kernel_optimize_test/virt/kvm
Sean Christopherson d5c48debcc KVM: Move initialization of preempt notifier to kvm_vcpu_init()
Initialize the preempt notifier immediately in kvm_vcpu_init() to pave
the way for removing kvm_arch_vcpu_setup(), i.e. to allow arch specific
code to call vcpu_load() during kvm_arch_vcpu_create().

Back when preemption support was added, the location of the call to init
the preempt notifier was perfectly sane.  The overall vCPU creation flow
featured a single arch specific hook and the preempt notifer was used
immediately after its initialization (by vcpu_load()).  E.g.:

        vcpu = kvm_arch_ops->vcpu_create(kvm, n);
        if (IS_ERR(vcpu))
                return PTR_ERR(vcpu);

        preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);

        vcpu_load(vcpu);
        r = kvm_mmu_setup(vcpu);
        vcpu_put(vcpu);
        if (r < 0)
                goto free_vcpu;

Today, the call to preempt_notifier_init() is sandwiched between two
arch specific calls, kvm_arch_vcpu_create() and kvm_arch_vcpu_setup(),
which needlessly forces x86 (and possibly others?) to split its vCPU
creation flow.  Init the preempt notifier prior to any arch specific
call so that each arch can independently decide how best to organize
its creation flow.

Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27 19:59:25 +01:00
..
arm KVM: Move vcpu alloc and init invocation to common code 2020-01-27 19:59:20 +01:00
async_pf.c KVM: async_pf: drop kvm_arch_async_page_present wrappers 2020-01-23 09:51:08 +01:00
async_pf.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 2019-06-19 17:09:56 +02:00
coalesced_mmio.c KVM: MMIO: get rid of odd out_err label in kvm_coalesced_mmio_init 2019-11-15 11:44:01 +01:00
coalesced_mmio.h
eventfd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 2019-06-19 17:09:56 +02:00
irqchip.c KVM/arm updates for 5.3 2019-07-11 15:14:16 +02:00
Kconfig
kvm_main.c KVM: Move initialization of preempt notifier to kvm_vcpu_init() 2020-01-27 19:59:25 +01:00
vfio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vfio.h