diff mbox

[03/10] ppc: Rework POWER7 & POWER8 exception model (part 2)

Message ID 1465795496-15071-4-git-send-email-clg@kaod.org (mailing list archive)
State New, archived
Headers show

Commit Message

Cédric Le Goater June 13, 2016, 5:24 a.m. UTC
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Properly implement LPES0/1 handling for HV vs. !HV mode.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[clg: AIL implementation was fixed in commit 5c94b2a5e5ef
      fixed checkpatch.pl errors ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 target-ppc/excp_helper.c | 134 ++++++++++++++++-------------------------------
 1 file changed, 45 insertions(+), 89 deletions(-)

Comments

David Gibson June 14, 2016, 6:25 a.m. UTC | #1
On Mon, Jun 13, 2016 at 07:24:49AM +0200, Cédric Le Goater wrote:
> From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
> Properly implement LPES0/1 handling for HV vs. !HV mode.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> [clg: AIL implementation was fixed in commit 5c94b2a5e5ef
>       fixed checkpatch.pl errors ]

Code looks ok, but the short description really needs an update, since
this has been taken out of its original series context.

> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---
>  target-ppc/excp_helper.c | 134 ++++++++++++++++-------------------------------
>  1 file changed, 45 insertions(+), 89 deletions(-)
> 
> diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
> index aa0b63f4b0de..7c44c102db39 100644
> --- a/target-ppc/excp_helper.c
> +++ b/target-ppc/excp_helper.c
> @@ -77,18 +77,8 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>      CPUState *cs = CPU(cpu);
>      CPUPPCState *env = &cpu->env;
>      target_ulong msr, new_msr, vector;
> -    int srr0, srr1, asrr0, asrr1;
> -    int lpes0, lpes1, lev, ail;
> -
> -    if (0) {
> -        /* XXX: find a suitable condition to enable the hypervisor mode */
> -        lpes0 = (env->spr[SPR_LPCR] >> 1) & 1;
> -        lpes1 = (env->spr[SPR_LPCR] >> 2) & 1;
> -    } else {
> -        /* Those values ensure we won't enter the hypervisor mode */
> -        lpes0 = 0;
> -        lpes1 = 1;
> -    }
> +    int srr0, srr1, asrr0, asrr1, lev, ail;
> +    bool lpes0;
>  
>      qemu_log_mask(CPU_LOG_INT, "Raise exception at " TARGET_FMT_lx
>                    " => %08x (%02x)\n", env->nip, excp, env->error_code);
> @@ -100,8 +90,10 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>          msr = env->msr & ~0x783f0000ULL;
>      }
>  
> -    /* new interrupt handler msr */
> -    new_msr = env->msr & ((target_ulong)1 << MSR_ME);
> +    /* new interrupt handler msr preserves existing HV and ME unless
> +     * explicitly overriden
> +     */
> +    new_msr = env->msr & (((target_ulong)1 << MSR_ME) | MSR_HVB);
>  
>      /* target registers */
>      srr0 = SPR_SRR0;
> @@ -111,12 +103,19 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>  
>      /* Exception targetting modifiers
>       *
> +     * LPES0 is supported on POWER7/8
> +     * LPES1 is not supported (old iSeries mode)
> +     *
> +     * On anything else, we behave as if LPES0 is 1
> +     * (externals don't alter MSR:HV)
> +     *
>       * AIL is initialized here but can be cleared by
>       * selected exceptions
>       */
>  #if defined(TARGET_PPC64)
>      if (excp_model == POWERPC_EXCP_POWER7 ||
>          excp_model == POWERPC_EXCP_POWER8) {
> +        lpes0 = !!(env->spr[SPR_LPCR] & LPCR_LPES0);
>          if (excp_model == POWERPC_EXCP_POWER8) {
>              ail = (env->spr[SPR_LPCR] & LPCR_AIL) >> LPCR_AIL_SHIFT;
>          } else {
> @@ -125,6 +124,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>      } else
>  #endif /* defined(TARGET_PPC64) */
>      {
> +        lpes0 = true;
>          ail = 0;
>      }
>  
> @@ -162,10 +162,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>              cs->halted = 1;
>              cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
>          }
> -        if (0) {
> -            /* XXX: find a suitable condition to enable the hypervisor mode */
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
> +        new_msr |= (target_ulong)MSR_HVB;
>          ail = 0;
>  
>          /* machine check exceptions don't have ME set */
> @@ -191,23 +188,20 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>      case POWERPC_EXCP_DSI:       /* Data storage exception                   */
>          LOG_EXCP("DSI exception: DSISR=" TARGET_FMT_lx" DAR=" TARGET_FMT_lx
>                   "\n", env->spr[SPR_DSISR], env->spr[SPR_DAR]);
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_next;
>      case POWERPC_EXCP_ISI:       /* Instruction storage exception            */
>          LOG_EXCP("ISI exception: msr=" TARGET_FMT_lx ", nip=" TARGET_FMT_lx
>                   "\n", msr, env->nip);
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          msr |= env->error_code;
>          goto store_next;
>      case POWERPC_EXCP_EXTERNAL:  /* External input                           */
>          cs = CPU(cpu);
>  
> -        if (lpes0 == 1) {
> +        if (!lpes0) {
>              new_msr |= (target_ulong)MSR_HVB;
> +            new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
> +            srr0 = SPR_HSRR0;
> +            srr1 = SPR_HSRR1;
>          }
>          if (env->mpic_proxy) {
>              /* IACK the IRQ on delivery */
> @@ -215,9 +209,6 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>          }
>          goto store_next;
>      case POWERPC_EXCP_ALIGN:     /* Alignment exception                      */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          /* XXX: this is false */
>          /* Get rS/rD and rA from faulting opcode */
>          env->spr[SPR_DSISR] |= (cpu_ldl_code(env, (env->nip - 4))
> @@ -232,9 +223,6 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>                  env->error_code = 0;
>                  return;
>              }
> -            if (lpes1 == 0) {
> -                new_msr |= (target_ulong)MSR_HVB;
> -            }
>              msr |= 0x00100000;
>              if (msr_fe0 == msr_fe1) {
>                  goto store_next;
> @@ -243,23 +231,14 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>              break;
>          case POWERPC_EXCP_INVAL:
>              LOG_EXCP("Invalid instruction at " TARGET_FMT_lx "\n", env->nip);
> -            if (lpes1 == 0) {
> -                new_msr |= (target_ulong)MSR_HVB;
> -            }
>              msr |= 0x00080000;
>              env->spr[SPR_BOOKE_ESR] = ESR_PIL;
>              break;
>          case POWERPC_EXCP_PRIV:
> -            if (lpes1 == 0) {
> -                new_msr |= (target_ulong)MSR_HVB;
> -            }
>              msr |= 0x00040000;
>              env->spr[SPR_BOOKE_ESR] = ESR_PPR;
>              break;
>          case POWERPC_EXCP_TRAP:
> -            if (lpes1 == 0) {
> -                new_msr |= (target_ulong)MSR_HVB;
> -            }
>              msr |= 0x00020000;
>              env->spr[SPR_BOOKE_ESR] = ESR_PTR;
>              break;
> @@ -271,27 +250,23 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>          }
>          goto store_current;
>      case POWERPC_EXCP_FPU:       /* Floating-point unavailable exception     */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_current;
>      case POWERPC_EXCP_SYSCALL:   /* System call exception                    */
>          dump_syscall(env);
>          lev = env->error_code;
> +
> +        /* "PAPR mode" built-in hypercall emulation */
>          if ((lev == 1) && cpu_ppc_hypercall) {
>              cpu_ppc_hypercall(cpu);
>              return;
>          }
> -        if (lev == 1 || (lpes0 == 0 && lpes1 == 0)) {
> +        if (lev == 1) {
>              new_msr |= (target_ulong)MSR_HVB;
>          }
>          goto store_next;
>      case POWERPC_EXCP_APU:       /* Auxiliary processor unavailable          */
>          goto store_current;
>      case POWERPC_EXCP_DECR:      /* Decrementer exception                    */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_next;
>      case POWERPC_EXCP_FIT:       /* Fixed-interval timer interrupt           */
>          /* FIT on 4xx */
> @@ -361,21 +336,12 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>              new_msr &= ~((target_ulong)1 << MSR_ME);
>          }
>  
> -        if (0) {
> -            /* XXX: find a suitable condition to enable the hypervisor mode */
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
> +        new_msr |= (target_ulong)MSR_HVB;
>          ail = 0;
>          goto store_next;
>      case POWERPC_EXCP_DSEG:      /* Data segment exception                   */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_next;
>      case POWERPC_EXCP_ISEG:      /* Instruction segment exception            */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_next;
>      case POWERPC_EXCP_HDECR:     /* Hypervisor decrementer exception         */
>          srr0 = SPR_HSRR0;
> @@ -384,9 +350,6 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>          new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
>          goto store_next;
>      case POWERPC_EXCP_TRACE:     /* Trace exception                          */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_next;
>      case POWERPC_EXCP_HDSI:      /* Hypervisor data storage exception        */
>          srr0 = SPR_HSRR0;
> @@ -413,19 +376,10 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>          new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
>          goto store_next;
>      case POWERPC_EXCP_VPU:       /* Vector unavailable exception             */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_current;
>      case POWERPC_EXCP_VSXU:       /* VSX unavailable exception               */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_current;
>      case POWERPC_EXCP_FU:         /* Facility unavailable exception          */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          goto store_current;
>      case POWERPC_EXCP_PIT:       /* Programmable interval timer interrupt    */
>          LOG_EXCP("PIT exception\n");
> @@ -444,9 +398,6 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>                    "is not implemented yet !\n");
>          goto store_next;
>      case POWERPC_EXCP_IFTLB:     /* Instruction fetch TLB error              */
> -        if (lpes1 == 0) { /* XXX: check this */
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          switch (excp_model) {
>          case POWERPC_EXCP_602:
>          case POWERPC_EXCP_603:
> @@ -463,9 +414,6 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>          }
>          break;
>      case POWERPC_EXCP_DLTLB:     /* Data load TLB miss                       */
> -        if (lpes1 == 0) { /* XXX: check this */
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          switch (excp_model) {
>          case POWERPC_EXCP_602:
>          case POWERPC_EXCP_603:
> @@ -482,9 +430,6 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>          }
>          break;
>      case POWERPC_EXCP_DSTLB:     /* Data store TLB miss                      */
> -        if (lpes1 == 0) { /* XXX: check this */
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          switch (excp_model) {
>          case POWERPC_EXCP_602:
>          case POWERPC_EXCP_603:
> @@ -590,9 +535,6 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>                    "is not implemented yet !\n");
>          goto store_next;
>      case POWERPC_EXCP_PERFM:     /* Embedded performance monitor interrupt   */
> -        if (lpes1 == 0) {
> -            new_msr |= (target_ulong)MSR_HVB;
> -        }
>          /* XXX: TODO */
>          cpu_abort(cs,
>                    "Performance counter exception is not implemented yet !\n");
> @@ -636,6 +578,13 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>      }
>      /* Save MSR */
>      env->spr[srr1] = msr;
> +
> +    /* Sanity check */
> +    if (!(env->msr_mask & MSR_HVB) && (srr0 == SPR_HSRR0)) {
> +        cpu_abort(cs, "Trying to deliver HV exception %d with "
> +                  "no HV support\n", excp);
> +    }
> +
>      /* If any alternate SRR register are defined, duplicate saved values */
>      if (asrr0 != -1) {
>          env->spr[asrr0] = env->spr[srr0];
> @@ -644,14 +593,20 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>          env->spr[asrr1] = env->spr[srr1];
>      }
>  
> -    if (env->spr[SPR_LPCR] & LPCR_AIL) {
> -        new_msr |= (1 << MSR_IR) | (1 << MSR_DR);
> -    }
> -
> +    /* Sort out endianness of interrupt, this differs depending on the
> +     * CPU, the HV mode, etc...
> +     */
>  #ifdef TARGET_PPC64
> -    if (excp_model == POWERPC_EXCP_POWER7 ||
> -        excp_model == POWERPC_EXCP_POWER8) {
> -        if (env->spr[SPR_LPCR] & LPCR_ILE) {
> +    if (excp_model == POWERPC_EXCP_POWER7) {
> +        if (!(new_msr & MSR_HVB) && (env->spr[SPR_LPCR] & LPCR_ILE)) {
> +            new_msr |= (target_ulong)1 << MSR_LE;
> +        }
> +    } else if (excp_model == POWERPC_EXCP_POWER8) {
> +        if (new_msr & MSR_HVB) {
> +            if (env->spr[SPR_HID0] & HID0_HILE) {
> +                new_msr |= (target_ulong)1 << MSR_LE;
> +            }
> +        } else if (env->spr[SPR_LPCR] & LPCR_ILE) {
>              new_msr |= (target_ulong)1 << MSR_LE;
>          }
>      } else if (msr_ile) {
> @@ -674,7 +629,8 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>      /* AIL only works if there is no HV transition and we are running with
>       * translations enabled
>       */
> -    if (!((msr >> MSR_IR) & 1) || !((msr >> MSR_DR) & 1)) {
> +    if (!((msr >> MSR_IR) & 1) || !((msr >> MSR_DR) & 1) ||
> +        ((new_msr & MSR_HVB) && !(msr & MSR_HVB))) {
>          ail = 0;
>      }
>      /* Handle AIL */
Benjamin Herrenschmidt June 14, 2016, 9:19 p.m. UTC | #2
On Tue, 2016-06-14 at 16:25 +1000, David Gibson wrote:
> > Properly implement LPES0/1 handling for HV vs. !HV mode.
> > 
> > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > [clg: AIL implementation was fixed in commit 5c94b2a5e5ef
> >       fixed checkpatch.pl errors ]
> 
> Code looks ok, but the short description really needs an update,
> since
> this has been taken out of its original series context.

This is still what this does. It properly implements support for LPCR0
(LPCR1 isn't supported). It also fixes how the HV bit is handled when
taking interrupts and which set of SRR's are used in some cases.

Cheers,
Ben.
David Gibson June 15, 2016, 1 a.m. UTC | #3
On Wed, Jun 15, 2016 at 07:19:39AM +1000, Benjamin Herrenschmidt wrote:
> On Tue, 2016-06-14 at 16:25 +1000, David Gibson wrote:
> > > Properly implement LPES0/1 handling for HV vs. !HV mode.
> > > 
> > > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > > [clg: AIL implementation was fixed in commit 5c94b2a5e5ef
> > >       fixed checkpatch.pl errors ]
> > 
> > Code looks ok, but the short description really needs an update,
> > since
> > this has been taken out of its original series context.
> 
> This is still what this does. It properly implements support for LPCR0
> (LPCR1 isn't supported). It also fixes how the HV bit is handled when
> taking interrupts and which set of SRR's are used in some cases.

It's the "Rework POWER7 & POWER8 exception model (part 2)" bit which
is the problem.
diff mbox

Patch

diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
index aa0b63f4b0de..7c44c102db39 100644
--- a/target-ppc/excp_helper.c
+++ b/target-ppc/excp_helper.c
@@ -77,18 +77,8 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
     CPUState *cs = CPU(cpu);
     CPUPPCState *env = &cpu->env;
     target_ulong msr, new_msr, vector;
-    int srr0, srr1, asrr0, asrr1;
-    int lpes0, lpes1, lev, ail;
-
-    if (0) {
-        /* XXX: find a suitable condition to enable the hypervisor mode */
-        lpes0 = (env->spr[SPR_LPCR] >> 1) & 1;
-        lpes1 = (env->spr[SPR_LPCR] >> 2) & 1;
-    } else {
-        /* Those values ensure we won't enter the hypervisor mode */
-        lpes0 = 0;
-        lpes1 = 1;
-    }
+    int srr0, srr1, asrr0, asrr1, lev, ail;
+    bool lpes0;
 
     qemu_log_mask(CPU_LOG_INT, "Raise exception at " TARGET_FMT_lx
                   " => %08x (%02x)\n", env->nip, excp, env->error_code);
@@ -100,8 +90,10 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         msr = env->msr & ~0x783f0000ULL;
     }
 
-    /* new interrupt handler msr */
-    new_msr = env->msr & ((target_ulong)1 << MSR_ME);
+    /* new interrupt handler msr preserves existing HV and ME unless
+     * explicitly overriden
+     */
+    new_msr = env->msr & (((target_ulong)1 << MSR_ME) | MSR_HVB);
 
     /* target registers */
     srr0 = SPR_SRR0;
@@ -111,12 +103,19 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
 
     /* Exception targetting modifiers
      *
+     * LPES0 is supported on POWER7/8
+     * LPES1 is not supported (old iSeries mode)
+     *
+     * On anything else, we behave as if LPES0 is 1
+     * (externals don't alter MSR:HV)
+     *
      * AIL is initialized here but can be cleared by
      * selected exceptions
      */
 #if defined(TARGET_PPC64)
     if (excp_model == POWERPC_EXCP_POWER7 ||
         excp_model == POWERPC_EXCP_POWER8) {
+        lpes0 = !!(env->spr[SPR_LPCR] & LPCR_LPES0);
         if (excp_model == POWERPC_EXCP_POWER8) {
             ail = (env->spr[SPR_LPCR] & LPCR_AIL) >> LPCR_AIL_SHIFT;
         } else {
@@ -125,6 +124,7 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
     } else
 #endif /* defined(TARGET_PPC64) */
     {
+        lpes0 = true;
         ail = 0;
     }
 
@@ -162,10 +162,7 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
             cs->halted = 1;
             cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
         }
-        if (0) {
-            /* XXX: find a suitable condition to enable the hypervisor mode */
-            new_msr |= (target_ulong)MSR_HVB;
-        }
+        new_msr |= (target_ulong)MSR_HVB;
         ail = 0;
 
         /* machine check exceptions don't have ME set */
@@ -191,23 +188,20 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
     case POWERPC_EXCP_DSI:       /* Data storage exception                   */
         LOG_EXCP("DSI exception: DSISR=" TARGET_FMT_lx" DAR=" TARGET_FMT_lx
                  "\n", env->spr[SPR_DSISR], env->spr[SPR_DAR]);
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_next;
     case POWERPC_EXCP_ISI:       /* Instruction storage exception            */
         LOG_EXCP("ISI exception: msr=" TARGET_FMT_lx ", nip=" TARGET_FMT_lx
                  "\n", msr, env->nip);
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         msr |= env->error_code;
         goto store_next;
     case POWERPC_EXCP_EXTERNAL:  /* External input                           */
         cs = CPU(cpu);
 
-        if (lpes0 == 1) {
+        if (!lpes0) {
             new_msr |= (target_ulong)MSR_HVB;
+            new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
+            srr0 = SPR_HSRR0;
+            srr1 = SPR_HSRR1;
         }
         if (env->mpic_proxy) {
             /* IACK the IRQ on delivery */
@@ -215,9 +209,6 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         }
         goto store_next;
     case POWERPC_EXCP_ALIGN:     /* Alignment exception                      */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         /* XXX: this is false */
         /* Get rS/rD and rA from faulting opcode */
         env->spr[SPR_DSISR] |= (cpu_ldl_code(env, (env->nip - 4))
@@ -232,9 +223,6 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
                 env->error_code = 0;
                 return;
             }
-            if (lpes1 == 0) {
-                new_msr |= (target_ulong)MSR_HVB;
-            }
             msr |= 0x00100000;
             if (msr_fe0 == msr_fe1) {
                 goto store_next;
@@ -243,23 +231,14 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
             break;
         case POWERPC_EXCP_INVAL:
             LOG_EXCP("Invalid instruction at " TARGET_FMT_lx "\n", env->nip);
-            if (lpes1 == 0) {
-                new_msr |= (target_ulong)MSR_HVB;
-            }
             msr |= 0x00080000;
             env->spr[SPR_BOOKE_ESR] = ESR_PIL;
             break;
         case POWERPC_EXCP_PRIV:
-            if (lpes1 == 0) {
-                new_msr |= (target_ulong)MSR_HVB;
-            }
             msr |= 0x00040000;
             env->spr[SPR_BOOKE_ESR] = ESR_PPR;
             break;
         case POWERPC_EXCP_TRAP:
-            if (lpes1 == 0) {
-                new_msr |= (target_ulong)MSR_HVB;
-            }
             msr |= 0x00020000;
             env->spr[SPR_BOOKE_ESR] = ESR_PTR;
             break;
@@ -271,27 +250,23 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         }
         goto store_current;
     case POWERPC_EXCP_FPU:       /* Floating-point unavailable exception     */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_current;
     case POWERPC_EXCP_SYSCALL:   /* System call exception                    */
         dump_syscall(env);
         lev = env->error_code;
+
+        /* "PAPR mode" built-in hypercall emulation */
         if ((lev == 1) && cpu_ppc_hypercall) {
             cpu_ppc_hypercall(cpu);
             return;
         }
-        if (lev == 1 || (lpes0 == 0 && lpes1 == 0)) {
+        if (lev == 1) {
             new_msr |= (target_ulong)MSR_HVB;
         }
         goto store_next;
     case POWERPC_EXCP_APU:       /* Auxiliary processor unavailable          */
         goto store_current;
     case POWERPC_EXCP_DECR:      /* Decrementer exception                    */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_next;
     case POWERPC_EXCP_FIT:       /* Fixed-interval timer interrupt           */
         /* FIT on 4xx */
@@ -361,21 +336,12 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
             new_msr &= ~((target_ulong)1 << MSR_ME);
         }
 
-        if (0) {
-            /* XXX: find a suitable condition to enable the hypervisor mode */
-            new_msr |= (target_ulong)MSR_HVB;
-        }
+        new_msr |= (target_ulong)MSR_HVB;
         ail = 0;
         goto store_next;
     case POWERPC_EXCP_DSEG:      /* Data segment exception                   */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_next;
     case POWERPC_EXCP_ISEG:      /* Instruction segment exception            */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_next;
     case POWERPC_EXCP_HDECR:     /* Hypervisor decrementer exception         */
         srr0 = SPR_HSRR0;
@@ -384,9 +350,6 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
         goto store_next;
     case POWERPC_EXCP_TRACE:     /* Trace exception                          */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_next;
     case POWERPC_EXCP_HDSI:      /* Hypervisor data storage exception        */
         srr0 = SPR_HSRR0;
@@ -413,19 +376,10 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
         goto store_next;
     case POWERPC_EXCP_VPU:       /* Vector unavailable exception             */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_current;
     case POWERPC_EXCP_VSXU:       /* VSX unavailable exception               */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_current;
     case POWERPC_EXCP_FU:         /* Facility unavailable exception          */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         goto store_current;
     case POWERPC_EXCP_PIT:       /* Programmable interval timer interrupt    */
         LOG_EXCP("PIT exception\n");
@@ -444,9 +398,6 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
                   "is not implemented yet !\n");
         goto store_next;
     case POWERPC_EXCP_IFTLB:     /* Instruction fetch TLB error              */
-        if (lpes1 == 0) { /* XXX: check this */
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         switch (excp_model) {
         case POWERPC_EXCP_602:
         case POWERPC_EXCP_603:
@@ -463,9 +414,6 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         }
         break;
     case POWERPC_EXCP_DLTLB:     /* Data load TLB miss                       */
-        if (lpes1 == 0) { /* XXX: check this */
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         switch (excp_model) {
         case POWERPC_EXCP_602:
         case POWERPC_EXCP_603:
@@ -482,9 +430,6 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         }
         break;
     case POWERPC_EXCP_DSTLB:     /* Data store TLB miss                      */
-        if (lpes1 == 0) { /* XXX: check this */
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         switch (excp_model) {
         case POWERPC_EXCP_602:
         case POWERPC_EXCP_603:
@@ -590,9 +535,6 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
                   "is not implemented yet !\n");
         goto store_next;
     case POWERPC_EXCP_PERFM:     /* Embedded performance monitor interrupt   */
-        if (lpes1 == 0) {
-            new_msr |= (target_ulong)MSR_HVB;
-        }
         /* XXX: TODO */
         cpu_abort(cs,
                   "Performance counter exception is not implemented yet !\n");
@@ -636,6 +578,13 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
     }
     /* Save MSR */
     env->spr[srr1] = msr;
+
+    /* Sanity check */
+    if (!(env->msr_mask & MSR_HVB) && (srr0 == SPR_HSRR0)) {
+        cpu_abort(cs, "Trying to deliver HV exception %d with "
+                  "no HV support\n", excp);
+    }
+
     /* If any alternate SRR register are defined, duplicate saved values */
     if (asrr0 != -1) {
         env->spr[asrr0] = env->spr[srr0];
@@ -644,14 +593,20 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         env->spr[asrr1] = env->spr[srr1];
     }
 
-    if (env->spr[SPR_LPCR] & LPCR_AIL) {
-        new_msr |= (1 << MSR_IR) | (1 << MSR_DR);
-    }
-
+    /* Sort out endianness of interrupt, this differs depending on the
+     * CPU, the HV mode, etc...
+     */
 #ifdef TARGET_PPC64
-    if (excp_model == POWERPC_EXCP_POWER7 ||
-        excp_model == POWERPC_EXCP_POWER8) {
-        if (env->spr[SPR_LPCR] & LPCR_ILE) {
+    if (excp_model == POWERPC_EXCP_POWER7) {
+        if (!(new_msr & MSR_HVB) && (env->spr[SPR_LPCR] & LPCR_ILE)) {
+            new_msr |= (target_ulong)1 << MSR_LE;
+        }
+    } else if (excp_model == POWERPC_EXCP_POWER8) {
+        if (new_msr & MSR_HVB) {
+            if (env->spr[SPR_HID0] & HID0_HILE) {
+                new_msr |= (target_ulong)1 << MSR_LE;
+            }
+        } else if (env->spr[SPR_LPCR] & LPCR_ILE) {
             new_msr |= (target_ulong)1 << MSR_LE;
         }
     } else if (msr_ile) {
@@ -674,7 +629,8 @@  static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
     /* AIL only works if there is no HV transition and we are running with
      * translations enabled
      */
-    if (!((msr >> MSR_IR) & 1) || !((msr >> MSR_DR) & 1)) {
+    if (!((msr >> MSR_IR) & 1) || !((msr >> MSR_DR) & 1) ||
+        ((new_msr & MSR_HVB) && !(msr & MSR_HVB))) {
         ail = 0;
     }
     /* Handle AIL */