s390x/kvm: Support access register mode for KVM_S390_MEM_OP ioctl

Access register mode is one of the modes that control dynamic address
translation. In this mode the address space is specified by values of
the access registers. The effective address-space-control element is
obtained from the result of the access register translation. See
the "Access-Register Introduction" section of the chapter 5 "Program
Execution" in "Principles of Operations" for more details.

When the CPU is in AR mode, the s390_cpu_virt_mem_rw() function must
know which access register number to use for address translation.
This patch does several things:
- add new parameter 'uint8_t ar' to that function
- decode ar number from intercepted instructions
- pass the ar number to s390_cpu_virt_mem_rw(), which in turn passes it
to the KVM_S390_MEM_OP ioctl.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

4 files changed, 75 insertions, 48 deletions

diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index 9c42743..ba7d250 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -356,7 +356,8 @@ int s390_cpu_handle_mmu_fault(CPUState *cpu, vaddr address, int rw,
 #ifndef CONFIG_USER_ONLY
 void do_restart_interrupt(CPUS390XState *env);
 
-static inline hwaddr decode_basedisp_s(CPUS390XState *env, uint32_t ipb)
+static inline hwaddr decode_basedisp_s(CPUS390XState *env, uint32_t ipb,
+                                       uint8_t *ar)
 {
     hwaddr addr = 0;
     uint8_t reg;
@@ -366,6 +367,9 @@ static inline hwaddr decode_basedisp_s(CPUS390XState *env, uint32_t ipb)
         addr = env->regs[reg];
     }
     addr += (ipb >> 16) & 0xfff;
+    if (ar) {
+        *ar = reg;
+    }
 
     return addr;
 }
@@ -401,8 +405,8 @@ void kvm_s390_vcpu_interrupt(S390CPU *cpu, struct kvm_s390_irq *irq);
 void kvm_s390_floating_interrupt(struct kvm_s390_irq *irq);
 int kvm_s390_inject_flic(struct kvm_s390_irq *irq);
 void kvm_s390_access_exception(S390CPU *cpu, uint16_t code, uint64_t te_code);
-int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf, int len,
-                    bool is_write);
+int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, uint8_t ar, void *hostbuf,
+                    int len, bool is_write);
 int kvm_s390_get_clock(uint8_t *tod_high, uint64_t *tod_clock);
 int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_clock);
 #else
@@ -420,8 +424,8 @@ static inline int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low)
 {
     return -ENOSYS;
 }
-static inline int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf,
-                                  int len, bool is_write)
+static inline int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, uint8_t ar,
+                                  void *hostbuf, int len, bool is_write)
 {
     return -ENOSYS;
 }
@@ -963,15 +967,15 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code);
 uint32_t calc_cc(CPUS390XState *env, uint32_t cc_op, uint64_t src, uint64_t dst,
                  uint64_t vr);
 
-int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, void *hostbuf, int len,
-                         bool is_write);
+int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, uint8_t ar, void *hostbuf,
+                         int len, bool is_write);
 
-#define s390_cpu_virt_mem_read(cpu, laddr, dest, len) \
-        s390_cpu_virt_mem_rw(cpu, laddr, dest, len, false)
-#define s390_cpu_virt_mem_write(cpu, laddr, dest, len) \
-        s390_cpu_virt_mem_rw(cpu, laddr, dest, len, true)
-#define s390_cpu_virt_mem_check_write(cpu, laddr, len) \
-        s390_cpu_virt_mem_rw(cpu, laddr, NULL, len, true)
+#define s390_cpu_virt_mem_read(cpu, laddr, ar, dest, len)    \
+        s390_cpu_virt_mem_rw(cpu, laddr, ar, dest, len, false)
+#define s390_cpu_virt_mem_write(cpu, laddr, ar, dest, len)       \
+        s390_cpu_virt_mem_rw(cpu, laddr, ar, dest, len, true)
+#define s390_cpu_virt_mem_check_write(cpu, laddr, ar, len)   \
+        s390_cpu_virt_mem_rw(cpu, laddr, ar, NULL, len, true)
 
 /* The value of the TOD clock for 1.1.1970. */
 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
diff --git a/target-s390x/ioinst.c b/target-s390x/ioinst.c
index b00a00c..e220cea 100644
--- a/target-s390x/ioinst.c
+++ b/target-s390x/ioinst.c
@@ -149,13 +149,14 @@ void ioinst_handle_msch(S390CPU *cpu, uint64_t reg1, uint32_t ipb)
     int ret = -ENODEV;
     int cc;
     CPUS390XState *env = &cpu->env;
+    uint8_t ar;
 
-    addr = decode_basedisp_s(env, ipb);
+    addr = decode_basedisp_s(env, ipb, &ar);
     if (addr & 3) {
         program_interrupt(env, PGM_SPECIFICATION, 2);
         return;
     }
-    if (s390_cpu_virt_mem_read(cpu, addr, &schib, sizeof(schib))) {
+    if (s390_cpu_virt_mem_read(cpu, addr, ar, &schib, sizeof(schib))) {
         return;
     }
     if (ioinst_disassemble_sch_ident(reg1, &m, &cssid, &ssid, &schid) ||
@@ -215,13 +216,14 @@ void ioinst_handle_ssch(S390CPU *cpu, uint64_t reg1, uint32_t ipb)
     int ret = -ENODEV;
     int cc;
     CPUS390XState *env = &cpu->env;
+    uint8_t ar;
 
-    addr = decode_basedisp_s(env, ipb);
+    addr = decode_basedisp_s(env, ipb, &ar);
     if (addr & 3) {
         program_interrupt(env, PGM_SPECIFICATION, 2);
         return;
     }
-    if (s390_cpu_virt_mem_read(cpu, addr, &orig_orb, sizeof(orb))) {
+    if (s390_cpu_virt_mem_read(cpu, addr, ar, &orig_orb, sizeof(orb))) {
         return;
     }
     copy_orb_from_guest(&orb, &orig_orb);
@@ -258,8 +260,9 @@ void ioinst_handle_stcrw(S390CPU *cpu, uint32_t ipb)
     uint64_t addr;
     int cc;
     CPUS390XState *env = &cpu->env;
+    uint8_t ar;
 
-    addr = decode_basedisp_s(env, ipb);
+    addr = decode_basedisp_s(env, ipb, &ar);
     if (addr & 3) {
         program_interrupt(env, PGM_SPECIFICATION, 2);
         return;
@@ -268,7 +271,7 @@ void ioinst_handle_stcrw(S390CPU *cpu, uint32_t ipb)
     cc = css_do_stcrw(&crw);
     /* 0 - crw stored, 1 - zeroes stored */
 
-    if (s390_cpu_virt_mem_write(cpu, addr, &crw, sizeof(crw)) == 0) {
+    if (s390_cpu_virt_mem_write(cpu, addr, ar, &crw, sizeof(crw)) == 0) {
         setcc(cpu, cc);
     } else if (cc == 0) {
         /* Write failed: requeue CRW since STCRW is a suppressing instruction */
@@ -284,8 +287,9 @@ void ioinst_handle_stsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb)
     int cc;
     SCHIB schib;
     CPUS390XState *env = &cpu->env;
+    uint8_t ar;
 
-    addr = decode_basedisp_s(env, ipb);
+    addr = decode_basedisp_s(env, ipb, &ar);
     if (addr & 3) {
         program_interrupt(env, PGM_SPECIFICATION, 2);
         return;
@@ -297,7 +301,7 @@ void ioinst_handle_stsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb)
          * we check whether the memory area is writeable (injecting the
          * access execption if it is not) first.
          */
-        if (!s390_cpu_virt_mem_check_write(cpu, addr, sizeof(schib))) {
+        if (!s390_cpu_virt_mem_check_write(cpu, addr, ar, sizeof(schib))) {
             program_interrupt(env, PGM_OPERAND, 2);
         }
         return;
@@ -322,12 +326,13 @@ void ioinst_handle_stsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb)
         }
     }
     if (cc != 3) {
-        if (s390_cpu_virt_mem_write(cpu, addr, &schib, sizeof(schib)) != 0) {
+        if (s390_cpu_virt_mem_write(cpu, addr, ar, &schib,
+                                    sizeof(schib)) != 0) {
             return;
         }
     } else {
         /* Access exceptions have a higher priority than cc3 */
-        if (s390_cpu_virt_mem_check_write(cpu, addr, sizeof(schib)) != 0) {
+        if (s390_cpu_virt_mem_check_write(cpu, addr, ar, sizeof(schib)) != 0) {
             return;
         }
     }
@@ -342,13 +347,14 @@ int ioinst_handle_tsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb)
     IRB irb;
     uint64_t addr;
     int cc, irb_len;
+    uint8_t ar;
 
     if (ioinst_disassemble_sch_ident(reg1, &m, &cssid, &ssid, &schid)) {
         program_interrupt(env, PGM_OPERAND, 2);
         return -EIO;
     }
     trace_ioinst_sch_id("tsch", cssid, ssid, schid);
-    addr = decode_basedisp_s(env, ipb);
+    addr = decode_basedisp_s(env, ipb, &ar);
     if (addr & 3) {
         program_interrupt(env, PGM_SPECIFICATION, 2);
         return -EIO;
@@ -362,14 +368,14 @@ int ioinst_handle_tsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb)
     }
     /* 0 - status pending, 1 - not status pending, 3 - not operational */
     if (cc != 3) {
-        if (s390_cpu_virt_mem_write(cpu, addr, &irb, irb_len) != 0) {
+        if (s390_cpu_virt_mem_write(cpu, addr, ar, &irb, irb_len) != 0) {
             return -EFAULT;
         }
         css_do_tsch_update_subch(sch);
     } else {
         irb_len = sizeof(irb) - sizeof(irb.emw);
         /* Access exceptions have a higher priority than cc3 */
-        if (s390_cpu_virt_mem_check_write(cpu, addr, irb_len) != 0) {
+        if (s390_cpu_virt_mem_check_write(cpu, addr, ar, irb_len) != 0) {
             return -EFAULT;
         }
     }
@@ -645,7 +651,7 @@ void ioinst_handle_chsc(S390CPU *cpu, uint32_t ipb)
      * present CHSC sub-handlers ... if we ever need more, we should take
      * care of req->len here first.
      */
-    if (s390_cpu_virt_mem_read(cpu, addr, buf, sizeof(ChscReq))) {
+    if (s390_cpu_virt_mem_read(cpu, addr, reg, buf, sizeof(ChscReq))) {
         return;
     }
     req = (ChscReq *)buf;
@@ -677,7 +683,8 @@ void ioinst_handle_chsc(S390CPU *cpu, uint32_t ipb)
         break;
     }
 
-    if (!s390_cpu_virt_mem_write(cpu, addr + len, res, be16_to_cpu(res->len))) {
+    if (!s390_cpu_virt_mem_write(cpu, addr + len, reg, res,
+                                 be16_to_cpu(res->len))) {
         setcc(cpu, 0);    /* Command execution complete */
     }
 }
@@ -690,9 +697,10 @@ int ioinst_handle_tpi(S390CPU *cpu, uint32_t ipb)
     IOIntCode int_code;
     hwaddr len;
     int ret;
+    uint8_t ar;
 
     trace_ioinst("tpi");
-    addr = decode_basedisp_s(env, ipb);
+    addr = decode_basedisp_s(env, ipb, &ar);
     if (addr & 3) {
         program_interrupt(env, PGM_SPECIFICATION, 2);
         return -EIO;
@@ -702,7 +710,7 @@ int ioinst_handle_tpi(S390CPU *cpu, uint32_t ipb)
     len = lowcore ? 8 /* two words */ : 12 /* three words */;
     ret = css_do_tpi(&int_code, lowcore);
     if (ret == 1) {
-        s390_cpu_virt_mem_write(cpu, lowcore ? 184 : addr, &int_code, len);
+        s390_cpu_virt_mem_write(cpu, lowcore ? 184 : addr, ar, &int_code, len);
     }
     return ret;
 }
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index 1c0e78c..8e65e43 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -555,6 +555,7 @@ int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low)
 /**
  * kvm_s390_mem_op:
  * @addr:      the logical start address in guest memory
+ * @ar:        the access register number
  * @hostbuf:   buffer in host memory. NULL = do only checks w/o copying
  * @len:       length that should be transfered
  * @is_write:  true = write, false = read
@@ -563,8 +564,8 @@ int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low)
  * Use KVM ioctl to read/write from/to guest memory. An access exception
  * is injected into the vCPU in case of translation errors.
  */
-int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf, int len,
-                    bool is_write)
+int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, uint8_t ar, void *hostbuf,
+                    int len, bool is_write)
 {
     struct kvm_s390_mem_op mem_op = {
         .gaddr = addr,
@@ -573,6 +574,7 @@ int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf, int len,
         .op = is_write ? KVM_S390_MEMOP_LOGICAL_WRITE
                        : KVM_S390_MEMOP_LOGICAL_READ,
         .buf = (uint64_t)hostbuf,
+        .ar = ar,
     };
     int ret;
 
@@ -1017,7 +1019,8 @@ static int handle_b2(S390CPU *cpu, struct kvm_run *run, uint8_t ipa1)
     return rc;
 }
 
-static uint64_t get_base_disp_rxy(S390CPU *cpu, struct kvm_run *run)
+static uint64_t get_base_disp_rxy(S390CPU *cpu, struct kvm_run *run,
+                                  uint8_t *ar)
 {
     CPUS390XState *env = &cpu->env;
     uint32_t x2 = (run->s390_sieic.ipa & 0x000f);
@@ -1028,12 +1031,16 @@ static uint64_t get_base_disp_rxy(S390CPU *cpu, struct kvm_run *run)
     if (disp2 & 0x80000) {
         disp2 += 0xfff00000;
     }
+    if (ar) {
+        *ar = base2;
+    }
 
     return (base2 ? env->regs[base2] : 0) +
            (x2 ? env->regs[x2] : 0) + (long)(int)disp2;
 }
 
-static uint64_t get_base_disp_rsy(S390CPU *cpu, struct kvm_run *run)
+static uint64_t get_base_disp_rsy(S390CPU *cpu, struct kvm_run *run,
+                                  uint8_t *ar)
 {
     CPUS390XState *env = &cpu->env;
     uint32_t base2 = run->s390_sieic.ipb >> 28;
@@ -1043,6 +1050,9 @@ static uint64_t get_base_disp_rsy(S390CPU *cpu, struct kvm_run *run)
     if (disp2 & 0x80000) {
         disp2 += 0xfff00000;
     }
+    if (ar) {
+        *ar = base2;
+    }
 
     return (base2 ? env->regs[base2] : 0) + (long)(int)disp2;
 }
@@ -1074,11 +1084,12 @@ static int kvm_stpcifc_service_call(S390CPU *cpu, struct kvm_run *run)
 {
     uint8_t r1 = (run->s390_sieic.ipa & 0x00f0) >> 4;
     uint64_t fiba;
+    uint8_t ar;
 
     cpu_synchronize_state(CPU(cpu));
-    fiba = get_base_disp_rxy(cpu, run);
+    fiba = get_base_disp_rxy(cpu, run, &ar);
 
-    return stpcifc_service_call(cpu, r1, fiba);
+    return stpcifc_service_call(cpu, r1, fiba, ar);
 }
 
 static int kvm_sic_service_call(S390CPU *cpu, struct kvm_run *run)
@@ -1100,22 +1111,24 @@ static int kvm_pcistb_service_call(S390CPU *cpu, struct kvm_run *run)
     uint8_t r1 = (run->s390_sieic.ipa & 0x00f0) >> 4;
     uint8_t r3 = run->s390_sieic.ipa & 0x000f;
     uint64_t gaddr;
+    uint8_t ar;
 
     cpu_synchronize_state(CPU(cpu));
-    gaddr = get_base_disp_rsy(cpu, run);
+    gaddr = get_base_disp_rsy(cpu, run, &ar);
 
-    return pcistb_service_call(cpu, r1, r3, gaddr);
+    return pcistb_service_call(cpu, r1, r3, gaddr, ar);
 }
 
 static int kvm_mpcifc_service_call(S390CPU *cpu, struct kvm_run *run)
 {
     uint8_t r1 = (run->s390_sieic.ipa & 0x00f0) >> 4;
     uint64_t fiba;
+    uint8_t ar;
 
     cpu_synchronize_state(CPU(cpu));
-    fiba = get_base_disp_rxy(cpu, run);
+    fiba = get_base_disp_rxy(cpu, run, &ar);
 
-    return mpcifc_service_call(cpu, r1, fiba);
+    return mpcifc_service_call(cpu, r1, fiba, ar);
 }
 
 static int handle_b9(S390CPU *cpu, struct kvm_run *run, uint8_t ipa1)
@@ -1244,7 +1257,7 @@ static int handle_diag(S390CPU *cpu, struct kvm_run *run, uint32_t ipb)
      * For any diagnose call we support, bits 48-63 of the resulting
      * address specify the function code; the remainder is ignored.
      */
-    func_code = decode_basedisp_rs(&cpu->env, ipb) & DIAG_KVM_CODE_MASK;
+    func_code = decode_basedisp_rs(&cpu->env, ipb, NULL) & DIAG_KVM_CODE_MASK;
     switch (func_code) {
     case DIAG_IPL:
         kvm_handle_diag_308(cpu, run);
@@ -1591,7 +1604,8 @@ static int handle_sigp(S390CPU *cpu, struct kvm_run *run, uint8_t ipa1)
     cpu_synchronize_state(CPU(cpu));
 
     /* get order code */
-    order = decode_basedisp_rs(env, run->s390_sieic.ipb) & SIGP_ORDER_MASK;
+    order = decode_basedisp_rs(env, run->s390_sieic.ipb, NULL)
+        & SIGP_ORDER_MASK;
     status_reg = &env->regs[r1];
     param = (r1 % 2) ? env->regs[r1] : env->regs[r1 + 1];
 
@@ -1765,12 +1779,12 @@ static int handle_tsch(S390CPU *cpu)
     return ret;
 }
 
-static void insert_stsi_3_2_2(S390CPU *cpu, __u64 addr)
+static void insert_stsi_3_2_2(S390CPU *cpu, __u64 addr, uint8_t ar)
 {
     struct sysib_322 sysib;
     int del;
 
-    if (s390_cpu_virt_mem_read(cpu, addr, &sysib, sizeof(sysib))) {
+    if (s390_cpu_virt_mem_read(cpu, addr, ar, &sysib, sizeof(sysib))) {
         return;
     }
     /* Shift the stack of Extended Names to prepare for our own data */
@@ -1810,7 +1824,7 @@ static void insert_stsi_3_2_2(S390CPU *cpu, __u64 addr)
     /* Insert UUID */
     memcpy(sysib.vm[0].uuid, qemu_uuid, sizeof(sysib.vm[0].uuid));
 
-    s390_cpu_virt_mem_write(cpu, addr, &sysib, sizeof(sysib));
+    s390_cpu_virt_mem_write(cpu, addr, ar, &sysib, sizeof(sysib));
 }
 
 static int handle_stsi(S390CPU *cpu)
@@ -1824,7 +1838,7 @@ static int handle_stsi(S390CPU *cpu)
             return 0;
         }
         /* Only sysib 3.2.2 needs post-handling for now. */
-        insert_stsi_3_2_2(cpu, run->s390_stsi.addr);
+        insert_stsi_3_2_2(cpu, run->s390_stsi.addr, run->s390_stsi.ar);
         return 0;
     default:
         return 0;
diff --git a/target-s390x/mmu_helper.c b/target-s390x/mmu_helper.c
index cd2cb51..30a38ec 100644
--- a/target-s390x/mmu_helper.c
+++ b/target-s390x/mmu_helper.c
@@ -435,6 +435,7 @@ static int translate_pages(S390CPU *cpu, vaddr addr, int nr_pages,
 /**
  * s390_cpu_virt_mem_rw:
  * @laddr:     the logical start address
+ * @ar:        the access register number
  * @hostbuf:   buffer in host memory. NULL = do only checks w/o copying
  * @len:       length that should be transfered
  * @is_write:  true = write, false = read
@@ -443,7 +444,7 @@ static int translate_pages(S390CPU *cpu, vaddr addr, int nr_pages,
  * Copy from/to guest memory using logical addresses. Note that we inject a
  * program interrupt in case there is an error while accessing the memory.
  */
-int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, void *hostbuf,
+int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, uint8_t ar, void *hostbuf,
                          int len, bool is_write)
 {
     int currlen, nr_pages, i;
@@ -451,7 +452,7 @@ int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, void *hostbuf,
     int ret;
 
     if (kvm_enabled()) {
-        ret = kvm_s390_mem_op(cpu, laddr, hostbuf, len, is_write);
+        ret = kvm_s390_mem_op(cpu, laddr, ar, hostbuf, len, is_write);
         if (ret >= 0) {
             return ret;
         }