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

isaku.yamahata
2022-06-27T21:54:57Z

From: Sean Christopherson <sean.j.christopherson@intel.com>

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 <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
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