linux_dsm_epyc7002/arch/x86/kvm
Srivatsa S. Bhat 460dd42e11 x86, kvm: Fix CPU hotplug callback registration
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the kvm code in x86 by using this latter form of callback registration.

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-20 13:43:44 +01:00
..
cpuid.c kvm, cpuid: Fix sparse warning 2013-11-07 12:27:46 +02:00
cpuid.h KVM: x86: Validate guest writes to MSR_IA32_APICBASE 2014-01-27 14:39:44 +01:00
emulate.c KVM: emulator: cleanup decode_register_operand() a bit 2013-11-05 09:11:30 +02:00
i8254.c KVM: x86: limit PIT timer frequency 2014-01-15 12:43:54 +01:00
i8254.h KVM: fold kvm_pit_timer into kvm_kpit_state 2012-08-01 00:21:07 -03:00
i8259.c KVM: inject ExtINT interrupt before APIC interrupts 2012-12-13 23:05:21 -02:00
irq.c x86, apicv: add virtual interrupt delivery support 2013-01-29 10:48:19 +02:00
irq.h KVM: switch to symbolic name for irq_states size 2012-07-20 16:12:16 -03:00
Kconfig kvm: make KVM_MMU_AUDIT help text more readable 2014-01-20 12:59:26 +01:00
kvm_cache_regs.h KVM: MMU: Do not unconditionally read PDPTE from guest memory 2011-09-25 19:18:01 +03:00
lapic.c First round of KVM updates for 3.14; PPC parts will come next week. 2014-01-22 21:40:43 -08:00
lapic.h KVM: x86: Validate guest writes to MSR_IA32_APICBASE 2014-01-27 14:39:44 +01:00
Makefile kvm: Add VFIO device 2013-10-30 19:02:03 +01:00
mmu_audit.c kvm: mmu: delay mmu audit activation 2013-11-20 11:12:56 +02:00
mmu.c KVM: MMU: drop read-only large sptes when creating lower level sptes 2014-02-26 17:23:32 +01:00
mmu.h KVM: mmu: change useless int return types to void 2013-10-03 15:44:02 +03:00
mmutrace.h KVM: MMU: add tracepoint for check_mmio_spte 2013-06-27 14:20:37 +03:00
paging_tmpl.h KVM: x86: handle invalid root_hpa everywhere 2014-01-15 12:16:16 +01:00
pmu.c perf, kvm: Support the in_tx/in_tx_cp modifiers in KVM arch perfmon emulation v5 2013-07-19 18:24:45 +02:00
svm.c KVM: SVM: fix cr8 intercept window 2014-03-12 18:21:10 +01:00
trace.h kvm: Add a tracepoint write_tsc_offset 2013-06-27 14:20:51 +03:00
tss.h KVM: x86: hardware task switching support 2008-04-27 12:00:39 +03:00
vmx.c kvm, vmx: Really fix lazy FPU on nested guest 2014-02-27 22:54:11 +01:00
x86.c x86, kvm: Fix CPU hotplug callback registration 2014-03-20 13:43:44 +01:00
x86.h KVM: x86: limit PIT timer frequency 2014-01-15 12:43:54 +01:00