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 <[email protected]>
---
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 8b7534cc953b..f592dd4ce8f2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -5961,6 +5961,7 @@ 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);
@@ -5970,7 +5971,6 @@ 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);
--
2.38.1.431.g37b22c650d-goog
On Wed, Nov 02 2022, Sean Christopherson <[email protected]> wrote:
> 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 <[email protected]>
> ---
> virt/kvm/kvm_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Looks safe to me.
Reviewed-by: Cornelia Huck <[email protected]>
On Wed, 2022-11-02 at 23:18 +0000, Sean Christopherson wrote:
> 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 <[email protected]>
> ---
> virt/kvm/kvm_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Eric Farman <[email protected]>