diff mbox series

[08/30] x86/xen/smp_pv: Register fake APICs

Message ID 20240213210251.940043512@linutronix.de
State New
Headers
Series x86/apic: Rework APIC registration |

Commit Message

Thomas Gleixner Feb. 13, 2024, 9:05 p.m. UTC 
  From: Thomas Gleixner <tglx@linutronix.de>

XENPV does not use the APIC. It's just piggy packing on the infrastructure
and fiddles with global variables as it sees fit.

These global variables are going away, so let XENPV register pseudo APIC
IDs to keep the accounting correct and keep up the illusion that XEN/PV is
something sane.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>


---
 arch/x86/xen/smp_pv.c |   35 +++++++++--------------------------
 1 file changed, 9 insertions(+), 26 deletions(-)
---
diff mbox series

Patch

--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -29,6 +29,7 @@ 
 #include <asm/idtentry.h>
 #include <asm/desc.h>
 #include <asm/cpu.h>
+#include <asm/apic.h>
 #include <asm/io_apic.h>
 
 #include <xen/interface/xen.h>
@@ -150,34 +151,16 @@  int xen_smp_intr_init_pv(unsigned int cp
 
 static void __init xen_pv_smp_config(void)
 {
-	int i, rc;
-	unsigned int subtract = 0;
+	u32 apicid = 0;
+	int i;
 
-	num_processors = 0;
-	disabled_cpus = 0;
-	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);
-		} else {
-			set_cpu_possible(i, false);
-			set_cpu_present(i, false);
-			subtract++;
-		}
+	topology_register_boot_apic(apicid++);
+
+	for (i = 1; i < nr_cpu_ids; i++) {
+		if (HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL) < 0)
+			break;
+		topology_register_apic(apicid++, CPU_ACPIID_INVALID, true);
 	}
-#ifdef CONFIG_HOTPLUG_CPU
-	/* This is akin to using 'nr_cpus' on the Linux command line.
-	 * Which is OK as when we use 'dom0_max_vcpus=X' we can only
-	 * have up to X, while nr_cpu_ids is greater than X. This
-	 * normally is not a problem, except when CPU hotplugging
-	 * is involved and then there might be more than X CPUs
-	 * in the guest - which will not work as there is no
-	 * hypercall to expand the max number of VCPUs an already
-	 * running guest has. So cap it up to X. */
-	if (subtract)
-		set_nr_cpu_ids(nr_cpu_ids - subtract);
-#endif
 	/* Pretend to be a proper enumerated system */
 	smp_found_config = 1;
 }