Merge tag 'for-linus-6.12a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fix from Juergen Gross:
 "A fix for topology information of Xen PV guests"

* tag 'for-linus-6.12a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: mark boot CPU of PV guest in MSR_IA32_APICBASE

Author: torvalds

arch/x86/xen/enlighten_pv.c

@@ -1032,6 +1032,10 @@ static u64 xen_do_read_msr(unsigned int msr, int *err)
 	switch (msr) {
 	case MSR_IA32_APICBASE:
 		val &= ~X2APIC_ENABLE;
+		if (smp_processor_id() == 0)
+			val |= MSR_IA32_APICBASE_BSP;
+		else
+			val &= ~MSR_IA32_APICBASE_BSP;
 		break;
 	}
 	return val;