Mailing List Archive

Previous commits enable the toolstack to get the domain memory map,
therefore instead of hardcoding the guest magic pages region, use
the XEN_DOMCTL_get_mem_map domctl to get the start address of the
guest magic pages region. Add the (XEN)MEMF_force_heap_alloc memory
flags to force populate_physmap() to allocate page from domheap
instead of using 1:1 or static allocated pages to map the magic pages.

Reported-by: Alec Kwapis <alec.kwapis@medtronic.com>
Signed-off-by: Henry Wang <xin.wang2@amd.com>
---
v2:
- New patch
---
tools/helpers/init-dom0less.c | 22 ++++++++++++++++++----
xen/common/memory.c | 10 ++++++++--
xen/include/public/memory.h | 5 +++++
xen/include/xen/mm.h | 2 ++
4 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/tools/helpers/init-dom0less.c b/tools/helpers/init-dom0less.c
index fee93459c4..92c612f6da 100644
--- a/tools/helpers/init-dom0less.c
+++ b/tools/helpers/init-dom0less.c
@@ -23,16 +23,30 @@ static int alloc_xs_page(struct xc_interface_core *xch,
libxl_dominfo *info,
uint64_t *xenstore_pfn)
{
- int rc;
- const xen_pfn_t base = GUEST_MAGIC_BASE >> XC_PAGE_SHIFT;
- xen_pfn_t p2m = (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET;
+ int rc, i;
+ xen_pfn_t base = ((xen_pfn_t)-1);
+ xen_pfn_t p2m = ((xen_pfn_t)-1);
+ uint32_t nr_regions = XEN_MAX_MEM_REGIONS;
+ struct xen_mem_region mem_regions[XEN_MAX_MEM_REGIONS] = {0};
+
+ rc = xc_get_domain_mem_map(xch, info->domid, mem_regions, &nr_regions);
+
+ for ( i = 0; i < nr_regions; i++ )
+ {
+ if ( mem_regions[i].type == GUEST_MEM_REGION_MAGIC )
+ {
+ base = mem_regions[i].start >> XC_PAGE_SHIFT;
+ p2m = (mem_regions[i].start >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET;
+ }
+ }

rc = xc_domain_setmaxmem(xch, info->domid,
info->max_memkb + (XC_PAGE_SIZE/1024));
if (rc < 0)
return rc;

- rc = xc_domain_populate_physmap_exact(xch, info->domid, 1, 0, 0, &p2m);
+ rc = xc_domain_populate_physmap_exact(xch, info->domid, 1, 0,
+ XENMEMF_force_heap_alloc, &p2m);
if (rc < 0)
return rc;

diff --git a/xen/common/memory.c b/xen/common/memory.c
index b3b05c2ec0..18b6c16aed 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -219,7 +219,8 @@ static void populate_physmap(struct memop_args *a)
}
else
{
- if ( is_domain_direct_mapped(d) )
+ if ( is_domain_direct_mapped(d) &&
+ !(a->memflags & MEMF_force_heap_alloc) )
{
mfn = _mfn(gpfn);

@@ -246,7 +247,8 @@ static void populate_physmap(struct memop_args *a)

mfn = _mfn(gpfn);
}
- else if ( is_domain_using_staticmem(d) )
+ else if ( is_domain_using_staticmem(d) &&
+ !(a->memflags & MEMF_force_heap_alloc) )
{
/*
* No easy way to guarantee the retrieved pages are contiguous,
@@ -1433,6 +1435,10 @@ long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
&& (reservation.mem_flags & XENMEMF_populate_on_demand) )
args.memflags |= MEMF_populate_on_demand;

+ if ( op == XENMEM_populate_physmap
+ && (reservation.mem_flags & XENMEMF_force_heap_alloc) )
+ args.memflags |= MEMF_force_heap_alloc;
+
if ( xsm_memory_adjust_reservation(XSM_TARGET, curr_d, d) )
{
rcu_unlock_domain(d);
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 5e545ae9a4..2a1bfa5bfa 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -41,6 +41,11 @@
#define XENMEMF_exact_node(n) (XENMEMF_node(n) | XENMEMF_exact_node_request)
/* Flag to indicate the node specified is virtual node */
#define XENMEMF_vnode (1<<18)
+/*
+ * Flag to force populate physmap to use pages from domheap instead of 1:1
+ * or static allocation.
+ */
+#define XENMEMF_force_heap_alloc (1<<19)
#endif

struct xen_memory_reservation {
diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index bb29b352ec..a4554f730d 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -205,6 +205,8 @@ struct npfec {
#define MEMF_no_icache_flush (1U<<_MEMF_no_icache_flush)
#define _MEMF_no_scrub 8
#define MEMF_no_scrub (1U<<_MEMF_no_scrub)
+#define _MEMF_force_heap_alloc 9
+#define MEMF_force_heap_alloc (1U<<_MEMF_force_heap_alloc)
#define _MEMF_node 16
#define MEMF_node_mask ((1U << (8 * sizeof(nodeid_t))) - 1)
#define MEMF_node(n) ((((n) + 1) & MEMF_node_mask) << _MEMF_node)
--
2.34.1