KVM: svm: avic: Add support for dynamic setup/teardown of virtual APIC backing page

Re-factor avic_init_access_page() to avic_update_access_page() since
activate/deactivate AVIC requires setting/unsetting the memory region used
for virtual APIC backing page (APIC_ACCESS_PAGE_PRIVATE_MEMSLOT).

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index e6118d1..dcea6b6 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1729,23 +1729,22 @@ static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu,
  * field of the VMCB. Therefore, we set up the
  * APIC_ACCESS_PAGE_PRIVATE_MEMSLOT (4KB) here.
  */
-static int avic_init_access_page(struct kvm_vcpu *vcpu)
+static int avic_update_access_page(struct kvm *kvm, bool activate)
 {
-       struct kvm *kvm = vcpu->kvm;
        int ret = 0;
 
        mutex_lock(&kvm->slots_lock);
-       if (kvm->arch.apic_access_page_done)
+       if (kvm->arch.apic_access_page_done == activate)
                goto out;
 
        ret = __x86_set_memory_region(kvm,
                                      APIC_ACCESS_PAGE_PRIVATE_MEMSLOT,
                                      APIC_DEFAULT_PHYS_BASE,
-                                     PAGE_SIZE);
+                                     activate ? PAGE_SIZE : 0);
        if (ret)
                goto out;
 
-       kvm->arch.apic_access_page_done = true;
+       kvm->arch.apic_access_page_done = activate;
 out:
        mutex_unlock(&kvm->slots_lock);
        return ret;
@@ -1758,7 +1757,7 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu)
        int id = vcpu->vcpu_id;
        struct vcpu_svm *svm = to_svm(vcpu);
 
-       ret = avic_init_access_page(vcpu);
+       ret = avic_update_access_page(vcpu->kvm, true);
        if (ret)
                return ret;