KVM: PPC: Book3S HV: Support reset of secure guest
Add support for reset of secure guest via a new ioctl KVM_PPC_SVM_OFF.
This ioctl will be issued by QEMU during reset and includes the
the following steps:
- Release all device pages of the secure guest.
- Ask UV to terminate the guest via UV_SVM_TERMINATE ucall
- Unpin the VPA pages so that they can be migrated back to secure
side when guest becomes secure again. This is required because
pinned pages can't be migrated.
- Reinit the partition scoped page tables
After these steps, guest is ready to issue UV_ESM call once again
to switch to secure mode.
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
[Implementation of uv_svm_terminate() and its call from
guest shutdown path]
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[Unpinning of VPA pages]
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index a8e8156..dc53578 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4983,6 +4983,7 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm)
if (nesting_enabled(kvm))
kvmhv_release_all_nested(kvm);
kvm->arch.process_table = 0;
+ uv_svm_terminate(kvm->arch.lpid);
kvmhv_set_ptbl_entry(kvm->arch.lpid, 0, 0);
}
@@ -5425,6 +5426,94 @@ static int kvmhv_store_to_eaddr(struct kvm_vcpu *vcpu, ulong *eaddr, void *ptr,
return rc;
}
+static void unpin_vpa_reset(struct kvm *kvm, struct kvmppc_vpa *vpa)
+{
+ unpin_vpa(kvm, vpa);
+ vpa->gpa = 0;
+ vpa->pinned_addr = NULL;
+ vpa->dirty = false;
+ vpa->update_pending = 0;
+}
+
+/*
+ * IOCTL handler to turn off secure mode of guest
+ *
+ * - Release all device pages
+ * - Issue ucall to terminate the guest on the UV side
+ * - Unpin the VPA pages.
+ * - Reinit the partition scoped page tables
+ */
+static int kvmhv_svm_off(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ int mmu_was_ready;
+ int srcu_idx;
+ int ret = 0;
+ int i;
+
+ if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START))
+ return ret;
+
+ mutex_lock(&kvm->arch.mmu_setup_lock);
+ mmu_was_ready = kvm->arch.mmu_ready;
+ if (kvm->arch.mmu_ready) {
+ kvm->arch.mmu_ready = 0;
+ /* order mmu_ready vs. vcpus_running */
+ smp_mb();
+ if (atomic_read(&kvm->arch.vcpus_running)) {
+ kvm->arch.mmu_ready = 1;
+ ret = -EBUSY;
+ goto out;
+ }
+ }
+
+ srcu_idx = srcu_read_lock(&kvm->srcu);
+ for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+ struct kvm_memory_slot *memslot;
+ struct kvm_memslots *slots = __kvm_memslots(kvm, i);
+
+ if (!slots)
+ continue;
+
+ kvm_for_each_memslot(memslot, slots) {
+ kvmppc_uvmem_drop_pages(memslot, kvm);
+ uv_unregister_mem_slot(kvm->arch.lpid, memslot->id);
+ }
+ }
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
+
+ ret = uv_svm_terminate(kvm->arch.lpid);
+ if (ret != U_SUCCESS) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * When secure guest is reset, all the guest pages are sent
+ * to UV via UV_PAGE_IN before the non-boot vcpus get a
+ * chance to run and unpin their VPA pages. Unpinning of all
+ * VPA pages is done here explicitly so that VPA pages
+ * can be migrated to the secure side.
+ *
+ * This is required to for the secure SMP guest to reboot
+ * correctly.
+ */
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ spin_lock(&vcpu->arch.vpa_update_lock);
+ unpin_vpa_reset(kvm, &vcpu->arch.dtl);
+ unpin_vpa_reset(kvm, &vcpu->arch.slb_shadow);
+ unpin_vpa_reset(kvm, &vcpu->arch.vpa);
+ spin_unlock(&vcpu->arch.vpa_update_lock);
+ }
+
+ kvmppc_setup_partition_table(kvm);
+ kvm->arch.secure_guest = 0;
+ kvm->arch.mmu_ready = mmu_was_ready;
+out:
+ mutex_unlock(&kvm->arch.mmu_setup_lock);
+ return ret;
+}
+
static struct kvmppc_ops kvm_ops_hv = {
.get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv,
.set_sregs = kvm_arch_vcpu_ioctl_set_sregs_hv,
@@ -5468,6 +5557,7 @@ static struct kvmppc_ops kvm_ops_hv = {
.enable_nested = kvmhv_enable_nested,
.load_from_eaddr = kvmhv_load_from_eaddr,
.store_to_eaddr = kvmhv_store_to_eaddr,
+ .svm_off = kvmhv_svm_off,
};
static int kvm_init_subcore_bitmap(void)
