include/xlat.lst | 1
11 files changed, 219 insertions(+), 26 deletions(-)
diff -r 152dc0d812b2 -r 1f7a6456c330 linux-2.6-xen-sparse/include/xen/gnttab.h
--- a/linux-2.6-xen-sparse/include/xen/gnttab.h Wed May 30 10:06:23 2007 +0100
+++ b/linux-2.6-xen-sparse/include/xen/gnttab.h Wed May 30 10:45:44 2007 +0100
@@ -135,4 +135,19 @@ gnttab_set_unmap_op(struct gnttab_unmap_
unmap->dev_bus_addr = 0;
}
+static inline void
+gnttab_set_replace_op(struct gnttab_unmap_and_replace *unmap, maddr_t addr,
+ maddr_t new_addr, grant_handle_t handle)
+{
+ if (xen_feature(XENFEAT_auto_translated_physmap)) {
+ unmap->host_addr = __pa(addr);
+ unmap->new_addr = __pa(new_addr);
+ } else {
+ unmap->host_addr = addr;
+ unmap->new_addr = new_addr;
+ }
+
+ unmap->handle = handle;
+}
+
#endif /* __ASM_GNTTAB_H__ */
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/arch/ia64/xen/mm.c
--- a/xen/arch/ia64/xen/mm.c Wed May 30 10:06:23 2007 +0100
+++ b/xen/arch/ia64/xen/mm.c Wed May 30 10:45:44 2007 +0100
@@ -63,7 +63,7 @@
* assign_domain_page_replace()
* - cmpxchg p2m entry
* assign_domain_page_cmpxchg_rel()
- * destroy_grant_host_mapping()
+ * replace_grant_host_mapping()
* steal_page()
* zap_domain_page_one()
* - read p2m entry
@@ -133,7 +133,7 @@
* - races between p2m entry update and tlb insert
* This is a race between reading/writing the p2m entry.
* reader: vcpu_itc_i(), vcpu_itc_d(), ia64_do_page_fault(), vcpu_fc()
- * writer: assign_domain_page_cmpxchg_rel(), destroy_grant_host_mapping(),
+ * writer: assign_domain_page_cmpxchg_rel(), replace_grant_host_mapping(),
* steal_page(), zap_domain_page_one()
*
* For example, vcpu_itc_i() is about to insert tlb by calling
@@ -151,7 +151,7 @@
* This is a race between reading/writing the p2m entry.
* reader: vcpu_get_domain_bundle(), vmx_get_domain_bundle(),
* efi_emulate_get_time()
- * writer: assign_domain_page_cmpxchg_rel(), destroy_grant_host_mapping(),
+ * writer: assign_domain_page_cmpxchg_rel(), replace_grant_host_mapping(),
* steal_page(), zap_domain_page_one()
*
* A page which assigned to a domain can be de-assigned by another vcpu.
@@ -1512,8 +1512,8 @@ create_grant_host_mapping(unsigned long
// grant table host unmapping
int
-destroy_grant_host_mapping(unsigned long gpaddr,
- unsigned long mfn, unsigned int flags)
+replace_grant_host_mapping(unsigned long gpaddr,
+ unsigned long mfn, unsigned long new_gpaddr, unsigned int flags)
{
struct domain* d = current->domain;
unsigned long gpfn = gpaddr >> PAGE_SHIFT;
@@ -1524,6 +1524,11 @@ destroy_grant_host_mapping(unsigned long
pte_t old_pte;
struct page_info* page = mfn_to_page(mfn);
+ if (new_gpaddr) {
+ gdprintk(XENLOG_INFO, "%s: new_gpaddr 0x%lx\n", __func__, new_gpaddr);
+ return GNTST_general_error;
+ }
+
if (flags & (GNTMAP_application_map | GNTMAP_contains_pte)) {
gdprintk(XENLOG_INFO, "%s: flags 0x%x\n", __func__, flags);
return GNTST_general_error;
@@ -1571,7 +1576,7 @@ destroy_grant_host_mapping(unsigned long
BUG_ON(pte_pgc_allocated(old_pte));
domain_page_flush_and_put(d, gpaddr, pte, old_pte, page);
- perfc_incr(destroy_grant_host_mapping);
+ perfc_incr(replace_grant_host_mapping);
return GNTST_okay;
}
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/arch/powerpc/mm.c
--- a/xen/arch/powerpc/mm.c Wed May 30 10:06:23 2007 +0100
+++ b/xen/arch/powerpc/mm.c Wed May 30 10:45:44 2007 +0100
@@ -183,9 +183,16 @@ int create_grant_host_mapping(
return create_grant_va_mapping(addr, frame, current);
}
-int destroy_grant_host_mapping(
- unsigned long addr, unsigned long frame, unsigned int flags)
-{
+int replace_grant_host_mapping(
+ unsigned long addr, unsigned long frame, unsigned long new_addr,
+ unsigned int flags)
+{
+ if (new_addr)
+ printk("%s: new_addr not supported\n", __func__);
+ BUG();
+ return GNTST_general_error;
+ }
+
if (flags & GNTMAP_contains_pte) {
printk("%s: GNTMAP_contains_pte not supported\n", __func__);
BUG();
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Wed May 30 10:06:23 2007 +0100
+++ b/xen/arch/x86/mm.c Wed May 30 10:45:44 2007 +0100
@@ -2621,8 +2621,8 @@ static int create_grant_va_mapping(
return GNTST_okay;
}
-static int destroy_grant_va_mapping(
- unsigned long addr, unsigned long frame, struct vcpu *v)
+static int replace_grant_va_mapping(
+ unsigned long addr, unsigned long frame, l1_pgentry_t nl1e, struct vcpu *v)
{
l1_pgentry_t *pl1e, ol1e;
unsigned long gl1mfn;
@@ -2646,7 +2646,7 @@ static int destroy_grant_va_mapping(
}
/* Delete pagetable entry. */
- if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, l1e_empty(), gl1mfn, v)) )
+ if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v)) )
{
MEM_LOG("Cannot delete PTE entry at %p", (unsigned long *)pl1e);
rc = GNTST_general_error;
@@ -2656,6 +2656,12 @@ static int destroy_grant_va_mapping(
out:
guest_unmap_l1e(v, pl1e);
return rc;
+}
+
+static int destroy_grant_va_mapping(
+ unsigned long addr, unsigned long frame, struct vcpu *v)
+{
+ return replace_grant_va_mapping(addr, frame, l1e_empty(), v);
}
int create_grant_host_mapping(
@@ -2673,12 +2679,48 @@ int create_grant_host_mapping(
return create_grant_va_mapping(addr, pte, current);
}
-int destroy_grant_host_mapping(
- uint64_t addr, unsigned long frame, unsigned int flags)
-{
+int replace_grant_host_mapping(
+ uint64_t addr, unsigned long frame, uint64_t new_addr, unsigned int flags)
+{
+ l1_pgentry_t *pl1e, ol1e;
+ unsigned long gl1mfn;
+ int rc;
+
if ( flags & GNTMAP_contains_pte )
- return destroy_grant_pte_mapping(addr, frame, current->domain);
- return destroy_grant_va_mapping(addr, frame, current);
+ {
+ if (!new_addr)
+ return destroy_grant_pte_mapping(addr, frame, current->domain);
+
+ MEM_LOG("Unsupported grant table operation");
+ return GNTST_general_error;
+ }
+
+ if (!new_addr)
+ return destroy_grant_va_mapping(addr, frame, current);
+
+ pl1e = guest_map_l1e(current, new_addr, &gl1mfn);
+ if ( !pl1e )
+ {
+ MEM_LOG("Could not find L1 PTE for address %lx",
+ (unsigned long)new_addr);
+ return GNTST_general_error;
+ }
+ ol1e = *pl1e;
+
+ if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, l1e_empty(), gl1mfn, current))
)
+ {
+ MEM_LOG("Cannot delete PTE entry at %p", (unsigned long *)pl1e);
+ guest_unmap_l1e(current, pl1e);
+ return GNTST_general_error;
+ }
+
+ guest_unmap_l1e(current, pl1e);
+
+ rc = replace_grant_va_mapping(addr, frame, ol1e, current);
+ if ( rc && !paging_mode_refcounts(current->domain) )
+ put_page_from_l1e(ol1e, current->domain);
+
+ return rc;
}
int steal_page(
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/common/compat/grant_table.c
--- a/xen/common/compat/grant_table.c Wed May 30 10:06:23 2007 +0100
+++ b/xen/common/compat/grant_table.c Wed May 30 10:45:44 2007 +0100
@@ -16,6 +16,10 @@ CHECK_gnttab_map_grant_ref;
#define xen_gnttab_unmap_grant_ref gnttab_unmap_grant_ref
CHECK_gnttab_unmap_grant_ref;
#undef xen_gnttab_unmap_grant_ref
+
+#define xen_gnttab_unmap_and_replace gnttab_unmap_and_replace
+CHECK_gnttab_unmap_and_replace;
+#undef xen_gnttab_unmap_and_replace
DEFINE_XEN_GUEST_HANDLE(gnttab_setup_table_compat_t);
DEFINE_XEN_GUEST_HANDLE(gnttab_transfer_compat_t);
@@ -48,6 +52,10 @@ int compat_grant_table_op(unsigned int c
#ifndef CHECK_gnttab_unmap_grant_ref
CASE(unmap_grant_ref);
+#endif
+
+#ifndef CHECK_gnttab_unmap_and_replace
+ CASE(unmap_and_replace);
#endif
#ifndef CHECK_gnttab_setup_table
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/common/grant_table.c
--- a/xen/common/grant_table.c Wed May 30 10:06:23 2007 +0100
+++ b/xen/common/grant_table.c Wed May 30 10:45:44 2007 +0100
@@ -58,6 +58,16 @@ union grant_combo {
} shorts;
};
+/* Used to share code between unmap_grant_ref and unmap_and_replace. */
+struct gnttab_unmap_common {
+ uint64_t host_addr;
+ uint64_t dev_bus_addr;
+ uint64_t new_addr;
+ grant_handle_t handle;
+
+ int16_t status;
+};
+
#define PIN_FAIL(_lbl, _rc, _f, _a...) \
do { \
gdprintk(XENLOG_WARNING, _f, ## _a ); \
@@ -397,8 +407,8 @@ gnttab_map_grant_ref(
}
static void
-__gnttab_unmap_grant_ref(
- struct gnttab_unmap_grant_ref *op)
+__gnttab_unmap_common(
+ struct gnttab_unmap_common *op)
{
domid_t dom;
grant_ref_t ref;
@@ -477,8 +487,8 @@ __gnttab_unmap_grant_ref(
if ( (op->host_addr != 0) && (flags & GNTMAP_host_map) )
{
- if ( (rc = destroy_grant_host_mapping(op->host_addr,
- frame, flags)) < 0 )
+ if ( (rc = replace_grant_host_mapping(op->host_addr,
+ frame, op->new_addr, flags)) < 0
)
goto unmap_out;
ASSERT(act->pin & (GNTPIN_hstw_mask | GNTPIN_hstr_mask));
@@ -518,6 +528,20 @@ __gnttab_unmap_grant_ref(
rcu_unlock_domain(rd);
}
+static void
+__gnttab_unmap_grant_ref(
+ struct gnttab_unmap_grant_ref *op)
+{
+ struct gnttab_unmap_common common = {
+ .host_addr = op->host_addr,
+ .dev_bus_addr = op->dev_bus_addr,
+ .handle = op->handle,
+ };
+
+ __gnttab_unmap_common(&common);
+ op->status = common.status;
+}
+
static long
gnttab_unmap_grant_ref(
XEN_GUEST_HANDLE(gnttab_unmap_grant_ref_t) uop, unsigned int count)
@@ -530,6 +554,44 @@ gnttab_unmap_grant_ref(
if ( unlikely(__copy_from_guest_offset(&op, uop, i, 1)) )
goto fault;
__gnttab_unmap_grant_ref(&op);
+ if ( unlikely(__copy_to_guest_offset(uop, i, &op, 1)) )
+ goto fault;
+ }
+
+ flush_tlb_mask(current->domain->domain_dirty_cpumask);
+ return 0;
+
+fault:
+ flush_tlb_mask(current->domain->domain_dirty_cpumask);
+ return -EFAULT;
+}
+
+static void
+__gnttab_unmap_and_replace(
+ struct gnttab_unmap_and_replace *op)
+{
+ struct gnttab_unmap_common common = {
+ .host_addr = op->host_addr,
+ .new_addr = op->new_addr,
+ .handle = op->handle,
+ };
+
+ __gnttab_unmap_common(&common);
+ op->status = common.status;
+}
+
+static long
+gnttab_unmap_and_replace(
+ XEN_GUEST_HANDLE(gnttab_unmap_and_replace_t) uop, unsigned int count)
+{
+ int i;
+ struct gnttab_unmap_and_replace op;
+
+ for ( i = 0; i < count; i++ )
+ {
+ if ( unlikely(__copy_from_guest_offset(&op, uop, i, 1)) )
+ goto fault;
+ __gnttab_unmap_and_replace(&op);
if ( unlikely(__copy_to_guest_offset(uop, i, &op, 1)) )
goto fault;
}
@@ -1203,6 +1265,21 @@ do_grant_table_op(
if ( unlikely(!grant_operation_permitted(d)) )
goto out;
rc = gnttab_unmap_grant_ref(unmap, count);
+ break;
+ }
+ case GNTTABOP_unmap_and_replace:
+ {
+ XEN_GUEST_HANDLE(gnttab_unmap_and_replace_t) unmap =
+ guest_handle_cast(uop, gnttab_unmap_and_replace_t);
+ if ( unlikely(!guest_handle_okay(unmap, count)) )
+ goto out;
+ rc = -EPERM;
+ if ( unlikely(!grant_operation_permitted(d)) )
+ goto out;
+ rc = -ENOSYS;
+ if ( unlikely(!replace_grant_supported()) )
+ goto out;
+ rc = gnttab_unmap_and_replace(unmap, count);
break;
}
case GNTTABOP_setup_table:
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/include/asm-ia64/grant_table.h
--- a/xen/include/asm-ia64/grant_table.h Wed May 30 10:06:23 2007 +0100
+++ b/xen/include/asm-ia64/grant_table.h Wed May 30 10:45:44 2007 +0100
@@ -9,7 +9,7 @@
// for grant map/unmap
int create_grant_host_mapping(unsigned long gpaddr, unsigned long mfn,
unsigned int flags);
-int destroy_grant_host_mapping(unsigned long gpaddr, unsigned long mfn,
unsigned int flags);
+int replace_grant_host_mapping(unsigned long gpaddr, unsigned long mfn,
unsigned long new_gpaddr, unsigned int flags);
// for grant transfer
void guest_physmap_add_page(struct domain *d, unsigned long gpfn, unsigned
long mfn);
@@ -67,4 +67,9 @@ static inline void gnttab_clear_flag(uns
#define gnttab_release_put_page(page) put_page((page))
#define gnttab_release_put_page_and_type(page) put_page_and_type((page))
+static inline int replace_grant_supported(void)
+{
+ return 0;
+}
+
#endif /* __ASM_GRANT_TABLE_H__ */
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/include/asm-powerpc/grant_table.h
--- a/xen/include/asm-powerpc/grant_table.h Wed May 30 10:06:23 2007 +0100
+++ b/xen/include/asm-powerpc/grant_table.h Wed May 30 10:45:44 2007 +0100
@@ -35,8 +35,9 @@ extern long pte_remove(ulong flags, ulon
int create_grant_host_mapping(
unsigned long addr, unsigned long frame, unsigned int flags);
-int destroy_grant_host_mapping(
- unsigned long addr, unsigned long frame, unsigned int flags);
+int replace_grant_host_mapping(
+ unsigned long addr, unsigned long frame, unsigned long new_addr,
+ unsigned int flags);
#define gnttab_create_shared_page(d, t, i) \
do { \
@@ -82,4 +83,8 @@ static inline uint cpu_foreign_map_order
#define gnttab_release_put_page_and_type(page) do { } while (0)
#endif
+static inline int replace_grant_supported(void)
+{
+ return 0;
+}
#endif /* __ASM_PPC_GRANT_TABLE_H__ */
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/include/asm-x86/grant_table.h
--- a/xen/include/asm-x86/grant_table.h Wed May 30 10:06:23 2007 +0100
+++ b/xen/include/asm-x86/grant_table.h Wed May 30 10:45:44 2007 +0100
@@ -15,8 +15,8 @@
*/
int create_grant_host_mapping(
uint64_t addr, unsigned long frame, unsigned int flags);
-int destroy_grant_host_mapping(
- uint64_t addr, unsigned long frame, unsigned int flags);
+int replace_grant_host_mapping(
+ uint64_t addr, unsigned long frame, uint64_t new_addr, unsigned int flags);
#define gnttab_create_shared_page(d, t, i) \
do { \
@@ -48,4 +48,9 @@ static inline void gnttab_clear_flag(uns
/* Done implicitly when page tables are destroyed. */ \
} while (0)
+static inline int replace_grant_supported(void)
+{
+ return 1;
+}
+
#endif /* __ASM_GRANT_TABLE_H__ */
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/include/public/grant_table.h
--- a/xen/include/public/grant_table.h Wed May 30 10:06:23 2007 +0100
+++ b/xen/include/public/grant_table.h Wed May 30 10:45:44 2007 +0100
@@ -327,6 +327,29 @@ struct gnttab_query_size {
};
typedef struct gnttab_query_size gnttab_query_size_t;
DEFINE_XEN_GUEST_HANDLE(gnttab_query_size_t);
+
+/*
+ * GNTTABOP_unmap_and_replace: Destroy one or more grant-reference mappings
+ * tracked by <handle> but atomically replace the page table entry with one
+ * pointing to the machine address under <new_addr>. <new_addr> will be
+ * redirected to the null entry.
+ * NOTES:
+ * 1. The call may fail in an undefined manner if either mapping is not
+ * tracked by <handle>.
+ * 2. After executing a batch of unmaps, it is guaranteed that no stale
+ * mappings will remain in the device or host TLBs.
+ */
+#define GNTTABOP_unmap_and_replace 7
+struct gnttab_unmap_and_replace {
+ /* IN parameters. */
+ uint64_t host_addr;
+ uint64_t new_addr;
+ grant_handle_t handle;
+ /* OUT parameters. */
+ int16_t status; /* GNTST_* */
+};
+typedef struct gnttab_unmap_and_replace gnttab_unmap_and_replace_t;
+DEFINE_XEN_GUEST_HANDLE(gnttab_unmap_and_replace_t);
/*
diff -r 152dc0d812b2 -r 1f7a6456c330 xen/include/xlat.lst
--- a/xen/include/xlat.lst Wed May 30 10:06:23 2007 +0100
+++ b/xen/include/xlat.lst Wed May 30 10:45:44 2007 +0100
@@ -26,6 +26,7 @@
! gnttab_setup_table grant_table.h
! gnttab_transfer grant_table.h
? gnttab_unmap_grant_ref grant_table.h
+? gnttab_unmap_and_replace grant_table.h
? grant_entry grant_table.h
? kexec_exec kexec.h
! kexec_image kexec.h
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