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authorLinus Torvalds <torvalds@linux-foundation.org>2021-03-04 11:24:47 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-03-04 11:24:47 -0800
commitc5a58f877ca645a3303f7a57476f2de837fdb97a (patch)
treed2dccb46b1e676027ebeade1891f30313e7b2305
parent43df5242af4ed67e8811257ab1bfe6a07e4a5858 (diff)
parent882213990d32fd224340a4533f6318dd152be4b2 (diff)
downloadlinux-stericsson-c5a58f877ca645a3303f7a57476f2de837fdb97a.tar.gz
Merge tag 'for-linus-5.12b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross: "Two security issues (XSA-367 and XSA-369)" * tag 'for-linus-5.12b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: fix p2m size in dom0 for disabled memory hotplug case xen-netback: respect gnttab_map_refs()'s return value Xen/gnttab: handle p2m update errors on a per-slot basis
-rw-r--r--arch/arm/xen/p2m.c35
-rw-r--r--arch/x86/include/asm/xen/page.h12
-rw-r--r--arch/x86/xen/p2m.c54
-rw-r--r--arch/x86/xen/setup.c25
-rw-r--r--drivers/net/xen-netback/netback.c12
5 files changed, 104 insertions, 34 deletions
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
index fd6e3aafe272..acb464547a54 100644
--- a/arch/arm/xen/p2m.c
+++ b/arch/arm/xen/p2m.c
@@ -93,12 +93,39 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
int i;
for (i = 0; i < count; i++) {
+ struct gnttab_unmap_grant_ref unmap;
+ int rc;
+
if (map_ops[i].status)
continue;
- if (unlikely(!set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
- map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) {
- return -ENOMEM;
- }
+ if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
+ map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT)))
+ continue;
+
+ /*
+ * Signal an error for this slot. This in turn requires
+ * immediate unmapping.
+ */
+ map_ops[i].status = GNTST_general_error;
+ unmap.host_addr = map_ops[i].host_addr,
+ unmap.handle = map_ops[i].handle;
+ map_ops[i].handle = ~0;
+ if (map_ops[i].flags & GNTMAP_device_map)
+ unmap.dev_bus_addr = map_ops[i].dev_bus_addr;
+ else
+ unmap.dev_bus_addr = 0;
+
+ /*
+ * Pre-populate the status field, to be recognizable in
+ * the log message below.
+ */
+ unmap.status = 1;
+
+ rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+ &unmap, 1);
+ if (rc || unmap.status != GNTST_okay)
+ pr_err_once("gnttab unmap failed: rc=%d st=%d\n",
+ rc, unmap.status);
}
return 0;
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 1a162e559753..7068e4bb057d 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -87,6 +87,18 @@ clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
#endif
/*
+ * The maximum amount of extra memory compared to the base size. The
+ * main scaling factor is the size of struct page. At extreme ratios
+ * of base:extra, all the base memory can be filled with page
+ * structures for the extra memory, leaving no space for anything
+ * else.
+ *
+ * 10x seems like a reasonable balance between scaling flexibility and
+ * leaving a practically usable system.
+ */
+#define XEN_EXTRA_MEM_RATIO (10)
+
+/*
* Helper functions to write or read unsigned long values to/from
* memory, when the access may fault.
*/
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index b5949e5a83ec..a3cc33091f46 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -416,6 +416,9 @@ void __init xen_vmalloc_p2m_tree(void)
xen_p2m_last_pfn = xen_max_p2m_pfn;
p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE;
+ if (!p2m_limit && IS_ENABLED(CONFIG_XEN_UNPOPULATED_ALLOC))
+ p2m_limit = xen_start_info->nr_pages * XEN_EXTRA_MEM_RATIO;
+
vm.flags = VM_ALLOC;
vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit),
PMD_SIZE * PMDS_PER_MID_PAGE);
@@ -652,10 +655,9 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
pte_t *ptep;
unsigned int level;
- if (unlikely(pfn >= xen_p2m_size)) {
- BUG_ON(mfn != INVALID_P2M_ENTRY);
- return true;
- }
+ /* Only invalid entries allowed above the highest p2m covered frame. */
+ if (unlikely(pfn >= xen_p2m_size))
+ return mfn == INVALID_P2M_ENTRY;
/*
* The interface requires atomic updates on p2m elements.
@@ -710,6 +712,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
for (i = 0; i < count; i++) {
unsigned long mfn, pfn;
+ struct gnttab_unmap_grant_ref unmap[2];
+ int rc;
/* Do not add to override if the map failed. */
if (map_ops[i].status != GNTST_okay ||
@@ -727,10 +731,46 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
WARN(pfn_to_mfn(pfn) != INVALID_P2M_ENTRY, "page must be ballooned");
- if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
- ret = -ENOMEM;
- goto out;
+ if (likely(set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
+ continue;
+
+ /*
+ * Signal an error for this slot. This in turn requires
+ * immediate unmapping.
+ */
+ map_ops[i].status = GNTST_general_error;
+ unmap[0].host_addr = map_ops[i].host_addr,
+ unmap[0].handle = map_ops[i].handle;
+ map_ops[i].handle = ~0;
+ if (map_ops[i].flags & GNTMAP_device_map)
+ unmap[0].dev_bus_addr = map_ops[i].dev_bus_addr;
+ else
+ unmap[0].dev_bus_addr = 0;
+
+ if (kmap_ops) {
+ kmap_ops[i].status = GNTST_general_error;
+ unmap[1].host_addr = kmap_ops[i].host_addr,
+ unmap[1].handle = kmap_ops[i].handle;
+ kmap_ops[i].handle = ~0;
+ if (kmap_ops[i].flags & GNTMAP_device_map)
+ unmap[1].dev_bus_addr = kmap_ops[i].dev_bus_addr;
+ else
+ unmap[1].dev_bus_addr = 0;
}
+
+ /*
+ * Pre-populate both status fields, to be recognizable in
+ * the log message below.
+ */
+ unmap[0].status = 1;
+ unmap[1].status = 1;
+
+ rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+ unmap, 1 + !!kmap_ops);
+ if (rc || unmap[0].status != GNTST_okay ||
+ unmap[1].status != GNTST_okay)
+ pr_err_once("gnttab unmap failed: rc=%d st0=%d st1=%d\n",
+ rc, unmap[0].status, unmap[1].status);
}
out:
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 7eab14d56369..1a3b75652fa4 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -59,18 +59,6 @@ static struct {
} xen_remap_buf __initdata __aligned(PAGE_SIZE);
static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
-/*
- * The maximum amount of extra memory compared to the base size. The
- * main scaling factor is the size of struct page. At extreme ratios
- * of base:extra, all the base memory can be filled with page
- * structures for the extra memory, leaving no space for anything
- * else.
- *
- * 10x seems like a reasonable balance between scaling flexibility and
- * leaving a practically usable system.
- */
-#define EXTRA_MEM_RATIO (10)
-
static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
static void __init xen_parse_512gb(void)
@@ -790,20 +778,13 @@ char * __init xen_memory_setup(void)
extra_pages += max_pages - max_pfn;
/*
- * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
- * factor the base size. On non-highmem systems, the base
- * size is the full initial memory allocation; on highmem it
- * is limited to the max size of lowmem, so that it doesn't
- * get completely filled.
+ * Clamp the amount of extra memory to a XEN_EXTRA_MEM_RATIO
+ * factor the base size.
*
* Make sure we have no memory above max_pages, as this area
* isn't handled by the p2m management.
- *
- * In principle there could be a problem in lowmem systems if
- * the initial memory is also very large with respect to
- * lowmem, but we won't try to deal with that here.
*/
- extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
+ extra_pages = min3(XEN_EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
extra_pages, max_pages - max_pfn);
i = 0;
addr = xen_e820_table.entries[0].addr;
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index e5c73f819662..6afb5ca999c2 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1343,11 +1343,21 @@ int xenvif_tx_action(struct xenvif_queue *queue, int budget)
return 0;
gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
- if (nr_mops != 0)
+ if (nr_mops != 0) {
ret = gnttab_map_refs(queue->tx_map_ops,
NULL,
queue->pages_to_map,
nr_mops);
+ if (ret) {
+ unsigned int i;
+
+ netdev_err(queue->vif->dev, "Map fail: nr %u ret %d\n",
+ nr_mops, ret);
+ for (i = 0; i < nr_mops; ++i)
+ WARN_ON_ONCE(queue->tx_map_ops[i].status ==
+ GNTST_okay);
+ }
+ }
work_done = xenvif_tx_submit(queue);