2022-06-27 21:56:18

by Isaku Yamahata

Subject: [PATCH v7 007/102] KVM: Enable hardware before doing arch VM initialization

From: Sean Christopherson <[email protected]>

Swap the order of hardware_enable_all() and kvm_arch_init_vm() to
accommodate Intel's TDX, which needs VMX to be enabled during VM init in
order to make SEAMCALLs.

This also provides consistent ordering between kvm_create_vm() and
kvm_destroy_vm() with respect to calling kvm_arch_destroy_vm() and
hardware_disable_all().

Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Isaku Yamahata <[email protected]>
Reviewed-by: Paolo Bonzini <[email protected]>
---
virt/kvm/kvm_main.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cee799265ce6..0acb0b6d1f82 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1138,19 +1138,19 @@ static struct kvm *kvm_create_vm(unsigned long type)
rcu_assign_pointer(kvm->buses[i],
kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
if (!kvm->buses[i])
- goto out_err_no_arch_destroy_vm;
+ goto out_err_no_disable;
}

kvm->max_halt_poll_ns = halt_poll_ns;

- r = kvm_arch_init_vm(kvm, type);
- if (r)
- goto out_err_no_arch_destroy_vm;
-
r = hardware_enable_all();
if (r)
goto out_err_no_disable;

+ r = kvm_arch_init_vm(kvm, type);
+ if (r)
+ goto out_err_no_arch_destroy_vm;
+
#ifdef CONFIG_HAVE_KVM_IRQFD
INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
#endif
@@ -1188,10 +1188,10 @@ static struct kvm *kvm_create_vm(unsigned long type)
mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
#endif
out_err_no_mmu_notifier:
- hardware_disable_all();
-out_err_no_disable:
kvm_arch_destroy_vm(kvm);
out_err_no_arch_destroy_vm:
+ hardware_disable_all();
+out_err_no_disable:
WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count));
for (i = 0; i < KVM_NR_BUSES; i++)
kfree(kvm_get_bus(kvm, i));
--
2.25.1

2022-06-28 03:17:21

by Kai Huang

Subject: Re: [PATCH v7 007/102] KVM: Enable hardware before doing arch VM initialization

On Mon, 2022-06-27 at 14:52 -0700, [email protected] wrote:
> From: Sean Christopherson <[email protected]>
>
> Swap the order of hardware_enable_all() and kvm_arch_init_vm() to
> accommodate Intel's TDX, which needs VMX to be enabled during VM init in
> order to make SEAMCALLs.
>
> This also provides consistent ordering between kvm_create_vm() and
> kvm_destroy_vm() with respect to calling kvm_arch_destroy_vm() and
> hardware_disable_all().

Reviewed-by: Kai Huang <[email protected]>

>
> Signed-off-by: Sean Christopherson <[email protected]>
> Signed-off-by: Isaku Yamahata <[email protected]>
> Reviewed-by: Paolo Bonzini <[email protected]>
> ---
> virt/kvm/kvm_main.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index cee799265ce6..0acb0b6d1f82 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1138,19 +1138,19 @@ static struct kvm *kvm_create_vm(unsigned long type)
> rcu_assign_pointer(kvm->buses[i],
> kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
> if (!kvm->buses[i])
> - goto out_err_no_arch_destroy_vm;
> + goto out_err_no_disable;
> }
>
> kvm->max_halt_poll_ns = halt_poll_ns;
>
> - r = kvm_arch_init_vm(kvm, type);
> - if (r)
> - goto out_err_no_arch_destroy_vm;
> -
> r = hardware_enable_all();
> if (r)
> goto out_err_no_disable;
>
> + r = kvm_arch_init_vm(kvm, type);
> + if (r)
> + goto out_err_no_arch_destroy_vm;
> +
> #ifdef CONFIG_HAVE_KVM_IRQFD
> INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
> #endif
> @@ -1188,10 +1188,10 @@ static struct kvm *kvm_create_vm(unsigned long type)
> mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
> #endif
> out_err_no_mmu_notifier:
> - hardware_disable_all();
> -out_err_no_disable:
> kvm_arch_destroy_vm(kvm);
> out_err_no_arch_destroy_vm:
> + hardware_disable_all();
> +out_err_no_disable:
> WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count));
> for (i = 0; i < KVM_NR_BUSES; i++)
> kfree(kvm_get_bus(kvm, i));