[PATCH v2 04/50] KVM: Teardown VFIO ops earlier in kvm_exit()

From: Sean Christopherson
Date: Wed Nov 30 2022 - 18:10:11 EST


Move the call to kvm_vfio_ops_exit() further up kvm_exit() to try and
bring some amount of symmetry to the setup order in kvm_init(), and more
importantly so that the arch hooks are invoked dead last by kvm_exit().
This will allow arch code to move away from the arch hooks without any
change in ordering between arch code and common code in kvm_exit().

That kvm_vfio_ops_exit() is called last appears to be 100% arbitrary. It
was bolted on after the fact by commit 571ee1b68598 ("kvm: vfio: fix
unregister kvm_device_ops of vfio"). The nullified kvm_device_ops_table
is also local to kvm_main.c and is used only when there are active VMs,
so unless arch code is doing something truly bizarre, nullifying the
table earlier in kvm_exit() is little more than a nop.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Reviewed-by: Eric Farman <farman@xxxxxxxxxxxxx>
---
virt/kvm/kvm_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ded88ad6c2d8..988f7d92db2e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -5980,6 +5980,7 @@ void kvm_exit(void)
for_each_possible_cpu(cpu)
free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
kmem_cache_destroy(kvm_vcpu_cache);
+ kvm_vfio_ops_exit();
kvm_async_pf_deinit();
unregister_syscore_ops(&kvm_syscore_ops);
unregister_reboot_notifier(&kvm_reboot_notifier);
@@ -5989,7 +5990,6 @@ void kvm_exit(void)
free_cpumask_var(cpus_hardware_enabled);
kvm_arch_hardware_unsetup();
kvm_arch_exit();
- kvm_vfio_ops_exit();
}
EXPORT_SYMBOL_GPL(kvm_exit);

--
2.38.1.584.g0f3c55d4c2-goog