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-rw-r--r--system/xen/xsa/xsa246-4.9.patch74
-rw-r--r--system/xen/xsa/xsa247-4.9-0001-p2m-Always-check-to-see-if-removing-a-p2m-entry-actu.patch176
-rw-r--r--system/xen/xsa/xsa247-4.9-0002-p2m-Check-return-value-of-p2m_set_entry-when-decreas.patch109
-rw-r--r--system/xen/xsa/xsa248.patch164
-rw-r--r--system/xen/xsa/xsa249.patch42
-rw-r--r--system/xen/xsa/xsa250.patch67
-rw-r--r--system/xen/xsa/xsa251.patch21
7 files changed, 653 insertions, 0 deletions
diff --git a/system/xen/xsa/xsa246-4.9.patch b/system/xen/xsa/xsa246-4.9.patch
new file mode 100644
index 0000000000..6370a10625
--- /dev/null
+++ b/system/xen/xsa/xsa246-4.9.patch
@@ -0,0 +1,74 @@
+From: Julien Grall <julien.grall@linaro.org>
+Subject: x86/pod: prevent infinite loop when shattering large pages
+
+When populating pages, the PoD may need to split large ones using
+p2m_set_entry and request the caller to retry (see ept_get_entry for
+instance).
+
+p2m_set_entry may fail to shatter if it is not possible to allocate
+memory for the new page table. However, the error is not propagated
+resulting to the callers to retry infinitely the PoD.
+
+Prevent the infinite loop by return false when it is not possible to
+shatter the large mapping.
+
+This is XSA-246.
+
+Signed-off-by: Julien Grall <julien.grall@linaro.org>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: George Dunlap <george.dunlap@citrix.com>
+
+--- a/xen/arch/x86/mm/p2m-pod.c
++++ b/xen/arch/x86/mm/p2m-pod.c
+@@ -1071,9 +1071,8 @@ p2m_pod_demand_populate(struct p2m_domai
+ * NOTE: In a fine-grained p2m locking scenario this operation
+ * may need to promote its locking from gfn->1g superpage
+ */
+- p2m_set_entry(p2m, gfn_aligned, INVALID_MFN, PAGE_ORDER_2M,
+- p2m_populate_on_demand, p2m->default_access);
+- return 0;
++ return p2m_set_entry(p2m, gfn_aligned, INVALID_MFN, PAGE_ORDER_2M,
++ p2m_populate_on_demand, p2m->default_access);
+ }
+
+ /* Only reclaim if we're in actual need of more cache. */
+@@ -1104,8 +1103,12 @@ p2m_pod_demand_populate(struct p2m_domai
+
+ gfn_aligned = (gfn >> order) << order;
+
+- p2m_set_entry(p2m, gfn_aligned, mfn, order, p2m_ram_rw,
+- p2m->default_access);
++ if ( p2m_set_entry(p2m, gfn_aligned, mfn, order, p2m_ram_rw,
++ p2m->default_access) )
++ {
++ p2m_pod_cache_add(p2m, p, order);
++ goto out_fail;
++ }
+
+ for( i = 0; i < (1UL << order); i++ )
+ {
+@@ -1150,13 +1153,18 @@ remap_and_retry:
+ BUG_ON(order != PAGE_ORDER_2M);
+ pod_unlock(p2m);
+
+- /* Remap this 2-meg region in singleton chunks */
+- /* NOTE: In a p2m fine-grained lock scenario this might
+- * need promoting the gfn lock from gfn->2M superpage */
++ /*
++ * Remap this 2-meg region in singleton chunks. See the comment on the
++ * 1G page splitting path above for why a single call suffices.
++ *
++ * NOTE: In a p2m fine-grained lock scenario this might
++ * need promoting the gfn lock from gfn->2M superpage.
++ */
+ gfn_aligned = (gfn>>order)<<order;
+- for(i=0; i<(1<<order); i++)
+- p2m_set_entry(p2m, gfn_aligned + i, INVALID_MFN, PAGE_ORDER_4K,
+- p2m_populate_on_demand, p2m->default_access);
++ if ( p2m_set_entry(p2m, gfn_aligned, INVALID_MFN, PAGE_ORDER_4K,
++ p2m_populate_on_demand, p2m->default_access) )
++ return -1;
++
+ if ( tb_init_done )
+ {
+ struct {
diff --git a/system/xen/xsa/xsa247-4.9-0001-p2m-Always-check-to-see-if-removing-a-p2m-entry-actu.patch b/system/xen/xsa/xsa247-4.9-0001-p2m-Always-check-to-see-if-removing-a-p2m-entry-actu.patch
new file mode 100644
index 0000000000..ad9524a304
--- /dev/null
+++ b/system/xen/xsa/xsa247-4.9-0001-p2m-Always-check-to-see-if-removing-a-p2m-entry-actu.patch
@@ -0,0 +1,176 @@
+From ad208b8b7e45fb2b7c572b86c61c26412609e82d Mon Sep 17 00:00:00 2001
+From: George Dunlap <george.dunlap@citrix.com>
+Date: Fri, 10 Nov 2017 16:53:54 +0000
+Subject: [PATCH 1/2] p2m: Always check to see if removing a p2m entry actually
+ worked
+
+The PoD zero-check functions speculatively remove memory from the p2m,
+then check to see if it's completely zeroed, before putting it in the
+cache.
+
+Unfortunately, the p2m_set_entry() calls may fail if the underlying
+pagetable structure needs to change and the domain has exhausted its
+p2m memory pool: for instance, if we're removing a 2MiB region out of
+a 1GiB entry (in the p2m_pod_zero_check_superpage() case), or a 4k
+region out of a 2MiB or larger entry (in the p2m_pod_zero_check()
+case); and the return value is not checked.
+
+The underlying mfn will then be added into the PoD cache, and at some
+point mapped into another location in the p2m. If the guest
+afterwards ballons out this memory, it will be freed to the hypervisor
+and potentially reused by another domain, in spite of the fact that
+the original domain still has writable mappings to it.
+
+There are several places where p2m_set_entry() shouldn't be able to
+fail, as it is guaranteed to write an entry of the same order that
+succeeded before. Add a backstop of crashing the domain just in case,
+and an ASSERT_UNREACHABLE() to flag up the broken assumption on debug
+builds.
+
+While we're here, use PAGE_ORDER_2M rather than a magic constant.
+
+This is part of XSA-247.
+
+Reported-by: George Dunlap <george.dunlap.com>
+Signed-off-by: George Dunlap <george.dunlap@citrix.com>
+Reviewed-by: Jan Beulich <jbeulich@suse.com>
+---
+v4:
+- Removed some training whitespace
+v3:
+- Reformat reset clause to be more compact
+- Make sure to set map[i] = NULL when unmapping in case we need to bail
+v2:
+- Crash a domain if a p2m_set_entry we think cannot fail fails anyway.
+---
+ xen/arch/x86/mm/p2m-pod.c | 77 +++++++++++++++++++++++++++++++++++++----------
+ 1 file changed, 61 insertions(+), 16 deletions(-)
+
+diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c
+index 730a48f928..f2ed751892 100644
+--- a/xen/arch/x86/mm/p2m-pod.c
++++ b/xen/arch/x86/mm/p2m-pod.c
+@@ -752,8 +752,10 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn)
+ }
+
+ /* Try to remove the page, restoring old mapping if it fails. */
+- p2m_set_entry(p2m, gfn, INVALID_MFN, PAGE_ORDER_2M,
+- p2m_populate_on_demand, p2m->default_access);
++ if ( p2m_set_entry(p2m, gfn, INVALID_MFN, PAGE_ORDER_2M,
++ p2m_populate_on_demand, p2m->default_access) )
++ goto out;
++
+ p2m_tlb_flush_sync(p2m);
+
+ /* Make none of the MFNs are used elsewhere... for example, mapped
+@@ -810,9 +812,18 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn)
+ ret = SUPERPAGE_PAGES;
+
+ out_reset:
+- if ( reset )
+- p2m_set_entry(p2m, gfn, mfn0, 9, type0, p2m->default_access);
+-
++ /*
++ * This p2m_set_entry() call shouldn't be able to fail, since the same order
++ * on the same gfn succeeded above. If that turns out to be false, crashing
++ * the domain should be the safest way of making sure we don't leak memory.
++ */
++ if ( reset && p2m_set_entry(p2m, gfn, mfn0, PAGE_ORDER_2M,
++ type0, p2m->default_access) )
++ {
++ ASSERT_UNREACHABLE();
++ domain_crash(d);
++ }
++
+ out:
+ gfn_unlock(p2m, gfn, SUPERPAGE_ORDER);
+ return ret;
+@@ -869,19 +880,30 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count)
+ }
+
+ /* Try to remove the page, restoring old mapping if it fails. */
+- p2m_set_entry(p2m, gfns[i], INVALID_MFN, PAGE_ORDER_4K,
+- p2m_populate_on_demand, p2m->default_access);
++ if ( p2m_set_entry(p2m, gfns[i], INVALID_MFN, PAGE_ORDER_4K,
++ p2m_populate_on_demand, p2m->default_access) )
++ goto skip;
+
+ /* See if the page was successfully unmapped. (Allow one refcount
+ * for being allocated to a domain.) */
+ if ( (mfn_to_page(mfns[i])->count_info & PGC_count_mask) > 1 )
+ {
++ /*
++ * If the previous p2m_set_entry call succeeded, this one shouldn't
++ * be able to fail. If it does, crashing the domain should be safe.
++ */
++ if ( p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K,
++ types[i], p2m->default_access) )
++ {
++ ASSERT_UNREACHABLE();
++ domain_crash(d);
++ goto out_unmap;
++ }
++
++ skip:
+ unmap_domain_page(map[i]);
+ map[i] = NULL;
+
+- p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K,
+- types[i], p2m->default_access);
+-
+ continue;
+ }
+ }
+@@ -900,12 +922,25 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count)
+
+ unmap_domain_page(map[i]);
+
+- /* See comment in p2m_pod_zero_check_superpage() re gnttab
+- * check timing. */
+- if ( j < PAGE_SIZE/sizeof(*map[i]) )
++ map[i] = NULL;
++
++ /*
++ * See comment in p2m_pod_zero_check_superpage() re gnttab
++ * check timing.
++ */
++ if ( j < (PAGE_SIZE / sizeof(*map[i])) )
+ {
+- p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K,
+- types[i], p2m->default_access);
++ /*
++ * If the previous p2m_set_entry call succeeded, this one shouldn't
++ * be able to fail. If it does, crashing the domain should be safe.
++ */
++ if ( p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K,
++ types[i], p2m->default_access) )
++ {
++ ASSERT_UNREACHABLE();
++ domain_crash(d);
++ goto out_unmap;
++ }
+ }
+ else
+ {
+@@ -929,7 +964,17 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count)
+ p2m->pod.entry_count++;
+ }
+ }
+-
++
++ return;
++
++out_unmap:
++ /*
++ * Something went wrong, probably crashing the domain. Unmap
++ * everything and return.
++ */
++ for ( i = 0; i < count; i++ )
++ if ( map[i] )
++ unmap_domain_page(map[i]);
+ }
+
+ #define POD_SWEEP_LIMIT 1024
+--
+2.15.0
+
diff --git a/system/xen/xsa/xsa247-4.9-0002-p2m-Check-return-value-of-p2m_set_entry-when-decreas.patch b/system/xen/xsa/xsa247-4.9-0002-p2m-Check-return-value-of-p2m_set_entry-when-decreas.patch
new file mode 100644
index 0000000000..8c850bd7f5
--- /dev/null
+++ b/system/xen/xsa/xsa247-4.9-0002-p2m-Check-return-value-of-p2m_set_entry-when-decreas.patch
@@ -0,0 +1,109 @@
+From d4bc7833707351a5341a6bdf04c752a028d9560d Mon Sep 17 00:00:00 2001
+From: George Dunlap <george.dunlap@citrix.com>
+Date: Fri, 10 Nov 2017 16:53:55 +0000
+Subject: [PATCH 2/2] p2m: Check return value of p2m_set_entry() when
+ decreasing reservation
+
+If the entire range specified to p2m_pod_decrease_reservation() is marked
+populate-on-demand, then it will make a single p2m_set_entry() call,
+reducing its PoD entry count.
+
+Unfortunately, in the right circumstances, this p2m_set_entry() call
+may fail. It that case, repeated calls to decrease_reservation() may
+cause p2m->pod.entry_count to fall below zero, potentially tripping
+over BUG_ON()s to the contrary.
+
+Instead, check to see if the entry succeeded, and return false if not.
+The caller will then call guest_remove_page() on the gfns, which will
+return -EINVAL upon finding no valid memory there to return.
+
+Unfortunately if the order > 0, the entry may have partially changed.
+A domain_crash() is probably the safest thing in that case.
+
+Other p2m_set_entry() calls in the same function should be fine,
+because they are writing the entry at its current order. Nonetheless,
+check the return value and crash if our assumption turns otu to be
+wrong.
+
+This is part of XSA-247.
+
+Reported-by: George Dunlap <george.dunlap.com>
+Signed-off-by: George Dunlap <george.dunlap@citrix.com>
+Reviewed-by: Jan Beulich <jbeulich@suse.com>
+---
+v2: Crash the domain if we're not sure it's safe (or if we think it
+can't happen)
+---
+ xen/arch/x86/mm/p2m-pod.c | 42 +++++++++++++++++++++++++++++++++---------
+ 1 file changed, 33 insertions(+), 9 deletions(-)
+
+diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c
+index f2ed751892..473d6a6dbf 100644
+--- a/xen/arch/x86/mm/p2m-pod.c
++++ b/xen/arch/x86/mm/p2m-pod.c
+@@ -555,11 +555,23 @@ p2m_pod_decrease_reservation(struct domain *d,
+
+ if ( !nonpod )
+ {
+- /* All PoD: Mark the whole region invalid and tell caller
+- * we're done. */
+- p2m_set_entry(p2m, gpfn, INVALID_MFN, order, p2m_invalid,
+- p2m->default_access);
+- p2m->pod.entry_count-=(1<<order);
++ /*
++ * All PoD: Mark the whole region invalid and tell caller
++ * we're done.
++ */
++ if ( p2m_set_entry(p2m, gpfn, INVALID_MFN, order, p2m_invalid,
++ p2m->default_access) )
++ {
++ /*
++ * If this fails, we can't tell how much of the range was changed.
++ * Best to crash the domain unless we're sure a partial change is
++ * impossible.
++ */
++ if ( order != 0 )
++ domain_crash(d);
++ goto out_unlock;
++ }
++ p2m->pod.entry_count -= 1UL << order;
+ BUG_ON(p2m->pod.entry_count < 0);
+ ret = 1;
+ goto out_entry_check;
+@@ -600,8 +612,14 @@ p2m_pod_decrease_reservation(struct domain *d,
+ n = 1UL << cur_order;
+ if ( t == p2m_populate_on_demand )
+ {
+- p2m_set_entry(p2m, gpfn + i, INVALID_MFN, cur_order,
+- p2m_invalid, p2m->default_access);
++ /* This shouldn't be able to fail */
++ if ( p2m_set_entry(p2m, gpfn + i, INVALID_MFN, cur_order,
++ p2m_invalid, p2m->default_access) )
++ {
++ ASSERT_UNREACHABLE();
++ domain_crash(d);
++ goto out_unlock;
++ }
+ p2m->pod.entry_count -= n;
+ BUG_ON(p2m->pod.entry_count < 0);
+ pod -= n;
+@@ -622,8 +640,14 @@ p2m_pod_decrease_reservation(struct domain *d,
+
+ page = mfn_to_page(mfn);
+
+- p2m_set_entry(p2m, gpfn + i, INVALID_MFN, cur_order,
+- p2m_invalid, p2m->default_access);
++ /* This shouldn't be able to fail */
++ if ( p2m_set_entry(p2m, gpfn + i, INVALID_MFN, cur_order,
++ p2m_invalid, p2m->default_access) )
++ {
++ ASSERT_UNREACHABLE();
++ domain_crash(d);
++ goto out_unlock;
++ }
+ p2m_tlb_flush_sync(p2m);
+ for ( j = 0; j < n; ++j )
+ set_gpfn_from_mfn(mfn_x(mfn), INVALID_M2P_ENTRY);
+--
+2.15.0
+
diff --git a/system/xen/xsa/xsa248.patch b/system/xen/xsa/xsa248.patch
new file mode 100644
index 0000000000..966c16e043
--- /dev/null
+++ b/system/xen/xsa/xsa248.patch
@@ -0,0 +1,164 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86/mm: don't wrongly set page ownership
+
+PV domains can obtain mappings of any pages owned by the correct domain,
+including ones that aren't actually assigned as "normal" RAM, but used
+by Xen internally. At the moment such "internal" pages marked as owned
+by a guest include pages used to track logdirty bits, as well as p2m
+pages and the "unpaged pagetable" for HVM guests. Since the PV memory
+management and shadow code conflict in their use of struct page_info
+fields, and since shadow code is being used for log-dirty handling for
+PV domains, pages coming from the shadow pool must, for PV domains, not
+have the domain set as their owner.
+
+While the change could be done conditionally for just the PV case in
+shadow code, do it unconditionally (and for consistency also for HAP),
+just to be on the safe side.
+
+There's one special case though for shadow code: The page table used for
+running a HVM guest in unpaged mode is subject to get_page() (in
+set_shadow_status()) and hence must have its owner set.
+
+This is XSA-248.
+
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: Tim Deegan <tim@xen.org>
+Reviewed-by: George Dunlap <george.dunlap@citrix.com>
+---
+v2: Drop PGC_page_table related pieces.
+
+--- a/xen/arch/x86/mm/hap/hap.c
++++ b/xen/arch/x86/mm/hap/hap.c
+@@ -286,8 +286,7 @@ static struct page_info *hap_alloc_p2m_p
+ {
+ d->arch.paging.hap.total_pages--;
+ d->arch.paging.hap.p2m_pages++;
+- page_set_owner(pg, d);
+- pg->count_info |= 1;
++ ASSERT(!page_get_owner(pg) && !(pg->count_info & PGC_count_mask));
+ }
+ else if ( !d->arch.paging.p2m_alloc_failed )
+ {
+@@ -302,21 +301,23 @@ static struct page_info *hap_alloc_p2m_p
+
+ static void hap_free_p2m_page(struct domain *d, struct page_info *pg)
+ {
++ struct domain *owner = page_get_owner(pg);
++
+ /* This is called both from the p2m code (which never holds the
+ * paging lock) and the log-dirty code (which always does). */
+ paging_lock_recursive(d);
+
+- ASSERT(page_get_owner(pg) == d);
+- /* Should have just the one ref we gave it in alloc_p2m_page() */
+- if ( (pg->count_info & PGC_count_mask) != 1 ) {
+- HAP_ERROR("Odd p2m page %p count c=%#lx t=%"PRtype_info"\n",
+- pg, pg->count_info, pg->u.inuse.type_info);
++ /* Should still have no owner and count zero. */
++ if ( owner || (pg->count_info & PGC_count_mask) )
++ {
++ HAP_ERROR("d%d: Odd p2m page %"PRI_mfn" d=%d c=%lx t=%"PRtype_info"\n",
++ d->domain_id, mfn_x(page_to_mfn(pg)),
++ owner ? owner->domain_id : DOMID_INVALID,
++ pg->count_info, pg->u.inuse.type_info);
+ WARN();
++ pg->count_info &= ~PGC_count_mask;
++ page_set_owner(pg, NULL);
+ }
+- pg->count_info &= ~PGC_count_mask;
+- /* Free should not decrement domain's total allocation, since
+- * these pages were allocated without an owner. */
+- page_set_owner(pg, NULL);
+ d->arch.paging.hap.p2m_pages--;
+ d->arch.paging.hap.total_pages++;
+ hap_free(d, page_to_mfn(pg));
+--- a/xen/arch/x86/mm/shadow/common.c
++++ b/xen/arch/x86/mm/shadow/common.c
+@@ -1503,32 +1503,29 @@ shadow_alloc_p2m_page(struct domain *d)
+ pg = mfn_to_page(shadow_alloc(d, SH_type_p2m_table, 0));
+ d->arch.paging.shadow.p2m_pages++;
+ d->arch.paging.shadow.total_pages--;
++ ASSERT(!page_get_owner(pg) && !(pg->count_info & PGC_count_mask));
+
+ paging_unlock(d);
+
+- /* Unlike shadow pages, mark p2m pages as owned by the domain.
+- * Marking the domain as the owner would normally allow the guest to
+- * create mappings of these pages, but these p2m pages will never be
+- * in the domain's guest-physical address space, and so that is not
+- * believed to be a concern. */
+- page_set_owner(pg, d);
+- pg->count_info |= 1;
+ return pg;
+ }
+
+ static void
+ shadow_free_p2m_page(struct domain *d, struct page_info *pg)
+ {
+- ASSERT(page_get_owner(pg) == d);
+- /* Should have just the one ref we gave it in alloc_p2m_page() */
+- if ( (pg->count_info & PGC_count_mask) != 1 )
++ struct domain *owner = page_get_owner(pg);
++
++ /* Should still have no owner and count zero. */
++ if ( owner || (pg->count_info & PGC_count_mask) )
+ {
+- SHADOW_ERROR("Odd p2m page count c=%#lx t=%"PRtype_info"\n",
++ SHADOW_ERROR("d%d: Odd p2m page %"PRI_mfn" d=%d c=%lx t=%"PRtype_info"\n",
++ d->domain_id, mfn_x(page_to_mfn(pg)),
++ owner ? owner->domain_id : DOMID_INVALID,
+ pg->count_info, pg->u.inuse.type_info);
++ pg->count_info &= ~PGC_count_mask;
++ page_set_owner(pg, NULL);
+ }
+- pg->count_info &= ~PGC_count_mask;
+ pg->u.sh.type = SH_type_p2m_table; /* p2m code reuses type-info */
+- page_set_owner(pg, NULL);
+
+ /* This is called both from the p2m code (which never holds the
+ * paging lock) and the log-dirty code (which always does). */
+@@ -3132,7 +3129,9 @@ int shadow_enable(struct domain *d, u32
+ e = __map_domain_page(pg);
+ write_32bit_pse_identmap(e);
+ unmap_domain_page(e);
++ pg->count_info = 1;
+ pg->u.inuse.type_info = PGT_l2_page_table | 1 | PGT_validated;
++ page_set_owner(pg, d);
+ }
+
+ paging_lock(d);
+@@ -3170,7 +3169,11 @@ int shadow_enable(struct domain *d, u32
+ if ( rv != 0 && !pagetable_is_null(p2m_get_pagetable(p2m)) )
+ p2m_teardown(p2m);
+ if ( rv != 0 && pg != NULL )
++ {
++ pg->count_info &= ~PGC_count_mask;
++ page_set_owner(pg, NULL);
+ shadow_free_p2m_page(d, pg);
++ }
+ domain_unpause(d);
+ return rv;
+ }
+@@ -3279,7 +3282,22 @@ out:
+
+ /* Must be called outside the lock */
+ if ( unpaged_pagetable )
++ {
++ if ( page_get_owner(unpaged_pagetable) == d &&
++ (unpaged_pagetable->count_info & PGC_count_mask) == 1 )
++ {
++ unpaged_pagetable->count_info &= ~PGC_count_mask;
++ page_set_owner(unpaged_pagetable, NULL);
++ }
++ /* Complain here in cases where shadow_free_p2m_page() won't. */
++ else if ( !page_get_owner(unpaged_pagetable) &&
++ !(unpaged_pagetable->count_info & PGC_count_mask) )
++ SHADOW_ERROR("d%d: Odd unpaged pt %"PRI_mfn" c=%lx t=%"PRtype_info"\n",
++ d->domain_id, mfn_x(page_to_mfn(unpaged_pagetable)),
++ unpaged_pagetable->count_info,
++ unpaged_pagetable->u.inuse.type_info);
+ shadow_free_p2m_page(d, unpaged_pagetable);
++ }
+ }
+
+ void shadow_final_teardown(struct domain *d)
diff --git a/system/xen/xsa/xsa249.patch b/system/xen/xsa/xsa249.patch
new file mode 100644
index 0000000000..ecfa4305e5
--- /dev/null
+++ b/system/xen/xsa/xsa249.patch
@@ -0,0 +1,42 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86/shadow: fix refcount overflow check
+
+Commit c385d27079 ("x86 shadow: for multi-page shadows, explicitly track
+the first page") reduced the refcount width to 25, without adjusting the
+overflow check. Eliminate the disconnect by using a manifest constant.
+
+Interestingly, up to commit 047782fa01 ("Out-of-sync L1 shadows: OOS
+snapshot") the refcount was 27 bits wide, yet the check was already
+using 26.
+
+This is XSA-249.
+
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: George Dunlap <george.dunlap@citrix.com>
+Reviewed-by: Tim Deegan <tim@xen.org>
+---
+v2: Simplify expression back to the style it was.
+
+--- a/xen/arch/x86/mm/shadow/private.h
++++ b/xen/arch/x86/mm/shadow/private.h
+@@ -529,7 +529,7 @@ static inline int sh_get_ref(struct doma
+ x = sp->u.sh.count;
+ nx = x + 1;
+
+- if ( unlikely(nx >= 1U<<26) )
++ if ( unlikely(nx >= (1U << PAGE_SH_REFCOUNT_WIDTH)) )
+ {
+ SHADOW_PRINTK("shadow ref overflow, gmfn=%lx smfn=%lx\n",
+ __backpointer(sp), mfn_x(smfn));
+--- a/xen/include/asm-x86/mm.h
++++ b/xen/include/asm-x86/mm.h
+@@ -82,7 +82,8 @@ struct page_info
+ unsigned long type:5; /* What kind of shadow is this? */
+ unsigned long pinned:1; /* Is the shadow pinned? */
+ unsigned long head:1; /* Is this the first page of the shadow? */
+- unsigned long count:25; /* Reference count */
++#define PAGE_SH_REFCOUNT_WIDTH 25
++ unsigned long count:PAGE_SH_REFCOUNT_WIDTH; /* Reference count */
+ } sh;
+
+ /* Page is on a free list: ((count_info & PGC_count_mask) == 0). */
diff --git a/system/xen/xsa/xsa250.patch b/system/xen/xsa/xsa250.patch
new file mode 100644
index 0000000000..26aeb33fed
--- /dev/null
+++ b/system/xen/xsa/xsa250.patch
@@ -0,0 +1,67 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86/shadow: fix ref-counting error handling
+
+The old-Linux handling in shadow_set_l4e() mistakenly ORed together the
+results of sh_get_ref() and sh_pin(). As the latter failing is not a
+correctness problem, simply ignore its return value.
+
+In sh_set_toplevel_shadow() a failing sh_get_ref() must not be
+accompanied by installing the entry, despite the domain being crashed.
+
+This is XSA-250.
+
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: Tim Deegan <tim@xen.org>
+
+--- a/xen/arch/x86/mm/shadow/multi.c
++++ b/xen/arch/x86/mm/shadow/multi.c
+@@ -923,7 +923,7 @@ static int shadow_set_l4e(struct domain
+ shadow_l4e_t new_sl4e,
+ mfn_t sl4mfn)
+ {
+- int flags = 0, ok;
++ int flags = 0;
+ shadow_l4e_t old_sl4e;
+ paddr_t paddr;
+ ASSERT(sl4e != NULL);
+@@ -938,15 +938,16 @@ static int shadow_set_l4e(struct domain
+ {
+ /* About to install a new reference */
+ mfn_t sl3mfn = shadow_l4e_get_mfn(new_sl4e);
+- ok = sh_get_ref(d, sl3mfn, paddr);
+- /* Are we pinning l3 shadows to handle wierd linux behaviour? */
+- if ( sh_type_is_pinnable(d, SH_type_l3_64_shadow) )
+- ok |= sh_pin(d, sl3mfn);
+- if ( !ok )
++
++ if ( !sh_get_ref(d, sl3mfn, paddr) )
+ {
+ domain_crash(d);
+ return SHADOW_SET_ERROR;
+ }
++
++ /* Are we pinning l3 shadows to handle weird Linux behaviour? */
++ if ( sh_type_is_pinnable(d, SH_type_l3_64_shadow) )
++ sh_pin(d, sl3mfn);
+ }
+
+ /* Write the new entry */
+@@ -3965,14 +3966,15 @@ sh_set_toplevel_shadow(struct vcpu *v,
+
+ /* Take a ref to this page: it will be released in sh_detach_old_tables()
+ * or the next call to set_toplevel_shadow() */
+- if ( !sh_get_ref(d, smfn, 0) )
++ if ( sh_get_ref(d, smfn, 0) )
++ new_entry = pagetable_from_mfn(smfn);
++ else
+ {
+ SHADOW_ERROR("can't install %#lx as toplevel shadow\n", mfn_x(smfn));
+ domain_crash(d);
++ new_entry = pagetable_null();
+ }
+
+- new_entry = pagetable_from_mfn(smfn);
+-
+ install_new_entry:
+ /* Done. Install it */
+ SHADOW_PRINTK("%u/%u [%u] gmfn %#"PRI_mfn" smfn %#"PRI_mfn"\n",
diff --git a/system/xen/xsa/xsa251.patch b/system/xen/xsa/xsa251.patch
new file mode 100644
index 0000000000..582ef622eb
--- /dev/null
+++ b/system/xen/xsa/xsa251.patch
@@ -0,0 +1,21 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86/paging: don't unconditionally BUG() on finding SHARED_M2P_ENTRY
+
+PV guests can fully control the values written into the P2M.
+
+This is XSA-251.
+
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
+
+--- a/xen/arch/x86/mm/paging.c
++++ b/xen/arch/x86/mm/paging.c
+@@ -274,7 +274,7 @@ void paging_mark_pfn_dirty(struct domain
+ return;
+
+ /* Shared MFNs should NEVER be marked dirty */
+- BUG_ON(SHARED_M2P(pfn_x(pfn)));
++ BUG_ON(paging_mode_translate(d) && SHARED_M2P(pfn_x(pfn)));
+
+ /*
+ * Values with the MSB set denote MFNs that aren't really part of the
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-01 20:12:35 +0000