xen: features and fixes for 3.16-rc0

- Support foreign mappings in PVH domains (needed when dom0 is PVH)
 
 - Fix mapping high MMIO regions in x86 PV guests (this is also the
   first half of removing the PAGE_IOMAP PTE flag).
 
 - ARM suspend/resume support.
 
 - ARM multicall support.
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Merge tag 'stable/for-linus-3.16-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip into next

Pull Xen updates from David Vrabel:
 "xen: features and fixes for 3.16-rc0
   - support foreign mappings in PVH domains (needed when dom0 is PVH)

   - fix mapping high MMIO regions in x86 PV guests (this is also the
     first half of removing the PAGE_IOMAP PTE flag).

   - ARM suspend/resume support.

   - ARM multicall support"

* tag 'stable/for-linus-3.16-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: map foreign pfns for autotranslated guests
  xen-acpi-processor: Don't display errors when we get -ENOSYS
  xen/pciback: Document the entry points for 'pcistub_put_pci_dev'
  xen/pciback: Document when the 'unbind' and 'bind' functions are called.
  xen-pciback: Document when we FLR an PCI device.
  xen-pciback: First reset, then free.
  xen-pciback: Cleanup up pcistub_put_pci_dev
  x86/xen: do not use _PAGE_IOMAP in xen_remap_domain_mfn_range()
  x86/xen: set regions above the end of RAM as 1:1
  x86/xen: only warn once if bad MFNs are found during setup
  x86/xen: compactly store large identity ranges in the p2m
  x86/xen: fix set_phys_range_identity() if pfn_e > MAX_P2M_PFN
  x86/xen: rename early_p2m_alloc() and early_p2m_alloc_middle()
  xen/x86: set panic notifier priority to minimum
  arm,arm64/xen: introduce HYPERVISOR_suspend()
  xen: refactor suspend pre/post hooks
  arm: xen: export HYPERVISOR_multicall to modules.
  arm64: introduce virt_to_pfn
  arm/xen: Remove definiition of virt_to_pfn in asm/xen/page.h
  arm: xen: implement multicall hypercall support.

drivers/xen/manage.c

@@ -41,9 +41,6 @@ static enum shutdown_state shutting_down = SHUTDOWN_INVALID;
 
 struct suspend_info {
 	int cancelled;
-	unsigned long arg; /* extra hypercall argument */
-	void (*pre)(void);
-	void (*post)(int cancelled);
 };
 
 static RAW_NOTIFIER_HEAD(xen_resume_notifier);
@@ -61,26 +58,6 @@ void xen_resume_notifier_unregister(struct notifier_block *nb)
 EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister);
 
 #ifdef CONFIG_HIBERNATE_CALLBACKS
-static void xen_hvm_post_suspend(int cancelled)
-{
-	xen_arch_hvm_post_suspend(cancelled);
-	gnttab_resume();
-}
-
-static void xen_pre_suspend(void)
-{
-	xen_mm_pin_all();
-	gnttab_suspend();
-	xen_arch_pre_suspend();
-}
-
-static void xen_post_suspend(int cancelled)
-{
-	xen_arch_post_suspend(cancelled);
-	gnttab_resume();
-	xen_mm_unpin_all();
-}
-
 static int xen_suspend(void *data)
 {
 	struct suspend_info *si = data;
@@ -94,18 +71,20 @@ static int xen_suspend(void *data)
 		return err;
 	}
 
-	if (si->pre)
-		si->pre();
+	gnttab_suspend();
+	xen_arch_pre_suspend();
 
 	/*
 	 * This hypercall returns 1 if suspend was cancelled
 	 * or the domain was merely checkpointed, and 0 if it
 	 * is resuming in a new domain.
 	 */
-	si->cancelled = HYPERVISOR_suspend(si->arg);
+	si->cancelled = HYPERVISOR_suspend(xen_pv_domain()
+                                           ? virt_to_mfn(xen_start_info)
+                                           : 0);
 
-	if (si->post)
-		si->post(si->cancelled);
+	xen_arch_post_suspend(si->cancelled);
+	gnttab_resume();
 
 	if (!si->cancelled) {
 		xen_irq_resume();
@@ -154,16 +133,6 @@ static void do_suspend(void)
 
 	si.cancelled = 1;
 
-	if (xen_hvm_domain()) {
-		si.arg = 0UL;
-		si.pre = NULL;
-		si.post = &xen_hvm_post_suspend;
-	} else {
-		si.arg = virt_to_mfn(xen_start_info);
-		si.pre = &xen_pre_suspend;
-		si.post = &xen_post_suspend;
-	}
-
 	err = stop_machine(xen_suspend, &si, cpumask_of(0));
 
 	raw_notifier_call_chain(&xen_resume_notifier, 0, NULL);

drivers/xen/xen-acpi-processor.c

@@ -127,7 +127,7 @@ static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
 			pr_debug("     C%d: %s %d uS\n",
 				 cx->type, cx->desc, (u32)cx->latency);
 		}
-	} else if (ret != -EINVAL)
+	} else if ((ret != -EINVAL) && (ret != -ENOSYS))
 		/* EINVAL means the ACPI ID is incorrect - meaning the ACPI
 		 * table is referencing a non-existing CPU - which can happen
 		 * with broken ACPI tables. */
@@ -259,7 +259,7 @@ static int push_pxx_to_hypervisor(struct acpi_processor *_pr)
 			(u32) perf->states[i].power,
 			(u32) perf->states[i].transition_latency);
 		}
-	} else if (ret != -EINVAL)
+	} else if ((ret != -EINVAL) && (ret != -ENOSYS))
 		/* EINVAL means the ACPI ID is incorrect - meaning the ACPI
 		 * table is referencing a non-existing CPU - which can happen
 		 * with broken ACPI tables. */

drivers/xen/xen-pciback/pci_stub.c

@@ -242,6 +242,15 @@ struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
 	return found_dev;
 }
 
+/*
+ * Called when:
+ *  - XenBus state has been reconfigure (pci unplug). See xen_pcibk_remove_device
+ *  - XenBus state has been disconnected (guest shutdown). See xen_pcibk_xenbus_remove
+ *  - 'echo BDF > unbind' on pciback module with no guest attached. See pcistub_remove
+ *  - 'echo BDF > unbind' with a guest still using it. See pcistub_remove
+ *
+ *  As such we have to be careful.
+ */
 void pcistub_put_pci_dev(struct pci_dev *dev)
 {
 	struct pcistub_device *psdev, *found_psdev = NULL;
@@ -272,16 +281,16 @@ void pcistub_put_pci_dev(struct pci_dev *dev)
 	 * and want to inhibit the user from fiddling with 'reset'
 	 */
 	pci_reset_function(dev);
-	pci_restore_state(psdev->dev);
+	pci_restore_state(dev);
 
 	/* This disables the device. */
-	xen_pcibk_reset_device(found_psdev->dev);
+	xen_pcibk_reset_device(dev);
 
 	/* And cleanup up our emulated fields. */
-	xen_pcibk_config_free_dyn_fields(found_psdev->dev);
-	xen_pcibk_config_reset_dev(found_psdev->dev);
+	xen_pcibk_config_reset_dev(dev);
+	xen_pcibk_config_free_dyn_fields(dev);
 
-	xen_unregister_device_domain_owner(found_psdev->dev);
+	xen_unregister_device_domain_owner(dev);
 
 	spin_lock_irqsave(&found_psdev->lock, flags);
 	found_psdev->pdev = NULL;
@@ -493,6 +502,8 @@ static int pcistub_seize(struct pci_dev *dev)
 	return err;
 }
 
+/* Called when 'bind'. This means we must _NOT_ call pci_reset_function or
+ * other functions that take the sysfs lock. */
 static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
 	int err = 0;
@@ -520,6 +531,8 @@ out:
 	return err;
 }
 
+/* Called when 'unbind'. This means we must _NOT_ call pci_reset_function or
+ * other functions that take the sysfs lock. */
 static void pcistub_remove(struct pci_dev *dev)
 {
 	struct pcistub_device *psdev, *found_psdev = NULL;
@@ -551,6 +564,8 @@ static void pcistub_remove(struct pci_dev *dev)
 			pr_warn("****** shutdown driver domain before binding device\n");
 			pr_warn("****** to other drivers or domains\n");
 
+			/* N.B. This ends up calling pcistub_put_pci_dev which ends up
+			 * doing the FLR. */
 			xen_pcibk_release_pci_dev(found_psdev->pdev,
 						found_psdev->dev);
 		}

drivers/xen/xen-pciback/xenbus.c

@@ -93,6 +93,8 @@ static void free_pdev(struct xen_pcibk_device *pdev)
 
 	xen_pcibk_disconnect(pdev);
 
+	/* N.B. This calls pcistub_put_pci_dev which does the FLR on all
+	 * of the PCIe devices. */
 	xen_pcibk_release_devices(pdev);
 
 	dev_set_drvdata(&pdev->xdev->dev, NULL);
@@ -286,6 +288,8 @@ static int xen_pcibk_remove_device(struct xen_pcibk_device *pdev,
 	dev_dbg(&dev->dev, "unregistering for %d\n", pdev->xdev->otherend_id);
 	xen_unregister_device_domain_owner(dev);
 
+	/* N.B. This ends up calling pcistub_put_pci_dev which ends up
+	 * doing the FLR. */
 	xen_pcibk_release_pci_dev(pdev, dev);
 
 out: