[PATCH v2 04/13] s390x: protvirt: Handle diag 308 subcodes 0,1,3,4

[Janosch Frank]

Now that we know the protection state off the cpus, we can start
handling all diag 308 subcodes in the protected state.

For subcodes 0 and 1 we need to unshare all pages before continuing,
so the guest doesn't accidentally expose data when dumping.

For subcode 3/4 we tear down the protected VM and reboot into
unprotected mode. We do not provide a secure reboot.

Before we can do the unshare calls, we need to mark all cpus as
stopped.

Signed-off-by: Janosch Frank <fran...@linux.ibm.com>
---
 hw/s390x/s390-virtio-ccw.c | 31 ++++++++++++++++++++++++++++---
 target/s390x/diag.c        |  4 ++++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index f9481ccace..e2a302398d 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -319,11 +319,26 @@ static inline void s390_do_cpu_ipl(CPUState *cs, 
run_on_cpu_data arg)
     s390_cpu_set_state(S390_CPU_STATE_OPERATING, cpu);
 }
 
+static void s390_pv_prepare_reset(CPUS390XState *env)
+{
+    CPUState *cs;
+
+    if (!env->pv) {
+        return;
+    }
+    CPU_FOREACH(cs) {
+        s390_cpu_set_state(S390_CPU_STATE_STOPPED, S390_CPU(cs));
+    }
+    s390_pv_unshare();
+    s390_pv_perf_clear_reset();
+}
+
 static void s390_machine_reset(MachineState *machine)
 {
     enum s390_reset reset_type;
     CPUState *cs, *t;
     S390CPU *cpu;
+    CPUS390XState *env;
 
     /* get the reset parameters, reset them once done */
     s390_ipl_get_reset_request(&cs, &reset_type);
@@ -332,10 +347,18 @@ static void s390_machine_reset(MachineState *machine)
     s390_cmma_reset();
 
     cpu = S390_CPU(cs);
+    env = &cpu->env;
 
     switch (reset_type) {
     case S390_RESET_EXTERNAL:
     case S390_RESET_REIPL:
+        if (env->pv) {
+            CPU_FOREACH(t) {
+                s390_pv_vcpu_destroy(t);
+            }
+            s390_pv_vm_destroy();
+        }
+
         qemu_devices_reset();
         s390_crypto_reset();
 
@@ -343,21 +366,23 @@ static void s390_machine_reset(MachineState *machine)
         run_on_cpu(cs, s390_do_cpu_ipl, RUN_ON_CPU_NULL);
         break;
     case S390_RESET_MODIFIED_CLEAR:
+        subsystem_reset();
+        s390_crypto_reset();
+        s390_pv_prepare_reset(env);
         CPU_FOREACH(t) {
             run_on_cpu(t, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
         }
-        subsystem_reset();
-        s390_crypto_reset();
         run_on_cpu(cs, s390_do_cpu_load_normal, RUN_ON_CPU_NULL);
         break;
     case S390_RESET_LOAD_NORMAL:
+        subsystem_reset();
+        s390_pv_prepare_reset(env);
         CPU_FOREACH(t) {
             if (t == cs) {
                 continue;
             }
             run_on_cpu(t, s390_do_cpu_reset, RUN_ON_CPU_NULL);
         }
-        subsystem_reset();
         run_on_cpu(cs, s390_do_cpu_initial_reset, RUN_ON_CPU_NULL);
         run_on_cpu(cs, s390_do_cpu_load_normal, RUN_ON_CPU_NULL);
         break;
diff --git a/target/s390x/diag.c b/target/s390x/diag.c
index 112a6c92e0..5489fc721a 100644
--- a/target/s390x/diag.c
+++ b/target/s390x/diag.c
@@ -68,6 +68,10 @@ int handle_diag_288(CPUS390XState *env, uint64_t r1, 
uint64_t r3)
 static int diag308_parm_check(CPUS390XState *env, uint64_t r1, uint64_t addr,
                               uintptr_t ra, bool write)
 {
+    /* Handled by the Ultravisor */
+    if (env->pv) {
+        return 0;
+    }
     if ((r1 & 1) || (addr & ~TARGET_PAGE_MASK)) {
         s390_program_interrupt(env, PGM_SPECIFICATION, ra);
         return -1;
-- 
2.20.1