[PATCH v9] s390x: protvirt: Fence huge pages

[Janosch Frank]

Let's bail out of the protected transition if we detect that huge
pages might be in use.

Signed-off-by: Janosch Frank <address@hidden>
---

I'd like to squash this into the unpack patch to give a proper error
message if we try to transition into the protected mode while being
backed by huge pages. 

---
 hw/s390x/ipl.h             | 16 ++++++++++++++++
 hw/s390x/s390-virtio-ccw.c |  1 -
 target/s390x/diag.c        | 23 ++++++++---------------
 target/s390x/kvm-stub.c    |  5 +++++
 target/s390x/kvm.c         |  5 +++++
 target/s390x/kvm_s390x.h   |  1 +
 6 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h
index af5bb130a6334821..95e3183c9cccf8b6 100644
--- a/hw/s390x/ipl.h
+++ b/hw/s390x/ipl.h
@@ -185,6 +185,22 @@ struct S390IPLState {
 typedef struct S390IPLState S390IPLState;
 QEMU_BUILD_BUG_MSG(offsetof(S390IPLState, iplb) & 3, "alignment of iplb 
wrong");
 
+#define DIAG_308_RC_OK              0x0001
+#define DIAG_308_RC_NO_CONF         0x0102
+#define DIAG_308_RC_INVALID         0x0402
+#define DIAG_308_RC_NO_PV_CONF      0x0902
+#define DIAG_308_RC_INVAL_FOR_PV    0x0a02
+
+#define DIAG308_RESET_MOD_CLR       0
+#define DIAG308_RESET_LOAD_NORM     1
+#define DIAG308_LOAD_CLEAR          3
+#define DIAG308_LOAD_NORMAL_DUMP    4
+#define DIAG308_SET                 5
+#define DIAG308_STORE               6
+#define DIAG308_PV_SET              8
+#define DIAG308_PV_STORE            9
+#define DIAG308_PV_START            10
+
 #define S390_IPL_TYPE_FCP 0x00
 #define S390_IPL_TYPE_CCW 0x02
 #define S390_IPL_TYPE_PV 0x05
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index ebdaaa3a001f6e8c..d32f35c7f47b9c1d 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -361,7 +361,6 @@ out_err:
     return rc;
 }
 
-#define DIAG_308_RC_INVAL_FOR_PV    0x0a02
 static void s390_machine_inject_pv_error(CPUState *cs)
 {
     int r1 = (cs->kvm_run->s390_sieic.ipa & 0x00f0) >> 4;
diff --git a/target/s390x/diag.c b/target/s390x/diag.c
index b245e557037ded06..b1ca81633b83bbdc 100644
--- a/target/s390x/diag.c
+++ b/target/s390x/diag.c
@@ -21,6 +21,7 @@
 #include "hw/s390x/ipl.h"
 #include "hw/s390x/s390-virtio-ccw.h"
 #include "hw/s390x/pv.h"
+#include "kvm_s390x.h"
 
 int handle_diag_288(CPUS390XState *env, uint64_t r1, uint64_t r3)
 {
@@ -50,21 +51,6 @@ int handle_diag_288(CPUS390XState *env, uint64_t r1, 
uint64_t r3)
     return diag288_class->handle_timer(diag288, func, timeout);
 }
 
-#define DIAG_308_RC_OK              0x0001
-#define DIAG_308_RC_NO_CONF         0x0102
-#define DIAG_308_RC_INVALID         0x0402
-#define DIAG_308_RC_NO_PV_CONF      0x0902
-
-#define DIAG308_RESET_MOD_CLR       0
-#define DIAG308_RESET_LOAD_NORM     1
-#define DIAG308_LOAD_CLEAR          3
-#define DIAG308_LOAD_NORMAL_DUMP    4
-#define DIAG308_SET                 5
-#define DIAG308_STORE               6
-#define DIAG308_PV_SET              8
-#define DIAG308_PV_STORE            9
-#define DIAG308_PV_START            10
-
 static int diag308_parm_check(CPUS390XState *env, uint64_t r1, uint64_t addr,
                               uintptr_t ra, bool write)
 {
@@ -166,6 +152,13 @@ out:
             return;
         }
 
+        if (kvm_s390_get_hpage_1m()) {
+            error_report("Protected VMs can currently not be backed with "
+                         "huge pages");
+            env->regs[r1 + 1] = DIAG_308_RC_INVAL_FOR_PV;
+            return;
+        }
+
         s390_ipl_reset_request(cs, S390_RESET_PV);
         break;
     default:
diff --git a/target/s390x/kvm-stub.c b/target/s390x/kvm-stub.c
index c4cd497f850eb9c7..aa185017a2a886ca 100644
--- a/target/s390x/kvm-stub.c
+++ b/target/s390x/kvm-stub.c
@@ -39,6 +39,11 @@ int kvm_s390_vcpu_interrupt_post_load(S390CPU *cpu)
     return 0;
 }
 
+int kvm_s390_get_hpage_1m(void)
+{
+    return 0;
+}
+
 int kvm_s390_get_ri(void)
 {
     return 0;
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 1d6fd6a27b48e35f..c695941076b7aead 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -321,6 +321,11 @@ void kvm_s390_set_max_pagesize(uint64_t pagesize, Error 
**errp)
     cap_hpage_1m = 1;
 }
 
+int kvm_s390_get_hpage_1m(void)
+{
+    return cap_hpage_1m;
+}
+
 static void ccw_machine_class_foreach(ObjectClass *oc, void *opaque)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index 0b21789796d7c462..dea813f450153c34 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -23,6 +23,7 @@ void kvm_s390_program_interrupt(S390CPU *cpu, uint16_t code);
 int kvm_s390_set_cpu_state(S390CPU *cpu, uint8_t cpu_state);
 void kvm_s390_vcpu_interrupt_pre_save(S390CPU *cpu);
 int kvm_s390_vcpu_interrupt_post_load(S390CPU *cpu);
+int kvm_s390_get_hpage_1m(void);
 int kvm_s390_get_ri(void);
 int kvm_s390_get_gs(void);
 int kvm_s390_get_clock(uint8_t *tod_high, uint64_t *tod_clock);
-- 
2.25.1