Merge branch 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen

* 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen: do not release any memory under 1M in domain 0
  xen: events: do not unmask event channels on resume
  xen: correct size of level2_kernel_pgt

3 files changed, 30 insertions, 15 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index c237b810b03f..21ed8d7f75a5 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2126,7 +2126,7 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
 {
         pmd_t *kernel_pmd;
 
-        level2_kernel_pgt = extend_brk(sizeof(pmd_t *) * PTRS_PER_PMD, PAGE_SIZE);
+        level2_kernel_pgt = extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
 
         max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->pt_base) +
                                   xen_start_info->nr_pt_frames * PAGE_SIZE +
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index b1dbdaa23ecc..769c4b01fa32 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -118,16 +118,18 @@ static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
                                                      const struct e820map *e820)
 {
         phys_addr_t max_addr = PFN_PHYS(max_pfn);
-        phys_addr_t last_end = 0;
+        phys_addr_t last_end = ISA_END_ADDRESS;
         unsigned long released = 0;
         int i;
 
+        /* Free any unused memory above the low 1Mbyte. */
         for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
                 phys_addr_t end = e820->map[i].addr;
                 end = min(max_addr, end);
 
-                released += xen_release_chunk(last_end, end);
-                last_end = e820->map[i].addr + e820->map[i].size;
+                if (last_end < end)
+                        released += xen_release_chunk(last_end, end);
+                last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
         }
 
         if (last_end < max_addr)
@@ -164,6 +166,7 @@ char * __init xen_memory_setup(void)
                 XENMEM_memory_map;
         rc = HYPERVISOR_memory_op(op, &memmap);
         if (rc == -ENOSYS) {
+                BUG_ON(xen_initial_domain());
                 memmap.nr_entries = 1;
                 map[0].addr = 0ULL;
                 map[0].size = mem_end;
@@ -201,12 +204,13 @@ char * __init xen_memory_setup(void)
         }
 
         /*
-         * Even though this is normal, usable memory under Xen, reserve
-         * ISA memory anyway because too many things think they can poke
+         * In domU, the ISA region is normal, usable memory, but we
+         * reserve ISA memory anyway because too many things poke
          * about in there.
          *
-         * In a dom0 kernel, this region is identity mapped with the
-         * hardware ISA area, so it really is out of bounds.
+         * In Dom0, the host E820 information can leave gaps in the
+         * ISA range, which would cause us to release those pages.  To
+         * avoid this, we unconditionally reserve them here.
          */
         e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
                         E820_RESERVED);
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 97612f548a8e..321a0c8346e5 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -1299,9 +1299,6 @@ static void restore_cpu_virqs(unsigned int cpu)
                 evtchn_to_irq[evtchn] = irq;
                 irq_info[irq] = mk_virq_info(evtchn, virq);
                 bind_evtchn_to_cpu(evtchn, cpu);
-
-                /* Ready for use. */
-                unmask_evtchn(evtchn);
         }
 }
 
@@ -1327,10 +1324,6 @@ static void restore_cpu_ipis(unsigned int cpu)
                 evtchn_to_irq[evtchn] = irq;
                 irq_info[irq] = mk_ipi_info(evtchn, ipi);
                 bind_evtchn_to_cpu(evtchn, cpu);
-
-                /* Ready for use. */
-                unmask_evtchn(evtchn);
-
         }
 }
 
@@ -1390,6 +1383,7 @@ void xen_poll_irq(int irq)
 void xen_irq_resume(void)
 {
         unsigned int cpu, irq, evtchn;
+        struct irq_desc *desc;
 
         init_evtchn_cpu_bindings();
 
@@ -1408,6 +1402,23 @@ void xen_irq_resume(void)
                 restore_cpu_virqs(cpu);
                 restore_cpu_ipis(cpu);
         }
+
+        /*
+         * Unmask any IRQF_NO_SUSPEND IRQs which are enabled. These
+         * are not handled by the IRQ core.
+         */
+        for_each_irq_desc(irq, desc) {
+                if (!desc->action || !(desc->action->flags & IRQF_NO_SUSPEND))
+                        continue;
+                if (desc->status & IRQ_DISABLED)
+                        continue;
+
+                evtchn = evtchn_from_irq(irq);
+                if (evtchn == -1)
+                        continue;
+
+                unmask_evtchn(evtchn);
+        }
 }
 
 static struct irq_chip xen_dynamic_chip __read_mostly = {