@@ -51,6 +51,10 @@ CHECK_gnttab_get_version;
CHECK_gnttab_swap_grant_ref;
#undef xen_gnttab_swap_grant_ref
+#define xen_gnttab_cache_flush gnttab_cache_flush
+CHECK_gnttab_cache_flush;
+#undef xen_gnttab_cache_flush
+
int compat_grant_table_op(unsigned int cmd,
XEN_GUEST_HANDLE_PARAM(void) cmp_uop,
unsigned int count)
@@ -106,6 +110,10 @@ int compat_grant_table_op(unsigned int cmd,
CASE(swap_grant_ref);
#endif
+#ifndef CHECK_gnttab_cache_flush
+ CASE(cache_flush);
+#endif
+
#undef CASE
default:
return do_grant_table_op(cmd, cmp_uop, count);
@@ -483,6 +483,34 @@ static int _set_status(unsigned gt_version,
return _set_status_v2(domid, readonly, mapflag, shah, act, status);
}
+static bool_t grant_map_exists(const struct domain *ld,
+ struct grant_table *rgt,
+ unsigned long mfn)
+{
+ const struct active_grant_entry *act;
+ grant_ref_t ref;
+
+ ASSERT(spin_is_locked(&rgt->lock));
+
+ for ( ref = 0; ref != nr_grant_entries(rgt); ref++ )
+ {
+ act = &active_entry(rgt, ref);
+
+ if ( !act->pin )
+ continue;
+
+ if ( act->domid != ld->domain_id )
+ continue;
+
+ if ( act->frame != mfn )
+ continue;
+
+ return 1;
+ }
+
+ return 0;
+}
+
static void mapcount(
struct grant_table *lgt, struct domain *rd, unsigned long mfn,
unsigned int *wrc, unsigned int *rdc)
@@ -2481,6 +2509,98 @@ gnttab_swap_grant_ref(XEN_GUEST_HANDLE_PARAM(gnttab_swap_grant_ref_t) uop,
return 0;
}
+static int __gnttab_cache_flush(gnttab_cache_flush_t *cflush)
+{
+ struct domain *d, *owner;
+ struct page_info *page;
+ uint64_t mfn;
+ void *v;
+
+ if ( (cflush->offset >= PAGE_SIZE) ||
+ (cflush->length > PAGE_SIZE) ||
+ (cflush->offset + cflush->length > PAGE_SIZE) )
+ return -EINVAL;
+
+ if ( cflush->length == 0 || cflush->op == 0 )
+ return 0;
+
+ /* currently unimplemented */
+ if ( cflush->op & GNTTAB_CACHE_SOURCE_GREF )
+ return -EOPNOTSUPP;
+
+ d = rcu_lock_current_domain();
+ mfn = cflush->a.dev_bus_addr >> PAGE_SHIFT;
+
+ if ( !mfn_valid(mfn) )
+ {
+ rcu_unlock_domain(d);
+ return -EINVAL;
+ }
+
+ page = mfn_to_page(mfn);
+ owner = page_get_owner_and_reference(page);
+ if ( !owner )
+ {
+ rcu_unlock_domain(d);
+ return -EPERM;
+ }
+
+ if ( d != owner )
+ {
+ spin_lock(&owner->grant_table->lock);
+
+ if ( !grant_map_exists(d, owner->grant_table, mfn) )
+ {
+ spin_unlock(&owner->grant_table->lock);
+ rcu_unlock_domain(d);
+ put_page(page);
+ gdprintk(XENLOG_G_ERR, "mfn %"PRIx64" hasn't been granted by d%d to d%d\n",
+ mfn, owner->domain_id, d->domain_id);
+ return -EINVAL;
+ }
+ }
+
+ v = map_domain_page(mfn);
+ v += cflush->offset;
+
+ if ( (cflush->op & GNTTAB_CACHE_INVAL) && (cflush->op & GNTTAB_CACHE_CLEAN) )
+ clean_and_invalidate_dcache_va_range(v, cflush->length);
+ else if ( cflush->op & GNTTAB_CACHE_INVAL )
+ invalidate_dcache_va_range(v, cflush->length);
+ else if ( cflush->op & GNTTAB_CACHE_CLEAN )
+ clean_dcache_va_range(v, cflush->length);
+
+ if ( d != owner )
+ spin_unlock(&owner->grant_table->lock);
+ unmap_domain_page(v);
+ put_page(page);
+
+ return 0;
+}
+
+static long
+gnttab_cache_flush(XEN_GUEST_HANDLE_PARAM(gnttab_cache_flush_t) uop,
+ unsigned int count)
+{
+ int ret;
+ unsigned int i;
+ gnttab_cache_flush_t op;
+
+ for ( i = 0; i < count; i++ )
+ {
+ if ( i && hypercall_preempt_check() )
+ return i;
+ if ( unlikely(__copy_from_guest(&op, uop, 1)) )
+ return -EFAULT;
+ ret = __gnttab_cache_flush(&op);
+ if ( ret < 0 )
+ return ret;
+ guest_handle_add_offset(uop, 1);
+ }
+ return 0;
+}
+
+
long
do_grant_table_op(
unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) uop, unsigned int count)
@@ -2610,6 +2730,20 @@ do_grant_table_op(
}
break;
}
+ case GNTTABOP_cache_flush:
+ {
+ XEN_GUEST_HANDLE_PARAM(gnttab_cache_flush_t) cflush =
+ guest_handle_cast(uop, gnttab_cache_flush_t);
+ if ( unlikely(!guest_handle_okay(cflush, count)) )
+ goto out;
+ rc = gnttab_cache_flush(cflush, count);
+ if ( rc > 0 )
+ {
+ guest_handle_add_offset(cflush, rc);
+ uop = guest_handle_cast(cflush, void);
+ }
+ break;
+ }
default:
rc = -ENOSYS;
break;
@@ -309,6 +309,7 @@ typedef uint16_t grant_status_t;
#define GNTTABOP_get_status_frames 9
#define GNTTABOP_get_version 10
#define GNTTABOP_swap_grant_ref 11
+#define GNTTABOP_cache_flush 12
#endif /* __XEN_INTERFACE_VERSION__ */
/* ` } */
@@ -574,6 +575,25 @@ struct gnttab_swap_grant_ref {
typedef struct gnttab_swap_grant_ref gnttab_swap_grant_ref_t;
DEFINE_XEN_GUEST_HANDLE(gnttab_swap_grant_ref_t);
+/*
+ * Issue one or more cache maintenance operations on a portion of a
+ * page granted to the calling domain by a foreign domain.
+ */
+struct gnttab_cache_flush {
+ union {
+ uint64_t dev_bus_addr;
+ grant_ref_t ref;
+ } a;
+ uint16_t offset; /* offset from start of grant */
+ uint16_t length; /* size within the grant */
+#define GNTTAB_CACHE_CLEAN (1<<0)
+#define GNTTAB_CACHE_INVAL (1<<1)
+#define GNTTAB_CACHE_SOURCE_GREF (1<<31)
+ uint32_t op;
+};
+typedef struct gnttab_cache_flush gnttab_cache_flush_t;
+DEFINE_XEN_GUEST_HANDLE(gnttab_cache_flush_t);
+
#endif /* __XEN_INTERFACE_VERSION__ */
/*
@@ -51,6 +51,7 @@
? grant_entry_header grant_table.h
? grant_entry_v2 grant_table.h
? gnttab_swap_grant_ref grant_table.h
+? gnttab_cache_flush grant_table.h
? kexec_exec kexec.h
! kexec_image kexec.h
! kexec_range kexec.h
Introduce a new hypercall to perform cache maintenance operation on behalf of the guest. The argument is a machine address and a size. The implementation checks that the memory range is owned by the guest or the guest has been granted access to it by another domain. Introduce grant_map_exists: an internal grant table function to check whether an mfn has been granted to a given domain on a target grant table. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> --- Changes in v4: - ASSERT(spin_is_locked); - return instead of break in grant_map_exists; - pass a pointer to __gnttab_cache_flush; - code style; - unsigned int iterator in gnttab_cache_flush; - return ret instead -ret; - cflush.offset >= PAGE_SIZE return -EINVAL. Changes in v3: - reduce the time the grant_table lock is held; - fix warning message; - s/EFAULT/EPERM; - s/llx/PRIx64; - check offset and size independetly before checking their sum; - rcu_lock_current_domain cannot fail; - s/ENOSYS/EOPNOTSUPP; - use clean_and_invalidate_xen_dcache_va_range to do both operations at once; - fold grant_map_exists in this patch; - support "count" argument; - make correspondent changes to compat/grant_table.c; - introduce GNTTAB_CACHE_SOURCE_GREF to select the type of input in the union; - rename size field to length; - make length and offset uint16_t; - only take spin_lock if d != owner. Changes in v2: - do not check for mfn_to_page errors; - take a reference to the page; - replace printk with gdprintk; - split long line; - remove out label; - move rcu_lock_current_domain down before the loop. - move the hypercall to GNTTABOP; - take a spin_lock before calling grant_map_exists. --- xen/common/compat/grant_table.c | 8 +++ xen/common/grant_table.c | 134 ++++++++++++++++++++++++++++++++++++++ xen/include/public/grant_table.h | 20 ++++++ xen/include/xlat.lst | 1 + 4 files changed, 163 insertions(+)