Currently the GUEST_MAGIC_BASE in the init-dom0less application is
hardcoded, which will lead to failures for 1:1 direct-mapped Dom0less
DomUs.
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 a new sub-op XENMEM_populate_physmap_heap_alloc
and the MEMF_force_heap_alloc flag 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.kwa...@medtronic.com>
Signed-off-by: Henry Wang <xin.wa...@amd.com>
---
v4:
- Use the new subop.
- Add assert to check the flag isn't already set when coming back from
construct_memop_from_reservation().
- Use &= to clear the flag instead of clear_bit().
- Move the alias to xen/common/memory.c
v3:
- Don't ignore the error from xc_get_domain_mem_map().
- Re-purposing the _MEMF_no_refcount as _MEMF_force_heap_alloc to
avoid introduction of a new, single-use flag.
- Reject other reservation sub-ops to use the newly added flag.
- Replace all the GUEST_MAGIC_BASE usages.
v2:
- New patch
---
tools/helpers/init-dom0less.c | 35 +++++++++++-----
tools/include/xenctrl.h | 7 ++++
tools/libs/ctrl/xc_domain.c | 79 ++++++++++++++++++++++++++---------
xen/common/memory.c | 30 +++++++++++--
xen/include/public/memory.h | 3 +-
5 files changed, 120 insertions(+), 34 deletions(-)
diff --git a/tools/helpers/init-dom0less.c b/tools/helpers/init-dom0less.c
index fee93459c4..dccab7b29b 100644
--- a/tools/helpers/init-dom0less.c
+++ b/tools/helpers/init-dom0less.c
@@ -19,24 +19,42 @@
#define XENSTORE_PFN_OFFSET 1
#define STR_MAX_LENGTH 128
+static xen_pfn_t xs_page_base;
+static xen_pfn_t xs_page_p2m;
+
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;
+ 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);
+ if (rc < 0)
+ return rc;
+
+ for ( i = 0; i < nr_regions; i++ )
+ {
+ if ( mem_regions[i].type == XEN_MEM_REGION_MAGIC )
+ {
+ xs_page_base = mem_regions[i].start >> XC_PAGE_SHIFT;
+ xs_page_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_heap_exact(xch, info->domid, 1, 0, 0,
+ &xs_page_p2m);
if (rc < 0)
return rc;
- *xenstore_pfn = base + XENSTORE_PFN_OFFSET;
+ *xenstore_pfn = xs_page_base + XENSTORE_PFN_OFFSET;
rc = xc_clear_domain_page(xch, info->domid, *xenstore_pfn);
if (rc < 0)
return rc;
@@ -145,8 +163,7 @@ static int create_xenstore(struct xs_handle *xsh,
rc = snprintf(target_memkb_str, STR_MAX_LENGTH, "%"PRIu64,
info->current_memkb);
if (rc < 0 || rc >= STR_MAX_LENGTH)
return rc;
- rc = snprintf(ring_ref_str, STR_MAX_LENGTH, "%lld",
- (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET);
+ rc = snprintf(ring_ref_str, STR_MAX_LENGTH, "%"PRIu_xen_pfn, xs_page_p2m);
if (rc < 0 || rc >= STR_MAX_LENGTH)
return rc;
rc = snprintf(xenstore_port_str, STR_MAX_LENGTH, "%u", xenstore_port);
@@ -282,9 +299,7 @@ static int init_domain(struct xs_handle *xsh,
if (rc)
err(1, "writing to xenstore");
- rc = xs_introduce_domain(xsh, info->domid,
- (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET,
- xenstore_evtchn);
+ rc = xs_introduce_domain(xsh, info->domid, xs_page_p2m, xenstore_evtchn);
if (!rc)
err(1, "xs_introduce_domain");
return 0;
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index b25e9772a2..c1a601813a 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -1342,6 +1342,13 @@ int xc_domain_populate_physmap(xc_interface *xch,
unsigned int mem_flags,
xen_pfn_t *extent_start);
+int xc_domain_populate_physmap_heap_exact(xc_interface *xch,
+ uint32_t domid,
+ unsigned long nr_extents,
+ unsigned int extent_order,
+ unsigned int mem_flags,
+ xen_pfn_t *extent_start);
+
int xc_domain_populate_physmap_exact(xc_interface *xch,
uint32_t domid,
unsigned long nr_extents,
diff --git a/tools/libs/ctrl/xc_domain.c b/tools/libs/ctrl/xc_domain.c
index 4dba55d01d..82c1554613 100644
--- a/tools/libs/ctrl/xc_domain.c
+++ b/tools/libs/ctrl/xc_domain.c
@@ -916,6 +916,36 @@ int xc_domain_nr_gpfns(xc_interface *xch, uint32_t domid,
xen_pfn_t *gpfns)
return rc;
}
+static int xc_populate_physmap_cmd(xc_interface *xch,
+ unsigned int cmd,
+ uint32_t domid,
+ unsigned long nr_extents,
+ unsigned int extent_order,
+ unsigned int mem_flags,
+ xen_pfn_t *extent_start)
+{
+ int err;
+ DECLARE_HYPERCALL_BOUNCE(extent_start, nr_extents * sizeof(*extent_start),
XC_HYPERCALL_BUFFER_BOUNCE_BOTH);
+ struct xen_memory_reservation reservation = {
+ .nr_extents = nr_extents,
+ .extent_order = extent_order,
+ .mem_flags = mem_flags,
+ .domid = domid
+ };
+
+ if ( xc_hypercall_bounce_pre(xch, extent_start) )
+ {
+ PERROR("Could not bounce memory for XENMEM_populate_physmap
hypercall");
+ return -1;
+ }
+ set_xen_guest_handle(reservation.extent_start, extent_start);
+
+ err = xc_memory_op(xch, cmd, &reservation, sizeof(reservation));
+
+ xc_hypercall_bounce_post(xch, extent_start);
+ return err;
+}
+
int xc_domain_increase_reservation(xc_interface *xch,
uint32_t domid,
unsigned long nr_extents,
@@ -1135,26 +1165,9 @@ int xc_domain_populate_physmap(xc_interface *xch,
unsigned int mem_flags,
xen_pfn_t *extent_start)
{
- int err;
- DECLARE_HYPERCALL_BOUNCE(extent_start, nr_extents * sizeof(*extent_start),
XC_HYPERCALL_BUFFER_BOUNCE_BOTH);
- struct xen_memory_reservation reservation = {
- .nr_extents = nr_extents,
- .extent_order = extent_order,
- .mem_flags = mem_flags,
- .domid = domid
- };
-
- if ( xc_hypercall_bounce_pre(xch, extent_start) )
- {
- PERROR("Could not bounce memory for XENMEM_populate_physmap
hypercall");
- return -1;
- }
- set_xen_guest_handle(reservation.extent_start, extent_start);
-
- err = xc_memory_op(xch, XENMEM_populate_physmap, &reservation,
sizeof(reservation));
-
- xc_hypercall_bounce_post(xch, extent_start);
- return err;
+ return xc_populate_physmap_cmd(xch, XENMEM_populate_physmap, domid,
+ nr_extents, extent_order, mem_flags,
+ extent_start);
}
int xc_domain_populate_physmap_exact(xc_interface *xch,
@@ -1182,6 +1195,32 @@ int xc_domain_populate_physmap_exact(xc_interface *xch,
return err;
}
+int xc_domain_populate_physmap_heap_exact(xc_interface *xch,
+ uint32_t domid,
+ unsigned long nr_extents,
+ unsigned int extent_order,
+ unsigned int mem_flags,
+ xen_pfn_t *extent_start)
+{
+ int err;
+
+ err = xc_populate_physmap_cmd(xch, XENMEM_populate_physmap_heap_alloc,
+ domid, nr_extents, extent_order, mem_flags,
+ extent_start);
+ if ( err == nr_extents )
+ return 0;
+
+ if ( err >= 0 )
+ {
+ DPRINTF("Failed allocation for dom %d: %ld extents of order %d\n",
+ domid, nr_extents, extent_order);
+ errno = EBUSY;
+ err = -1;
+ }
+
+ return err;
+}
+
int xc_domain_memory_exchange_pages(xc_interface *xch,
uint32_t domid,
unsigned long nr_in_extents,
diff --git a/xen/common/memory.c b/xen/common/memory.c
index b4593f5f45..a4733869c2 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -155,6 +155,14 @@ static void increase_reservation(struct memop_args *a)
a->nr_done = i;
}
+/*
+ * Alias of _MEMF_no_refcount to avoid introduction of a new, single-use flag.
+ * This flag should be used for populate_physmap() only as a re-purposing of
+ * _MEMF_no_refcount to force a non-1:1 allocation from domheap.
+ */
+#define _MEMF_force_heap_alloc _MEMF_no_refcount
+#define MEMF_force_heap_alloc (1U<<_MEMF_force_heap_alloc)
+
static void populate_physmap(struct memop_args *a)
{
struct page_info *page;
@@ -219,7 +227,8 @@ 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 +255,8 @@ 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,
@@ -271,6 +281,14 @@ static void populate_physmap(struct memop_args *a)
}
else
{
+ /*
+ * Avoid passing MEMF_force_heap_alloc down to
+ * alloc_domheap_pages() where the meaning would be the
+ * original MEMF_no_refcount.
+ */
+ if ( unlikely(a->memflags & MEMF_force_heap_alloc) )
+ a->memflags &= ~MEMF_force_heap_alloc;
+
page = alloc_domheap_pages(d, a->extent_order, a->memflags);
if ( unlikely(!page) )
@@ -1404,6 +1422,7 @@ long do_memory_op(unsigned long cmd,
XEN_GUEST_HANDLE_PARAM(void) arg)
{
case XENMEM_increase_reservation:
case XENMEM_decrease_reservation:
+ case XENMEM_populate_physmap_heap_alloc:
case XENMEM_populate_physmap:
if ( copy_from_guest(&reservation, arg, 1) )
return start_extent;
@@ -1433,6 +1452,11 @@ 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;
+ /* Assert flag is not set from construct_memop_from_reservation(). */
+ ASSERT(!(args.memflags & MEMF_force_heap_alloc));
+ if ( op == XENMEM_populate_physmap_heap_alloc )
+ args.memflags |= MEMF_force_heap_alloc;
+
if ( xsm_memory_adjust_reservation(XSM_TARGET, curr_d, d) )
{
rcu_unlock_domain(d);
@@ -1453,7 +1477,7 @@ long do_memory_op(unsigned long cmd,
XEN_GUEST_HANDLE_PARAM(void) arg)
case XENMEM_decrease_reservation:
decrease_reservation(&args);
break;
- default: /* XENMEM_populate_physmap */
+ default: /* XENMEM_populate_{physmap, physmap_heap_alloc} */
populate_physmap(&args);
break;
}
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 5e545ae9a4..5e79992671 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -21,6 +21,7 @@
#define XENMEM_increase_reservation 0
#define XENMEM_decrease_reservation 1
#define XENMEM_populate_physmap 6
+#define XENMEM_populate_physmap_heap_alloc 29
#if __XEN_INTERFACE_VERSION__ >= 0x00030209
/*
@@ -731,7 +732,7 @@ struct xen_vnuma_topology_info {
typedef struct xen_vnuma_topology_info xen_vnuma_topology_info_t;
DEFINE_XEN_GUEST_HANDLE(xen_vnuma_topology_info_t);
-/* Next available subop number is 29 */
+/* Next available subop number is 30 */
#endif /* __XEN_PUBLIC_MEMORY_H__ */
--
2.34.1
