[PATCH linux v2 4/9] x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op

[Vitaly Kuznetsov]

HYPERVISOR_vcpu_op() passes Linux's idea of vCPU id as a parameter while
Xen's idea is expected. In some cases these ideas diverge so we need to
do remapping. Convert all callers of HYPERVISOR_vcpu_op() to use
xen_vcpu_nr(). Leave xen_fill_possible_map() and xen_filter_cpu_maps()
intact as they're only being called by PV guests before perpu areas are
initialized. While the issue could be solved by switching to early_percpu
for xen_vcpu_id I think it's not worth it: PV guests will probably never
get to the point where their idea of vCPU id diverges from Xen's.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
Changes since v1:
- Modify all callers of HYPERVISOR_vcpu_op() instead of modifying
  HYPERVISOR_vcpu_op() [David Vrabel]
---
 arch/arm/xen/enlighten.c         |  3 ++-
 arch/x86/xen/enlighten.c         | 10 ++++++----
 arch/x86/xen/irq.c               |  3 ++-
 arch/x86/xen/smp.c               | 11 ++++++-----
 arch/x86/xen/time.c              | 18 ++++++++++++------
 drivers/xen/events/events_base.c |  3 ++-
 drivers/xen/time.c               |  2 +-
 7 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 1678446..6d3a171 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -189,7 +189,8 @@ static void xen_percpu_init(void)
 	info.mfn = virt_to_gfn(vcpup);
 	info.offset = xen_offset_in_page(vcpup);
 
-	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
+	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
+				 &info);
 	BUG_ON(err);
 	per_cpu(xen_vcpu, cpu) = vcpup;
 
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index ff01f3d..7e3bf5a 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -228,7 +228,8 @@ static void xen_vcpu_setup(int cpu)
 	   hypervisor has no unregister variant and this hypercall does not
 	   allow to over-write info.mfn and info.offset.
 	 */
-	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
+	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
+				 &info);
 
 	if (err) {
 		printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
@@ -252,10 +253,11 @@ void xen_vcpu_restore(void)
 
 	for_each_possible_cpu(cpu) {
 		bool other_cpu = (cpu != smp_processor_id());
-		bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL);
+		bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu),
+						NULL);
 
 		if (other_cpu && is_up &&
-		    HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
+		    HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
 			BUG();
 
 		xen_setup_runstate_info(cpu);
@@ -264,7 +266,7 @@ void xen_vcpu_restore(void)
 			xen_vcpu_setup(cpu);
 
 		if (other_cpu && is_up &&
-		    HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
+		    HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
 			BUG();
 	}
 }
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index a1207cb..33e9295 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -109,7 +109,8 @@ static void xen_safe_halt(void)
 static void xen_halt(void)
 {
 	if (irqs_disabled())
-		HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
+		HYPERVISOR_vcpu_op(VCPUOP_down,
+				   xen_vcpu_nr(smp_processor_id()), NULL);
 	else
 		xen_safe_halt();
 }
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 719cf29..a3118f2 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -454,7 +454,7 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 #endif
 	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
 	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir));
-	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
+	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, xen_vcpu_nr(cpu), ctxt))
 		BUG();
 
 	kfree(ctxt);
@@ -492,7 +492,7 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
 	if (rc)
 		return rc;
 
-	rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
+	rc = HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL);
 	BUG_ON(rc);
 
 	while (cpu_report_state(cpu) != CPU_ONLINE)
@@ -520,7 +520,8 @@ static int xen_cpu_disable(void)
 
 static void xen_cpu_die(unsigned int cpu)
 {
-	while (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
+	while (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up,
+						     xen_vcpu_nr(cpu), NULL)) {
 		__set_current_state(TASK_UNINTERRUPTIBLE);
 		schedule_timeout(HZ/10);
 	}
@@ -536,7 +537,7 @@ static void xen_cpu_die(unsigned int cpu)
 static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
 {
 	play_dead_common();
-	HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
+	HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(smp_processor_id()), NULL);
 	cpu_bringup();
 	/*
 	 * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down)
@@ -576,7 +577,7 @@ static void stop_self(void *v)
 
 	set_cpu_online(cpu, false);
 
-	HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
+	HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL);
 	BUG();
 }
 
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 6deba5b..e89568c 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -263,8 +263,10 @@ static int xen_vcpuop_shutdown(struct clock_event_device *evt)
 {
 	int cpu = smp_processor_id();
 
-	if (HYPERVISOR_vcpu_op(VCPUOP_stop_singleshot_timer, cpu, NULL) ||
-	    HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL))
+	if (HYPERVISOR_vcpu_op(VCPUOP_stop_singleshot_timer, xen_vcpu_nr(cpu),
+			       NULL) ||
+	    HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, xen_vcpu_nr(cpu),
+			       NULL))
 		BUG();
 
 	return 0;
@@ -274,7 +276,8 @@ static int xen_vcpuop_set_oneshot(struct clock_event_device *evt)
 {
 	int cpu = smp_processor_id();
 
-	if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL))
+	if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, xen_vcpu_nr(cpu),
+			       NULL))
 		BUG();
 
 	return 0;
@@ -293,7 +296,8 @@ static int xen_vcpuop_set_next_event(unsigned long delta,
 	/* Get an event anyway, even if the timeout is already expired */
 	single.flags = 0;
 
-	ret = HYPERVISOR_vcpu_op(VCPUOP_set_singleshot_timer, cpu, &single);
+	ret = HYPERVISOR_vcpu_op(VCPUOP_set_singleshot_timer, xen_vcpu_nr(cpu),
+				 &single);
 	BUG_ON(ret != 0);
 
 	return ret;
@@ -394,7 +398,8 @@ void xen_timer_resume(void)
 		return;
 
 	for_each_online_cpu(cpu) {
-		if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL))
+		if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer,
+				       xen_vcpu_nr(cpu), NULL))
 			BUG();
 	}
 }
@@ -414,7 +419,8 @@ static void __init xen_time_init(void)
 
 	clocksource_register_hz(&xen_clocksource, NSEC_PER_SEC);
 
-	if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL) == 0) {
+	if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, xen_vcpu_nr(cpu),
+			       NULL) == 0) {
 		/* Successfully turned off 100Hz tick, so we have the
 		   vcpuop-based timer interface */
 		printk(KERN_DEBUG "Xen: using vcpuop timer interface\n");
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 71d49a9..8fb7cbf 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1211,7 +1211,8 @@ void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
 
 #ifdef CONFIG_X86
 	if (unlikely(vector == XEN_NMI_VECTOR)) {
-		int rc =  HYPERVISOR_vcpu_op(VCPUOP_send_nmi, cpu, NULL);
+		int rc =  HYPERVISOR_vcpu_op(VCPUOP_send_nmi, xen_vcpu_nr(cpu),
+					     NULL);
 		if (rc < 0)
 			printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
 		return;
diff --git a/drivers/xen/time.c b/drivers/xen/time.c
index 7107842..781a630 100644
--- a/drivers/xen/time.c
+++ b/drivers/xen/time.c
@@ -82,7 +82,7 @@ void xen_setup_runstate_info(int cpu)
 	area.addr.v = &per_cpu(xen_runstate, cpu);
 
 	if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area,
-			       cpu, &area))
+			       xen_vcpu_nr(cpu), &area))
 		BUG();
 }
 
-- 
2.5.5