summaryrefslogtreecommitdiff
path: root/drivers/xen
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-02 23:20:11 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-02 23:20:11 +0300
commit9ae5fceb9a20154d74586fe17d1096b981b23e34 (patch)
treef11664ab46a7b6b4b9c07f41f5b509500705d1c8 /drivers/xen
parenta2d616b935a0df24bc9375785b19bf30d7fc9c6a (diff)
parent58e636039b512697554b579c2bb23774061877f5 (diff)
downloadlinux-9ae5fceb9a20154d74586fe17d1096b981b23e34.tar.xz
Merge tag 'for-linus-5.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross: - some small cleanups - a fix for a bug when running as Xen PV guest which could result in not all memory being transferred in case of a migration of the guest - a small series for getting rid of code for supporting very old Xen hypervisor versions nobody should be using since many years now - a series for hardening the Xen block frontend driver - a fix for Xen PV boot code issuing warning messages due to a stray preempt_disable() on the non-boot processors * tag 'for-linus-5.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: remove stray preempt_disable() from PV AP startup code xen/pcifront: Removed unnecessary __ref annotation x86: xen: platform-pci-unplug: use pr_err() and pr_warn() instead of raw printk() drivers/xen/xenbus/xenbus_client.c: fix bugon.cocci warnings xen/blkfront: don't trust the backend response data blindly xen/blkfront: don't take local copy of a request from the ring page xen/blkfront: read response from backend only once xen: assume XENFEAT_gnttab_map_avail_bits being set for pv guests xen: assume XENFEAT_mmu_pt_update_preserve_ad being set for pv guests xen: check required Xen features xen: fix setting of max_pfn in shared_info
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/features.c18
-rw-r--r--drivers/xen/gntdev.c36
-rw-r--r--drivers/xen/xenbus/xenbus_client.c9
3 files changed, 23 insertions, 40 deletions
diff --git a/drivers/xen/features.c b/drivers/xen/features.c
index 25c053b09605..7b591443833c 100644
--- a/drivers/xen/features.c
+++ b/drivers/xen/features.c
@@ -9,13 +9,26 @@
#include <linux/types.h>
#include <linux/cache.h>
#include <linux/export.h>
+#include <linux/printk.h>
#include <asm/xen/hypercall.h>
+#include <xen/xen.h>
#include <xen/interface/xen.h>
#include <xen/interface/version.h>
#include <xen/features.h>
+/*
+ * Linux kernel expects at least Xen 4.0.
+ *
+ * Assume some features to be available for that reason (depending on guest
+ * mode, of course).
+ */
+#define chk_required_feature(f) { \
+ if (!xen_feature(f)) \
+ panic("Xen: feature %s not available!\n", #f); \
+ }
+
u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly;
EXPORT_SYMBOL_GPL(xen_features);
@@ -31,4 +44,9 @@ void xen_setup_features(void)
for (j = 0; j < 32; j++)
xen_features[i * 32 + j] = !!(fi.submap & 1<<j);
}
+
+ if (xen_pv_domain()) {
+ chk_required_feature(XENFEAT_mmu_pt_update_preserve_ad);
+ chk_required_feature(XENFEAT_gnttab_map_avail_bits);
+ }
}
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index a3e7be96527d..1e7f6b1c0c97 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -266,20 +266,13 @@ static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data)
{
struct gntdev_grant_map *map = data;
unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
- int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
+ int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte |
+ (1 << _GNTMAP_guest_avail0);
u64 pte_maddr;
BUG_ON(pgnr >= map->count);
pte_maddr = arbitrary_virt_to_machine(pte).maddr;
- /*
- * Set the PTE as special to force get_user_pages_fast() fall
- * back to the slow path. If this is not supported as part of
- * the grant map, it will be done afterwards.
- */
- if (xen_feature(XENFEAT_gnttab_map_avail_bits))
- flags |= (1 << _GNTMAP_guest_avail0);
-
gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
map->grants[pgnr].ref,
map->grants[pgnr].domid);
@@ -288,14 +281,6 @@ static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data)
return 0;
}
-#ifdef CONFIG_X86
-static int set_grant_ptes_as_special(pte_t *pte, unsigned long addr, void *data)
-{
- set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte));
- return 0;
-}
-#endif
-
int gntdev_map_grant_pages(struct gntdev_grant_map *map)
{
int i, err = 0;
@@ -1055,23 +1040,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
err = vm_map_pages_zero(vma, map->pages, map->count);
if (err)
goto out_put_map;
- } else {
-#ifdef CONFIG_X86
- /*
- * If the PTEs were not made special by the grant map
- * hypercall, do so here.
- *
- * This is racy since the mapping is already visible
- * to userspace but userspace should be well-behaved
- * enough to not touch it until the mmap() call
- * returns.
- */
- if (!xen_feature(XENFEAT_gnttab_map_avail_bits)) {
- apply_to_page_range(vma->vm_mm, vma->vm_start,
- vma->vm_end - vma->vm_start,
- set_grant_ptes_as_special, NULL);
- }
-#endif
}
return 0;
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 0cd728961fce..e8bed1cb76ba 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -542,8 +542,7 @@ static int __xenbus_map_ring(struct xenbus_device *dev,
}
}
- if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, info->unmap, j))
- BUG();
+ BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, info->unmap, j));
*leaked = false;
for (i = 0; i < j; i++) {
@@ -581,8 +580,7 @@ static int xenbus_unmap_ring(struct xenbus_device *dev, grant_handle_t *handles,
gnttab_set_unmap_op(&unmap[i], vaddrs[i],
GNTMAP_host_map, handles[i]);
- if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
- BUG();
+ BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i));
err = GNTST_okay;
for (i = 0; i < nr_handles; i++) {
@@ -778,8 +776,7 @@ static int xenbus_unmap_ring_pv(struct xenbus_device *dev, void *vaddr)
unmap[i].handle = node->handles[i];
}
- if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
- BUG();
+ BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i));
err = GNTST_okay;
leaked = false;