[Qemu-devel] [PATCH 04/11] Add KVM support for S390x

[Alexander Graf <agraf@suse.de>]

S390x was one of the first platforms that received support for KVM back in the
day. Unfortunately until now there hasn't been a qemu implementation that would
enable users to actually run guests.

So let's include support for KVM S390x in qemu!

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v5 -> v6:

  - use constants for sclp commands (kvm.c)
  - change _kvm... to kvm_..._internal
  - coding style
---
 configure          |    4 +-
 target-s390x/kvm.c |  482 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 485 insertions(+), 1 deletions(-)
 create mode 100644 target-s390x/kvm.c

diff --git a/configure b/configure
index 77c3ec1..b944e49 100755
--- a/configure
+++ b/configure
@@ -1377,6 +1377,8 @@ EOF
             kvm_cflags="$kvm_cflags -I$kerneldir/arch/x86/include"
 	elif test "$cpu" = "ppc" -a -d "$kerneldir/arch/powerpc/include" ; then
 	    kvm_cflags="$kvm_cflags -I$kerneldir/arch/powerpc/include"
+	elif test "$cpu" = "s390x" -a -d "$kerneldir/arch/s390/include" ; then
+	    kvm_cflags="$kvm_cflags -I$kerneldir/arch/s390/include"
         elif test -d "$kerneldir/arch/$cpu/include" ; then
             kvm_cflags="$kvm_cflags -I$kerneldir/arch/$cpu/include"
       fi
@@ -2393,7 +2395,7 @@ case "$target_arch2" in
     fi
 esac
 case "$target_arch2" in
-  i386|x86_64|ppcemb|ppc|ppc64)
+  i386|x86_64|ppcemb|ppc|ppc64|s390x)
     # Make sure the target and host cpus are compatible
     if test "$kvm" = "yes" -a "$target_softmmu" = "yes" -a \
       \( "$target_arch2" = "$cpu" -o \
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
new file mode 100644
index 0000000..da109fd
--- /dev/null
+++ b/target-s390x/kvm.c
@@ -0,0 +1,482 @@
+/*
+ * QEMU S390x KVM implementation
+ *
+ * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include <linux/kvm.h>
+#include <asm/ptrace.h>
+
+#include "qemu-common.h"
+#include "qemu-timer.h"
+#include "sysemu.h"
+#include "kvm.h"
+#include "cpu.h"
+#include "device_tree.h"
+
+/* #define DEBUG_KVM */
+
+#ifdef DEBUG_KVM
+#define dprintf(fmt, ...) \
+    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
+#else
+#define dprintf(fmt, ...) \
+    do { } while (0)
+#endif
+
+#define IPA0_DIAG                       0x8300
+#define IPA0_SIGP                       0xae00
+#define IPA0_PRIV                       0xb200
+
+#define PRIV_SCLP_CALL                  0x20
+#define DIAG_KVM_HYPERCALL              0x500
+#define DIAG_KVM_BREAKPOINT             0x501
+
+#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
+
+#define ICPT_INSTRUCTION                0x04
+#define ICPT_WAITPSW                    0x1c
+#define ICPT_SOFT_INTERCEPT             0x24
+#define ICPT_CPU_STOP                   0x28
+#define ICPT_IO                         0x40
+
+#define SIGP_RESTART                    0x06
+#define SIGP_INITIAL_CPU_RESET          0x0b
+#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
+
+int kvm_arch_init(KVMState *s, int smp_cpus)
+{
+    return 0;
+}
+
+int kvm_arch_init_vcpu(CPUState *env)
+{
+    int ret = 0;
+
+    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL) < 0) {
+        perror("cannot init reset vcpu");
+    }
+
+    return ret;
+}
+
+void kvm_arch_reset_vcpu(CPUState *env)
+{
+}
+
+int kvm_arch_put_registers(CPUState *env)
+{
+    struct kvm_regs regs;
+    int ret;
+    int i;
+
+    ret = kvm_vcpu_ioctl(env, KVM_GET_REGS, &regs);
+    if (ret < 0) {
+        return ret;
+    }
+
+    for (i = 0; i < 16; i++) {
+        regs.gprs[i] = env->regs[i];
+    }
+
+    ret = kvm_vcpu_ioctl(env, KVM_SET_REGS, &regs);
+    if (ret < 0) {
+        return ret;
+    }
+
+    env->kvm_run->psw_addr = env->psw.addr;
+    env->kvm_run->psw_mask = env->psw.mask;
+
+    return ret;
+}
+
+int kvm_arch_get_registers(CPUState *env)
+{
+    uint32_t ret;
+    struct kvm_regs regs;
+    int i;
+
+    ret = kvm_vcpu_ioctl(env, KVM_GET_REGS, &regs);
+    if (ret < 0) {
+        return ret;
+    }
+
+    for (i = 0; i < 16; i++) {
+        env->regs[i] = regs.gprs[i];
+    }
+
+    env->psw.addr = env->kvm_run->psw_addr;
+    env->psw.mask = env->kvm_run->psw_mask;
+
+    return 0;
+}
+
+int kvm_arch_insert_sw_breakpoint(CPUState *env, struct kvm_sw_breakpoint *bp)
+{
+    static const uint8_t diag_501[] = {0x83, 0x24, 0x05, 0x01};
+
+    if (cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
+        cpu_memory_rw_debug(env, bp->pc, (uint8_t *)diag_501, 4, 1)) {
+        return -EINVAL;
+    }
+    return 0;
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUState *env, struct kvm_sw_breakpoint *bp)
+{
+    uint8_t t[4];
+    static const uint8_t diag_501[] = {0x83, 0x24, 0x05, 0x01};
+
+    if (cpu_memory_rw_debug(env, bp->pc, t, 4, 0)) {
+        return -EINVAL;
+    } else if (memcmp(t, diag_501, 4)) {
+        return -EINVAL;
+    } else if (cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&bp->saved_insn, 1, 1)) {
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
+int kvm_arch_pre_run(CPUState *env, struct kvm_run *run)
+{
+    return 0;
+}
+
+int kvm_arch_post_run(CPUState *env, struct kvm_run *run)
+{
+    return 0;
+}
+
+static void kvm_s390_interrupt_internal(CPUState *env, int type, uint32_t parm,
+                                        uint64_t parm64, int vm)
+{
+    struct kvm_s390_interrupt kvmint;
+    int r;
+
+    if (!env->kvm_state) {
+        return;
+    }
+
+    env->halted = 0;
+    env->exception_index = 0;
+
+    kvmint.type = type;
+    kvmint.parm = parm;
+    kvmint.parm64 = parm64;
+
+    if (vm) {
+        r = kvm_vm_ioctl(env->kvm_state, KVM_S390_INTERRUPT, &kvmint);
+    } else {
+        r = kvm_vcpu_ioctl(env, KVM_S390_INTERRUPT, &kvmint);
+    }
+
+    if (r < 0) {
+        fprintf(stderr, "KVM failed to inject interrupt\n");
+        exit(1);
+    }
+}
+
+void kvm_s390_virtio_irq(CPUState *env, int config_change, uint64_t token)
+{
+    kvm_s390_interrupt_internal(env, KVM_S390_INT_VIRTIO, config_change,
+                                token, 1);
+}
+
+static void kvm_s390_interrupt(CPUState *env, int type, uint32_t code)
+{
+    kvm_s390_interrupt_internal(env, type, code, 0, 0);
+}
+
+static void enter_pgmcheck(CPUState *env, uint16_t code)
+{
+    kvm_s390_interrupt(env, KVM_S390_PROGRAM_INT, code);
+}
+
+static void setcc(CPUState *env, uint64_t cc)
+{
+    env->kvm_run->psw_mask &= ~(3ul << 44);
+    env->kvm_run->psw_mask |= (cc & 3) << 44;
+
+    env->psw.mask &= ~(3ul << 44);
+    env->psw.mask |= (cc & 3) << 44;
+}
+
+static int sclp_service_call(CPUState *env, struct kvm_run *run, uint16_t ipbh0)
+{
+    uint32_t sccb;
+    uint64_t code;
+    int r = 0;
+
+    cpu_synchronize_state(env);
+    sccb = env->regs[ipbh0 & 0xf];
+    code = env->regs[(ipbh0 & 0xf0) >> 4];
+
+    dprintf("sclp(0x%x, 0x%lx)\n", sccb, code);
+
+    if (sccb & ~0x7ffffff8ul) {
+        fprintf(stderr, "KVM: invalid sccb address 0x%x\n", sccb);
+        r = -1;
+        goto out;
+    }
+
+    switch(code) {
+        case SCLP_CMDW_READ_SCP_INFO:
+        case SCLP_CMDW_READ_SCP_INFO_FORCED:
+            stw_phys(sccb + SCP_MEM_CODE, ram_size >> 20);
+            stb_phys(sccb + SCP_INCREMENT, 1);
+            stw_phys(sccb + SCP_RESPONSE_CODE, 0x10);
+            setcc(env, 0);
+
+            kvm_s390_interrupt_internal(env, KVM_S390_INT_SERVICE,
+                                        sccb & ~3, 0, 1);
+            break;
+        default:
+            dprintf("KVM: invalid sclp call 0x%x / 0x%lx\n", sccb, code);
+            r = -1;
+            break;
+    }
+
+out:
+    if (r < 0) {
+        setcc(env, 3);
+    }
+    return 0;
+}
+
+static int handle_priv(CPUState *env, struct kvm_run *run, uint8_t ipa1)
+{
+    int r = 0;
+    uint16_t ipbh0 = (run->s390_sieic.ipb & 0xffff0000) >> 16;
+
+    dprintf("KVM: PRIV: %d\n", ipa1);
+    switch (ipa1) {
+        case PRIV_SCLP_CALL:
+            r = sclp_service_call(env, run, ipbh0);
+            break;
+        default:
+            dprintf("KVM: unknown PRIV: 0x%x\n", ipa1);
+            r = -1;
+            break;
+    }
+
+    return r;
+}
+
+static int handle_hypercall(CPUState *env, struct kvm_run *run)
+{
+    int r;
+
+    cpu_synchronize_state(env);
+    r = s390_virtio_hypercall(env);
+    kvm_arch_put_registers(env);
+
+    return r;
+}
+
+static int handle_diag(CPUState *env, struct kvm_run *run, int ipb_code)
+{
+    int r = 0;
+
+    switch (ipb_code) {
+        case DIAG_KVM_HYPERCALL:
+            r = handle_hypercall(env, run);
+            break;
+        case DIAG_KVM_BREAKPOINT:
+            sleep(10);
+            break;
+        default:
+            dprintf("KVM: unknown DIAG: 0x%x\n", ipb_code);
+            r = -1;
+            break;
+    }
+
+    return r;
+}
+
+static int s390_cpu_restart(CPUState *env)
+{
+    kvm_s390_interrupt(env, KVM_S390_RESTART, 0);
+    env->halted = 0;
+    env->exception_index = 0;
+    qemu_cpu_kick(env);
+    dprintf("DONE: SIGP cpu restart: %p\n", env);
+    return 0;
+}
+
+static int s390_store_status(CPUState *env, uint32_t parameter)
+{
+    /* XXX */
+    fprintf(stderr, "XXX SIGP store status\n");
+    return -1;
+}
+
+static int s390_cpu_initial_reset(CPUState *env)
+{
+    /* XXX */
+    fprintf(stderr, "XXX SIGP init\n");
+    return -1;
+}
+
+static int handle_sigp(CPUState *env, struct kvm_run *run, uint8_t ipa1)
+{
+    uint8_t order_code;
+    uint32_t parameter;
+    uint16_t cpu_addr;
+    uint8_t t;
+    int r = -1;
+    CPUState *target_env;
+
+    cpu_synchronize_state(env);
+
+    /* get order code */
+    order_code = run->s390_sieic.ipb >> 28;
+    if (order_code > 0) {
+        order_code = env->regs[order_code];
+    }
+    order_code += (run->s390_sieic.ipb & 0x0fff0000) >> 16;
+
+    /* get parameters */
+    t = (ipa1 & 0xf0) >> 4;
+    if (!(t % 2)) {
+        t++;
+    }
+
+    parameter = env->regs[t] & 0x7ffffe00;
+    cpu_addr = env->regs[ipa1 & 0x0f];
+
+    target_env = s390_cpu_addr2state(cpu_addr);
+    if (!target_env) {
+        goto out;
+    }
+
+    switch (order_code) {
+        case SIGP_RESTART:
+            r = s390_cpu_restart(target_env);
+            break;
+        case SIGP_STORE_STATUS_ADDR:
+            r = s390_store_status(target_env, parameter);
+            break;
+        case SIGP_SET_ARCH:
+            /* make the caller panic */
+            return -1;
+        case SIGP_INITIAL_CPU_RESET:
+            r = s390_cpu_initial_reset(target_env);
+            break;
+        default:
+            fprintf(stderr, "KVM: unknown SIGP: 0x%x\n", ipa1);
+            break;
+    }
+
+out:
+    setcc(env, r ? 3 : 0);
+    return 0;
+}
+
+static int handle_instruction(CPUState *env, struct kvm_run *run)
+{
+    unsigned int ipa0 = (run->s390_sieic.ipa & 0xff00);
+    uint8_t ipa1 = run->s390_sieic.ipa & 0x00ff;
+    int ipb_code = (run->s390_sieic.ipb & 0x0fff0000) >> 16;
+    int r = 0;
+
+    dprintf("handle_instruction 0x%x 0x%x\n", run->s390_sieic.ipa, run->s390_sieic.ipb);
+    switch (ipa0) {
+        case IPA0_PRIV:
+            r = handle_priv(env, run, ipa1);
+            break;
+        case IPA0_DIAG:
+            r = handle_diag(env, run, ipb_code);
+            break;
+        case IPA0_SIGP:
+            r = handle_sigp(env, run, ipa1);
+            break;
+    }
+
+    if (r < 0) {
+        enter_pgmcheck(env, 0x0001);
+    }
+    return r;
+}
+
+static int handle_intercept(CPUState *env)
+{
+    struct kvm_run *run = env->kvm_run;
+    int icpt_code = run->s390_sieic.icptcode;
+    int r = 0;
+
+    dprintf("intercept: 0x%x (at 0x%lx)\n", icpt_code, env->kvm_run->psw_addr);
+    switch (icpt_code) {
+        case ICPT_INSTRUCTION:
+            r = handle_instruction(env, run);
+            break;
+        case ICPT_WAITPSW:
+            /* XXX What to do on system shutdown? */
+            env->halted = 1;
+            env->exception_index = EXCP_HLT;
+            break;
+        case ICPT_SOFT_INTERCEPT:
+            fprintf(stderr, "KVM unimplemented icpt SOFT\n");
+            exit(1);
+            break;
+        case ICPT_CPU_STOP:
+            qemu_system_shutdown_request();
+            break;
+        case ICPT_IO:
+            fprintf(stderr, "KVM unimplemented icpt IO\n");
+            exit(1);
+            break;
+        default:
+            fprintf(stderr, "Unknown intercept code: %d\n", icpt_code);
+            exit(1);
+            break;
+    }
+
+    return r;
+}
+
+int kvm_arch_handle_exit(CPUState *env, struct kvm_run *run)
+{
+    int ret = 0;
+
+    switch (run->exit_reason) {
+        case KVM_EXIT_S390_SIEIC:
+            ret = handle_intercept(env);
+            break;
+        case KVM_EXIT_S390_RESET:
+            fprintf(stderr, "RESET not implemented\n");
+            exit(1);
+            break;
+        default:
+            fprintf(stderr, "Unknown KVM exit: %d\n", run->exit_reason);
+            break;
+    }
+
+    return ret;
+}
-- 
1.6.0.2