[Qemu-devel] [PATCH 5/8] s390: Cleanup sclp functions

[Jens Freimann <jfrei@de.ibm.com>]

From: Christian Borntraeger <borntraeger@de.ibm.com>

The sclp facility on s390 is a hardware that is external to the cpu.
Lets cleanup the definitions and move the functionality into a separate
file under hw/.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Freimann <jfrei@de.ibm.com>
---
 Makefile.target          |    2 +-
 hw/s390-sclp.c           |   42 ++++++++++++++++++++++++++++++++++++++++++
 hw/s390-sclp.h           |   34 ++++++++++++++++++++++++++++++++++
 target-s390x/cpu.h       |   11 -----------
 target-s390x/kvm.c       |    5 ++---
 target-s390x/op_helper.c |   39 +++++++++++++++++----------------------
 6 files changed, 96 insertions(+), 37 deletions(-)
 create mode 100644 hw/s390-sclp.c
 create mode 100644 hw/s390-sclp.h

diff --git a/Makefile.target b/Makefile.target
index 1582904..fed2d72 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -374,7 +374,7 @@ obj-sh4-y += ide/mmio.o
 obj-m68k-y = an5206.o mcf5206.o mcf_uart.o mcf_intc.o mcf5208.o mcf_fec.o
 obj-m68k-y += m68k-semi.o dummy_m68k.o
 
-obj-s390x-y = s390-virtio-bus.o s390-virtio.o
+obj-s390x-y = s390-virtio-bus.o s390-virtio.o s390-sclp.o
 
 obj-alpha-y = mc146818rtc.o
 obj-alpha-y += alpha_pci.o alpha_dp264.o alpha_typhoon.o
diff --git a/hw/s390-sclp.c b/hw/s390-sclp.c
new file mode 100644
index 0000000..c046441
--- /dev/null
+++ b/hw/s390-sclp.c
@@ -0,0 +1,42 @@
+/*
+ * sclp facility
+ * Copyright IBM Corp. 2012
+ * Author: Christian Borntraeger <borntraeger@de.ibm.com>
+ *
+ */
+
+#include "cpu.h"
+#include "kvm.h"
+#include "hw/s390-sclp.h"
+
+int sclp_read_info(CPUS390XState *env, struct sccb *sccb)
+{
+    int shift = 0;
+
+    while ((ram_size >> (20 + shift)) > 65535) {
+        shift++;
+    }
+    sccb->c.read_info.rnmax = cpu_to_be16(ram_size >> (20 + shift));
+    sccb->c.read_info.rnsize = 1 << shift;
+    sccb->h.response_code = cpu_to_be16(0x10);
+
+    return 0;
+}
+
+void sclp_service_interrupt(CPUS390XState *env, uint32_t sccb)
+{
+    if (!sccb) {
+        return;
+    }
+
+    if (kvm_enabled()) {
+#ifdef CONFIG_KVM
+        kvm_s390_interrupt_internal(env, KVM_S390_INT_SERVICE,
+                                    (sccb & ~3), 0, 1);
+#endif
+    } else {
+        env->psw.addr += 4;
+        cpu_inject_ext(env, EXT_SERVICE, (sccb & ~3), 0);
+    }
+}
+
diff --git a/hw/s390-sclp.h b/hw/s390-sclp.h
new file mode 100644
index 0000000..e335b21
--- /dev/null
+++ b/hw/s390-sclp.h
@@ -0,0 +1,34 @@
+#include <stdint.h>
+#include <qemu-common.h>
+
+
+/* SCLP command codes */
+#define SCLP_CMDW_READ_SCP_INFO                 0x00020001
+#define SCLP_CMDW_READ_SCP_INFO_FORCED          0x00120001
+
+/* SCLP response codes */
+#define SCLP_RC_SCCB_RESOURCE_INSUFFICENT       0x07f0
+
+struct sccb_header {
+    uint16_t length;
+#define SCLP_FC_NORMAL_WRITE                    0
+    uint8_t function_code;
+    uint8_t control_mask[3];
+    uint16_t response_code;
+} __attribute__((packed));
+
+struct read_info_sccb {
+    uint16_t rnmax;
+    uint8_t rnsize;
+} __attribute__((packed));
+
+struct sccb {
+    struct sccb_header h;
+    union {
+        struct read_info_sccb read_info;
+        char data[4088];
+    } c;
+ } __attribute__((packed));
+
+int sclp_read_info(CPUS390XState *env, struct sccb *sccb);
+void sclp_service_interrupt(CPUS390XState *env, uint32_t sccb);
diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index 2f3f394..d0199d7 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -591,17 +591,6 @@ static inline const char *cc_name(int cc_op)
     return cc_names[cc_op];
 }
 
-/* SCLP PV interface defines */
-#define SCLP_CMDW_READ_SCP_INFO         0x00020001
-#define SCLP_CMDW_READ_SCP_INFO_FORCED  0x00120001
-
-#define SCP_LENGTH                      0x00
-#define SCP_FUNCTION_CODE               0x02
-#define SCP_CONTROL_MASK                0x03
-#define SCP_RESPONSE_CODE               0x06
-#define SCP_MEM_CODE                    0x08
-#define SCP_INCREMENT                   0x0a
-
 typedef struct LowCore
 {
     /* prefix area: defined by architecture */
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index 73cfd1f..7a7604b 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -60,9 +60,6 @@
 #define SIGP_STORE_STATUS_ADDR          0x0e
 #define SIGP_SET_ARCH                   0x12
 
-#define SCLP_CMDW_READ_SCP_INFO         0x00020001
-#define SCLP_CMDW_READ_SCP_INFO_FORCED  0x00120001
-
 const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_LAST_INFO
 };
@@ -246,6 +243,8 @@ static int kvm_sclp_service_call(CPUS390XState *env, struct kvm_run *run,
     r = sclp_service_call(env, sccb, code);
     if (r) {
         setcc(env, 3);
+    } else {
+        setcc(env, 0);
     }
 
     return 0;
diff --git a/target-s390x/op_helper.c b/target-s390x/op_helper.c
index 7b72473..74bd9ad 100644
--- a/target-s390x/op_helper.c
+++ b/target-s390x/op_helper.c
@@ -31,6 +31,7 @@
 
 #if !defined (CONFIG_USER_ONLY)
 #include "sysemu.h"
+#include "hw/s390-sclp.h"
 #endif
 
 /*****************************************************************************/
@@ -2360,16 +2361,13 @@ static void program_interrupt(CPUS390XState *env, uint32_t code, int ilc)
     }
 }
 
-static void ext_interrupt(CPUS390XState *env, int type, uint32_t param,
-                          uint64_t param64)
-{
-    cpu_inject_ext(env, type, param, param64);
-}
 
 int sclp_service_call(CPUS390XState *env, uint32_t sccb, uint64_t code)
 {
     int r = 0;
-    int shift = 0;
+    struct sccb work_sccb;
+    struct sccb *guest_sccb;
+    target_phys_addr_t sccb_len = sizeof(*guest_sccb);
 
 #ifdef DEBUG_HELPER
     printf("sclp(0x%x, 0x%" PRIx64 ")\n", sccb, code);
@@ -2380,26 +2378,18 @@ int sclp_service_call(CPUS390XState *env, uint32_t sccb, uint64_t code)
         r = -1;
         goto out;
     }
+    /*
+     * we want to work on a private copy of the sccb, to prevent guests
+     * from playing dirty tricks by modifying the memory content after
+     * the host has checked the values
+     */
+    guest_sccb = cpu_physical_memory_map(sccb, &sccb_len, true);
+    memcpy(&work_sccb, guest_sccb, sizeof(*guest_sccb));
 
     switch(code) {
         case SCLP_CMDW_READ_SCP_INFO:
         case SCLP_CMDW_READ_SCP_INFO_FORCED:
-            while ((ram_size >> (20 + shift)) > 65535) {
-                shift++;
-            }
-            stw_phys(sccb + SCP_MEM_CODE, ram_size >> (20 + shift));
-            stb_phys(sccb + SCP_INCREMENT, 1 << shift);
-            stw_phys(sccb + SCP_RESPONSE_CODE, 0x10);
-
-            if (kvm_enabled()) {
-#ifdef CONFIG_KVM
-                kvm_s390_interrupt_internal(env, KVM_S390_INT_SERVICE,
-                                            sccb & ~3, 0, 1);
-#endif
-            } else {
-                env->psw.addr += 4;
-                ext_interrupt(env, EXT_SERVICE, sccb & ~3, 0);
-            }
+            r = sclp_read_info(env, &work_sccb);
             break;
         default:
 #ifdef DEBUG_HELPER
@@ -2408,6 +2398,11 @@ int sclp_service_call(CPUS390XState *env, uint32_t sccb, uint64_t code)
             r = -1;
             break;
     }
+    memcpy(guest_sccb, &work_sccb, work_sccb.h.length);
+    cpu_physical_memory_unmap(guest_sccb, 4096, true, 4096);
+    if (!r) {
+        sclp_service_interrupt(env, sccb);
+    }
 
 out:
     return r;
-- 
1.7.10.4