From: Penny Zheng <penny.zh...@arm.com>
This commits introduces a new helper guest_physmap_add_shm to set up shared
memory foreign mapping for borrower domain.
Firstly it should get and take reference of statically shared pages from
owner dom_shared. Then it will setup P2M foreign memory map of these statically
shared pages for borrower domain.
This commits only considers owner domain is the default dom_shared, the
other scenario will be covered in the following patches.
Signed-off-by: Penny Zheng <penny.zh...@arm.com>
---
xen/arch/arm/domain_build.c | 52 +++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 984e70e5fc..8cee5ffbd1 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -798,6 +798,48 @@ static int __init allocate_shared_memory(struct domain *d,
return ret;
}
+static int __init guest_physmap_add_shm(struct domain *od, struct domain *bd,
+ unsigned long o_gfn,
+ unsigned long b_gfn,
+ unsigned long nr_gfns)
+{
+ struct page_info **pages = NULL;
+ p2m_type_t p2mt, t;
+ int ret = 0;
+
+ pages = xmalloc_array(struct page_info *, nr_gfns);
+ if ( !pages )
+ return -ENOMEM;
+
+ /*
+ * Take reference of statically shared pages from owner domain.
+ * Reference will be released when destroying shared memory region.
+ */
+ ret = get_pages_from_gfn(od, o_gfn, nr_gfns, pages, &p2mt, P2M_ALLOC);
+ if ( ret )
+ {
+ ret = -EINVAL;
+ goto fail_pages;
+ }
+
+ if ( p2m_is_ram(p2mt) )
+ t = (p2mt == p2m_ram_rw) ? p2m_map_foreign_rw : p2m_map_foreign_ro;
+ else
+ {
+ ret = -EINVAL;
+ goto fail_pages;
+ }
+
+ /* Set up guest foreign map. */
+ ret = guest_physmap_add_pages(bd, _gfn(b_gfn), page_to_mfn(pages[0]),
+ nr_gfns, t);
+
+ fail_pages:
+ xfree(pages);
+
+ return ret;
+}
+
static int __init process_shm(struct domain *d,
const struct dt_device_node *node)
{
@@ -855,6 +897,16 @@ static int __init process_shm(struct domain *d,
set_bit(shm_id, shm_mask);
}
+
+ /*
+ * All domains are borrower domains when owner domain is the
+ * default dom_shared, so here we could just set up P2M foreign
+ * mapping for borrower domain immediately.
+ */
+ ret = guest_physmap_add_shm(dom_shared, d, PFN_DOWN(pbase),
+ PFN_DOWN(gbase), PFN_DOWN(psize));
+ if ( ret )
+ return ret;
}
return 0;
--
2.25.1
