Merge tag 'stable/for-linus-3.19-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen bug fixes from David Vrabel:
 "Several critical linear p2m fixes that prevented some hosts from
  booting"

* tag 'stable/for-linus-3.19-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: properly retrieve NMI reason
  xen: check for zero sized area when invalidating memory
  xen: use correct type for physical addresses
  xen: correct race in alloc_p2m_pmd()
  xen: correct error for building p2m list on 32 bits
  x86/xen: avoid freeing static 'name' when kasprintf() fails
  x86/xen: add extra memory for remapped frames during setup
  x86/xen: don't count how many PFNs are identity mapped
  x86/xen: Free bootmem in free_p2m_page() during early boot
  x86/xen: Remove unnecessary BUG_ON(preemptible()) in xen_setup_timer()

4 files changed, 56 insertions, 46 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 6bf3a13e3e0f..78a881b7fc41 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -40,6 +40,7 @@
 #include <xen/interface/physdev.h>
 #include <xen/interface/vcpu.h>
 #include <xen/interface/memory.h>
+#include <xen/interface/nmi.h>
 #include <xen/interface/xen-mca.h>
 #include <xen/features.h>
 #include <xen/page.h>
@@ -66,6 +67,7 @@
 #include <asm/reboot.h>
 #include <asm/stackprotector.h>
 #include <asm/hypervisor.h>
+#include <asm/mach_traps.h>
 #include <asm/mwait.h>
 #include <asm/pci_x86.h>
 #include <asm/pat.h>
@@ -1351,6 +1353,21 @@ static const struct machine_ops xen_machine_ops __initconst = {
         .emergency_restart = xen_emergency_restart,
 };
 
+static unsigned char xen_get_nmi_reason(void)
+{
+        unsigned char reason = 0;
+
+        /* Construct a value which looks like it came from port 0x61. */
+        if (test_bit(_XEN_NMIREASON_io_error,
+                     &HYPERVISOR_shared_info->arch.nmi_reason))
+                reason |= NMI_REASON_IOCHK;
+        if (test_bit(_XEN_NMIREASON_pci_serr,
+                     &HYPERVISOR_shared_info->arch.nmi_reason))
+                reason |= NMI_REASON_SERR;
+
+        return reason;
+}
+
 static void __init xen_boot_params_init_edd(void)
 {
 #if IS_ENABLED(CONFIG_EDD)
@@ -1535,9 +1552,12 @@ asmlinkage __visible void __init xen_start_kernel(void)
         pv_info = xen_info;
         pv_init_ops = xen_init_ops;
         pv_apic_ops = xen_apic_ops;
-        if (!xen_pvh_domain())
+        if (!xen_pvh_domain()) {
                 pv_cpu_ops = xen_cpu_ops;
 
+                x86_platform.get_nmi_reason = xen_get_nmi_reason;
+        }
+
         if (xen_feature(XENFEAT_auto_translated_physmap))
                 x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
         else
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index edbc7a63fd73..70fb5075c901 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -167,10 +167,13 @@ static void * __ref alloc_p2m_page(void)
         return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
 }
 
-/* Only to be called in case of a race for a page just allocated! */
-static void free_p2m_page(void *p)
+static void __ref free_p2m_page(void *p)
 {
-        BUG_ON(!slab_is_available());
+        if (unlikely(!slab_is_available())) {
+                free_bootmem((unsigned long)p, PAGE_SIZE);
+                return;
+        }
+
         free_page((unsigned long)p);
 }
 
@@ -375,7 +378,7 @@ static void __init xen_rebuild_p2m_list(unsigned long *p2m)
                         p2m_missing_pte : p2m_identity_pte;
                 for (i = 0; i < PMDS_PER_MID_PAGE; i++) {
                         pmdp = populate_extra_pmd(
-                                (unsigned long)(p2m + pfn + i * PTRS_PER_PTE));
+                                (unsigned long)(p2m + pfn) + i * PMD_SIZE);
                         set_pmd(pmdp, __pmd(__pa(ptep) | _KERNPG_TABLE));
                 }
         }
@@ -436,10 +439,9 @@ EXPORT_SYMBOL_GPL(get_phys_to_machine);
  * a new pmd is to replace p2m_missing_pte or p2m_identity_pte by a individual
  * pmd. In case of PAE/x86-32 there are multiple pmds to allocate!
  */
-static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *ptep, pte_t *pte_pg)
+static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg)
 {
         pte_t *ptechk;
-        pte_t *pteret = ptep;
         pte_t *pte_newpg[PMDS_PER_MID_PAGE];
         pmd_t *pmdp;
         unsigned int level;
@@ -473,8 +475,6 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *ptep, pte_t *pte_pg)
                 if (ptechk == pte_pg) {
                         set_pmd(pmdp,
                                 __pmd(__pa(pte_newpg[i]) | _KERNPG_TABLE));
-                        if (vaddr == (addr & ~(PMD_SIZE - 1)))
-                                pteret = pte_offset_kernel(pmdp, addr);
                         pte_newpg[i] = NULL;
                 }
 
@@ -488,7 +488,7 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *ptep, pte_t *pte_pg)
                 vaddr += PMD_SIZE;
         }
 
-        return pteret;
+        return lookup_address(addr, &level);
 }
 
 /*
@@ -517,7 +517,7 @@ static bool alloc_p2m(unsigned long pfn)
 
         if (pte_pg == p2m_missing_pte || pte_pg == p2m_identity_pte) {
                 /* PMD level is missing, allocate a new one */
-                ptep = alloc_p2m_pmd(addr, ptep, pte_pg);
+                ptep = alloc_p2m_pmd(addr, pte_pg);
                 if (!ptep)
                         return false;
         }
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index dfd77dec8e2b..865e56cea7a0 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -140,7 +140,7 @@ static void __init xen_del_extra_mem(u64 start, u64 size)
 unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
 {
         int i;
-        unsigned long addr = PFN_PHYS(pfn);
+        phys_addr_t addr = PFN_PHYS(pfn);
 
         for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
                 if (addr >= xen_extra_mem[i].start &&
@@ -160,6 +160,8 @@ void __init xen_inv_extra_mem(void)
         int i;
 
         for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+                if (!xen_extra_mem[i].size)
+                        continue;
                 pfn_s = PFN_DOWN(xen_extra_mem[i].start);
                 pfn_e = PFN_UP(xen_extra_mem[i].start + xen_extra_mem[i].size);
                 for (pfn = pfn_s; pfn < pfn_e; pfn++)
@@ -229,15 +231,14 @@ static int __init xen_free_mfn(unsigned long mfn)
  * as a fallback if the remapping fails.
  */
 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
-        unsigned long end_pfn, unsigned long nr_pages, unsigned long *identity,
-        unsigned long *released)
+        unsigned long end_pfn, unsigned long nr_pages, unsigned long *released)
 {
-        unsigned long len = 0;
         unsigned long pfn, end;
         int ret;
 
         WARN_ON(start_pfn > end_pfn);
 
+        /* Release pages first. */
         end = min(end_pfn, nr_pages);
         for (pfn = start_pfn; pfn < end; pfn++) {
                 unsigned long mfn = pfn_to_mfn(pfn);
@@ -250,16 +251,14 @@ static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
                 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
 
                 if (ret == 1) {
+                        (*released)++;
                         if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
                                 break;
-                        len++;
                 } else
                         break;
         }
 
-        /* Need to release pages first */
-        *released += len;
-        *identity += set_phys_range_identity(start_pfn, end_pfn);
+        set_phys_range_identity(start_pfn, end_pfn);
 }
 
 /*
@@ -287,7 +286,7 @@ static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
         }
 
         /* Update kernel mapping, but not for highmem. */
-        if ((pfn << PAGE_SHIFT) >= __pa(high_memory))
+        if (pfn >= PFN_UP(__pa(high_memory - 1)))
                 return;
 
         if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
@@ -318,7 +317,6 @@ static void __init xen_do_set_identity_and_remap_chunk(
         unsigned long ident_pfn_iter, remap_pfn_iter;
         unsigned long ident_end_pfn = start_pfn + size;
         unsigned long left = size;
-        unsigned long ident_cnt = 0;
         unsigned int i, chunk;
 
         WARN_ON(size == 0);
@@ -347,8 +345,7 @@ static void __init xen_do_set_identity_and_remap_chunk(
                 xen_remap_mfn = mfn;
 
                 /* Set identity map */
-                ident_cnt += set_phys_range_identity(ident_pfn_iter,
-                        ident_pfn_iter + chunk);
+                set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
 
                 left -= chunk;
         }
@@ -371,7 +368,7 @@ static void __init xen_do_set_identity_and_remap_chunk(
 static unsigned long __init xen_set_identity_and_remap_chunk(
         const struct e820entry *list, size_t map_size, unsigned long start_pfn,
         unsigned long end_pfn, unsigned long nr_pages, unsigned long remap_pfn,
-        unsigned long *identity, unsigned long *released)
+        unsigned long *released, unsigned long *remapped)
 {
         unsigned long pfn;
         unsigned long i = 0;
@@ -386,8 +383,7 @@ static unsigned long __init xen_set_identity_and_remap_chunk(
                 /* Do not remap pages beyond the current allocation */
                 if (cur_pfn >= nr_pages) {
                         /* Identity map remaining pages */
-                        *identity += set_phys_range_identity(cur_pfn,
-                                cur_pfn + size);
+                        set_phys_range_identity(cur_pfn, cur_pfn + size);
                         break;
                 }
                 if (cur_pfn + size > nr_pages)
@@ -398,7 +394,7 @@ static unsigned long __init xen_set_identity_and_remap_chunk(
                 if (!remap_range_size) {
                         pr_warning("Unable to find available pfn range, not remapping identity pages\n");
                         xen_set_identity_and_release_chunk(cur_pfn,
-                                cur_pfn + left, nr_pages, identity, released);
+                                cur_pfn + left, nr_pages, released);
                         break;
                 }
                 /* Adjust size to fit in current e820 RAM region */
@@ -410,7 +406,7 @@ static unsigned long __init xen_set_identity_and_remap_chunk(
                 /* Update variables to reflect new mappings. */
                 i += size;
                 remap_pfn += size;
-                *identity += size;
+                *remapped += size;
         }
 
         /*
@@ -427,13 +423,13 @@ static unsigned long __init xen_set_identity_and_remap_chunk(
 
 static void __init xen_set_identity_and_remap(
         const struct e820entry *list, size_t map_size, unsigned long nr_pages,
-        unsigned long *released)
+        unsigned long *released, unsigned long *remapped)
 {
         phys_addr_t start = 0;
-        unsigned long identity = 0;
         unsigned long last_pfn = nr_pages;
         const struct e820entry *entry;
         unsigned long num_released = 0;
+        unsigned long num_remapped = 0;
         int i;
 
         /*
@@ -460,14 +456,14 @@ static void __init xen_set_identity_and_remap(
                                 last_pfn = xen_set_identity_and_remap_chunk(
                                                 list, map_size, start_pfn,
                                                 end_pfn, nr_pages, last_pfn,
-                                                &identity, &num_released);
+                                                &num_released, &num_remapped);
                         start = end;
                 }
         }
 
         *released = num_released;
+        *remapped = num_remapped;
 
-        pr_info("Set %ld page(s) to 1-1 mapping\n", identity);
         pr_info("Released %ld page(s)\n", num_released);
 }
 
@@ -586,6 +582,7 @@ char * __init xen_memory_setup(void)
         struct xen_memory_map memmap;
         unsigned long max_pages;
         unsigned long extra_pages = 0;
+        unsigned long remapped_pages;
         int i;
         int op;
 
@@ -635,9 +632,10 @@ char * __init xen_memory_setup(void)
          * underlying RAM.
          */
         xen_set_identity_and_remap(map, memmap.nr_entries, max_pfn,
-                                   &xen_released_pages);
+                                   &xen_released_pages, &remapped_pages);
 
         extra_pages += xen_released_pages;
+        extra_pages += remapped_pages;
 
         /*
          * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index f473d268d387..69087341d9ae 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -391,7 +391,7 @@ static const struct clock_event_device *xen_clockevent =
 
 struct xen_clock_event_device {
         struct clock_event_device evt;
-        char *name;
+        char name[16];
 };
 static DEFINE_PER_CPU(struct xen_clock_event_device, xen_clock_events) = { .evt.irq = -1 };
 
@@ -420,46 +420,38 @@ void xen_teardown_timer(int cpu)
         if (evt->irq >= 0) {
                 unbind_from_irqhandler(evt->irq, NULL);
                 evt->irq = -1;
-                kfree(per_cpu(xen_clock_events, cpu).name);
-                per_cpu(xen_clock_events, cpu).name = NULL;
         }
 }
 
 void xen_setup_timer(int cpu)
 {
-        char *name;
-        struct clock_event_device *evt;
+        struct xen_clock_event_device *xevt = &per_cpu(xen_clock_events, cpu);
+        struct clock_event_device *evt = &xevt->evt;
         int irq;
 
-        evt = &per_cpu(xen_clock_events, cpu).evt;
         WARN(evt->irq >= 0, "IRQ%d for CPU%d is already allocated\n", evt->irq, cpu);
         if (evt->irq >= 0)
                 xen_teardown_timer(cpu);
 
         printk(KERN_INFO "installing Xen timer for CPU %d\n", cpu);
 
-        name = kasprintf(GFP_KERNEL, "timer%d", cpu);
-        if (!name)
-                name = "<timer kasprintf failed>";
+        snprintf(xevt->name, sizeof(xevt->name), "timer%d", cpu);
 
         irq = bind_virq_to_irqhandler(VIRQ_TIMER, cpu, xen_timer_interrupt,
                                       IRQF_PERCPU|IRQF_NOBALANCING|IRQF_TIMER|
                                       IRQF_FORCE_RESUME|IRQF_EARLY_RESUME,
-                                      name, NULL);
+                                      xevt->name, NULL);
         (void)xen_set_irq_priority(irq, XEN_IRQ_PRIORITY_MAX);
 
         memcpy(evt, xen_clockevent, sizeof(*evt));
 
         evt->cpumask = cpumask_of(cpu);
         evt->irq = irq;
-        per_cpu(xen_clock_events, cpu).name = name;
 }
 
 
 void xen_setup_cpu_clockevents(void)
 {
-        BUG_ON(preemptible());
-
         clockevents_register_device(this_cpu_ptr(&xen_clock_events.evt));
 }