KVM: s390: Add support for machine checks.

Add support for injecting machine checks (only repressible
conditions for now).

This is a bit more involved than I/O interrupts, for these reasons:

- Machine checks come in both floating and cpu varieties.
- We don't have a bit for machine checks enabling, but have to use
  a roundabout approach with trapping PSW changing instructions and
  watching for opened machine checks.

Reviewed-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

5 files changed, 255 insertions, 3 deletions

diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index df6c0ad085aa..950c13ecaf60 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -97,10 +97,12 @@ static int handle_lctl(struct kvm_vcpu *vcpu)
 
 static const intercept_handler_t instruction_handlers[256] = {
         [0x01] = kvm_s390_handle_01,
+        [0x82] = kvm_s390_handle_lpsw,
         [0x83] = kvm_s390_handle_diag,
         [0xae] = kvm_s390_handle_sigp,
         [0xb2] = kvm_s390_handle_b2,
         [0xb7] = handle_lctl,
+        [0xb9] = kvm_s390_handle_b9,
         [0xe5] = kvm_s390_handle_e5,
         [0xeb] = handle_lctlg,
 };
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 52cdf20906ab..b3b4748485ee 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -41,6 +41,11 @@ static int psw_ioint_disabled(struct kvm_vcpu *vcpu)
         return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_IO);
 }
 
+static int psw_mchk_disabled(struct kvm_vcpu *vcpu)
+{
+        return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_MCHECK);
+}
+
 static int psw_interrupts_disabled(struct kvm_vcpu *vcpu)
 {
         if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PER) ||
@@ -82,6 +87,12 @@ static int __interrupt_is_deliverable(struct kvm_vcpu *vcpu,
         case KVM_S390_SIGP_SET_PREFIX:
         case KVM_S390_RESTART:
                 return 1;
+        case KVM_S390_MCHK:
+                if (psw_mchk_disabled(vcpu))
+                        return 0;
+                if (vcpu->arch.sie_block->gcr[14] & inti->mchk.cr14)
+                        return 1;
+                return 0;
         case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
                 if (psw_ioint_disabled(vcpu))
                         return 0;
@@ -116,6 +127,7 @@ static void __reset_intercept_indicators(struct kvm_vcpu *vcpu)
                 CPUSTAT_IO_INT | CPUSTAT_EXT_INT | CPUSTAT_STOP_INT,
                 &vcpu->arch.sie_block->cpuflags);
         vcpu->arch.sie_block->lctl = 0x0000;
+        vcpu->arch.sie_block->ictl &= ~ICTL_LPSW;
 }
 
 static void __set_cpuflag(struct kvm_vcpu *vcpu, u32 flag)
@@ -139,6 +151,12 @@ static void __set_intercept_indicator(struct kvm_vcpu *vcpu,
         case KVM_S390_SIGP_STOP:
                 __set_cpuflag(vcpu, CPUSTAT_STOP_INT);
                 break;
+        case KVM_S390_MCHK:
+                if (psw_mchk_disabled(vcpu))
+                        vcpu->arch.sie_block->ictl |= ICTL_LPSW;
+                else
+                        vcpu->arch.sie_block->lctl |= LCTL_CR14;
+                break;
         case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
                 if (psw_ioint_disabled(vcpu))
                         __set_cpuflag(vcpu, CPUSTAT_IO_INT);
@@ -326,6 +344,32 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
                         exception = 1;
                 break;
 
+        case KVM_S390_MCHK:
+                VCPU_EVENT(vcpu, 4, "interrupt: machine check mcic=%llx",
+                           inti->mchk.mcic);
+                trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
+                                                 inti->mchk.cr14,
+                                                 inti->mchk.mcic);
+                rc = kvm_s390_vcpu_store_status(vcpu,
+                                                KVM_S390_STORE_STATUS_PREFIXED);
+                if (rc == -EFAULT)
+                        exception = 1;
+
+                rc = put_guest_u64(vcpu, __LC_MCCK_CODE, inti->mchk.mcic);
+                if (rc == -EFAULT)
+                        exception = 1;
+
+                rc = copy_to_guest(vcpu, __LC_MCK_OLD_PSW,
+                                   &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
+                if (rc == -EFAULT)
+                        exception = 1;
+
+                rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
+                                     __LC_MCK_NEW_PSW, sizeof(psw_t));
+                if (rc == -EFAULT)
+                        exception = 1;
+                break;
+
         case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
         {
                 __u32 param0 = ((__u32)inti->io.subchannel_id << 16) |
@@ -588,6 +632,61 @@ void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
         }
 }
 
+void kvm_s390_deliver_pending_machine_checks(struct kvm_vcpu *vcpu)
+{
+        struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
+        struct kvm_s390_float_interrupt *fi = vcpu->arch.local_int.float_int;
+        struct kvm_s390_interrupt_info  *n, *inti = NULL;
+        int deliver;
+
+        __reset_intercept_indicators(vcpu);
+        if (atomic_read(&li->active)) {
+                do {
+                        deliver = 0;
+                        spin_lock_bh(&li->lock);
+                        list_for_each_entry_safe(inti, n, &li->list, list) {
+                                if ((inti->type == KVM_S390_MCHK) &&
+                                    __interrupt_is_deliverable(vcpu, inti)) {
+                                        list_del(&inti->list);
+                                        deliver = 1;
+                                        break;
+                                }
+                                __set_intercept_indicator(vcpu, inti);
+                        }
+                        if (list_empty(&li->list))
+                                atomic_set(&li->active, 0);
+                        spin_unlock_bh(&li->lock);
+                        if (deliver) {
+                                __do_deliver_interrupt(vcpu, inti);
+                                kfree(inti);
+                        }
+                } while (deliver);
+        }
+
+        if (atomic_read(&fi->active)) {
+                do {
+                        deliver = 0;
+                        spin_lock(&fi->lock);
+                        list_for_each_entry_safe(inti, n, &fi->list, list) {
+                                if ((inti->type == KVM_S390_MCHK) &&
+                                    __interrupt_is_deliverable(vcpu, inti)) {
+                                        list_del(&inti->list);
+                                        deliver = 1;
+                                        break;
+                                }
+                                __set_intercept_indicator(vcpu, inti);
+                        }
+                        if (list_empty(&fi->list))
+                                atomic_set(&fi->active, 0);
+                        spin_unlock(&fi->lock);
+                        if (deliver) {
+                                __do_deliver_interrupt(vcpu, inti);
+                                kfree(inti);
+                        }
+                } while (deliver);
+        }
+}
+
 int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code)
 {
         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
@@ -641,6 +740,13 @@ int kvm_s390_inject_vm(struct kvm *kvm,
         case KVM_S390_INT_EMERGENCY:
                 kfree(inti);
                 return -EINVAL;
+        case KVM_S390_MCHK:
+                VM_EVENT(kvm, 5, "inject: machine check parm64:%llx",
+                         s390int->parm64);
+                inti->type = s390int->type;
+                inti->mchk.cr14 = s390int->parm; /* upper bits are not used */
+                inti->mchk.mcic = s390int->parm64;
+                break;
         case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
                 if (s390int->type & IOINT_AI_MASK)
                         VM_EVENT(kvm, 5, "%s", "inject: I/O (AI)");
@@ -749,6 +855,12 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
                 inti->type = s390int->type;
                 inti->emerg.code = s390int->parm;
                 break;
+        case KVM_S390_MCHK:
+                VCPU_EVENT(vcpu, 5, "inject: machine check parm64:%llx",
+                           s390int->parm64);
+                inti->type = s390int->type;
+                inti->mchk.mcic = s390int->parm64;
+                break;
         case KVM_S390_INT_VIRTIO:
         case KVM_S390_INT_SERVICE:
         case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index dccc0242b7ca..1f7cc6ccf102 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -106,6 +106,7 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu);
 enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer);
 void kvm_s390_tasklet(unsigned long parm);
 void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu);
+void kvm_s390_deliver_pending_machine_checks(struct kvm_vcpu *vcpu);
 int kvm_s390_inject_vm(struct kvm *kvm,
                 struct kvm_s390_interrupt *s390int);
 int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
@@ -117,6 +118,8 @@ int kvm_s390_inject_sigp_stop(struct kvm_vcpu *vcpu, int action);
 int kvm_s390_handle_b2(struct kvm_vcpu *vcpu);
 int kvm_s390_handle_e5(struct kvm_vcpu *vcpu);
 int kvm_s390_handle_01(struct kvm_vcpu *vcpu);
+int kvm_s390_handle_b9(struct kvm_vcpu *vcpu);
+int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu);
 
 /* implemented in sigp.c */
 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu);
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index d715842f56ca..d3cbcd3c9ada 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -18,6 +18,8 @@
 #include <asm/debug.h>
 #include <asm/ebcdic.h>
 #include <asm/sysinfo.h>
+#include <asm/ptrace.h>
+#include <asm/compat.h>
 #include "gaccess.h"
 #include "kvm-s390.h"
 #include "trace.h"
@@ -166,6 +168,99 @@ static int handle_stfl(struct kvm_vcpu *vcpu)
         return 0;
 }
 
+static void handle_new_psw(struct kvm_vcpu *vcpu)
+{
+        /* Check whether the new psw is enabled for machine checks. */
+        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_MCHECK)
+                kvm_s390_deliver_pending_machine_checks(vcpu);
+}
+
+#define PSW_MASK_ADDR_MODE (PSW_MASK_EA | PSW_MASK_BA)
+#define PSW_MASK_UNASSIGNED 0xb80800fe7fffffffUL
+#define PSW_ADDR_24 0x00000000000fffffUL
+#define PSW_ADDR_31 0x000000007fffffffUL
+
+int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu)
+{
+        u64 addr;
+        psw_compat_t new_psw;
+
+        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
+                return kvm_s390_inject_program_int(vcpu,
+                                                   PGM_PRIVILEGED_OPERATION);
+
+        addr = kvm_s390_get_base_disp_s(vcpu);
+
+        if (addr & 7) {
+                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+                goto out;
+        }
+
+        if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw))) {
+                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+                goto out;
+        }
+
+        if (!(new_psw.mask & PSW32_MASK_BASE)) {
+                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+                goto out;
+        }
+
+        vcpu->arch.sie_block->gpsw.mask =
+                (new_psw.mask & ~PSW32_MASK_BASE) << 32;
+        vcpu->arch.sie_block->gpsw.addr = new_psw.addr;
+
+        if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_UNASSIGNED) ||
+            (!(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) &&
+             (vcpu->arch.sie_block->gpsw.addr & ~PSW_ADDR_24)) ||
+            ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) ==
+             PSW_MASK_EA)) {
+                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+                goto out;
+        }
+
+        handle_new_psw(vcpu);
+out:
+        return 0;
+}
+
+static int handle_lpswe(struct kvm_vcpu *vcpu)
+{
+        u64 addr;
+        psw_t new_psw;
+
+        addr = kvm_s390_get_base_disp_s(vcpu);
+
+        if (addr & 7) {
+                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+                goto out;
+        }
+
+        if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw))) {
+                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+                goto out;
+        }
+
+        vcpu->arch.sie_block->gpsw.mask = new_psw.mask;
+        vcpu->arch.sie_block->gpsw.addr = new_psw.addr;
+
+        if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_UNASSIGNED) ||
+            (((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) ==
+              PSW_MASK_BA) &&
+             (vcpu->arch.sie_block->gpsw.addr & ~PSW_ADDR_31)) ||
+            (!(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) &&
+             (vcpu->arch.sie_block->gpsw.addr & ~PSW_ADDR_24)) ||
+            ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) ==
+             PSW_MASK_EA)) {
+                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+                goto out;
+        }
+
+        handle_new_psw(vcpu);
+out:
+        return 0;
+}
+
 static int handle_stidp(struct kvm_vcpu *vcpu)
 {
         u64 operand2;
@@ -292,6 +387,7 @@ static const intercept_handler_t priv_handlers[256] = {
         [0x5f] = handle_chsc,
         [0x7d] = handle_stsi,
         [0xb1] = handle_stfl,
+        [0xb2] = handle_lpswe,
 };
 
 int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
@@ -316,6 +412,45 @@ int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
         return -EOPNOTSUPP;
 }
 
+static int handle_epsw(struct kvm_vcpu *vcpu)
+{
+        int reg1, reg2;
+
+        reg1 = (vcpu->arch.sie_block->ipb & 0x00f00000) >> 24;
+        reg2 = (vcpu->arch.sie_block->ipb & 0x000f0000) >> 16;
+
+        /* This basically extracts the mask half of the psw. */
+        vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00000000;
+        vcpu->run->s.regs.gprs[reg1] |= vcpu->arch.sie_block->gpsw.mask >> 32;
+        if (reg2) {
+                vcpu->run->s.regs.gprs[reg2] &= 0xffffffff00000000;
+                vcpu->run->s.regs.gprs[reg2] |=
+                        vcpu->arch.sie_block->gpsw.mask & 0x00000000ffffffff;
+        }
+        return 0;
+}
+
+static const intercept_handler_t b9_handlers[256] = {
+        [0x8d] = handle_epsw,
+};
+
+int kvm_s390_handle_b9(struct kvm_vcpu *vcpu)
+{
+        intercept_handler_t handler;
+
+        /* This is handled just as for the B2 instructions. */
+        handler = b9_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
+        if (handler) {
+                if ((handler != handle_epsw) &&
+                    (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE))
+                        return kvm_s390_inject_program_int(vcpu,
+                                                   PGM_PRIVILEGED_OPERATION);
+                else
+                        return handler(vcpu);
+        }
+        return -EOPNOTSUPP;
+}
+
 static int handle_tprot(struct kvm_vcpu *vcpu)
 {
         u64 address1, address2;
diff --git a/arch/s390/kvm/trace-s390.h b/arch/s390/kvm/trace-s390.h
index 90fdf85b5ff7..95fbc1ab88dc 100644
--- a/arch/s390/kvm/trace-s390.h
+++ b/arch/s390/kvm/trace-s390.h
@@ -141,13 +141,13 @@ TRACE_EVENT(kvm_s390_inject_vcpu,
  * Trace point for the actual delivery of interrupts.
  */
 TRACE_EVENT(kvm_s390_deliver_interrupt,
-            TP_PROTO(unsigned int id, __u64 type, __u32 data0, __u64 data1),
+            TP_PROTO(unsigned int id, __u64 type, __u64 data0, __u64 data1),
             TP_ARGS(id, type, data0, data1),
 
             TP_STRUCT__entry(
                     __field(int, id)
                     __field(__u32, inttype)
-                    __field(__u32, data0)
+                    __field(__u64, data0)
                     __field(__u64, data1)
                     ),
 
@@ -159,7 +159,7 @@ TRACE_EVENT(kvm_s390_deliver_interrupt,
                     ),
 
             TP_printk("deliver interrupt (vcpu %d): type:%x (%s) "      \
-                      "data:%08x %016llx",
+                      "data:%08llx %016llx",
                       __entry->id, __entry->inttype,
                       __print_symbolic(__entry->inttype, kvm_s390_int_type),
                       __entry->data0, __entry->data1)