Here is the code path which shows kvm_mmu_setup() is invoked after
kvm_mmu_create(). Since kvm_mmu_setup() is only invoked in this code path,
this means the root_hpa and prev_roots are guaranteed to be invalid. And
it is not necessary to reset it again.
kvm_vm_ioctl_create_vcpu()
kvm_arch_vcpu_create()
vmx_create_vcpu()
kvm_vcpu_init()
kvm_arch_vcpu_init()
kvm_mmu_create()
kvm_arch_vcpu_setup()
kvm_mmu_setup()
kvm_init_mmu()
This patch set reset_roots to false in kmv_mmu_setup().
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Reviewed-by: Liran Alon <liran.alon@xxxxxxxxxx>
---
v3: add a comment in code based on Liran comment.
v2: adjust changelog based on Sean Christopherson comment
---
arch/x86/kvm/mmu.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index b2b88454b1d8..899c029cff0d 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5413,7 +5413,12 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu)
{
MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu.root_hpa));
- kvm_init_mmu(vcpu, true);
+ /*
+ * kvm_mmu_setup() is called only on vCPU initialization.
+ * Therefore, no need to reset mmu roots as they are not yet
+ * initialized.
+ */
+ kvm_init_mmu(vcpu, false);
}
static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm,
--
2.15.1
