Merge tag 'for-linus-5.17a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - documentation fixes related to Xen

 - enable x2apic mode when available when running as hardware
   virtualized guest under Xen

 - cleanup and fix a corner case of vcpu enumeration when running a
   paravirtualized Xen guest

* tag 'for-linus-5.17a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/Xen: streamline (and fix) PV CPU enumeration
  xen: update missing ioctl magic numers documentation
  Improve docs for IOCTL_GNTDEV_MAP_GRANT_REF
  xen: xenbus_dev.h: delete incorrect file name
  xen/x2apic: enable x2apic mode when supported for HVM

7 files changed, 20 insertions, 50 deletions

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 687efcf245c13d..e6fce2cbd99ed4 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -115,6 +115,7 @@ Code  Seq#    Include File                                           Comments
 'B'   00-1F  linux/cciss_ioctl.h                                     conflict!
 'B'   00-0F  include/linux/pmu.h                                     conflict!
 'B'   C0-FF  advanced bbus                                           <mailto:maassen@uni-freiburg.de>
+'B'   00-0F  xen/xenbus_dev.h                                        conflict!
 'C'   all    linux/soundcard.h                                       conflict!
 'C'   01-2F  linux/capi.h                                            conflict!
 'C'   F0-FF  drivers/net/wan/cosa.h                                  conflict!
@@ -134,6 +135,7 @@ Code  Seq#    Include File                                           Comments
 'F'   80-8F  linux/arcfb.h                                           conflict!
 'F'   DD     video/sstfb.h                                           conflict!
 'G'   00-3F  drivers/misc/sgi-gru/grulib.h                           conflict!
+'G'   00-0F  xen/gntalloc.h, xen/gntdev.h                            conflict!
 'H'   00-7F  linux/hiddev.h                                          conflict!
 'H'   00-0F  linux/hidraw.h                                          conflict!
 'H'   01     linux/mei.h                                             conflict!
@@ -176,6 +178,7 @@ Code  Seq#    Include File                                           Comments
 'P'   60-6F  sound/sscape_ioctl.h                                    conflict!
 'P'   00-0F  drivers/usb/class/usblp.c                               conflict!
 'P'   01-09  drivers/misc/pci_endpoint_test.c                        conflict!
+'P'   00-0F  xen/privcmd.h                                           conflict!
 'Q'   all    linux/soundcard.h
 'R'   00-1F  linux/random.h                                          conflict!
 'R'   01     linux/rfkill.h                                          conflict!
diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
index 1bf2ad34188ada..16f548a661cf6d 100644
--- a/arch/x86/include/asm/xen/hypervisor.h
+++ b/arch/x86/include/asm/xen/hypervisor.h
@@ -43,20 +43,6 @@ static inline uint32_t xen_cpuid_base(void)
 	return hypervisor_cpuid_base("XenVMMXenVMM", 2);
 }
 
-#ifdef CONFIG_XEN
-extern bool __init xen_hvm_need_lapic(void);
-
-static inline bool __init xen_x2apic_para_available(void)
-{
-	return xen_hvm_need_lapic();
-}
-#else
-static inline bool __init xen_x2apic_para_available(void)
-{
-	return (xen_cpuid_base() != 0);
-}
-#endif
-
 struct pci_dev;
 
 #ifdef CONFIG_XEN_PV_DOM0
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index 42300941ec2962..6448c5071117da 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -9,6 +9,7 @@
 #include <xen/events.h>
 #include <xen/interface/memory.h>
 
+#include <asm/apic.h>
 #include <asm/cpu.h>
 #include <asm/smp.h>
 #include <asm/io_apic.h>
@@ -242,15 +243,9 @@ static __init int xen_parse_no_vector_callback(char *arg)
 }
 early_param("xen_no_vector_callback", xen_parse_no_vector_callback);
 
-bool __init xen_hvm_need_lapic(void)
+static __init bool xen_x2apic_available(void)
 {
-	if (xen_pv_domain())
-		return false;
-	if (!xen_hvm_domain())
-		return false;
-	if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
-		return false;
-	return true;
+	return x2apic_supported();
 }
 
 static __init void xen_hvm_guest_late_init(void)
@@ -312,7 +307,7 @@ struct hypervisor_x86 x86_hyper_xen_hvm __initdata = {
 	.detect                 = xen_platform_hvm,
 	.type			= X86_HYPER_XEN_HVM,
 	.init.init_platform     = xen_hvm_guest_init,
-	.init.x2apic_available  = xen_x2apic_para_available,
+	.init.x2apic_available  = xen_x2apic_available,
 	.init.init_mem_mapping	= xen_hvm_init_mem_mapping,
 	.init.guest_late_init	= xen_hvm_guest_late_init,
 	.runtime.pin_vcpu       = xen_pin_vcpu,
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 5004feb16783d4..d47c3d176ae4b7 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1341,10 +1341,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
 
 		xen_acpi_sleep_register();
 
-		/* Avoid searching for BIOS MP tables */
-		x86_init.mpparse.find_smp_config = x86_init_noop;
-		x86_init.mpparse.get_smp_config = x86_init_uint_noop;
-
 		xen_boot_params_init_edd();
 
 #ifdef CONFIG_ACPI
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index 6a8f3b53ab8343..4a6019238ee7df 100644
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -148,28 +148,12 @@ int xen_smp_intr_init_pv(unsigned int cpu)
 	return rc;
 }
 
-static void __init xen_fill_possible_map(void)
-{
-	int i, rc;
-
-	if (xen_initial_domain())
-		return;
-
-	for (i = 0; i < nr_cpu_ids; i++) {
-		rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
-		if (rc >= 0) {
-			num_processors++;
-			set_cpu_possible(i, true);
-		}
-	}
-}
-
-static void __init xen_filter_cpu_maps(void)
+static void __init _get_smp_config(unsigned int early)
 {
 	int i, rc;
 	unsigned int subtract = 0;
 
-	if (!xen_initial_domain())
+	if (early)
 		return;
 
 	num_processors = 0;
@@ -210,7 +194,6 @@ static void __init xen_pv_smp_prepare_boot_cpu(void)
 		 * sure the old memory can be recycled. */
 		make_lowmem_page_readwrite(xen_initial_gdt);
 
-	xen_filter_cpu_maps();
 	xen_setup_vcpu_info_placement();
 
 	/*
@@ -476,5 +459,8 @@ static const struct smp_ops xen_smp_ops __initconst = {
 void __init xen_smp_init(void)
 {
 	smp_ops = xen_smp_ops;
-	xen_fill_possible_map();
+
+	/* Avoid searching for BIOS MP tables */
+	x86_init.mpparse.find_smp_config = x86_init_noop;
+	x86_init.mpparse.get_smp_config = _get_smp_config;
 }
diff --git a/include/uapi/xen/gntdev.h b/include/uapi/xen/gntdev.h
index 9ac5515b9bc220..7a7145395c09c8 100644
--- a/include/uapi/xen/gntdev.h
+++ b/include/uapi/xen/gntdev.h
@@ -47,7 +47,13 @@ struct ioctl_gntdev_grant_ref {
 /*
  * Inserts the grant references into the mapping table of an instance
  * of gntdev. N.B. This does not perform the mapping, which is deferred
- * until mmap() is called with @index as the offset.
+ * until mmap() is called with @index as the offset. @index should be
+ * considered opaque to userspace, with one exception: if no grant
+ * references have ever been inserted into the mapping table of this
+ * instance, @index will be set to 0. This is necessary to use gntdev
+ * with userspace APIs that expect a file descriptor that can be
+ * mmap()'d at offset 0, such as Wayland. If @count is set to 0, this
+ * ioctl will fail.
  */
 #define IOCTL_GNTDEV_MAP_GRANT_REF \
 _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
diff --git a/include/xen/xenbus_dev.h b/include/xen/xenbus_dev.h
index bbee8c6a349dec..4dc45a51c044f8 100644
--- a/include/xen/xenbus_dev.h
+++ b/include/xen/xenbus_dev.h
@@ -1,6 +1,4 @@
 /******************************************************************************
- * evtchn.h
- *
  * Interface to /dev/xen/xenbus_backend.
  *
  * Copyright (c) 2011 Bastian Blank <waldi@debian.org>