[PATCH v3 ppc-for-5.0 2/2] ppc/spapr: Support reboot of secure pseries guest

[Bharata B Rao <bharata@linux.ibm.com>]

A pseries guest can be run as a secure guest on Ultravisor-enabled
POWER platforms. When such a secure guest is reset, we need to
release/reset a few resources both on ultravisor and hypervisor side.
This is achieved by invoking this new ioctl KVM_PPC_SVM_OFF from the
machine reset path.

As part of this ioctl, the secure guest is essentially transitioned
back to normal mode so that it can reboot like a regular guest and
become secure again.

This ioctl has no effect when invoked for a normal guest. If this ioctl
fails for a secure guest, the guest is terminated.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
---
 hw/ppc/spapr.c       |  1 +
 target/ppc/kvm.c     | 15 +++++++++++++++
 target/ppc/kvm_ppc.h |  6 ++++++
 3 files changed, 22 insertions(+)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index f11422fc41..e62c89b3dd 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1597,6 +1597,7 @@ static void spapr_machine_reset(MachineState *machine)
     void *fdt;
     int rc;
 
+    kvmppc_svm_off(&error_fatal);
     spapr_caps_apply(spapr);
 
     first_ppc_cpu = POWERPC_CPU(first_cpu);
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 7406d18945..ae920ec310 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -2900,3 +2900,18 @@ void kvmppc_set_reg_tb_offset(PowerPCCPU *cpu, int64_t tb_offset)
         kvm_set_one_reg(cs, KVM_REG_PPC_TB_OFFSET, &tb_offset);
     }
 }
+
+/*
+ * Don't set error if KVM_PPC_SVM_OFF ioctl is invoked on kernels
+ * that don't support this ioctl.
+ */
+void kvmppc_svm_off(Error **errp)
+{
+    int rc;
+    KVMState *s = KVM_STATE(current_machine->accelerator);
+
+    rc = kvm_vm_ioctl(s, KVM_PPC_SVM_OFF);
+    if (rc && rc != -ENOTTY) {
+        error_setg(errp, "KVM_PPC_SVM_OFF ioctl failed");
+    }
+}
diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
index 47b08a4030..9a9bca1b72 100644
--- a/target/ppc/kvm_ppc.h
+++ b/target/ppc/kvm_ppc.h
@@ -37,6 +37,7 @@ int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu);
 target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu,
                                      bool radix, bool gtse,
                                      uint64_t proc_tbl);
+void kvmppc_svm_off(Error **errp);
 #ifndef CONFIG_USER_ONLY
 bool kvmppc_spapr_use_multitce(void);
 int kvmppc_spapr_enable_inkernel_multitce(void);
@@ -201,6 +202,11 @@ static inline target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu,
     return 0;
 }
 
+static inline void kvmppc_svm_off(Error **errp)
+{
+    return;
+}
+
 static inline void kvmppc_set_reg_ppc_online(PowerPCCPU *cpu,
                                              unsigned int online)
 {
-- 
2.21.0