Merge tag 'for-linus-6.0-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull more xen updates from Juergen Gross:

 - fix the handling of the "persistent grants" feature negotiation
   between Xen blkfront and Xen blkback drivers

 - a cleanup of xen.config and adding xen.config to Xen section in
   MAINTAINERS

 - support HVMOP_set_evtchn_upcall_vector, which is more compliant to
   "normal" interrupt handling than the global callback used up to now

 - further small cleanups

* tag 'for-linus-6.0-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  MAINTAINERS: add xen config fragments to XEN HYPERVISOR sections
  xen: remove XEN_SCRUB_PAGES in xen.config
  xen/pciback: Fix comment typo
  xen/xenbus: fix return type in xenbus_file_read()
  xen-blkfront: Apply 'feature_persistent' parameter when connect
  xen-blkback: Apply 'feature_persistent' parameter when connect
  xen-blkback: fix persistent grants negotiation
  x86/xen: Add support for HVMOP_set_evtchn_upcall_vector

5 files changed, 59 insertions, 24 deletions

diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 97de13b14175..ee7ad2fb432d 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -157,6 +157,11 @@ static int xen_blkif_alloc_rings(struct xen_blkif *blkif)
 	return 0;
 }
 
+/* Enable the persistent grants feature. */
+static bool feature_persistent = true;
+module_param(feature_persistent, bool, 0644);
+MODULE_PARM_DESC(feature_persistent, "Enables the persistent grants feature");
+
 static struct xen_blkif *xen_blkif_alloc(domid_t domid)
 {
 	struct xen_blkif *blkif;
@@ -472,12 +477,6 @@ static void xen_vbd_free(struct xen_vbd *vbd)
 	vbd->bdev = NULL;
 }
 
-/* Enable the persistent grants feature. */
-static bool feature_persistent = true;
-module_param(feature_persistent, bool, 0644);
-MODULE_PARM_DESC(feature_persistent,
-		"Enables the persistent grants feature");
-
 static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
 			  unsigned major, unsigned minor, int readonly,
 			  int cdrom)
@@ -520,8 +519,6 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
 	if (bdev_max_secure_erase_sectors(bdev))
 		vbd->discard_secure = true;
 
-	vbd->feature_gnt_persistent = feature_persistent;
-
 	pr_debug("Successful creation of handle=%04x (dom=%u)\n",
 		handle, blkif->domid);
 	return 0;
@@ -1087,10 +1084,9 @@ static int connect_ring(struct backend_info *be)
 		xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol);
 		return -ENOSYS;
 	}
-	if (blkif->vbd.feature_gnt_persistent)
-		blkif->vbd.feature_gnt_persistent =
-			xenbus_read_unsigned(dev->otherend,
-					"feature-persistent", 0);
+
+	blkif->vbd.feature_gnt_persistent = feature_persistent &&
+		xenbus_read_unsigned(dev->otherend, "feature-persistent", 0);
 
 	blkif->vbd.overflow_max_grants = 0;
 
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index dc48298225a6..8e56e69fb4c4 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1988,8 +1988,6 @@ static int blkfront_probe(struct xenbus_device *dev,
 	info->vdevice = vdevice;
 	info->connected = BLKIF_STATE_DISCONNECTED;
 
-	info->feature_persistent = feature_persistent;
-
 	/* Front end dir is a number, which is used as the id. */
 	info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
 	dev_set_drvdata(&dev->dev, info);
@@ -2283,7 +2281,7 @@ static void blkfront_gather_backend_features(struct blkfront_info *info)
 	if (xenbus_read_unsigned(info->xbdev->otherend, "feature-discard", 0))
 		blkfront_setup_discard(info);
 
-	if (info->feature_persistent)
+	if (feature_persistent)
 		info->feature_persistent =
 			!!xenbus_read_unsigned(info->xbdev->otherend,
 					       "feature-persistent", 0);
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 5e8321f43cbd..c443f04aaad7 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -45,6 +45,7 @@
 #include <asm/irq.h>
 #include <asm/io_apic.h>
 #include <asm/i8259.h>
+#include <asm/xen/cpuid.h>
 #include <asm/xen/pci.h>
 #endif
 #include <asm/sync_bitops.h>
@@ -2184,6 +2185,7 @@ static struct irq_chip xen_percpu_chip __read_mostly = {
 	.irq_ack		= ack_dynirq,
 };
 
+#ifdef CONFIG_X86
 #ifdef CONFIG_XEN_PVHVM
 /* Vector callbacks are better than PCI interrupts to receive event
  * channel notifications because we can receive vector callbacks on any
@@ -2196,11 +2198,48 @@ void xen_setup_callback_vector(void)
 		callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
 		if (xen_set_callback_via(callback_via)) {
 			pr_err("Request for Xen HVM callback vector failed\n");
-			xen_have_vector_callback = 0;
+			xen_have_vector_callback = false;
 		}
 	}
 }
 
+/*
+ * Setup per-vCPU vector-type callbacks. If this setup is unavailable,
+ * fallback to the global vector-type callback.
+ */
+static __init void xen_init_setup_upcall_vector(void)
+{
+	if (!xen_have_vector_callback)
+		return;
+
+	if ((cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_UPCALL_VECTOR) &&
+	    !xen_set_upcall_vector(0))
+		xen_percpu_upcall = true;
+	else if (xen_feature(XENFEAT_hvm_callback_vector))
+		xen_setup_callback_vector();
+	else
+		xen_have_vector_callback = false;
+}
+
+int xen_set_upcall_vector(unsigned int cpu)
+{
+	int rc;
+	xen_hvm_evtchn_upcall_vector_t op = {
+		.vector = HYPERVISOR_CALLBACK_VECTOR,
+		.vcpu = per_cpu(xen_vcpu_id, cpu),
+	};
+
+	rc = HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector, &op);
+	if (rc)
+		return rc;
+
+	/* Trick toolstack to think we are enlightened. */
+	if (!cpu)
+		rc = xen_set_callback_via(1);
+
+	return rc;
+}
+
 static __init void xen_alloc_callback_vector(void)
 {
 	if (!xen_have_vector_callback)
@@ -2211,8 +2250,11 @@ static __init void xen_alloc_callback_vector(void)
 }
 #else
 void xen_setup_callback_vector(void) {}
+static inline void xen_init_setup_upcall_vector(void) {}
+int xen_set_upcall_vector(unsigned int cpu) {}
 static inline void xen_alloc_callback_vector(void) {}
-#endif
+#endif /* CONFIG_XEN_PVHVM */
+#endif /* CONFIG_X86 */
 
 bool xen_fifo_events = true;
 module_param_named(fifo_events, xen_fifo_events, bool, 0);
@@ -2272,10 +2314,9 @@ void __init xen_init_IRQ(void)
 		if (xen_initial_domain())
 			pci_xen_initial_domain();
 	}
-	if (xen_feature(XENFEAT_hvm_callback_vector)) {
-		xen_setup_callback_vector();
-		xen_alloc_callback_vector();
-	}
+	xen_init_setup_upcall_vector();
+	xen_alloc_callback_vector();
+
 
 	if (xen_hvm_domain()) {
 		native_init_IRQ();
diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index 3fbc21466a93..84e014490950 100644
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -159,7 +159,7 @@ int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
 		return XEN_PCI_ERR_op_failed;
 	}
 
-	/* The value the guest needs is actually the IDT vector, not the
+	/* The value the guest needs is actually the IDT vector, not
 	 * the local domain's IRQ number. */
 
 	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index 597af455a522..0792fda49a15 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -128,7 +128,7 @@ static ssize_t xenbus_file_read(struct file *filp,
 {
 	struct xenbus_file_priv *u = filp->private_data;
 	struct read_buffer *rb;
-	unsigned i;
+	ssize_t i;
 	int ret;
 
 	mutex_lock(&u->reply_mutex);
@@ -148,7 +148,7 @@ again:
 	rb = list_entry(u->read_buffers.next, struct read_buffer, list);
 	i = 0;
 	while (i < len) {
-		unsigned sz = min((unsigned)len - i, rb->len - rb->cons);
+		size_t sz = min_t(size_t, len - i, rb->len - rb->cons);
 
 		ret = copy_to_user(ubuf + i, &rb->msg[rb->cons], sz);