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* [PATCH 0/4] Add IBM PPE42 CPU support
@ 2025-08-19 21:28 Glenn Miles
  2025-08-19 21:28 ` [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors Glenn Miles
                   ` (3 more replies)
  0 siblings, 4 replies; 19+ messages in thread
From: Glenn Miles @ 2025-08-19 21:28 UTC (permalink / raw)
  To: qemu-devel
  Cc: Glenn Miles, qemu-ppc, clg, npiggin, harshpb, thuth, rathc,
	richard.henderson

This patchset adds support for the IBM PPE42 processor,
including a simple machine providing a platform for
testing the PPE42 instructions.

The PPE42 processor is used as an embedded processor in
the IBM Power9, Power10 and Power12 processors for various
tasks.  It is basically a stripped down version of the
IBM PowerPC 405 processor, with some added instructions
for handling 64-bit loads and stores and some 64-bit
logical operations.
    
For more information on the PPE 42 processor please visit:
    
https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf

A functional test is included.  This test downloads a
prebuilt test image from:

https://github.com/milesg-github/ppe42-tests

Building the image rquires a forked version of an old
version of GCC, which can be found here:

https://github.com/open-power/ppe42-gcc

Thanks,

Glenn

Glenn Miles (4):
  target/ppc: Add IBM PPE42 family of processors
  target/ppc: Add IBM PPE42 special instructions
  hw/ppc: Add a test machine for the IBM PPE42 CPU
  tests/functional: Add test for IBM PPE42 instructions

 hw/ppc/Kconfig                      |   9 +
 hw/ppc/meson.build                  |   2 +
 hw/ppc/ppc_booke.c                  |   7 +-
 hw/ppc/ppe42_machine.c              |  69 +++
 include/hw/ppc/ppc.h                |   1 +
 target/ppc/cpu-models.c             |   7 +
 target/ppc/cpu-models.h             |   4 +
 target/ppc/cpu.h                    |  66 ++-
 target/ppc/cpu_init.c               | 286 ++++++++--
 target/ppc/excp_helper.c            | 171 ++++++
 target/ppc/helper_regs.c            |  28 +-
 target/ppc/insn32.decode            |  66 ++-
 target/ppc/tcg-excp_helper.c        |  12 +
 target/ppc/translate.c              |  35 +-
 target/ppc/translate/ppe-impl.c.inc | 805 ++++++++++++++++++++++++++++
 tests/functional/meson.build        |   1 +
 tests/functional/test_ppc_ppe42.py  |  79 +++
 17 files changed, 1592 insertions(+), 56 deletions(-)
 create mode 100644 hw/ppc/ppe42_machine.c
 create mode 100644 target/ppc/translate/ppe-impl.c.inc
 create mode 100644 tests/functional/test_ppc_ppe42.py

-- 
2.43.0



^ permalink raw reply	[flat|nested] 19+ messages in thread

* [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-19 21:28 [PATCH 0/4] Add IBM PPE42 CPU support Glenn Miles
@ 2025-08-19 21:28 ` Glenn Miles
  2025-08-25 11:24   ` Harsh Prateek Bora
  2025-08-19 21:28 ` [PATCH 2/4] target/ppc: Add IBM PPE42 special instructions Glenn Miles
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 19+ messages in thread
From: Glenn Miles @ 2025-08-19 21:28 UTC (permalink / raw)
  To: qemu-devel
  Cc: Glenn Miles, qemu-ppc, clg, npiggin, harshpb, thuth, rathc,
	richard.henderson

Adds the IBM PPE42 family of processors supporting the
PPE42, PPE42X and PPE42XM processor versions.  These
processors are used as embedded processors in the IBM
Power9, Power10 and Power12 processors for various
tasks.  It is basically a stripped down version of the
IBM PowerPC 405 processor, with some added instructions
for handling 64-bit loads and stores.

For more information on the PPE 42 processor please visit:

https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf

Supports PPE42 SPR's (Including the MSR) and  Exceptions.

Does not yet support new PPE42 instructions and does not
prevent access to some invalid instructions and registers
(currently allows for access to invalid GPR's and CR fields).

Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
---
 target/ppc/cpu-models.c      |   7 +
 target/ppc/cpu-models.h      |   4 +
 target/ppc/cpu.h             |  66 +++++++-
 target/ppc/cpu_init.c        | 286 ++++++++++++++++++++++++++++++-----
 target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
 target/ppc/helper_regs.c     |  28 +++-
 target/ppc/tcg-excp_helper.c |  12 ++
 target/ppc/translate.c       |   6 +-
 8 files changed, 535 insertions(+), 45 deletions(-)

diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
index ea86ea202a..09f73e23a8 100644
--- a/target/ppc/cpu-models.c
+++ b/target/ppc/cpu-models.c
@@ -116,6 +116,13 @@
                 NULL)
     POWERPC_DEF("x2vp20",        CPU_POWERPC_X2VP20,                 405,
                 NULL)
+    /* PPE42 Embedded Controllers                                            */
+    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42,                  ppe42,
+                "Generic PPE 42")
+    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X,                 ppe42x,
+                "Generic PPE 42X")
+    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM,                ppe42xm,
+                "Generic PPE 42XM")
     /* PowerPC 440 family                                                    */
 #if defined(TODO_USER_ONLY)
     POWERPC_DEF("440",           CPU_POWERPC_440,                    440GP,
diff --git a/target/ppc/cpu-models.h b/target/ppc/cpu-models.h
index 72ad31ba50..c6cd27f390 100644
--- a/target/ppc/cpu-models.h
+++ b/target/ppc/cpu-models.h
@@ -69,6 +69,10 @@ enum {
     /* Xilinx cores */
     CPU_POWERPC_X2VP4              = 0x20010820,
     CPU_POWERPC_X2VP20             = 0x20010860,
+    /* IBM PPE42 Family */
+    CPU_POWERPC_PPE42              = 0x42000000,
+    CPU_POWERPC_PPE42X             = 0x42100000,
+    CPU_POWERPC_PPE42XM            = 0x42200000,
     /* PowerPC 440 family */
     /* Generic PowerPC 440 */
 #define CPU_POWERPC_440              CPU_POWERPC_440GXf
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index 6b90543811..f2fc84f384 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -220,6 +220,8 @@ typedef enum powerpc_excp_t {
     POWERPC_EXCP_POWER10,
     /* POWER11 exception model           */
     POWERPC_EXCP_POWER11,
+    /* PPE42 exception model            */
+    POWERPC_EXCP_PPE42,
 } powerpc_excp_t;
 
 /*****************************************************************************/
@@ -282,6 +284,8 @@ typedef enum powerpc_input_t {
     PPC_FLAGS_INPUT_POWER9,
     /* Freescale RCPU bus               */
     PPC_FLAGS_INPUT_RCPU,
+    /* PPE42 bus                        */
+    PPC_FLAGS_INPUT_PPE42,
 } powerpc_input_t;
 
 #define PPC_INPUT(env) ((env)->bus_model)
@@ -433,39 +437,64 @@ typedef enum {
 #define MSR_TM   PPC_BIT_NR(31) /* Transactional Memory Available (Book3s)   */
 #define MSR_CM   PPC_BIT_NR(32) /* Computation mode for BookE         hflags */
 #define MSR_ICM  PPC_BIT_NR(33) /* Interrupt computation mode for BookE      */
+#define MSR_SEM0 PPC_BIT_NR(33) /* SIB Error Mask Bit 0 (PPE42)              */
+#define MSR_SEM1 PPC_BIT_NR(34) /* SIB Error Mask Bit 1 (PPE42)              */
+#define MSR_SEM2 PPC_BIT_NR(35) /* SIB Error Mask Bit 2 (PPE42)              */
 #define MSR_GS   PPC_BIT_NR(35) /* guest state for BookE                     */
+#define MSR_SEM3 PPC_BIT_NR(36) /* SIB Error Mask Bit 3 (PPE42)              */
+#define MSR_SEM4 PPC_BIT_NR(37) /* SIB Error Mask Bit 4 (PPE42)              */
 #define MSR_UCLE PPC_BIT_NR(37) /* User-mode cache lock enable for BookE     */
 #define MSR_VR   PPC_BIT_NR(38) /* altivec available                x hflags */
 #define MSR_SPE  PPC_BIT_NR(38) /* SPE enable for BookE             x hflags */
+#define MSR_SEM5 PPC_BIT_NR(38) /* SIB Error Mask Bit 5 (PPE42)              */
+#define MSR_SEM6 PPC_BIT_NR(39) /* SIB Error Mask Bit 6 (PPE42)              */
 #define MSR_VSX  PPC_BIT_NR(40) /* Vector Scalar Extension (>= 2.06)x hflags */
+#define MSR_IS0  PPC_BIT_NR(40) /* Instance Specific Bit 0 (PPE42)           */
 #define MSR_S    PPC_BIT_NR(41) /* Secure state                              */
+#define MSR_SIBRC0 PPC_BIT_NR(41) /* Last SIB return code Bit 0 (PPE42)      */
+#define MSR_SIBRC1 PPC_BIT_NR(42) /* Last SIB return code Bit 1 (PPE42)      */
+#define MSR_SIBRC2 PPC_BIT_NR(43) /* Last SIB return code Bit 2 (PPE42)      */
+#define MSR_LP   PPC_BIT_NR(44) /* Low Priority (PPE42)                      */
 #define MSR_KEY  PPC_BIT_NR(44) /* key bit on 603e                           */
 #define MSR_POW  PPC_BIT_NR(45) /* Power management                          */
 #define MSR_WE   PPC_BIT_NR(45) /* Wait State Enable on 405                  */
+#define MSR_IS1  PPC_BIT_NR(46) /* Instance Specific Bit 1 (PPE42)           */
 #define MSR_TGPR PPC_BIT_NR(46) /* TGPR usage on 602/603            x        */
 #define MSR_CE   PPC_BIT_NR(46) /* Critical int. enable on embedded PPC x    */
 #define MSR_ILE  PPC_BIT_NR(47) /* Interrupt little-endian mode              */
+#define MSR_UIE  PPC_BIT_NR(47) /* Unmaskable Interrupt Enable (PPE42)       */
 #define MSR_EE   PPC_BIT_NR(48) /* External interrupt enable                 */
 #define MSR_PR   PPC_BIT_NR(49) /* Problem state                      hflags */
 #define MSR_FP   PPC_BIT_NR(50) /* Floating point available           hflags */
 #define MSR_ME   PPC_BIT_NR(51) /* Machine check interrupt enable            */
 #define MSR_FE0  PPC_BIT_NR(52) /* Floating point exception mode 0           */
+#define MSR_IS2  PPC_BIT_NR(52) /* Instance Specific Bit 2 (PPE42)           */
+#define MSR_IS3  PPC_BIT_NR(53) /* Instance Specific Bit 3 (PPE42)           */
 #define MSR_SE   PPC_BIT_NR(53) /* Single-step trace enable         x hflags */
 #define MSR_DWE  PPC_BIT_NR(53) /* Debug wait enable on 405         x        */
 #define MSR_UBLE PPC_BIT_NR(53) /* User BTB lock enable on e500     x        */
 #define MSR_BE   PPC_BIT_NR(54) /* Branch trace enable              x hflags */
 #define MSR_DE   PPC_BIT_NR(54) /* Debug int. enable on embedded PPC   x     */
 #define MSR_FE1  PPC_BIT_NR(55) /* Floating point exception mode 1           */
+#define MSR_IPE  PPC_BIT_NR(55) /* Imprecise Mode Enable (PPE42)             */
 #define MSR_AL   PPC_BIT_NR(56) /* AL bit on POWER                           */
+#define MSR_SIBRCA0 PPC_BIT_NR(56) /* SIB Return Code Accumulator bit0 (PPE42) */
+#define MSR_SIBRCA1 PPC_BIT_NR(57) /* SIB Return Code Accumulator bit1 (PPE42) */
 #define MSR_EP   PPC_BIT_NR(57) /* Exception prefix on 601                   */
 #define MSR_IR   PPC_BIT_NR(58) /* Instruction relocate                      */
 #define MSR_IS   PPC_BIT_NR(58) /* Instruction address space (BookE)         */
+#define MSR_SIBRCA2 PPC_BIT_NR(58) /* SIB Return Code Accumulator bit2 (PPE42) */
+#define MSR_SIBRCA3 PPC_BIT_NR(59) /* SIB Return Code Accumulator bit3 (PPE42) */
 #define MSR_DR   PPC_BIT_NR(59) /* Data relocate                             */
 #define MSR_DS   PPC_BIT_NR(59) /* Data address space (BookE)                */
 #define MSR_PE   PPC_BIT_NR(60) /* Protection enable on 403                  */
+#define MSR_SIBRCA4 PPC_BIT_NR(60) /* SIB Return Code Accumulator bit4 (PPE42) */
+#define MSR_SIBRCA5 PPC_BIT_NR(61) /* SIB Return Code Accumulator bit5 (PPE42) */
 #define MSR_PX   PPC_BIT_NR(61) /* Protection exclusive on 403        x      */
 #define MSR_PMM  PPC_BIT_NR(61) /* Performance monitor mark on POWER  x      */
 #define MSR_RI   PPC_BIT_NR(62) /* Recoverable interrupt            1        */
+#define MSR_SIBRCA6 PPC_BIT_NR(62) /* SIB Return Code Accumulator bit6 (PPE42) */
+#define MSR_SIBRCA7 PPC_BIT_NR(63) /* SIB Return Code Accumulator bit7 (PPE42) */
 #define MSR_LE   PPC_BIT_NR(63) /* Little-endian mode               1 hflags */
 
 FIELD(MSR, SF, MSR_SF, 1)
@@ -517,6 +546,9 @@ FIELD(MSR, PX, MSR_PX, 1)
 FIELD(MSR, PMM, MSR_PMM, 1)
 FIELD(MSR, RI, MSR_RI, 1)
 FIELD(MSR, LE, MSR_LE, 1)
+FIELD(MSR, SEM, MSR_SEM6, 7)
+FIELD(MSR, SIBRC, MSR_SIBRC2, 3)
+FIELD(MSR, SIBRCA, MSR_SIBRCA7, 8)
 
 /*
  * FE0 and FE1 bits are not side-by-side
@@ -730,6 +762,21 @@ FIELD(MSR, LE, MSR_LE, 1)
 #define ESR_VLEMI PPC_BIT(58) /* VLE operation                          */
 #define ESR_MIF   PPC_BIT(62) /* Misaligned instruction (VLE)           */
 
+/* PPE42 Interrupt Status Register bits                                 */
+#define ISR_SRSMS0  PPC_BIT_NR(48) /* System Reset State Machine State 0   */
+#define ISR_SRSMS1  PPC_BIT_NR(49) /* System Reset State Machine State 1   */
+#define ISR_SRSMS2  PPC_BIT_NR(50) /* System Reset State Machine State 2   */
+#define ISR_SRSMS3  PPC_BIT_NR(51) /* System Reset State Machine State 3   */
+#define ISR_EP      PPC_BIT_NR(53) /* MSR[EE] Maskable Event Pending       */
+#define ISR_PTR     PPC_BIT_NR(56) /* Program Interrupt from trap          */
+#define ISR_ST      PPC_BIT_NR(57) /* Data Interrupt caused by store       */
+#define ISR_MFE     PPC_BIT_NR(60) /* Multiple Fault Error                 */
+#define ISR_MCS0    PPC_BIT_NR(61) /* Machine Check Status bit0            */
+#define ISR_MCS1    PPC_BIT_NR(62) /* Machine Check Status bit1            */
+#define ISR_MCS2    PPC_BIT_NR(63) /* Machine Check Status bit2            */
+FIELD(ISR, SRSMS, ISR_SRSMS3, 4)
+FIELD(ISR, MCS, ISR_MCS2, 3)
+
 /* Transaction EXception And Summary Register bits                           */
 #define TEXASR_FAILURE_PERSISTENT                (63 - 7)
 #define TEXASR_DISALLOWED                        (63 - 8)
@@ -785,6 +832,8 @@ enum {
     POWERPC_FLAG_SMT_1LPAR = 0x00800000,
     /* Has BHRB */
     POWERPC_FLAG_BHRB      = 0x01000000,
+    /* Use PPE42-specific behavior                                           */
+    POWERPC_FLAG_PPE42     = 0x02000000,
 };
 
 /*
@@ -1750,9 +1799,12 @@ void ppc_compat_add_property(Object *obj, const char *name,
 #define SPR_BOOKE_CSRR0       (0x03A)
 #define SPR_BOOKE_CSRR1       (0x03B)
 #define SPR_BOOKE_DEAR        (0x03D)
+#define SPR_PPE42_EDR         (0x03D)
 #define SPR_IAMR              (0x03D)
 #define SPR_BOOKE_ESR         (0x03E)
+#define SPR_PPE42_ISR         (0x03E)
 #define SPR_BOOKE_IVPR        (0x03F)
+#define SPR_PPE42_IVPR        (0x03F)
 #define SPR_MPC_EIE           (0x050)
 #define SPR_MPC_EID           (0x051)
 #define SPR_MPC_NRI           (0x052)
@@ -1818,6 +1870,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
 #define SPR_TBU40             (0x11E)
 #define SPR_SVR               (0x11E)
 #define SPR_BOOKE_PIR         (0x11E)
+#define SPR_PPE42_PIR         (0x11E)
 #define SPR_PVR               (0x11F)
 #define SPR_HSPRG0            (0x130)
 #define SPR_BOOKE_DBSR        (0x130)
@@ -1827,6 +1880,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
 #define SPR_BOOKE_EPCR        (0x133)
 #define SPR_SPURR             (0x134)
 #define SPR_BOOKE_DBCR0       (0x134)
+#define SPR_PPE42_DBCR        (0x134)
 #define SPR_IBCR              (0x135)
 #define SPR_PURR              (0x135)
 #define SPR_BOOKE_DBCR1       (0x135)
@@ -1844,6 +1898,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
 #define SPR_HSRR1             (0x13B)
 #define SPR_BOOKE_IAC4        (0x13B)
 #define SPR_BOOKE_DAC1        (0x13C)
+#define SPR_PPE42_DACR        (0x13C)
 #define SPR_MMCRH             (0x13C)
 #define SPR_DABR2             (0x13D)
 #define SPR_BOOKE_DAC2        (0x13D)
@@ -1853,12 +1908,14 @@ void ppc_compat_add_property(Object *obj, const char *name,
 #define SPR_BOOKE_DVC2        (0x13F)
 #define SPR_LPIDR             (0x13F)
 #define SPR_BOOKE_TSR         (0x150)
+#define SPR_PPE42_TSR         (0x150)
 #define SPR_HMER              (0x150)
 #define SPR_HMEER             (0x151)
 #define SPR_PCR               (0x152)
 #define SPR_HEIR              (0x153)
 #define SPR_BOOKE_LPIDR       (0x152)
 #define SPR_BOOKE_TCR         (0x154)
+#define SPR_PPE42_TCR         (0x154)
 #define SPR_BOOKE_TLB0PS      (0x158)
 #define SPR_BOOKE_TLB1PS      (0x159)
 #define SPR_BOOKE_TLB2PS      (0x15A)
@@ -2528,6 +2585,12 @@ enum {
     PPC2_MEM_LWSYNC    = 0x0000000000200000ULL,
     /* ISA 2.06 BCD assist instructions                                      */
     PPC2_BCDA_ISA206   = 0x0000000000400000ULL,
+    /* PPE42 instructions                                                    */
+    PPC2_PPE42         = 0x0000000000800000ULL,
+    /* PPE42X instructions                                                   */
+    PPC2_PPE42X        = 0x0000000001000000ULL,
+    /* PPE42XM instructions                                                  */
+    PPC2_PPE42XM       = 0x0000000002000000ULL,
 
 #define PPC_TCG_INSNS2 (PPC2_BOOKE206 | PPC2_VSX | PPC2_PRCNTL | PPC2_DBRX | \
                         PPC2_ISA205 | PPC2_VSX207 | PPC2_PERM_ISA206 | \
@@ -2537,7 +2600,8 @@ enum {
                         PPC2_ALTIVEC_207 | PPC2_ISA207S | PPC2_DFP | \
                         PPC2_FP_CVT_S64 | PPC2_TM | PPC2_PM_ISA206 | \
                         PPC2_ISA300 | PPC2_ISA310 | PPC2_MEM_LWSYNC | \
-                        PPC2_BCDA_ISA206)
+                        PPC2_BCDA_ISA206 | PPC2_PPE42 | PPC2_PPE42X | \
+                        PPC2_PPE42XM)
 };
 
 /*****************************************************************************/
diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index a0e77f2673..317670a96b 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -1653,6 +1653,47 @@ static void register_8xx_sprs(CPUPPCState *env)
  * ... and more (thermal management, performance counters, ...)
  */
 
+static void register_ppe42_sprs(CPUPPCState *env)
+{
+    spr_register(env, SPR_PPE42_EDR, "EDR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, &spr_write_generic,
+                 0x00000000);
+    spr_register(env, SPR_PPE42_ISR, "ISR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, &spr_write_generic,
+                 0x00000000);
+    spr_register(env, SPR_PPE42_IVPR, "IVPR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, SPR_NOACCESS,
+                 0xfff80000);
+    spr_register(env, SPR_PPE42_PIR, "PIR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, &spr_write_pir,
+                 0x00000000);
+    spr_register(env, SPR_PPE42_DBCR, "DBCR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, &spr_write_40x_dbcr0,
+                 0x00000000);
+    spr_register(env, SPR_PPE42_DACR, "DACR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, &spr_write_generic,
+                 0x00000000);
+    /* Timer */
+    spr_register(env, SPR_DECR, "DECR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_decr, &spr_write_decr,
+                 0x00000000);
+    spr_register(env, SPR_PPE42_TSR, "TSR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, &spr_write_booke_tsr,
+                 0x00000000);
+    spr_register(env, SPR_BOOKE_TCR, "TCR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, &spr_write_booke_tcr,
+                 0x00000000);
+}
+
 /*****************************************************************************/
 /* Exception vectors models                                                  */
 static void init_excp_4xx(CPUPPCState *env)
@@ -1679,6 +1720,30 @@ static void init_excp_4xx(CPUPPCState *env)
 #endif
 }
 
+static void init_excp_ppe42(CPUPPCState *env)
+{
+#if !defined(CONFIG_USER_ONLY)
+    /* Machine Check vector changed after version 0 */
+    if (((env->spr[SPR_PVR] & 0xf00000ul) >> 20) == 0) {
+        env->excp_vectors[POWERPC_EXCP_MCHECK]   = 0x00000000;
+    } else {
+        env->excp_vectors[POWERPC_EXCP_MCHECK]   = 0x00000020;
+    }
+    env->excp_vectors[POWERPC_EXCP_RESET]    = 0x00000040;
+    env->excp_vectors[POWERPC_EXCP_DSI]      = 0x00000060;
+    env->excp_vectors[POWERPC_EXCP_ISI]      = 0x00000080;
+    env->excp_vectors[POWERPC_EXCP_EXTERNAL] = 0x000000A0;
+    env->excp_vectors[POWERPC_EXCP_ALIGN]    = 0x000000C0;
+    env->excp_vectors[POWERPC_EXCP_PROGRAM]  = 0x000000E0;
+    env->excp_vectors[POWERPC_EXCP_DECR]     = 0x00000100;
+    env->excp_vectors[POWERPC_EXCP_FIT]      = 0x00000120;
+    env->excp_vectors[POWERPC_EXCP_WDT]      = 0x00000140;
+    env->ivpr_mask = 0xFFFFFE00UL;
+    /* Hardware reset vector */
+    env->hreset_vector = 0x00000040UL;
+#endif
+}
+
 static void init_excp_MPC5xx(CPUPPCState *env)
 {
 #if !defined(CONFIG_USER_ONLY)
@@ -2200,6 +2265,125 @@ POWERPC_FAMILY(405)(ObjectClass *oc, const void *data)
                  POWERPC_FLAG_DE | POWERPC_FLAG_BUS_CLK;
 }
 
+static void init_proc_ppe42(CPUPPCState *env)
+{
+    register_ppe42_sprs(env);
+
+    init_excp_ppe42(env);
+    env->dcache_line_size = 32;
+    env->icache_line_size = 32;
+    /* Allocate hardware IRQ controller */
+    ppc40x_irq_init(env_archcpu(env));
+
+    SET_FIT_PERIOD(8, 12, 16, 20);
+    SET_WDT_PERIOD(16, 20, 24, 28);
+}
+
+POWERPC_FAMILY(ppe42)(ObjectClass *oc, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
+
+    dc->desc = "PPE 42";
+    pcc->init_proc = init_proc_ppe42;
+    pcc->check_pow = check_pow_nocheck;
+    pcc->check_attn = check_attn_none;
+    pcc->insns_flags = PPC_INSNS_BASE |
+                       PPC_WRTEE |
+                       PPC_CACHE |
+                       PPC_CACHE_DCBZ |
+                       PPC_MEM_SYNC;
+    pcc->insns_flags2 = PPC2_PPE42;
+    pcc->msr_mask = R_MSR_SEM_MASK |
+                    (1ull << MSR_IS0) |
+                    R_MSR_SIBRC_MASK |
+                    (1ull << MSR_LP) |
+                    (1ull << MSR_WE) |
+                    (1ull << MSR_IS1) |
+                    (1ull << MSR_UIE) |
+                    (1ull << MSR_EE) |
+                    (1ull << MSR_ME) |
+                    (1ull << MSR_IS2) |
+                    (1ull << MSR_IS3) |
+                    (1ull << MSR_IPE) |
+                    R_MSR_SIBRCA_MASK;
+    pcc->mmu_model = POWERPC_MMU_REAL;
+    pcc->excp_model = POWERPC_EXCP_PPE42;
+    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
+    pcc->bfd_mach = bfd_mach_ppc_403;
+    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;
+}
+
+POWERPC_FAMILY(ppe42x)(ObjectClass *oc, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
+
+    dc->desc = "PPE 42X";
+    pcc->init_proc = init_proc_ppe42;
+    pcc->check_pow = check_pow_nocheck;
+    pcc->check_attn = check_attn_none;
+    pcc->insns_flags = PPC_INSNS_BASE |
+                       PPC_WRTEE |
+                       PPC_CACHE |
+                       PPC_CACHE_DCBZ |
+                       PPC_MEM_SYNC;
+    pcc->insns_flags2 = PPC2_PPE42 | PPC2_PPE42X;
+    pcc->msr_mask = R_MSR_SEM_MASK |
+                    (1ull << MSR_IS0) |
+                    R_MSR_SIBRC_MASK |
+                    (1ull << MSR_LP) |
+                    (1ull << MSR_WE) |
+                    (1ull << MSR_IS1) |
+                    (1ull << MSR_UIE) |
+                    (1ull << MSR_EE) |
+                    (1ull << MSR_ME) |
+                    (1ull << MSR_IS2) |
+                    (1ull << MSR_IS3) |
+                    (1ull << MSR_IPE) |
+                    R_MSR_SIBRCA_MASK;
+    pcc->mmu_model = POWERPC_MMU_REAL;
+    pcc->excp_model = POWERPC_EXCP_PPE42;
+    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
+    pcc->bfd_mach = bfd_mach_ppc_403;
+    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;
+}
+
+POWERPC_FAMILY(ppe42xm)(ObjectClass *oc, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
+
+    dc->desc = "PPE 42XM";
+    pcc->init_proc = init_proc_ppe42;
+    pcc->check_pow = check_pow_nocheck;
+    pcc->check_attn = check_attn_none;
+    pcc->insns_flags = PPC_INSNS_BASE |
+                       PPC_WRTEE |
+                       PPC_CACHE |
+                       PPC_CACHE_DCBZ |
+                       PPC_MEM_SYNC;
+    pcc->insns_flags2 = PPC2_PPE42 | PPC2_PPE42X | PPC2_PPE42XM;
+    pcc->msr_mask = R_MSR_SEM_MASK |
+                    (1ull << MSR_IS0) |
+                    R_MSR_SIBRC_MASK |
+                    (1ull << MSR_LP) |
+                    (1ull << MSR_WE) |
+                    (1ull << MSR_IS1) |
+                    (1ull << MSR_UIE) |
+                    (1ull << MSR_EE) |
+                    (1ull << MSR_ME) |
+                    (1ull << MSR_IS2) |
+                    (1ull << MSR_IS3) |
+                    (1ull << MSR_IPE) |
+                    R_MSR_SIBRCA_MASK;
+    pcc->mmu_model = POWERPC_MMU_REAL;
+    pcc->excp_model = POWERPC_EXCP_PPE42;
+    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
+    pcc->bfd_mach = bfd_mach_ppc_403;
+    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;
+}
+
 static void init_proc_440EP(CPUPPCState *env)
 {
     register_BookE_sprs(env, 0x000000000000FFFFULL);
@@ -6802,53 +6986,63 @@ static void init_ppc_proc(PowerPCCPU *cpu)
 
     /* MSR bits & flags consistency checks */
     if (env->msr_mask & (1 << 25)) {
-        switch (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE)) {
+        switch (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE |
+                              POWERPC_FLAG_PPE42)) {
         case POWERPC_FLAG_SPE:
         case POWERPC_FLAG_VRE:
+        case POWERPC_FLAG_PPE42:
             break;
         default:
             fprintf(stderr, "PowerPC MSR definition inconsistency\n"
-                    "Should define POWERPC_FLAG_SPE or POWERPC_FLAG_VRE\n");
+                    "Should define POWERPC_FLAG_SPE or POWERPC_FLAG_VRE\n"
+                    "or POWERPC_FLAG_PPE42\n");
             exit(1);
         }
     } else if (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE)) {
         fprintf(stderr, "PowerPC MSR definition inconsistency\n"
-                "Should not define POWERPC_FLAG_SPE nor POWERPC_FLAG_VRE\n");
+                "Should not define POWERPC_FLAG_SPE nor POWERPC_FLAG_VRE\n"
+                "nor POWERPC_FLAG_PPE42\n");
         exit(1);
     }
     if (env->msr_mask & (1 << 17)) {
-        switch (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE)) {
+        switch (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE |
+                              POWERPC_FLAG_PPE42)) {
         case POWERPC_FLAG_TGPR:
         case POWERPC_FLAG_CE:
+        case POWERPC_FLAG_PPE42:
             break;
         default:
             fprintf(stderr, "PowerPC MSR definition inconsistency\n"
-                    "Should define POWERPC_FLAG_TGPR or POWERPC_FLAG_CE\n");
+                    "Should define POWERPC_FLAG_TGPR or POWERPC_FLAG_CE\n"
+                    "or POWERPC_FLAG_PPE42\n");
             exit(1);
         }
-    } else if (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE)) {
+    } else if (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE |
+                             POWERPC_FLAG_PPE42)) {
         fprintf(stderr, "PowerPC MSR definition inconsistency\n"
-                "Should not define POWERPC_FLAG_TGPR nor POWERPC_FLAG_CE\n");
+                "Should not define POWERPC_FLAG_TGPR nor POWERPC_FLAG_CE\n"
+                "nor POWERPC_FLAG_PPE42\n");
         exit(1);
     }
     if (env->msr_mask & (1 << 10)) {
         switch (env->flags & (POWERPC_FLAG_SE | POWERPC_FLAG_DWE |
-                              POWERPC_FLAG_UBLE)) {
+                              POWERPC_FLAG_UBLE | POWERPC_FLAG_PPE42)) {
         case POWERPC_FLAG_SE:
         case POWERPC_FLAG_DWE:
         case POWERPC_FLAG_UBLE:
+        case POWERPC_FLAG_PPE42:
             break;
         default:
             fprintf(stderr, "PowerPC MSR definition inconsistency\n"
                     "Should define POWERPC_FLAG_SE or POWERPC_FLAG_DWE or "
-                    "POWERPC_FLAG_UBLE\n");
+                    "POWERPC_FLAG_UBLE or POWERPC_FLAG_PPE42\n");
             exit(1);
         }
     } else if (env->flags & (POWERPC_FLAG_SE | POWERPC_FLAG_DWE |
-                             POWERPC_FLAG_UBLE)) {
+                             POWERPC_FLAG_UBLE | POWERPC_FLAG_PPE42)) {
         fprintf(stderr, "PowerPC MSR definition inconsistency\n"
                 "Should not define POWERPC_FLAG_SE nor POWERPC_FLAG_DWE nor "
-                "POWERPC_FLAG_UBLE\n");
+                "POWERPC_FLAG_UBLE nor POWERPC_FLAG_PPE42\n");
             exit(1);
     }
     if (env->msr_mask & (1 << 9)) {
@@ -6867,18 +7061,23 @@ static void init_ppc_proc(PowerPCCPU *cpu)
         exit(1);
     }
     if (env->msr_mask & (1 << 2)) {
-        switch (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM)) {
+        switch (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM |
+                              POWERPC_FLAG_PPE42)) {
         case POWERPC_FLAG_PX:
         case POWERPC_FLAG_PMM:
+        case POWERPC_FLAG_PPE42:
             break;
         default:
             fprintf(stderr, "PowerPC MSR definition inconsistency\n"
-                    "Should define POWERPC_FLAG_PX or POWERPC_FLAG_PMM\n");
+                    "Should define POWERPC_FLAG_PX or POWERPC_FLAG_PMM\n"
+                    "or POWERPC_FLAG_PPE42\n");
             exit(1);
         }
-    } else if (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM)) {
+    } else if (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM |
+                             POWERPC_FLAG_PPE42)) {
         fprintf(stderr, "PowerPC MSR definition inconsistency\n"
-                "Should not define POWERPC_FLAG_PX nor POWERPC_FLAG_PMM\n");
+                "Should not define POWERPC_FLAG_PX nor POWERPC_FLAG_PMM\n"
+                "nor POWERPC_FLAG_PPE42\n");
         exit(1);
     }
     if ((env->flags & POWERPC_FLAG_BUS_CLK) == 0) {
@@ -7243,39 +7442,40 @@ static void ppc_cpu_reset_hold(Object *obj, ResetType type)
     }
 
     msr = (target_ulong)0;
-    msr |= (target_ulong)MSR_HVB;
-    msr |= (target_ulong)1 << MSR_EP;
+    if (!(env->flags & POWERPC_FLAG_PPE42)) {
+        msr |= (target_ulong)MSR_HVB;
+        msr |= (target_ulong)1 << MSR_EP;
 #if defined(DO_SINGLE_STEP) && 0
-    /* Single step trace mode */
-    msr |= (target_ulong)1 << MSR_SE;
-    msr |= (target_ulong)1 << MSR_BE;
+        /* Single step trace mode */
+        msr |= (target_ulong)1 << MSR_SE;
+        msr |= (target_ulong)1 << MSR_BE;
 #endif
 #if defined(CONFIG_USER_ONLY)
-    msr |= (target_ulong)1 << MSR_FP; /* Allow floating point usage */
-    msr |= (target_ulong)1 << MSR_FE0; /* Allow floating point exceptions */
-    msr |= (target_ulong)1 << MSR_FE1;
-    msr |= (target_ulong)1 << MSR_VR; /* Allow altivec usage */
-    msr |= (target_ulong)1 << MSR_VSX; /* Allow VSX usage */
-    msr |= (target_ulong)1 << MSR_SPE; /* Allow SPE usage */
-    msr |= (target_ulong)1 << MSR_PR;
+        msr |= (target_ulong)1 << MSR_FP; /* Allow floating point usage */
+        msr |= (target_ulong)1 << MSR_FE0; /* Allow floating point exceptions */
+        msr |= (target_ulong)1 << MSR_FE1;
+        msr |= (target_ulong)1 << MSR_VR; /* Allow altivec usage */
+        msr |= (target_ulong)1 << MSR_VSX; /* Allow VSX usage */
+        msr |= (target_ulong)1 << MSR_SPE; /* Allow SPE usage */
+        msr |= (target_ulong)1 << MSR_PR;
 #if defined(TARGET_PPC64)
-    msr |= (target_ulong)1 << MSR_TM; /* Transactional memory */
+        msr |= (target_ulong)1 << MSR_TM; /* Transactional memory */
 #endif
 #if !TARGET_BIG_ENDIAN
-    msr |= (target_ulong)1 << MSR_LE; /* Little-endian user mode */
-    if (!((env->msr_mask >> MSR_LE) & 1)) {
-        fprintf(stderr, "Selected CPU does not support little-endian.\n");
-        exit(1);
-    }
+        msr |= (target_ulong)1 << MSR_LE; /* Little-endian user mode */
+        if (!((env->msr_mask >> MSR_LE) & 1)) {
+            fprintf(stderr, "Selected CPU does not support little-endian.\n");
+            exit(1);
+        }
 #endif
 #endif
 
 #if defined(TARGET_PPC64)
-    if (mmu_is_64bit(env->mmu_model)) {
-        msr |= (1ULL << MSR_SF);
-    }
+        if (mmu_is_64bit(env->mmu_model)) {
+            msr |= (1ULL << MSR_SF);
+        }
 #endif
-
+    }
     hreg_store_msr(env, msr, 1);
 
 #if !defined(CONFIG_USER_ONLY)
@@ -7725,6 +7925,18 @@ void ppc_cpu_dump_state(CPUState *cs, FILE *f, int flags)
          * they can be read with "p $ivor0", "p $ivor1", etc.
          */
         break;
+    case POWERPC_EXCP_PPE42:
+        qemu_fprintf(f, "SRR0 " TARGET_FMT_lx " SRR1 " TARGET_FMT_lx "\n",
+                     env->spr[SPR_SRR0], env->spr[SPR_SRR1]);
+
+        qemu_fprintf(f, "  TCR " TARGET_FMT_lx "   TSR " TARGET_FMT_lx
+                     "    ISR " TARGET_FMT_lx "   EDR " TARGET_FMT_lx "\n",
+                     env->spr[SPR_PPE42_TCR], env->spr[SPR_PPE42_TSR],
+                     env->spr[SPR_PPE42_ISR], env->spr[SPR_PPE42_EDR]);
+
+        qemu_fprintf(f, "  PIR " TARGET_FMT_lx "   IVPR " TARGET_FMT_lx "\n",
+                     env->spr[SPR_PPE42_PIR], env->spr[SPR_PPE42_IVPR]);
+        break;
     case POWERPC_EXCP_40x:
         qemu_fprintf(f, "  TCR " TARGET_FMT_lx "   TSR " TARGET_FMT_lx
                      "    ESR " TARGET_FMT_lx "   DEAR " TARGET_FMT_lx "\n",
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index 1efdc4066e..2e35e63826 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -949,6 +949,133 @@ static void powerpc_excp_74xx(PowerPCCPU *cpu, int excp)
     powerpc_set_excp_state(cpu, vector, new_msr);
 }
 
+#define ISR_MCS_INSTRUCTION             0
+#define ISR_MCS_DATA_LOAD               1
+#define ISR_MCS_DATA_PRECISE_STORE      2
+#define ISR_MCS_DATA_IMPRECISE_STORE    3
+#define ISR_MCS_PROGRAM                 4
+#define ISR_MCS_ISI                     5
+#define ISR_MCS_ALIGNMENT               6
+#define ISR_MCS_DSI                     7
+static void powerpc_excp_ppe42(PowerPCCPU *cpu, int excp)
+{
+    CPUPPCState *env = &cpu->env;
+    target_ulong msr, new_msr, vector;
+    target_ulong mcs = ISR_MCS_INSTRUCTION;
+    bool promote_unmaskable;
+
+    msr = env->msr;
+
+    /*
+     * New interrupt handler msr preserves SIBRC and ME unless explicitly
+     * overridden by the exception.  All other MSR bits are zeroed out.
+     */
+    new_msr = env->msr & (((target_ulong)1 << MSR_ME) | R_MSR_SIBRC_MASK);
+
+    /* HV emu assistance interrupt only exists on server arch 2.05 or later */
+    if (excp == POWERPC_EXCP_HV_EMU) {
+        excp = POWERPC_EXCP_PROGRAM;
+    }
+
+    /*
+     * Unmaskable interrupts (Program, ISI, Alignment and DSI) are promoted to
+     * machine check if MSR_UIE is 0.
+     */
+    promote_unmaskable = !(msr & ((target_ulong)1 << MSR_UIE));
+
+
+    switch (excp) {
+    case POWERPC_EXCP_MCHECK:    /* Machine check exception                  */
+        break;
+    case POWERPC_EXCP_DSI:       /* Data storage exception                   */
+        trace_ppc_excp_dsi(env->spr[SPR_PPE42_ISR], env->spr[SPR_PPE42_EDR]);
+        if (promote_unmaskable) {
+            excp = POWERPC_EXCP_MCHECK;
+            mcs = ISR_MCS_DSI;
+        }
+        break;
+    case POWERPC_EXCP_ISI:       /* Instruction storage exception            */
+        trace_ppc_excp_isi(msr, env->nip);
+        if (promote_unmaskable) {
+            excp = POWERPC_EXCP_MCHECK;
+            mcs = ISR_MCS_ISI;
+        }
+        break;
+    case POWERPC_EXCP_EXTERNAL:  /* External input                           */
+        break;
+    case POWERPC_EXCP_ALIGN:     /* Alignment exception                      */
+        if (promote_unmaskable) {
+            excp = POWERPC_EXCP_MCHECK;
+            mcs = ISR_MCS_ALIGNMENT;
+        }
+        break;
+    case POWERPC_EXCP_PROGRAM:   /* Program exception                        */
+        if (promote_unmaskable) {
+            excp = POWERPC_EXCP_MCHECK;
+            mcs = ISR_MCS_PROGRAM;
+        }
+        switch (env->error_code & ~0xF) {
+        case POWERPC_EXCP_INVAL:
+            trace_ppc_excp_inval(env->nip);
+            env->spr[SPR_PPE42_ISR] &= ~((target_ulong)1 << ISR_PTR);
+            break;
+        case POWERPC_EXCP_TRAP:
+            env->spr[SPR_PPE42_ISR] |= ((target_ulong)1 << ISR_PTR);
+            break;
+        default:
+            /* Should never occur */
+            cpu_abort(env_cpu(env), "Invalid program exception %d. Aborting\n",
+                      env->error_code);
+            break;
+        }
+#ifdef CONFIG_TCG
+        env->spr[SPR_PPE42_EDR] = ppc_ldl_code(env, env->nip);
+#endif
+        break;
+    case POWERPC_EXCP_DECR:      /* Decrementer exception                    */
+        break;
+    case POWERPC_EXCP_FIT:       /* Fixed-interval timer interrupt           */
+        trace_ppc_excp_print("FIT");
+        break;
+    case POWERPC_EXCP_WDT:       /* Watchdog timer interrupt                 */
+        trace_ppc_excp_print("WDT");
+        break;
+    case POWERPC_EXCP_RESET:     /* System reset exception                   */
+        /* reset exceptions don't have ME set */
+        new_msr &= ~((target_ulong)1 << MSR_ME);
+        break;
+    default:
+        cpu_abort(env_cpu(env), "Invalid PPE42 exception %d. Aborting\n",
+                  excp);
+        break;
+    }
+
+    env->spr[SPR_SRR0] = env->nip;
+    env->spr[SPR_SRR1] = msr;
+
+    vector = env->excp_vectors[excp];
+    if (vector == (target_ulong)-1ULL) {
+        cpu_abort(env_cpu(env),
+                  "Raised an exception without defined vector %d\n", excp);
+    }
+    vector |= env->spr[SPR_PPE42_IVPR];
+
+    if (excp == POWERPC_EXCP_MCHECK) {
+        /* Also set the Machine Check Status (MCS) */
+        env->spr[SPR_PPE42_ISR] &= ~R_ISR_MCS_MASK;
+        env->spr[SPR_PPE42_ISR] |= (mcs & R_ISR_MCS_MASK);
+        env->spr[SPR_PPE42_ISR] &= ~((target_ulong)1 << ISR_MFE);
+
+        /* Machine checks halt execution if MSR_ME is 0 */
+        powerpc_mcheck_checkstop(env);
+
+        /* machine check exceptions don't have ME set */
+        new_msr &= ~((target_ulong)1 << MSR_ME);
+    }
+
+    powerpc_set_excp_state(cpu, vector, new_msr);
+}
+
 static void powerpc_excp_booke(PowerPCCPU *cpu, int excp)
 {
     CPUPPCState *env = &cpu->env;
@@ -1589,6 +1716,9 @@ void powerpc_excp(PowerPCCPU *cpu, int excp)
     case POWERPC_EXCP_POWER11:
         powerpc_excp_books(cpu, excp);
         break;
+    case POWERPC_EXCP_PPE42:
+        powerpc_excp_ppe42(cpu, excp);
+        break;
     default:
         g_assert_not_reached();
     }
@@ -1945,6 +2075,43 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env,
 }
 #endif /* TARGET_PPC64 */
 
+static int ppe42_next_unmasked_interrupt(CPUPPCState *env)
+{
+    bool async_deliver;
+
+    /* External reset */
+    if (env->pending_interrupts & PPC_INTERRUPT_RESET) {
+        return PPC_INTERRUPT_RESET;
+    }
+    /* Machine check exception */
+    if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
+        return PPC_INTERRUPT_MCK;
+    }
+
+    async_deliver = FIELD_EX64(env->msr, MSR, EE);
+
+    if (async_deliver != 0) {
+        /* Watchdog timer */
+        if (env->pending_interrupts & PPC_INTERRUPT_WDT) {
+            return PPC_INTERRUPT_WDT;
+        }
+        /* External Interrupt */
+        if (env->pending_interrupts & PPC_INTERRUPT_EXT) {
+            return PPC_INTERRUPT_EXT;
+        }
+        /* Fixed interval timer */
+        if (env->pending_interrupts & PPC_INTERRUPT_FIT) {
+            return PPC_INTERRUPT_FIT;
+        }
+        /* Decrementer exception */
+        if (env->pending_interrupts & PPC_INTERRUPT_DECR) {
+            return PPC_INTERRUPT_DECR;
+        }
+    }
+
+    return 0;
+}
+
 static int ppc_next_unmasked_interrupt(CPUPPCState *env)
 {
     uint32_t pending_interrupts = env->pending_interrupts;
@@ -1970,6 +2137,10 @@ static int ppc_next_unmasked_interrupt(CPUPPCState *env)
     }
 #endif
 
+    if (env->excp_model == POWERPC_EXCP_PPE42) {
+        return ppe42_next_unmasked_interrupt(env);
+    }
+
     /* External reset */
     if (pending_interrupts & PPC_INTERRUPT_RESET) {
         return PPC_INTERRUPT_RESET;
diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c
index 7e5726871e..7be00f5bbe 100644
--- a/target/ppc/helper_regs.c
+++ b/target/ppc/helper_regs.c
@@ -186,6 +186,10 @@ static uint32_t hreg_compute_hflags_value(CPUPPCState *env)
     if (env->spr[SPR_LPCR] & LPCR_HR) {
         hflags |= 1 << HFLAGS_HR;
     }
+    if (ppc_flags & POWERPC_FLAG_PPE42) {
+        /* PPE42 has a single address space and no problem state */
+        msr = 0;
+    }
 
 #ifndef CONFIG_USER_ONLY
     if (!env->has_hv_mode || (msr & (1ull << MSR_HV))) {
@@ -306,9 +310,6 @@ int hreg_store_msr(CPUPPCState *env, target_ulong value, int alter_hv)
         value &= ~(1 << MSR_ME);
         value |= env->msr & (1 << MSR_ME);
     }
-    if ((value ^ env->msr) & (R_MSR_IR_MASK | R_MSR_DR_MASK)) {
-        cpu_interrupt_exittb(cs);
-    }
     if ((env->mmu_model == POWERPC_MMU_BOOKE ||
          env->mmu_model == POWERPC_MMU_BOOKE206) &&
         ((value ^ env->msr) & R_MSR_GS_MASK)) {
@@ -319,8 +320,14 @@ int hreg_store_msr(CPUPPCState *env, target_ulong value, int alter_hv)
         /* Swap temporary saved registers with GPRs */
         hreg_swap_gpr_tgpr(env);
     }
-    if (unlikely((value ^ env->msr) & R_MSR_EP_MASK)) {
-        env->excp_prefix = FIELD_EX64(value, MSR, EP) * 0xFFF00000;
+    /* PPE42 MSR has bits overlapping with others */
+    if (!(env->flags & POWERPC_FLAG_PPE42)) {
+        if ((value ^ env->msr) & (R_MSR_IR_MASK | R_MSR_DR_MASK)) {
+            cpu_interrupt_exittb(cs);
+        }
+        if (unlikely((value ^ env->msr) & R_MSR_EP_MASK)) {
+            env->excp_prefix = FIELD_EX64(value, MSR, EP) * 0xFFF00000;
+        }
     }
     /*
      * If PR=1 then EE, IR and DR must be 1
@@ -462,6 +469,17 @@ void register_generic_sprs(PowerPCCPU *cpu)
                  SPR_NOACCESS, SPR_NOACCESS,
                  &spr_read_generic, &spr_write_generic,
                  0x00000000);
+
+    if (env->insns_flags2 & PPC2_PPE42) {
+        spr_register(env, SPR_PVR, "PVR",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, SPR_NOACCESS,
+                 pcc->pvr);
+
+        /* PPE42 doesn't support additional SPRG regs or timebase */
+        return;
+    }
+
     spr_register(env, SPR_SPRG1, "SPRG1",
                  SPR_NOACCESS, SPR_NOACCESS,
                  &spr_read_generic, &spr_write_generic,
diff --git a/target/ppc/tcg-excp_helper.c b/target/ppc/tcg-excp_helper.c
index f835be5156..14f3ad92fe 100644
--- a/target/ppc/tcg-excp_helper.c
+++ b/target/ppc/tcg-excp_helper.c
@@ -229,6 +229,18 @@ void ppc_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr,
     case POWERPC_MMU_BOOKE206:
         env->spr[SPR_BOOKE_DEAR] = vaddr;
         break;
+    case POWERPC_MMU_REAL:
+        if (env->flags & POWERPC_FLAG_PPE42) {
+            env->spr[SPR_PPE42_EDR] = vaddr;
+            if (access_type == MMU_DATA_STORE) {
+                env->spr[SPR_PPE42_ISR] |= ISR_ST;
+            } else {
+                env->spr[SPR_PPE42_ISR] &= ~ISR_ST;
+            }
+        } else {
+            env->spr[SPR_DAR] = vaddr;
+        }
+        break;
     default:
         env->spr[SPR_DAR] = vaddr;
         break;
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 27f90c3cc5..b4f4d10384 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -4264,8 +4264,10 @@ static void gen_mtmsr(DisasContext *ctx)
         /* L=1 form only updates EE and RI */
         mask &= (1ULL << MSR_RI) | (1ULL << MSR_EE);
     } else {
-        /* mtmsr does not alter S, ME, or LE */
-        mask &= ~((1ULL << MSR_LE) | (1ULL << MSR_ME) | (1ULL << MSR_S));
+        if (!(ctx->insns_flags2 & PPC2_PPE42)) {
+            /* mtmsr does not alter S, ME, or LE */
+            mask &= ~((1ULL << MSR_LE) | (1ULL << MSR_ME) | (1ULL << MSR_S));
+        }
 
         /*
          * XXX: we need to update nip before the store if we enter
-- 
2.43.0



^ permalink raw reply related	[flat|nested] 19+ messages in thread

* [PATCH 2/4] target/ppc: Add IBM PPE42 special instructions
  2025-08-19 21:28 [PATCH 0/4] Add IBM PPE42 CPU support Glenn Miles
  2025-08-19 21:28 ` [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors Glenn Miles
@ 2025-08-19 21:28 ` Glenn Miles
  2025-08-19 21:28 ` [PATCH 3/4] hw/ppc: Add a test machine for the IBM PPE42 CPU Glenn Miles
  2025-08-19 21:28 ` [PATCH 4/4] tests/functional: Add test for IBM PPE42 instructions Glenn Miles
  3 siblings, 0 replies; 19+ messages in thread
From: Glenn Miles @ 2025-08-19 21:28 UTC (permalink / raw)
  To: qemu-devel
  Cc: Glenn Miles, qemu-ppc, clg, npiggin, harshpb, thuth, rathc,
	richard.henderson

Adds the following instructions exclusively for
IBM PPE42 processors:

  LSKU
  LCXU
  STSKU
  STCXU
  LVD
  LVDU
  LVDX
  STVD
  STVDU
  STVDX
  SLVD
  SRVD
  CMPWBC
  CMPLWBC
  CMPWIBC
  BNBWI
  BNBW
  CLRBWIBC
  CLRWBC
  DCBQ
  RLDICL
  RLDICR
  RLDIMI

A PPE42 GCC compiler is available here:
https://github.com/open-power/ppe42-gcc

For more information on the PPE42 processors please visit:
https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf

Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
---
 target/ppc/insn32.decode            |  66 ++-
 target/ppc/translate.c              |  29 +-
 target/ppc/translate/ppe-impl.c.inc | 805 ++++++++++++++++++++++++++++
 3 files changed, 890 insertions(+), 10 deletions(-)
 create mode 100644 target/ppc/translate/ppe-impl.c.inc

diff --git a/target/ppc/insn32.decode b/target/ppc/insn32.decode
index e53fd2840d..8beb588a2a 100644
--- a/target/ppc/insn32.decode
+++ b/target/ppc/insn32.decode
@@ -58,6 +58,10 @@
 %ds_rtp         22:4   !function=times_2
 @DS_rtp         ...... ....0 ra:5 .............. ..             &D rt=%ds_rtp si=%ds_si
 
+%dd_si          3:s13
+&DD             rt ra si:int64_t
+@DD             ...... rt:5 ra:5 ............. . ..             &DD si=%dd_si
+
 &DX_b           vrt b
 %dx_b           6:10 16:5 0:1
 @DX_b           ...... vrt:5  ..... .......... ..... .          &DX_b b=%dx_b
@@ -66,6 +70,11 @@
 %dx_d           6:s10 16:5 0:1
 @DX             ...... rt:5  ..... .......... ..... .           &DX d=%dx_d
 
+%md_sh          1:1 11:5
+%md_mb          5:1 6:5
+&MD             rs ra sh mb rc
+@MD             ...... rs:5 ra:5 ..... ...... ... . rc:1        &MD sh=%md_sh mb=%md_mb
+
 &VA             vrt vra vrb rc
 @VA             ...... vrt:5 vra:5 vrb:5 rc:5 ......            &VA
 
@@ -322,6 +331,13 @@ LDUX            011111 ..... ..... ..... 0000110101 -   @X
 
 LQ              111000 ..... ..... ............ ----    @DQ_rtp
 
+LVD             000101 ..... ..... ................     @D
+LVDU            001001 ..... ..... ................     @D
+LVDX            011111 ..... ..... ..... 0000010001 -   @X
+LSKU            111010 ..... ..... ............. 0 11   @DD
+LCXU            111010 ..... ..... ............. 1 11   @DD
+
+
 ### Fixed-Point Store Instructions
 
 STB             100110 ..... ..... ................     @D
@@ -346,6 +362,11 @@ STDUX           011111 ..... ..... ..... 0010110101 -   @X
 
 STQ             111110 ..... ..... ..............10     @DS_rtp
 
+STVDU           010110 ..... ..... ................     @D
+STVDX           011111 ..... ..... ..... 0010010001 -   @X
+STSKU           111110 ..... ..... ............. 0 11   @DD
+STCXU           111110 ..... ..... ............. 1 11   @DD
+
 ### Fixed-Point Compare Instructions
 
 CMP             011111 ... - . ..... ..... 0000000000 - @X_bfl
@@ -461,8 +482,14 @@ PRTYD           011111 ..... ..... ----- 0010111010 -   @X_sa
 
 BPERMD          011111 ..... ..... ..... 0011111100 -   @X
 CFUGED          011111 ..... ..... ..... 0011011100 -   @X
-CNTLZDM         011111 ..... ..... ..... 0000111011 -   @X
-CNTTZDM         011111 ..... ..... ..... 1000111011 -   @X
+{
+  SLVD            011111 ..... ..... ..... 0000111011 .   @X_rc
+  CNTLZDM         011111 ..... ..... ..... 0000111011 -   @X
+}
+{
+  SRVD            011111 ..... ..... ..... 1000111011 .   @X_rc
+  CNTTZDM         011111 ..... ..... ..... 1000111011 -   @X
+}
 PDEPD           011111 ..... ..... ..... 0010011100 -   @X
 PEXTD           011111 ..... ..... ..... 0010111100 -   @X
 
@@ -981,8 +1008,16 @@ LXSSP           111001 ..... ..... .............. 11    @DS
 STXSSP          111101 ..... ..... .............. 11    @DS
 LXV             111101 ..... ..... ............ . 001   @DQ_TSX
 STXV            111101 ..... ..... ............ . 101   @DQ_TSX
-LXVP            000110 ..... ..... ............ 0000    @DQ_TSXP
-STXVP           000110 ..... ..... ............ 0001    @DQ_TSXP
+
+# STVD PPE instruction overlaps with the LXVP and STXVP instructions
+{
+  STVD          000110 ..... ..... ................     @D
+  [
+    LXVP        000110 ..... ..... ............ 0000    @DQ_TSXP
+    STXVP       000110 ..... ..... ............ 0001    @DQ_TSXP
+  ]
+}
+
 LXVX            011111 ..... ..... ..... 0100 - 01100 . @X_TSX
 STXVX           011111 ..... ..... ..... 0110001100 .   @X_TSX
 LXVPX           011111 ..... ..... ..... 0101001101 -   @X_TSXP
@@ -1300,3 +1335,26 @@ CLRBHRB         011111 ----- ----- ----- 0110101110 -
 ## Misc POWER instructions
 
 ATTN            000000 00000 00000 00000 0100000000 0
+
+# Fused compare-branch instructions for PPE only
+%fcb_bdx        1:s10  !function=times_4
+&FCB            px:bool ra rb:uint64_t bdx lk:bool
+@FCB            ...... .. px:1 .. ra:5 rb:5 .......... lk:1       &FCB bdx=%fcb_bdx
+&FCB_bix        px:bool bix ra rb:uint64_t bdx lk:bool
+@FCB_bix        ...... .. px:1 bix:2 ra:5 rb:5 .......... lk:1    &FCB_bix bdx=%fcb_bdx
+
+CMPWBC          000001 00 . .. ..... ..... .......... .     @FCB_bix
+CMPLWBC         000001 01 . .. ..... ..... .......... .     @FCB_bix
+CMPWIBC         000001 10 . .. ..... ..... .......... .     @FCB_bix
+BNBWI           000001 11 . 00 ..... ..... .......... .     @FCB
+BNBW            000001 11 . 01 ..... ..... .......... .     @FCB
+CLRBWIBC        000001 11 . 10 ..... ..... .......... .     @FCB
+CLRBWBC         000001 11 . 11 ..... ..... .......... .     @FCB
+
+# Data Cache Block Query for PPE only
+DCBQ            011111 ..... ..... ..... 0110010110 -       @X
+
+# Rotate Doubleword Instructions for PPE only (if TARGET_PPC64 not defined)
+RLDICL          011110 ..... ..... ..... ...... 000 . .     @MD
+RLDICR          011110 ..... ..... ..... ...... 001 . .     @MD
+RLDIMI          011110 ..... ..... ..... ...... 011 . .     @MD
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index b4f4d10384..a8416e1ef1 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -209,6 +209,11 @@ struct DisasContext {
 #define DISAS_CHAIN        DISAS_TARGET_2  /* lookup next tb, pc updated */
 #define DISAS_CHAIN_UPDATE DISAS_TARGET_3  /* lookup next tb, pc stale */
 
+static inline bool is_ppe(const DisasContext *ctx)
+{
+    return !!(ctx->flags & POWERPC_FLAG_PPE42);
+}
+
 /* Return true iff byteswap is needed in a scalar memop */
 static inline bool need_byteswap(const DisasContext *ctx)
 {
@@ -556,11 +561,8 @@ void spr_access_nop(DisasContext *ctx, int sprn, int gprn)
 
 #endif
 
-/* SPR common to all PowerPC */
-/* XER */
-void spr_read_xer(DisasContext *ctx, int gprn, int sprn)
+static void gen_get_xer(DisasContext *ctx, TCGv dst)
 {
-    TCGv dst = cpu_gpr[gprn];
     TCGv t0 = tcg_temp_new();
     TCGv t1 = tcg_temp_new();
     TCGv t2 = tcg_temp_new();
@@ -579,9 +581,16 @@ void spr_read_xer(DisasContext *ctx, int gprn, int sprn)
     }
 }
 
-void spr_write_xer(DisasContext *ctx, int sprn, int gprn)
+/* SPR common to all PowerPC */
+/* XER */
+void spr_read_xer(DisasContext *ctx, int gprn, int sprn)
+{
+    TCGv dst = cpu_gpr[gprn];
+    gen_get_xer(ctx, dst);
+}
+
+static void gen_set_xer(DisasContext *ctx, TCGv src)
 {
-    TCGv src = cpu_gpr[gprn];
     /* Write all flags, while reading back check for isa300 */
     tcg_gen_andi_tl(cpu_xer, src,
                     ~((1u << XER_SO) |
@@ -594,6 +603,12 @@ void spr_write_xer(DisasContext *ctx, int sprn, int gprn)
     tcg_gen_extract_tl(cpu_ca, src, XER_CA, 1);
 }
 
+void spr_write_xer(DisasContext *ctx, int sprn, int gprn)
+{
+    TCGv src = cpu_gpr[gprn];
+    gen_set_xer(ctx, src);
+}
+
 /* LR */
 void spr_read_lr(DisasContext *ctx, int gprn, int sprn)
 {
@@ -5755,6 +5770,8 @@ static bool resolve_PLS_D(DisasContext *ctx, arg_D *d, arg_PLS_D *a)
 
 #include "translate/bhrb-impl.c.inc"
 
+#include "translate/ppe-impl.c.inc"
+
 /* Handles lfdp */
 static void gen_dform39(DisasContext *ctx)
 {
diff --git a/target/ppc/translate/ppe-impl.c.inc b/target/ppc/translate/ppe-impl.c.inc
new file mode 100644
index 0000000000..98fd794aa4
--- /dev/null
+++ b/target/ppc/translate/ppe-impl.c.inc
@@ -0,0 +1,805 @@
+/*
+ * IBM PPE Instructions
+ *
+ * Copyright (c) 2024, IBM Corporation.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+
+#if !defined(TARGET_PPC64)
+static bool vdr_is_valid(uint32_t vdr)
+{
+    const uint32_t valid_bitmap = 0xf00003ff;
+    return !!((1ul << (vdr & 0x1f)) & valid_bitmap);
+}
+
+static bool ppe_gpr_is_valid(uint32_t reg)
+{
+    const uint32_t valid_bitmap = 0xf00027ff;
+    return !!((1ul << (reg & 0x1f)) & valid_bitmap);
+}
+#endif
+
+#define CHECK_VDR(CTX, VDR)                             \
+    do {                                                \
+        if (unlikely(!vdr_is_valid(VDR))) {             \
+            gen_invalid(CTX);                           \
+            return true;                                \
+        }                                               \
+    } while (0)
+
+#define CHECK_PPE_GPR(CTX, REG)                         \
+    do {                                                \
+        if (unlikely(!ppe_gpr_is_valid(REG))) {         \
+            gen_invalid(CTX);                           \
+            return true;                                \
+        }                                               \
+    } while (0)
+
+#define CHECK_VDR(CTX, VDR)                             \
+    do {                                                \
+        if (unlikely(!vdr_is_valid(VDR))) {             \
+            gen_invalid(CTX);                           \
+            return true;                                \
+        }                                               \
+    } while (0)
+
+#define VDR_PAIR_REG(VDR) (((VDR) + 1) & 0x1f)
+
+#define CHECK_PPE_LEVEL(CTX, LVL)                       \
+    do {                                                \
+        if (unlikely(!((CTX)->insns_flags2 & (LVL)))) { \
+            gen_invalid(CTX);                           \
+            return true;                                \
+        }                                               \
+    } while (0)
+
+static bool trans_LCXU(DisasContext *ctx, arg_LCXU *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    int i;
+    TCGv base, EA;
+    TCGv lo, hi;
+    TCGv_i64 t8;
+    const uint8_t vd_list[] = {9, 7, 5, 3, 0};
+
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_LEVEL(ctx, PPC2_PPE42X);
+    CHECK_PPE_GPR(ctx, a->rt);
+
+    if (unlikely((a->rt != a->ra) || (a->ra == 0) || (a->si < 0xB))) {
+        gen_invalid(ctx);
+        return true;
+    }
+
+    EA = tcg_temp_new();
+    base = tcg_temp_new();
+
+    tcg_gen_addi_tl(base, cpu_gpr[a->ra], a->si * 8);
+    gen_store_spr(SPR_PPE42_EDR, base);
+
+    t8 = tcg_temp_new_i64();
+
+    tcg_gen_addi_tl(EA, base, -8);
+    tcg_gen_qemu_ld_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+    tcg_gen_extr_i64_tl(cpu_gpr[31], cpu_gpr[30], t8);
+
+    tcg_gen_addi_tl(EA, EA, -8);
+    tcg_gen_qemu_ld_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+    tcg_gen_extr_i64_tl(cpu_gpr[29], cpu_gpr[28], t8);
+
+    lo = tcg_temp_new();
+    hi = tcg_temp_new();
+
+    tcg_gen_addi_tl(EA, EA, -8);
+    tcg_gen_qemu_ld_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+    tcg_gen_extr_i64_tl(lo, hi, t8);
+    gen_store_spr(SPR_SRR0, hi);
+    gen_store_spr(SPR_SRR1, lo);
+
+    tcg_gen_addi_tl(EA, EA, -8);
+    tcg_gen_qemu_ld_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+    tcg_gen_extr_i64_tl(lo, hi, t8);
+    gen_set_xer(ctx, hi);
+    tcg_gen_mov_tl(cpu_ctr, lo);
+
+    for (i = 0; i < sizeof(vd_list); i++) {
+        int vd = vd_list[i];
+        tcg_gen_addi_tl(EA, EA, -8);
+        tcg_gen_qemu_ld_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+        tcg_gen_extr_i64_tl(cpu_gpr[VDR_PAIR_REG(vd)], cpu_gpr[vd], t8);
+    }
+
+    tcg_gen_addi_tl(EA, EA, -8);
+    tcg_gen_qemu_ld_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+    tcg_gen_extr_i64_tl(lo, hi, t8);
+    tcg_gen_shri_tl(hi, hi, 28);
+    tcg_gen_trunc_tl_i32(cpu_crf[0], hi);
+    gen_store_spr(SPR_SPRG0, lo);
+
+    tcg_gen_addi_tl(EA, base, 4);
+    tcg_gen_qemu_ld_tl(cpu_lr, EA, ctx->mem_idx, DEF_MEMOP(MO_32) | MO_ALIGN);
+    tcg_gen_mov_tl(cpu_gpr[a->ra], base);
+    return true;
+#endif
+}
+
+static bool trans_LSKU(DisasContext *ctx, arg_LSKU *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    int64_t n;
+    TCGv base, EA;
+    TCGv_i32 lo, hi;
+    TCGv_i64 t8;
+
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+
+    CHECK_PPE_LEVEL(ctx, PPC2_PPE42X);
+    CHECK_PPE_GPR(ctx, a->rt);
+
+    if (unlikely((a->rt != a->ra) || (a->ra == 0) ||
+                 (a->si & PPC_BIT(0)) || (a->si == 0))) {
+        gen_invalid(ctx);
+        return true;
+    }
+
+    EA = tcg_temp_new();
+    base = tcg_temp_new();
+    gen_addr_register(ctx, base);
+
+
+    tcg_gen_addi_tl(base, base, a->si * 8);
+    gen_store_spr(SPR_PPE42_EDR, base);
+
+    n = a->si - 1;
+    t8 = tcg_temp_new_i64();
+    if (n > 0) {
+        tcg_gen_addi_tl(EA, base, -8);
+        tcg_gen_qemu_ld_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+        hi = cpu_gpr[30];
+        lo = cpu_gpr[31];
+        tcg_gen_extr_i64_i32(lo, hi, t8);
+    }
+    if (n > 1) {
+        tcg_gen_addi_tl(EA, base, -16);
+        tcg_gen_qemu_ld_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+        hi = cpu_gpr[28];
+        lo = cpu_gpr[29];
+        tcg_gen_extr_i64_i32(lo, hi, t8);
+    }
+    tcg_gen_addi_tl(EA, base, 4);
+    tcg_gen_qemu_ld_i32(cpu_lr, EA, ctx->mem_idx, DEF_MEMOP(MO_32) | MO_ALIGN);
+    tcg_gen_mov_tl(cpu_gpr[a->ra], base);
+    return true;
+#endif
+}
+
+static bool trans_STCXU(DisasContext *ctx, arg_STCXU *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    TCGv EA;
+    TCGv lo, hi;
+    TCGv_i64 t8;
+    int i;
+    const uint8_t vd_list[] = {9, 7, 5, 3, 0};
+
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+
+    CHECK_PPE_LEVEL(ctx, PPC2_PPE42X);
+    CHECK_PPE_GPR(ctx, a->rt);
+
+    if (unlikely((a->rt != a->ra) || (a->ra == 0) || !(a->si & PPC_BIT(0)))) {
+        gen_invalid(ctx);
+        return true;
+    }
+
+    EA = tcg_temp_new();
+    tcg_gen_addi_tl(EA, cpu_gpr[a->ra], 4);
+    tcg_gen_qemu_st_i32(cpu_lr, EA, ctx->mem_idx, DEF_MEMOP(MO_32) | MO_ALIGN);
+
+    gen_store_spr(SPR_PPE42_EDR, cpu_gpr[a->ra]);
+
+    t8 = tcg_temp_new_i64();
+
+    tcg_gen_concat_tl_i64(t8, cpu_gpr[31], cpu_gpr[30]);
+    tcg_gen_addi_tl(EA, cpu_gpr[a->ra], -8);
+    tcg_gen_qemu_st_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+
+    tcg_gen_concat_tl_i64(t8, cpu_gpr[29], cpu_gpr[28]);
+    tcg_gen_addi_tl(EA, EA, -8);
+    tcg_gen_qemu_st_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+
+    lo = tcg_temp_new();
+    hi = tcg_temp_new();
+
+    gen_load_spr(hi, SPR_SRR0);
+    gen_load_spr(lo, SPR_SRR1);
+    tcg_gen_concat_tl_i64(t8, lo, hi);
+    tcg_gen_addi_tl(EA, EA, -8);
+    tcg_gen_qemu_st_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+
+    gen_get_xer(ctx, hi);
+    tcg_gen_mov_tl(lo, cpu_ctr);
+    tcg_gen_concat_tl_i64(t8, lo, hi);
+    tcg_gen_addi_tl(EA, EA, -8);
+    tcg_gen_qemu_st_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+
+    for (i = 0; i < sizeof(vd_list); i++) {
+        int vd = vd_list[i];
+        tcg_gen_concat_tl_i64(t8, cpu_gpr[VDR_PAIR_REG(vd)], cpu_gpr[vd]);
+        tcg_gen_addi_tl(EA, EA, -8);
+        tcg_gen_qemu_st_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+    }
+
+    gen_load_spr(lo, SPR_SPRG0);
+    tcg_gen_extu_i32_tl(hi, cpu_crf[0]);
+    tcg_gen_shli_tl(hi, hi, 28);
+    tcg_gen_concat_tl_i64(t8, lo, hi);
+    tcg_gen_addi_tl(EA, EA, -8);
+    tcg_gen_qemu_st_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+
+    tcg_gen_addi_tl(EA, cpu_gpr[a->ra], a->si * 8);
+    tcg_gen_qemu_st_i32(cpu_gpr[a->rt], EA, ctx->mem_idx, DEF_MEMOP(MO_32) |
+                                                          MO_ALIGN);
+    tcg_gen_mov_tl(cpu_gpr[a->ra], EA);
+    return true;
+#endif
+}
+
+static bool trans_STSKU(DisasContext *ctx, arg_STSKU *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    int64_t n;
+    TCGv base, EA;
+    TCGv_i32 lo, hi;
+    TCGv_i64 t8;
+
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+
+    CHECK_PPE_LEVEL(ctx, PPC2_PPE42X);
+    CHECK_PPE_GPR(ctx, a->rt);
+
+    if (unlikely((a->rt != a->ra) || (a->ra == 0) || !(a->si & PPC_BIT(0)))) {
+        gen_invalid(ctx);
+        return true;
+    }
+
+    EA = tcg_temp_new();
+    base = tcg_temp_new();
+    gen_addr_register(ctx, base);
+    tcg_gen_addi_tl(EA, base, 4);
+    tcg_gen_qemu_st_i32(cpu_lr, EA, ctx->mem_idx, DEF_MEMOP(MO_32) | MO_ALIGN);
+
+    gen_store_spr(SPR_PPE42_EDR, base);
+
+    n = ~(a->si);
+
+    t8 = tcg_temp_new_i64();
+    if (n > 0) {
+        hi = cpu_gpr[30];
+        lo = cpu_gpr[31];
+        tcg_gen_concat_i32_i64(t8, lo, hi);
+        tcg_gen_addi_tl(EA, base, -8);
+        tcg_gen_qemu_st_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+    }
+    if (n > 1) {
+        hi = cpu_gpr[28];
+        lo = cpu_gpr[29];
+        tcg_gen_concat_i32_i64(t8, lo, hi);
+        tcg_gen_addi_tl(EA, base, -16);
+        tcg_gen_qemu_st_i64(t8, EA, ctx->mem_idx, DEF_MEMOP(MO_64) | MO_ALIGN);
+    }
+
+    tcg_gen_addi_tl(EA, base, a->si * 8);
+    tcg_gen_qemu_st_i32(cpu_gpr[a->rt], EA, ctx->mem_idx, DEF_MEMOP(MO_32) |
+                                                          MO_ALIGN);
+    tcg_gen_mov_tl(cpu_gpr[a->ra], EA);
+    return true;
+#endif
+}
+
+#if !defined(TARGET_PPC64)
+static bool do_ppe_ldst(DisasContext *ctx, int rt, int ra, TCGv displ,
+                        bool update, bool store)
+{
+    TCGv ea;
+    int rt_lo;
+    TCGv_i64 t8;
+
+    CHECK_VDR(ctx, rt);
+    CHECK_PPE_GPR(ctx, ra);
+    rt_lo = VDR_PAIR_REG(rt);
+    if (update && (ra == 0 || (!store && ((ra == rt) || (ra == rt_lo))))) {
+        gen_invalid(ctx);
+        return true;
+    }
+    gen_set_access_type(ctx, ACCESS_INT);
+
+    ea = do_ea_calc(ctx, ra, displ);
+    t8 = tcg_temp_new_i64();
+    if (store) {
+        tcg_gen_concat_i32_i64(t8, cpu_gpr[rt_lo], cpu_gpr[rt]);
+        tcg_gen_qemu_st_i64(t8, ea, ctx->mem_idx, DEF_MEMOP(MO_64));
+    } else {
+        tcg_gen_qemu_ld_i64(t8, ea, ctx->mem_idx, DEF_MEMOP(MO_64));
+        tcg_gen_extr_i64_i32(cpu_gpr[rt_lo], cpu_gpr[rt], t8);
+    }
+    if (update) {
+        tcg_gen_mov_tl(cpu_gpr[ra], ea);
+    }
+    return true;
+}
+#endif
+
+static bool trans_LVD(DisasContext *ctx, arg_LVD *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    return do_ppe_ldst(ctx, a->rt, a->ra, tcg_constant_tl(a->si), false, false);
+#endif
+}
+
+static bool trans_LVDU(DisasContext *ctx, arg_LVDU *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    return do_ppe_ldst(ctx, a->rt, a->ra, tcg_constant_tl(a->si), true, false);
+#endif
+}
+
+static bool trans_LVDX(DisasContext *ctx, arg_LVDX *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_GPR(ctx, a->rb);
+    return do_ppe_ldst(ctx, a->rt, a->ra, cpu_gpr[a->rb], false, false);
+#endif
+}
+
+static bool trans_STVD(DisasContext *ctx, arg_STVD *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    return do_ppe_ldst(ctx, a->rt, a->ra, tcg_constant_tl(a->si), false, true);
+#endif
+}
+
+static bool trans_STVDU(DisasContext *ctx, arg_STVDU *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    return do_ppe_ldst(ctx, a->rt, a->ra, tcg_constant_tl(a->si), true, true);
+#endif
+}
+
+static bool trans_STVDX(DisasContext *ctx, arg_STVDX *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_GPR(ctx, a->rb);
+    return do_ppe_ldst(ctx, a->rt, a->ra, cpu_gpr[a->rb], false, true);
+#endif
+}
+
+#if !defined(TARGET_PPC64)
+static bool do_fcb(DisasContext *ctx, TCGv ra_val, TCGv rb_val, int bix,
+                          int32_t bdx, bool s, bool px, bool lk)
+{
+    TCGCond cond;
+    uint32_t mask;
+    TCGLabel *no_branch;
+    target_ulong dest;
+
+    /* Update CR0 */
+    gen_op_cmp32(ra_val, rb_val, s, 0);
+
+    if (lk) {
+        gen_setlr(ctx, ctx->base.pc_next);
+    }
+
+
+    mask = PPC_BIT32(28 + bix);
+    cond = (px) ? TCG_COND_TSTEQ : TCG_COND_TSTNE;
+    no_branch = gen_new_label();
+    dest = ctx->cia + bdx;
+
+    /* Do the branch if CR0[bix] == PX */
+    tcg_gen_brcondi_i32(cond, cpu_crf[0], mask, no_branch);
+    gen_goto_tb(ctx, 0, dest);
+    gen_set_label(no_branch);
+    gen_goto_tb(ctx, 1, ctx->base.pc_next);
+    ctx->base.is_jmp = DISAS_NORETURN;
+    return true;
+}
+#endif
+
+#if !defined(TARGET_PPC64)
+static bool do_cmp_branch(DisasContext *ctx, int ra, TCGv rb_val, int bix,
+                          int32_t bdx, bool s, bool px, bool lk)
+{
+    TCGv old_ra;
+
+    CHECK_PPE_GPR(ctx, ra);
+    if (bix == 3) {
+        old_ra = tcg_temp_new();
+        tcg_gen_mov_tl(old_ra, cpu_gpr[ra]);
+        tcg_gen_sub_tl(cpu_gpr[ra], cpu_gpr[ra], rb_val);
+        return do_fcb(ctx, old_ra, rb_val, 2,
+                  bdx, s, px, lk);
+    } else {
+        return do_fcb(ctx, cpu_gpr[ra], rb_val, bix,
+                  bdx, s, px, lk);
+    }
+}
+#endif
+
+#if !defined(TARGET_PPC64)
+static bool do_mask_branch(DisasContext *ctx, int ra, TCGv mask,
+                          int32_t bdx, bool invert, bool px, bool lk,
+                          bool update)
+{
+    TCGv r;
+    CHECK_PPE_GPR(ctx, ra);
+    if (invert) {
+        tcg_gen_not_tl(mask, mask);
+    }
+
+    /* apply mask to ra */
+    r = tcg_temp_new();
+    tcg_gen_and_tl(r, cpu_gpr[ra], mask);
+    if (update) {
+        tcg_gen_mov_tl(cpu_gpr[ra], r);
+    }
+    return do_fcb(ctx, r, tcg_constant_tl(0), 2,
+                  bdx, false, px, lk);
+}
+#endif
+
+static bool trans_CMPWBC(DisasContext *ctx, arg_CMPWBC *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_GPR(ctx, a->rb);
+    return do_cmp_branch(ctx, a->ra, cpu_gpr[a->rb], a->bix, a->bdx,
+                         true, a->px, a->lk);
+#endif
+}
+
+static bool trans_CMPLWBC(DisasContext *ctx, arg_CMPLWBC *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_GPR(ctx, a->rb);
+    return do_cmp_branch(ctx, a->ra, cpu_gpr[a->rb], a->bix, a->bdx,
+                         false, a->px, a->lk);
+#endif
+}
+
+static bool trans_CMPWIBC(DisasContext *ctx, arg_CMPWIBC *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    return do_cmp_branch(ctx, a->ra, tcg_constant_tl(a->rb), a->bix, a->bdx,
+                         true, a->px, a->lk);
+#endif
+}
+
+static bool trans_BNBWI(DisasContext *ctx, arg_BNBWI *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    return do_mask_branch(ctx, a->ra, tcg_constant_tl(PPC_BIT32(a->rb)),
+                          a->bdx, false, a->px, a->lk, false);
+#endif
+}
+
+static bool trans_BNBW(DisasContext *ctx, arg_BNBW *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    TCGv mask, shift;
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_GPR(ctx, a->rb);
+    mask = tcg_temp_new();
+    shift = tcg_temp_new();
+    tcg_gen_andi_tl(shift, cpu_gpr[a->rb], 0x1f);
+    tcg_gen_shr_tl(mask, tcg_constant_tl(0x80000000), shift);
+    return do_mask_branch(ctx, a->ra, mask, a->bdx, false, a->px, a->lk, false);
+#endif
+}
+
+static bool trans_CLRBWIBC(DisasContext *ctx, arg_CLRBWIBC *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    return do_mask_branch(ctx, a->ra, tcg_constant_tl(PPC_BIT32(a->rb)),
+                          a->bdx, true, a->px, a->lk, true);
+#endif
+}
+
+static bool trans_CLRBWBC(DisasContext *ctx, arg_CLRBWBC *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    TCGv mask, shift;
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_GPR(ctx, a->rb);
+    mask = tcg_temp_new();
+    shift = tcg_temp_new();
+    tcg_gen_andi_tl(shift, cpu_gpr[a->rb], 0x1f);
+    tcg_gen_shr_tl(mask, tcg_constant_tl(0x80000000), shift);
+    return do_mask_branch(ctx, a->ra, mask, a->bdx, true, a->px, a->lk, true);
+#endif
+}
+
+#if !defined(TARGET_PPC64)
+static void gen_set_Rc0_i64(DisasContext *ctx, TCGv_i64 reg)
+{
+    TCGv_i64 t0 = tcg_temp_new_i64();
+    TCGv_i64 t1 = tcg_temp_new_i64();
+    TCGv_i32 t = tcg_temp_new_i32();
+
+    tcg_gen_movi_i64(t0, CRF_EQ);
+    tcg_gen_movi_i64(t1, CRF_LT);
+    tcg_gen_movcond_i64(TCG_COND_LT, t0, reg, tcg_constant_i64(0), t1, t0);
+    tcg_gen_movi_i64(t1, CRF_GT);
+    tcg_gen_movcond_i64(TCG_COND_GT, t0, reg, tcg_constant_i64(0), t1, t0);
+    tcg_gen_extrl_i64_i32(t, t0);
+    tcg_gen_trunc_tl_i32(cpu_crf[0], cpu_so);
+    tcg_gen_or_i32(cpu_crf[0], cpu_crf[0], t);
+}
+#endif
+
+#if !defined(TARGET_PPC64)
+static bool do_shift64(DisasContext *ctx, arg_X_rc *a, bool left)
+{
+    int rt_lo, ra_lo;
+    TCGv_i64 t0, t8;
+
+    /* Check for PPE since opcode overlaps with CNTTZDM instruction */
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_LEVEL(ctx, PPC2_PPE42X);
+    CHECK_VDR(ctx, a->rt);
+    CHECK_VDR(ctx, a->ra);
+    CHECK_PPE_GPR(ctx, a->rb);
+    rt_lo = VDR_PAIR_REG(a->rt);
+    ra_lo = VDR_PAIR_REG(a->ra);
+    t8 = tcg_temp_new_i64();
+
+    /* AND rt with a mask that is 0 when rb >= 0x40 */
+    t0 = tcg_temp_new_i64();
+    tcg_gen_extu_tl_i64(t0, cpu_gpr[a->rb]);
+    tcg_gen_shli_i64(t0, t0, 0x39);
+    tcg_gen_sari_i64(t0, t0, 0x3f);
+
+    /* form 64bit value from two 32bit regs */
+    tcg_gen_concat_tl_i64(t8, cpu_gpr[rt_lo], cpu_gpr[a->rt]);
+
+    /* apply mask */
+    tcg_gen_andc_i64(t8, t8, t0);
+
+    /* do the shift */
+    tcg_gen_extu_tl_i64(t0, cpu_gpr[a->rb]);
+    tcg_gen_andi_i64(t0, t0, 0x3f);
+    if (left) {
+        tcg_gen_shl_i64(t8, t8, t0);
+    } else {
+        tcg_gen_shr_i64(t8, t8, t0);
+    }
+
+    /* split the 64bit word back into two 32bit regs */
+    tcg_gen_extr_i64_tl(cpu_gpr[ra_lo], cpu_gpr[a->ra], t8);
+
+    /* update CR0 if requested */
+    if (unlikely(a->rc != 0)) {
+        gen_set_Rc0_i64(ctx, t8);
+    }
+    return true;
+}
+#endif
+
+static bool trans_SRVD(DisasContext *ctx, arg_SRVD *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    return do_shift64(ctx, a, false);
+#endif
+}
+
+static bool trans_SLVD(DisasContext *ctx, arg_SLVD *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    return do_shift64(ctx, a, true);
+#endif
+}
+
+static bool trans_DCBQ(DisasContext *ctx, arg_DCBQ *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+
+    CHECK_PPE_GPR(ctx, a->rt);
+    CHECK_PPE_GPR(ctx, a->ra);
+    CHECK_PPE_GPR(ctx, a->rb);
+
+    /* No cache exists, so just set RT to 0 */
+    tcg_gen_movi_tl(cpu_gpr[a->rt], 0);
+    return true;
+#endif
+}
+
+static bool trans_RLDIMI(DisasContext *ctx, arg_RLDIMI *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    TCGv_i64 t_rs, t_ra;
+    int ra_lo, rs_lo;
+    uint32_t sh = a->sh;
+    uint32_t mb = a->mb;
+    uint32_t me = 63 - sh;
+
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_LEVEL(ctx, PPC2_PPE42X);
+    CHECK_VDR(ctx, a->rs);
+    CHECK_VDR(ctx, a->ra);
+
+    rs_lo = VDR_PAIR_REG(a->rs);
+    ra_lo = VDR_PAIR_REG(a->ra);
+
+    t_rs = tcg_temp_new_i64();
+    t_ra = tcg_temp_new_i64();
+
+    tcg_gen_concat_tl_i64(t_rs, cpu_gpr[rs_lo], cpu_gpr[a->rs]);
+    tcg_gen_concat_tl_i64(t_ra, cpu_gpr[ra_lo], cpu_gpr[a->ra]);
+
+    if (mb <= me) {
+        tcg_gen_deposit_i64(t_ra, t_ra, t_rs, sh, me - mb + 1);
+    } else {
+        uint64_t mask = mask_u64(mb, me);
+        TCGv_i64 t1 = tcg_temp_new_i64();
+
+        tcg_gen_rotli_i64(t1, t_rs, sh);
+        tcg_gen_andi_i64(t1, t1, mask);
+        tcg_gen_andi_i64(t_ra, t_ra, ~mask);
+        tcg_gen_or_i64(t_ra, t_ra, t1);
+    }
+
+    tcg_gen_extr_i64_tl(cpu_gpr[ra_lo], cpu_gpr[a->ra], t_ra);
+
+    if (unlikely(a->rc != 0)) {
+        gen_set_Rc0_i64(ctx, t_ra);
+    }
+    return true;
+#endif
+}
+
+
+#if !defined(TARGET_PPC64)
+static bool gen_rldinm_i64(DisasContext *ctx, arg_MD *a, int mb, int me, int sh)
+{
+    int len = me - mb + 1;
+    int rsh = (64 - sh) & 63;
+    int ra_lo, rs_lo;
+    TCGv_i64 t8;
+
+    if (unlikely(!is_ppe(ctx))) {
+        return false;
+    }
+    CHECK_PPE_LEVEL(ctx, PPC2_PPE42X);
+    CHECK_VDR(ctx, a->rs);
+    CHECK_VDR(ctx, a->ra);
+
+    rs_lo = VDR_PAIR_REG(a->rs);
+    ra_lo = VDR_PAIR_REG(a->ra);
+    t8 = tcg_temp_new_i64();
+    tcg_gen_concat_tl_i64(t8, cpu_gpr[rs_lo], cpu_gpr[a->rs]);
+    if (sh != 0 && len > 0 && me == (63 - sh)) {
+        tcg_gen_deposit_z_i64(t8, t8, sh, len);
+    } else if (me == 63 && rsh + len <= 64) {
+        tcg_gen_extract_i64(t8, t8, rsh, len);
+    } else {
+        tcg_gen_rotli_i64(t8, t8, sh);
+        tcg_gen_andi_i64(t8, t8, mask_u64(mb, me));
+    }
+    tcg_gen_extr_i64_tl(cpu_gpr[ra_lo], cpu_gpr[a->ra], t8);
+    if (unlikely(a->rc != 0)) {
+        gen_set_Rc0_i64(ctx, t8);
+    }
+    return true;
+}
+#endif
+
+static bool trans_RLDICL(DisasContext *ctx, arg_RLDICL *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    return gen_rldinm_i64(ctx, a, a->mb, 63, a->sh);
+#endif
+}
+
+static bool trans_RLDICR(DisasContext *ctx, arg_RLDICR *a)
+{
+#if defined(TARGET_PPC64)
+    return false;
+#else
+    return gen_rldinm_i64(ctx, a, 0, a->mb, a->sh);
+#endif
+}
+
-- 
2.43.0



^ permalink raw reply related	[flat|nested] 19+ messages in thread

* [PATCH 3/4] hw/ppc: Add a test machine for the IBM PPE42 CPU
  2025-08-19 21:28 [PATCH 0/4] Add IBM PPE42 CPU support Glenn Miles
  2025-08-19 21:28 ` [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors Glenn Miles
  2025-08-19 21:28 ` [PATCH 2/4] target/ppc: Add IBM PPE42 special instructions Glenn Miles
@ 2025-08-19 21:28 ` Glenn Miles
  2025-08-19 21:28 ` [PATCH 4/4] tests/functional: Add test for IBM PPE42 instructions Glenn Miles
  3 siblings, 0 replies; 19+ messages in thread
From: Glenn Miles @ 2025-08-19 21:28 UTC (permalink / raw)
  To: qemu-devel
  Cc: Glenn Miles, qemu-ppc, clg, npiggin, harshpb, thuth, rathc,
	richard.henderson

Adds a test machine for the IBM PPE42 processor, including a
DEC, FIT, WDT and 1MB of ram.

The purpose of this machine is only to provide a generic platform
for testing instructions of the recently  added PPE42 processor
model which is used extensively in the IBM Power9, Power10 and
future Power server processors.

Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
---
 hw/ppc/Kconfig         |  9 ++++++
 hw/ppc/meson.build     |  2 ++
 hw/ppc/ppc_booke.c     |  7 ++++-
 hw/ppc/ppe42_machine.c | 69 ++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/ppc.h   |  1 +
 5 files changed, 87 insertions(+), 1 deletion(-)
 create mode 100644 hw/ppc/ppe42_machine.c

diff --git a/hw/ppc/Kconfig b/hw/ppc/Kconfig
index ced6bbc740..3fdea5919c 100644
--- a/hw/ppc/Kconfig
+++ b/hw/ppc/Kconfig
@@ -44,6 +44,15 @@ config POWERNV
     select SSI_M25P80
     select PNV_SPI
 
+config PPC405
+    bool
+    default y
+    depends on PPC
+    select M48T59
+    select PFLASH_CFI02
+    select PPC4XX
+    select SERIAL
+
 config PPC440
     bool
     default y
diff --git a/hw/ppc/meson.build b/hw/ppc/meson.build
index 9893f8adeb..170b90ae7d 100644
--- a/hw/ppc/meson.build
+++ b/hw/ppc/meson.build
@@ -57,6 +57,8 @@ ppc_ss.add(when: 'CONFIG_POWERNV', if_true: files(
   'pnv_n1_chiplet.c',
 ))
 # PowerPC 4xx boards
+ppc_ss.add(when: 'CONFIG_PPC405', if_true: files(
+  'ppe42_machine.c'))
 ppc_ss.add(when: 'CONFIG_PPC440', if_true: files(
   'ppc440_bamboo.c',
   'ppc440_uc.c'))
diff --git a/hw/ppc/ppc_booke.c b/hw/ppc/ppc_booke.c
index 3872ae2822..13403a56b1 100644
--- a/hw/ppc/ppc_booke.c
+++ b/hw/ppc/ppc_booke.c
@@ -352,7 +352,12 @@ void ppc_booke_timers_init(PowerPCCPU *cpu, uint32_t freq, uint32_t flags)
     booke_timer = g_new0(booke_timer_t, 1);
 
     cpu->env.tb_env = tb_env;
-    tb_env->flags = flags | PPC_TIMER_BOOKE | PPC_DECR_ZERO_TRIGGERED;
+    if (flags & PPC_TIMER_PPE) {
+        /* PPE's use a modified version of the booke behavior */
+        tb_env->flags = flags | PPC_DECR_UNDERFLOW_TRIGGERED;
+    } else {
+        tb_env->flags = flags | PPC_TIMER_BOOKE | PPC_DECR_ZERO_TRIGGERED;
+    }
 
     tb_env->tb_freq    = freq;
     tb_env->decr_freq  = freq;
diff --git a/hw/ppc/ppe42_machine.c b/hw/ppc/ppe42_machine.c
new file mode 100644
index 0000000000..0bc295da28
--- /dev/null
+++ b/hw/ppc/ppe42_machine.c
@@ -0,0 +1,69 @@
+
+/*
+ * Test Machine for the IBM PPE42 processor
+ *
+ * Copyright (c) 2025, IBM Corporation.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+#include "qemu/error-report.h"
+#include "system/address-spaces.h"
+#include "hw/boards.h"
+#include "hw/ppc/ppc.h"
+#include "system/system.h"
+#include "system/reset.h"
+#include "system/kvm.h"
+
+static void main_cpu_reset(void *opaque)
+{
+    PowerPCCPU *cpu = opaque;
+
+    cpu_reset(CPU(cpu));
+}
+
+static void ppe42_machine_init(MachineState *machine)
+{
+    PowerPCCPU *cpu;
+    CPUPPCState *env;
+
+    if (kvm_enabled()) {
+        error_report("machine %s does not support the KVM accelerator",
+                     MACHINE_GET_CLASS(machine)->name);
+        exit(EXIT_FAILURE);
+    }
+
+    /* init CPU */
+    cpu = POWERPC_CPU(cpu_create(machine->cpu_type));
+    env = &cpu->env;
+    if (PPC_INPUT(env) != PPC_FLAGS_INPUT_PPE42) {
+        error_report("Incompatible CPU, only PPE42 bus supported");
+        exit(1);
+    }
+
+    qemu_register_reset(main_cpu_reset, cpu);
+
+    /* This sets the decrementer timebase */
+    ppc_booke_timers_init(cpu, 37500000, PPC_TIMER_PPE);
+
+    /* RAM */
+    if (machine->ram_size > 2 * GiB) {
+        error_report("RAM size more than 2 GiB is not supported");
+        exit(1);
+    }
+    memory_region_add_subregion(get_system_memory(), 0xfff80000, machine->ram);
+}
+
+
+static void ppe42_machine_class_init(MachineClass *mc)
+{
+    mc->desc = "PPE42 Test Machine";
+    mc->init = ppe42_machine_init;
+    mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("PPE42XM");
+    mc->default_ram_id = "ram";
+    mc->default_ram_size = 1 * MiB;
+}
+
+DEFINE_MACHINE("ppe42_machine", ppe42_machine_class_init)
diff --git a/include/hw/ppc/ppc.h b/include/hw/ppc/ppc.h
index 8a14d623f8..cb51d704c6 100644
--- a/include/hw/ppc/ppc.h
+++ b/include/hw/ppc/ppc.h
@@ -52,6 +52,7 @@ struct ppc_tb_t {
 #define PPC_DECR_UNDERFLOW_LEVEL     (1 << 4) /* Decr interrupt active when
                                                * the most significant bit is 1.
                                                */
+#define PPC_TIMER_PPE                (1 << 5) /* Enable PPE support */
 
 uint64_t cpu_ppc_get_tb(ppc_tb_t *tb_env, uint64_t vmclk, int64_t tb_offset);
 void cpu_ppc_tb_init(CPUPPCState *env, uint32_t freq);
-- 
2.43.0



^ permalink raw reply related	[flat|nested] 19+ messages in thread

* [PATCH 4/4] tests/functional: Add test for IBM PPE42 instructions
  2025-08-19 21:28 [PATCH 0/4] Add IBM PPE42 CPU support Glenn Miles
                   ` (2 preceding siblings ...)
  2025-08-19 21:28 ` [PATCH 3/4] hw/ppc: Add a test machine for the IBM PPE42 CPU Glenn Miles
@ 2025-08-19 21:28 ` Glenn Miles
  2025-08-25  9:10   ` Thomas Huth
  3 siblings, 1 reply; 19+ messages in thread
From: Glenn Miles @ 2025-08-19 21:28 UTC (permalink / raw)
  To: qemu-devel
  Cc: Glenn Miles, qemu-ppc, clg, npiggin, harshpb, thuth, rathc,
	richard.henderson

Adds a functional test for the IBM PPE42 instructions which
downloads a test image from a public github repo and then
loads and executes the image.
(see https://github.com/milesg-github/ppe42-tests for details)

Test status is checked by periodically issuing 'info register'
commands and checking the NIP value.  If the NIP is 0xFFF80200
then the test successfully executed to completion.  If the
machine stops before the test completes or if a 90 second
timeout is reached, then the test is marked as having failed.

This test does not test any PowerPC instructions as it is
expected that these instructions are well covered in other
tests.  Only instructions that are unique to the IBM PPE42
processor are tested.

Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
---
 tests/functional/meson.build       |  1 +
 tests/functional/test_ppc_ppe42.py | 79 ++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100644 tests/functional/test_ppc_ppe42.py

diff --git a/tests/functional/meson.build b/tests/functional/meson.build
index 311c6f1806..ddfef55bd2 100644
--- a/tests/functional/meson.build
+++ b/tests/functional/meson.build
@@ -233,6 +233,7 @@ tests_ppc_system_quick = [
 ]
 
 tests_ppc_system_thorough = [
+  'ppc_ppe42',
   'ppc_40p',
   'ppc_amiga',
   'ppc_bamboo',
diff --git a/tests/functional/test_ppc_ppe42.py b/tests/functional/test_ppc_ppe42.py
new file mode 100644
index 0000000000..26bbe11b2d
--- /dev/null
+++ b/tests/functional/test_ppc_ppe42.py
@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+#
+# Functional tests for the IBM PPE42 processor
+#
+# Copyright (c) 2025, IBM Corporation
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+from qemu_test import QemuSystemTest, Asset
+import asyncio
+
+class Ppe42Machine(QemuSystemTest):
+
+    timeout = 90
+    poll_period = 1.0
+
+    ASSET_PPE42_TEST_IMAGE = Asset(
+        ('https://github.com/milesg-github/ppe42-tests/raw/refs/heads/main/'
+         'images/ppe42-test.out'),
+        '03c1ac0fb7f6c025102a02776a93b35101dae7c14b75e4eab36a337e39042ea8')
+
+    def _test_completed(self):
+        self.log.info("Checking for test completion...")
+        try:
+            output = self.vm.cmd('human-monitor-command',
+                                 command_line='info registers')
+        except Exception as err:
+            self.log.debug(f"'info registers' cmd failed due to {err=},"
+                            " {type(err)=}")
+            raise
+
+        self.log.info(output)
+        if "NIP fff80200" in output:
+            self.log.info("<test completed>")
+            return True
+        else:
+            self.log.info("<test not completed>")
+            return False
+
+    def _wait_pass_fail(self, timeout):
+        while not self._test_completed():
+            if timeout >= self.poll_period:
+                timeout = timeout - self.poll_period
+                self.log.info(f"Waiting {self.poll_period} seconds for test"
+                               " to complete...")
+                e = None
+                try:
+                    e = self.vm.event_wait('STOP', self.poll_period)
+
+                except asyncio.TimeoutError:
+                    self.log.info("Poll period ended.")
+                    pass
+
+                except Exception as err:
+                    self.log.debug(f"event_wait() failed due to {err=},"
+                                    " {type(err)=}")
+                    raise
+
+                if e != None:
+                    self.log.debug(f"Execution stopped: {e}")
+                    self.log.debug("Exiting due to test failure")
+                    self.fail("Failure detected!")
+                    break
+            else:
+                self.fail("Timed out waiting for test completion.")
+
+    def test_ppe42_instructions(self):
+        self.set_machine('ppe42_machine')
+        self.require_accelerator("tcg")
+        image_path = self.ASSET_PPE42_TEST_IMAGE.fetch()
+        self.vm.add_args('-nographic')
+        self.vm.add_args('-device', f'loader,file={image_path}')
+        self.vm.add_args('-device', 'loader,addr=0xfff80040,cpu-num=0')
+        self.vm.add_args('-action', 'panic=pause')
+        self.vm.launch()
+        self._wait_pass_fail(self.timeout)
+
+if __name__ == '__main__':
+    QemuSystemTest.main()
-- 
2.43.0



^ permalink raw reply related	[flat|nested] 19+ messages in thread

* Re: [PATCH 4/4] tests/functional: Add test for IBM PPE42 instructions
  2025-08-19 21:28 ` [PATCH 4/4] tests/functional: Add test for IBM PPE42 instructions Glenn Miles
@ 2025-08-25  9:10   ` Thomas Huth
  0 siblings, 0 replies; 19+ messages in thread
From: Thomas Huth @ 2025-08-25  9:10 UTC (permalink / raw)
  To: Glenn Miles, qemu-devel
  Cc: qemu-ppc, clg, npiggin, harshpb, rathc, richard.henderson

On 19/08/2025 23.28, Glenn Miles wrote:
> Adds a functional test for the IBM PPE42 instructions which
> downloads a test image from a public github repo and then
> loads and executes the image.
> (see https://github.com/milesg-github/ppe42-tests for details)
> 
> Test status is checked by periodically issuing 'info register'
> commands and checking the NIP value.  If the NIP is 0xFFF80200
> then the test successfully executed to completion.  If the
> machine stops before the test completes or if a 90 second
> timeout is reached, then the test is marked as having failed.
> 
> This test does not test any PowerPC instructions as it is
> expected that these instructions are well covered in other
> tests.  Only instructions that are unique to the IBM PPE42
> processor are tested.
> 
> Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
> ---
>   tests/functional/meson.build       |  1 +
>   tests/functional/test_ppc_ppe42.py | 79 ++++++++++++++++++++++++++++++
>   2 files changed, 80 insertions(+)
>   create mode 100644 tests/functional/test_ppc_ppe42.py

Reviewed-by: Thomas Huth <thuth@redhat.com>



^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-19 21:28 ` [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors Glenn Miles
@ 2025-08-25 11:24   ` Harsh Prateek Bora
  2025-08-25 11:34     ` Thomas Huth
  2025-08-25 16:56     ` Miles Glenn
  0 siblings, 2 replies; 19+ messages in thread
From: Harsh Prateek Bora @ 2025-08-25 11:24 UTC (permalink / raw)
  To: Glenn Miles, qemu-devel
  Cc: qemu-ppc, clg, npiggin, thuth, rathc, richard.henderson

Hi Glenn,

This seems significant work. Thanks for upstreaming.

On 8/20/25 02:58, Glenn Miles wrote:
> Adds the IBM PPE42 family of processors supporting the

family of 32-bit processors ?

> PPE42, PPE42X and PPE42XM processor versions.  These
> processors are used as embedded processors in the IBM
> Power9, Power10 and Power12 processors for various
> tasks.  It is basically a stripped down version of the
> IBM PowerPC 405 processor, with some added instructions
> for handling 64-bit loads and stores.
> 
> For more information on the PPE 42 processor please visit:
> 
> https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf
> 
> Supports PPE42 SPR's (Including the MSR) and  Exceptions.
> 
> Does not yet support new PPE42 instructions and does not
> prevent access to some invalid instructions and registers
> (currently allows for access to invalid GPR's and CR fields).
> 
> Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
> ---
>   target/ppc/cpu-models.c      |   7 +
>   target/ppc/cpu-models.h      |   4 +
>   target/ppc/cpu.h             |  66 +++++++-
>   target/ppc/cpu_init.c        | 286 ++++++++++++++++++++++++++++++-----
>   target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
>   target/ppc/helper_regs.c     |  28 +++-
>   target/ppc/tcg-excp_helper.c |  12 ++
>   target/ppc/translate.c       |   6 +-
>   8 files changed, 535 insertions(+), 45 deletions(-)
> 
> diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
> index ea86ea202a..09f73e23a8 100644
> --- a/target/ppc/cpu-models.c
> +++ b/target/ppc/cpu-models.c
> @@ -116,6 +116,13 @@
>                   NULL)
>       POWERPC_DEF("x2vp20",        CPU_POWERPC_X2VP20,                 405,
>                   NULL)
> +    /* PPE42 Embedded Controllers                                            */
> +    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42,                  ppe42,
> +                "Generic PPE 42")
> +    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X,                 ppe42x,
> +                "Generic PPE 42X")
> +    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM,                ppe42xm,
> +                "Generic PPE 42XM")

Can all the PPE42 specific code be conditionally compiled only for
!TARGET_PPC64 (and !CONFIG_USER_ONLY wherever possible)?
Not only to reduce the bloating size of respective binaries, but also to
avoid some code being added to hot path routines like 
hreg_compute_hflags_value().

>       /* PowerPC 440 family                                                    */
>   #if defined(TODO_USER_ONLY)
>       POWERPC_DEF("440",           CPU_POWERPC_440,                    440GP,
> diff --git a/target/ppc/cpu-models.h b/target/ppc/cpu-models.h
> index 72ad31ba50..c6cd27f390 100644
> --- a/target/ppc/cpu-models.h
> +++ b/target/ppc/cpu-models.h
> @@ -69,6 +69,10 @@ enum {
>       /* Xilinx cores */
>       CPU_POWERPC_X2VP4              = 0x20010820,
>       CPU_POWERPC_X2VP20             = 0x20010860,
> +    /* IBM PPE42 Family */
> +    CPU_POWERPC_PPE42              = 0x42000000,
> +    CPU_POWERPC_PPE42X             = 0x42100000,
> +    CPU_POWERPC_PPE42XM            = 0x42200000,
>       /* PowerPC 440 family */
>       /* Generic PowerPC 440 */
>   #define CPU_POWERPC_440              CPU_POWERPC_440GXf
> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> index 6b90543811..f2fc84f384 100644
> --- a/target/ppc/cpu.h
> +++ b/target/ppc/cpu.h
> @@ -220,6 +220,8 @@ typedef enum powerpc_excp_t {
>       POWERPC_EXCP_POWER10,
>       /* POWER11 exception model           */
>       POWERPC_EXCP_POWER11,
> +    /* PPE42 exception model            */
> +    POWERPC_EXCP_PPE42,
>   } powerpc_excp_t;
>   
>   /*****************************************************************************/
> @@ -282,6 +284,8 @@ typedef enum powerpc_input_t {
>       PPC_FLAGS_INPUT_POWER9,
>       /* Freescale RCPU bus               */
>       PPC_FLAGS_INPUT_RCPU,
> +    /* PPE42 bus                        */
> +    PPC_FLAGS_INPUT_PPE42,
>   } powerpc_input_t;
>   
>   #define PPC_INPUT(env) ((env)->bus_model)
> @@ -433,39 +437,64 @@ typedef enum {
>   #define MSR_TM   PPC_BIT_NR(31) /* Transactional Memory Available (Book3s)   */
>   #define MSR_CM   PPC_BIT_NR(32) /* Computation mode for BookE         hflags */
>   #define MSR_ICM  PPC_BIT_NR(33) /* Interrupt computation mode for BookE      */
> +#define MSR_SEM0 PPC_BIT_NR(33) /* SIB Error Mask Bit 0 (PPE42)              */
> +#define MSR_SEM1 PPC_BIT_NR(34) /* SIB Error Mask Bit 1 (PPE42)              */
> +#define MSR_SEM2 PPC_BIT_NR(35) /* SIB Error Mask Bit 2 (PPE42)              */
>   #define MSR_GS   PPC_BIT_NR(35) /* guest state for BookE                     */
> +#define MSR_SEM3 PPC_BIT_NR(36) /* SIB Error Mask Bit 3 (PPE42)              */
> +#define MSR_SEM4 PPC_BIT_NR(37) /* SIB Error Mask Bit 4 (PPE42)              */
>   #define MSR_UCLE PPC_BIT_NR(37) /* User-mode cache lock enable for BookE     */
>   #define MSR_VR   PPC_BIT_NR(38) /* altivec available                x hflags */
>   #define MSR_SPE  PPC_BIT_NR(38) /* SPE enable for BookE             x hflags */
> +#define MSR_SEM5 PPC_BIT_NR(38) /* SIB Error Mask Bit 5 (PPE42)              */
> +#define MSR_SEM6 PPC_BIT_NR(39) /* SIB Error Mask Bit 6 (PPE42)              */
>   #define MSR_VSX  PPC_BIT_NR(40) /* Vector Scalar Extension (>= 2.06)x hflags */
> +#define MSR_IS0  PPC_BIT_NR(40) /* Instance Specific Bit 0 (PPE42)           */
>   #define MSR_S    PPC_BIT_NR(41) /* Secure state                              */
> +#define MSR_SIBRC0 PPC_BIT_NR(41) /* Last SIB return code Bit 0 (PPE42)      */
> +#define MSR_SIBRC1 PPC_BIT_NR(42) /* Last SIB return code Bit 1 (PPE42)      */
> +#define MSR_SIBRC2 PPC_BIT_NR(43) /* Last SIB return code Bit 2 (PPE42)      */
> +#define MSR_LP   PPC_BIT_NR(44) /* Low Priority (PPE42)                      */
>   #define MSR_KEY  PPC_BIT_NR(44) /* key bit on 603e                           */
>   #define MSR_POW  PPC_BIT_NR(45) /* Power management                          */
>   #define MSR_WE   PPC_BIT_NR(45) /* Wait State Enable on 405                  */
> +#define MSR_IS1  PPC_BIT_NR(46) /* Instance Specific Bit 1 (PPE42)           */
>   #define MSR_TGPR PPC_BIT_NR(46) /* TGPR usage on 602/603            x        */
>   #define MSR_CE   PPC_BIT_NR(46) /* Critical int. enable on embedded PPC x    */
>   #define MSR_ILE  PPC_BIT_NR(47) /* Interrupt little-endian mode              */
> +#define MSR_UIE  PPC_BIT_NR(47) /* Unmaskable Interrupt Enable (PPE42)       */
>   #define MSR_EE   PPC_BIT_NR(48) /* External interrupt enable                 */
>   #define MSR_PR   PPC_BIT_NR(49) /* Problem state                      hflags */
>   #define MSR_FP   PPC_BIT_NR(50) /* Floating point available           hflags */
>   #define MSR_ME   PPC_BIT_NR(51) /* Machine check interrupt enable            */
>   #define MSR_FE0  PPC_BIT_NR(52) /* Floating point exception mode 0           */
> +#define MSR_IS2  PPC_BIT_NR(52) /* Instance Specific Bit 2 (PPE42)           */
> +#define MSR_IS3  PPC_BIT_NR(53) /* Instance Specific Bit 3 (PPE42)           */
>   #define MSR_SE   PPC_BIT_NR(53) /* Single-step trace enable         x hflags */
>   #define MSR_DWE  PPC_BIT_NR(53) /* Debug wait enable on 405         x        */
>   #define MSR_UBLE PPC_BIT_NR(53) /* User BTB lock enable on e500     x        */
>   #define MSR_BE   PPC_BIT_NR(54) /* Branch trace enable              x hflags */
>   #define MSR_DE   PPC_BIT_NR(54) /* Debug int. enable on embedded PPC   x     */
>   #define MSR_FE1  PPC_BIT_NR(55) /* Floating point exception mode 1           */
> +#define MSR_IPE  PPC_BIT_NR(55) /* Imprecise Mode Enable (PPE42)             */
>   #define MSR_AL   PPC_BIT_NR(56) /* AL bit on POWER                           */
> +#define MSR_SIBRCA0 PPC_BIT_NR(56) /* SIB Return Code Accumulator bit0 (PPE42) */
> +#define MSR_SIBRCA1 PPC_BIT_NR(57) /* SIB Return Code Accumulator bit1 (PPE42) */
>   #define MSR_EP   PPC_BIT_NR(57) /* Exception prefix on 601                   */
>   #define MSR_IR   PPC_BIT_NR(58) /* Instruction relocate                      */
>   #define MSR_IS   PPC_BIT_NR(58) /* Instruction address space (BookE)         */
> +#define MSR_SIBRCA2 PPC_BIT_NR(58) /* SIB Return Code Accumulator bit2 (PPE42) */
> +#define MSR_SIBRCA3 PPC_BIT_NR(59) /* SIB Return Code Accumulator bit3 (PPE42) */
>   #define MSR_DR   PPC_BIT_NR(59) /* Data relocate                             */
>   #define MSR_DS   PPC_BIT_NR(59) /* Data address space (BookE)                */
>   #define MSR_PE   PPC_BIT_NR(60) /* Protection enable on 403                  */
> +#define MSR_SIBRCA4 PPC_BIT_NR(60) /* SIB Return Code Accumulator bit4 (PPE42) */
> +#define MSR_SIBRCA5 PPC_BIT_NR(61) /* SIB Return Code Accumulator bit5 (PPE42) */
>   #define MSR_PX   PPC_BIT_NR(61) /* Protection exclusive on 403        x      */
>   #define MSR_PMM  PPC_BIT_NR(61) /* Performance monitor mark on POWER  x      */
>   #define MSR_RI   PPC_BIT_NR(62) /* Recoverable interrupt            1        */
> +#define MSR_SIBRCA6 PPC_BIT_NR(62) /* SIB Return Code Accumulator bit6 (PPE42) */
> +#define MSR_SIBRCA7 PPC_BIT_NR(63) /* SIB Return Code Accumulator bit7 (PPE42) */
>   #define MSR_LE   PPC_BIT_NR(63) /* Little-endian mode               1 hflags */
>   

You may keep PPE42 bits together for easier review/maintenance with
conditional compilation getting enabled, but I am ok with either.

>   FIELD(MSR, SF, MSR_SF, 1)
> @@ -517,6 +546,9 @@ FIELD(MSR, PX, MSR_PX, 1)
>   FIELD(MSR, PMM, MSR_PMM, 1)
>   FIELD(MSR, RI, MSR_RI, 1)
>   FIELD(MSR, LE, MSR_LE, 1)
> +FIELD(MSR, SEM, MSR_SEM6, 7)
> +FIELD(MSR, SIBRC, MSR_SIBRC2, 3)
> +FIELD(MSR, SIBRCA, MSR_SIBRCA7, 8)
>   
>   /*
>    * FE0 and FE1 bits are not side-by-side
> @@ -730,6 +762,21 @@ FIELD(MSR, LE, MSR_LE, 1)
>   #define ESR_VLEMI PPC_BIT(58) /* VLE operation                          */
>   #define ESR_MIF   PPC_BIT(62) /* Misaligned instruction (VLE)           */
>   
> +/* PPE42 Interrupt Status Register bits                                 */
> +#define ISR_SRSMS0  PPC_BIT_NR(48) /* System Reset State Machine State 0   */
> +#define ISR_SRSMS1  PPC_BIT_NR(49) /* System Reset State Machine State 1   */
> +#define ISR_SRSMS2  PPC_BIT_NR(50) /* System Reset State Machine State 2   */
> +#define ISR_SRSMS3  PPC_BIT_NR(51) /* System Reset State Machine State 3   */
> +#define ISR_EP      PPC_BIT_NR(53) /* MSR[EE] Maskable Event Pending       */
> +#define ISR_PTR     PPC_BIT_NR(56) /* Program Interrupt from trap          */
> +#define ISR_ST      PPC_BIT_NR(57) /* Data Interrupt caused by store       */
> +#define ISR_MFE     PPC_BIT_NR(60) /* Multiple Fault Error                 */
> +#define ISR_MCS0    PPC_BIT_NR(61) /* Machine Check Status bit0            */
> +#define ISR_MCS1    PPC_BIT_NR(62) /* Machine Check Status bit1            */
> +#define ISR_MCS2    PPC_BIT_NR(63) /* Machine Check Status bit2            */

Better to have PPE42_ prefix ?

> +FIELD(ISR, SRSMS, ISR_SRSMS3, 4)
> +FIELD(ISR, MCS, ISR_MCS2, 3)
> +
>   /* Transaction EXception And Summary Register bits                           */
>   #define TEXASR_FAILURE_PERSISTENT                (63 - 7)
>   #define TEXASR_DISALLOWED                        (63 - 8)
> @@ -785,6 +832,8 @@ enum {
>       POWERPC_FLAG_SMT_1LPAR = 0x00800000,
>       /* Has BHRB */
>       POWERPC_FLAG_BHRB      = 0x01000000,
> +    /* Use PPE42-specific behavior                                           */
> +    POWERPC_FLAG_PPE42     = 0x02000000,
>   };
>   
>   /*
> @@ -1750,9 +1799,12 @@ void ppc_compat_add_property(Object *obj, const char *name,
>   #define SPR_BOOKE_CSRR0       (0x03A)
>   #define SPR_BOOKE_CSRR1       (0x03B)
>   #define SPR_BOOKE_DEAR        (0x03D)
> +#define SPR_PPE42_EDR         (0x03D)
>   #define SPR_IAMR              (0x03D)
>   #define SPR_BOOKE_ESR         (0x03E)
> +#define SPR_PPE42_ISR         (0x03E)
>   #define SPR_BOOKE_IVPR        (0x03F)
> +#define SPR_PPE42_IVPR        (0x03F)
>   #define SPR_MPC_EIE           (0x050)
>   #define SPR_MPC_EID           (0x051)
>   #define SPR_MPC_NRI           (0x052)
> @@ -1818,6 +1870,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
>   #define SPR_TBU40             (0x11E)
>   #define SPR_SVR               (0x11E)
>   #define SPR_BOOKE_PIR         (0x11E)
> +#define SPR_PPE42_PIR         (0x11E)
>   #define SPR_PVR               (0x11F)
>   #define SPR_HSPRG0            (0x130)
>   #define SPR_BOOKE_DBSR        (0x130)
> @@ -1827,6 +1880,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
>   #define SPR_BOOKE_EPCR        (0x133)
>   #define SPR_SPURR             (0x134)
>   #define SPR_BOOKE_DBCR0       (0x134)
> +#define SPR_PPE42_DBCR        (0x134)
>   #define SPR_IBCR              (0x135)
>   #define SPR_PURR              (0x135)
>   #define SPR_BOOKE_DBCR1       (0x135)
> @@ -1844,6 +1898,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
>   #define SPR_HSRR1             (0x13B)
>   #define SPR_BOOKE_IAC4        (0x13B)
>   #define SPR_BOOKE_DAC1        (0x13C)
> +#define SPR_PPE42_DACR        (0x13C)
>   #define SPR_MMCRH             (0x13C)
>   #define SPR_DABR2             (0x13D)
>   #define SPR_BOOKE_DAC2        (0x13D)
> @@ -1853,12 +1908,14 @@ void ppc_compat_add_property(Object *obj, const char *name,
>   #define SPR_BOOKE_DVC2        (0x13F)
>   #define SPR_LPIDR             (0x13F)
>   #define SPR_BOOKE_TSR         (0x150)
> +#define SPR_PPE42_TSR         (0x150)
>   #define SPR_HMER              (0x150)
>   #define SPR_HMEER             (0x151)
>   #define SPR_PCR               (0x152)
>   #define SPR_HEIR              (0x153)
>   #define SPR_BOOKE_LPIDR       (0x152)
>   #define SPR_BOOKE_TCR         (0x154)
> +#define SPR_PPE42_TCR         (0x154)
>   #define SPR_BOOKE_TLB0PS      (0x158)
>   #define SPR_BOOKE_TLB1PS      (0x159)
>   #define SPR_BOOKE_TLB2PS      (0x15A)
> @@ -2528,6 +2585,12 @@ enum {
>       PPC2_MEM_LWSYNC    = 0x0000000000200000ULL,
>       /* ISA 2.06 BCD assist instructions                                      */
>       PPC2_BCDA_ISA206   = 0x0000000000400000ULL,
> +    /* PPE42 instructions                                                    */
> +    PPC2_PPE42         = 0x0000000000800000ULL,
> +    /* PPE42X instructions                                                   */
> +    PPC2_PPE42X        = 0x0000000001000000ULL,
> +    /* PPE42XM instructions                                                  */
> +    PPC2_PPE42XM       = 0x0000000002000000ULL,
>   
>   #define PPC_TCG_INSNS2 (PPC2_BOOKE206 | PPC2_VSX | PPC2_PRCNTL | PPC2_DBRX | \
>                           PPC2_ISA205 | PPC2_VSX207 | PPC2_PERM_ISA206 | \
> @@ -2537,7 +2600,8 @@ enum {
>                           PPC2_ALTIVEC_207 | PPC2_ISA207S | PPC2_DFP | \
>                           PPC2_FP_CVT_S64 | PPC2_TM | PPC2_PM_ISA206 | \
>                           PPC2_ISA300 | PPC2_ISA310 | PPC2_MEM_LWSYNC | \
> -                        PPC2_BCDA_ISA206)
> +                        PPC2_BCDA_ISA206 | PPC2_PPE42 | PPC2_PPE42X | \
> +                        PPC2_PPE42XM)
>   };
>   
>   /*****************************************************************************/
> diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
> index a0e77f2673..317670a96b 100644
> --- a/target/ppc/cpu_init.c
> +++ b/target/ppc/cpu_init.c
> @@ -1653,6 +1653,47 @@ static void register_8xx_sprs(CPUPPCState *env)
>    * ... and more (thermal management, performance counters, ...)
>    */
>   
> +static void register_ppe42_sprs(CPUPPCState *env)
> +{
> +    spr_register(env, SPR_PPE42_EDR, "EDR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, &spr_write_generic,
> +                 0x00000000);
> +    spr_register(env, SPR_PPE42_ISR, "ISR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, &spr_write_generic,
> +                 0x00000000);
> +    spr_register(env, SPR_PPE42_IVPR, "IVPR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, SPR_NOACCESS,
> +                 0xfff80000);
> +    spr_register(env, SPR_PPE42_PIR, "PIR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, &spr_write_pir,
> +                 0x00000000);
> +    spr_register(env, SPR_PPE42_DBCR, "DBCR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, &spr_write_40x_dbcr0,
> +                 0x00000000);
> +    spr_register(env, SPR_PPE42_DACR, "DACR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, &spr_write_generic,
> +                 0x00000000);
> +    /* Timer */
> +    spr_register(env, SPR_DECR, "DECR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_decr, &spr_write_decr,
> +                 0x00000000);
> +    spr_register(env, SPR_PPE42_TSR, "TSR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, &spr_write_booke_tsr,
> +                 0x00000000);
> +    spr_register(env, SPR_BOOKE_TCR, "TCR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, &spr_write_booke_tcr,
> +                 0x00000000);
> +}
> +
>   /*****************************************************************************/
>   /* Exception vectors models                                                  */
>   static void init_excp_4xx(CPUPPCState *env)
> @@ -1679,6 +1720,30 @@ static void init_excp_4xx(CPUPPCState *env)
>   #endif
>   }
>   
> +static void init_excp_ppe42(CPUPPCState *env)
> +{
> +#if !defined(CONFIG_USER_ONLY)
> +    /* Machine Check vector changed after version 0 */
> +    if (((env->spr[SPR_PVR] & 0xf00000ul) >> 20) == 0) {
> +        env->excp_vectors[POWERPC_EXCP_MCHECK]   = 0x00000000;
> +    } else {
> +        env->excp_vectors[POWERPC_EXCP_MCHECK]   = 0x00000020;
> +    }
> +    env->excp_vectors[POWERPC_EXCP_RESET]    = 0x00000040;
> +    env->excp_vectors[POWERPC_EXCP_DSI]      = 0x00000060;
> +    env->excp_vectors[POWERPC_EXCP_ISI]      = 0x00000080;
> +    env->excp_vectors[POWERPC_EXCP_EXTERNAL] = 0x000000A0;
> +    env->excp_vectors[POWERPC_EXCP_ALIGN]    = 0x000000C0;
> +    env->excp_vectors[POWERPC_EXCP_PROGRAM]  = 0x000000E0;
> +    env->excp_vectors[POWERPC_EXCP_DECR]     = 0x00000100;
> +    env->excp_vectors[POWERPC_EXCP_FIT]      = 0x00000120;
> +    env->excp_vectors[POWERPC_EXCP_WDT]      = 0x00000140;
> +    env->ivpr_mask = 0xFFFFFE00UL;
> +    /* Hardware reset vector */
> +    env->hreset_vector = 0x00000040UL;
> +#endif
> +}
> +
>   static void init_excp_MPC5xx(CPUPPCState *env)
>   {
>   #if !defined(CONFIG_USER_ONLY)
> @@ -2200,6 +2265,125 @@ POWERPC_FAMILY(405)(ObjectClass *oc, const void *data)
>                    POWERPC_FLAG_DE | POWERPC_FLAG_BUS_CLK;
>   }
>   
> +static void init_proc_ppe42(CPUPPCState *env)
> +{
> +    register_ppe42_sprs(env);
> +
> +    init_excp_ppe42(env);
> +    env->dcache_line_size = 32;
> +    env->icache_line_size = 32;
> +    /* Allocate hardware IRQ controller */
> +    ppc40x_irq_init(env_archcpu(env));
> +
> +    SET_FIT_PERIOD(8, 12, 16, 20);
> +    SET_WDT_PERIOD(16, 20, 24, 28);
> +}
> +
> +POWERPC_FAMILY(ppe42)(ObjectClass *oc, const void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(oc);
> +    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> +
> +    dc->desc = "PPE 42";
> +    pcc->init_proc = init_proc_ppe42;
> +    pcc->check_pow = check_pow_nocheck;
> +    pcc->check_attn = check_attn_none;
> +    pcc->insns_flags = PPC_INSNS_BASE |
> +                       PPC_WRTEE |
> +                       PPC_CACHE |
> +                       PPC_CACHE_DCBZ |
> +                       PPC_MEM_SYNC;
> +    pcc->insns_flags2 = PPC2_PPE42;
> +    pcc->msr_mask = R_MSR_SEM_MASK |
> +                    (1ull << MSR_IS0) |
> +                    R_MSR_SIBRC_MASK |
> +                    (1ull << MSR_LP) |
> +                    (1ull << MSR_WE) |
> +                    (1ull << MSR_IS1) |
> +                    (1ull << MSR_UIE) |
> +                    (1ull << MSR_EE) |
> +                    (1ull << MSR_ME) |
> +                    (1ull << MSR_IS2) |
> +                    (1ull << MSR_IS3) |
> +                    (1ull << MSR_IPE) |
> +                    R_MSR_SIBRCA_MASK;
> +    pcc->mmu_model = POWERPC_MMU_REAL;
> +    pcc->excp_model = POWERPC_EXCP_PPE42;
> +    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
> +    pcc->bfd_mach = bfd_mach_ppc_403;
> +    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;

This shares common code with ppe42x and ppe42xm variants.
Could this be re-used from a common routine?

> +}
> +
> +POWERPC_FAMILY(ppe42x)(ObjectClass *oc, const void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(oc);
> +    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> +
> +    dc->desc = "PPE 42X";
> +    pcc->init_proc = init_proc_ppe42;
> +    pcc->check_pow = check_pow_nocheck;
> +    pcc->check_attn = check_attn_none;
> +    pcc->insns_flags = PPC_INSNS_BASE |
> +                       PPC_WRTEE |
> +                       PPC_CACHE |
> +                       PPC_CACHE_DCBZ |
> +                       PPC_MEM_SYNC;
> +    pcc->insns_flags2 = PPC2_PPE42 | PPC2_PPE42X;
> +    pcc->msr_mask = R_MSR_SEM_MASK |
> +                    (1ull << MSR_IS0) |
> +                    R_MSR_SIBRC_MASK |
> +                    (1ull << MSR_LP) |
> +                    (1ull << MSR_WE) |
> +                    (1ull << MSR_IS1) |
> +                    (1ull << MSR_UIE) |
> +                    (1ull << MSR_EE) |
> +                    (1ull << MSR_ME) |
> +                    (1ull << MSR_IS2) |
> +                    (1ull << MSR_IS3) |
> +                    (1ull << MSR_IPE) |
> +                    R_MSR_SIBRCA_MASK;
> +    pcc->mmu_model = POWERPC_MMU_REAL;
> +    pcc->excp_model = POWERPC_EXCP_PPE42;
> +    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
> +    pcc->bfd_mach = bfd_mach_ppc_403;
> +    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;
> +}
> +
> +POWERPC_FAMILY(ppe42xm)(ObjectClass *oc, const void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(oc);
> +    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> +
> +    dc->desc = "PPE 42XM";
> +    pcc->init_proc = init_proc_ppe42;
> +    pcc->check_pow = check_pow_nocheck;
> +    pcc->check_attn = check_attn_none;
> +    pcc->insns_flags = PPC_INSNS_BASE |
> +                       PPC_WRTEE |
> +                       PPC_CACHE |
> +                       PPC_CACHE_DCBZ |
> +                       PPC_MEM_SYNC;
> +    pcc->insns_flags2 = PPC2_PPE42 | PPC2_PPE42X | PPC2_PPE42XM;
> +    pcc->msr_mask = R_MSR_SEM_MASK |
> +                    (1ull << MSR_IS0) |
> +                    R_MSR_SIBRC_MASK |
> +                    (1ull << MSR_LP) |
> +                    (1ull << MSR_WE) |
> +                    (1ull << MSR_IS1) |
> +                    (1ull << MSR_UIE) |
> +                    (1ull << MSR_EE) |
> +                    (1ull << MSR_ME) |
> +                    (1ull << MSR_IS2) |
> +                    (1ull << MSR_IS3) |
> +                    (1ull << MSR_IPE) |
> +                    R_MSR_SIBRCA_MASK;
> +    pcc->mmu_model = POWERPC_MMU_REAL;
> +    pcc->excp_model = POWERPC_EXCP_PPE42;
> +    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
> +    pcc->bfd_mach = bfd_mach_ppc_403;
> +    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;
> +}
> +
>   static void init_proc_440EP(CPUPPCState *env)
>   {
>       register_BookE_sprs(env, 0x000000000000FFFFULL);
> @@ -6802,53 +6986,63 @@ static void init_ppc_proc(PowerPCCPU *cpu)
>   
>       /* MSR bits & flags consistency checks */
>       if (env->msr_mask & (1 << 25)) {
> -        switch (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE)) {
> +        switch (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE |
> +                              POWERPC_FLAG_PPE42)) {
>           case POWERPC_FLAG_SPE:
>           case POWERPC_FLAG_VRE:
> +        case POWERPC_FLAG_PPE42:
>               break;
>           default:
>               fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> -                    "Should define POWERPC_FLAG_SPE or POWERPC_FLAG_VRE\n");
> +                    "Should define POWERPC_FLAG_SPE or POWERPC_FLAG_VRE\n"
> +                    "or POWERPC_FLAG_PPE42\n");
>               exit(1);
>           }
>       } else if (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE)) {
>           fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> -                "Should not define POWERPC_FLAG_SPE nor POWERPC_FLAG_VRE\n");
> +                "Should not define POWERPC_FLAG_SPE nor POWERPC_FLAG_VRE\n"
> +                "nor POWERPC_FLAG_PPE42\n");
>           exit(1);
>       }
>       if (env->msr_mask & (1 << 17)) {
> -        switch (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE)) {
> +        switch (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE |
> +                              POWERPC_FLAG_PPE42)) {
>           case POWERPC_FLAG_TGPR:
>           case POWERPC_FLAG_CE:
> +        case POWERPC_FLAG_PPE42:
>               break;
>           default:
>               fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> -                    "Should define POWERPC_FLAG_TGPR or POWERPC_FLAG_CE\n");
> +                    "Should define POWERPC_FLAG_TGPR or POWERPC_FLAG_CE\n"
> +                    "or POWERPC_FLAG_PPE42\n");
>               exit(1);
>           }
> -    } else if (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE)) {
> +    } else if (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE |
> +                             POWERPC_FLAG_PPE42)) {
>           fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> -                "Should not define POWERPC_FLAG_TGPR nor POWERPC_FLAG_CE\n");
> +                "Should not define POWERPC_FLAG_TGPR nor POWERPC_FLAG_CE\n"
> +                "nor POWERPC_FLAG_PPE42\n");
>           exit(1);
>       }
>       if (env->msr_mask & (1 << 10)) {
>           switch (env->flags & (POWERPC_FLAG_SE | POWERPC_FLAG_DWE |
> -                              POWERPC_FLAG_UBLE)) {
> +                              POWERPC_FLAG_UBLE | POWERPC_FLAG_PPE42)) {
>           case POWERPC_FLAG_SE:
>           case POWERPC_FLAG_DWE:
>           case POWERPC_FLAG_UBLE:
> +        case POWERPC_FLAG_PPE42:
>               break;
>           default:
>               fprintf(stderr, "PowerPC MSR definition inconsistency\n"
>                       "Should define POWERPC_FLAG_SE or POWERPC_FLAG_DWE or "
> -                    "POWERPC_FLAG_UBLE\n");
> +                    "POWERPC_FLAG_UBLE or POWERPC_FLAG_PPE42\n");
>               exit(1);
>           }
>       } else if (env->flags & (POWERPC_FLAG_SE | POWERPC_FLAG_DWE |
> -                             POWERPC_FLAG_UBLE)) {
> +                             POWERPC_FLAG_UBLE | POWERPC_FLAG_PPE42)) {
>           fprintf(stderr, "PowerPC MSR definition inconsistency\n"
>                   "Should not define POWERPC_FLAG_SE nor POWERPC_FLAG_DWE nor "
> -                "POWERPC_FLAG_UBLE\n");
> +                "POWERPC_FLAG_UBLE nor POWERPC_FLAG_PPE42\n");
>               exit(1);
>       }
>       if (env->msr_mask & (1 << 9)) {
> @@ -6867,18 +7061,23 @@ static void init_ppc_proc(PowerPCCPU *cpu)
>           exit(1);
>       }
>       if (env->msr_mask & (1 << 2)) {
> -        switch (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM)) {
> +        switch (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM |
> +                              POWERPC_FLAG_PPE42)) {
>           case POWERPC_FLAG_PX:
>           case POWERPC_FLAG_PMM:
> +        case POWERPC_FLAG_PPE42:
>               break;
>           default:
>               fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> -                    "Should define POWERPC_FLAG_PX or POWERPC_FLAG_PMM\n");
> +                    "Should define POWERPC_FLAG_PX or POWERPC_FLAG_PMM\n"
> +                    "or POWERPC_FLAG_PPE42\n");
>               exit(1);
>           }
> -    } else if (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM)) {
> +    } else if (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM |
> +                             POWERPC_FLAG_PPE42)) {
>           fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> -                "Should not define POWERPC_FLAG_PX nor POWERPC_FLAG_PMM\n");
> +                "Should not define POWERPC_FLAG_PX nor POWERPC_FLAG_PMM\n"
> +                "nor POWERPC_FLAG_PPE42\n");
>           exit(1);
>       }
>       if ((env->flags & POWERPC_FLAG_BUS_CLK) == 0) {
> @@ -7243,39 +7442,40 @@ static void ppc_cpu_reset_hold(Object *obj, ResetType type)
>       }
>   
>       msr = (target_ulong)0;
> -    msr |= (target_ulong)MSR_HVB;
> -    msr |= (target_ulong)1 << MSR_EP;
> +    if (!(env->flags & POWERPC_FLAG_PPE42)) {
> +        msr |= (target_ulong)MSR_HVB;
> +        msr |= (target_ulong)1 << MSR_EP;
>   #if defined(DO_SINGLE_STEP) && 0
> -    /* Single step trace mode */
> -    msr |= (target_ulong)1 << MSR_SE;
> -    msr |= (target_ulong)1 << MSR_BE;
> +        /* Single step trace mode */
> +        msr |= (target_ulong)1 << MSR_SE;
> +        msr |= (target_ulong)1 << MSR_BE;
>   #endif
>   #if defined(CONFIG_USER_ONLY)
> -    msr |= (target_ulong)1 << MSR_FP; /* Allow floating point usage */
> -    msr |= (target_ulong)1 << MSR_FE0; /* Allow floating point exceptions */
> -    msr |= (target_ulong)1 << MSR_FE1;
> -    msr |= (target_ulong)1 << MSR_VR; /* Allow altivec usage */
> -    msr |= (target_ulong)1 << MSR_VSX; /* Allow VSX usage */
> -    msr |= (target_ulong)1 << MSR_SPE; /* Allow SPE usage */
> -    msr |= (target_ulong)1 << MSR_PR;
> +        msr |= (target_ulong)1 << MSR_FP; /* Allow floating point usage */
> +        msr |= (target_ulong)1 << MSR_FE0; /* Allow floating point exceptions */
> +        msr |= (target_ulong)1 << MSR_FE1;
> +        msr |= (target_ulong)1 << MSR_VR; /* Allow altivec usage */
> +        msr |= (target_ulong)1 << MSR_VSX; /* Allow VSX usage */
> +        msr |= (target_ulong)1 << MSR_SPE; /* Allow SPE usage */
> +        msr |= (target_ulong)1 << MSR_PR;
>   #if defined(TARGET_PPC64)
> -    msr |= (target_ulong)1 << MSR_TM; /* Transactional memory */
> +        msr |= (target_ulong)1 << MSR_TM; /* Transactional memory */
>   #endif
>   #if !TARGET_BIG_ENDIAN
> -    msr |= (target_ulong)1 << MSR_LE; /* Little-endian user mode */
> -    if (!((env->msr_mask >> MSR_LE) & 1)) {
> -        fprintf(stderr, "Selected CPU does not support little-endian.\n");
> -        exit(1);
> -    }
> +        msr |= (target_ulong)1 << MSR_LE; /* Little-endian user mode */
> +        if (!((env->msr_mask >> MSR_LE) & 1)) {
> +            fprintf(stderr, "Selected CPU does not support little-endian.\n");
> +            exit(1);
> +        }
>   #endif
>   #endif
>   
>   #if defined(TARGET_PPC64)
> -    if (mmu_is_64bit(env->mmu_model)) {
> -        msr |= (1ULL << MSR_SF);
> -    }
> +        if (mmu_is_64bit(env->mmu_model)) {
> +            msr |= (1ULL << MSR_SF);
> +        }
>   #endif
> -
> +    }
>       hreg_store_msr(env, msr, 1);
>   
>   #if !defined(CONFIG_USER_ONLY)
> @@ -7725,6 +7925,18 @@ void ppc_cpu_dump_state(CPUState *cs, FILE *f, int flags)
>            * they can be read with "p $ivor0", "p $ivor1", etc.
>            */
>           break;
> +    case POWERPC_EXCP_PPE42:
> +        qemu_fprintf(f, "SRR0 " TARGET_FMT_lx " SRR1 " TARGET_FMT_lx "\n",
> +                     env->spr[SPR_SRR0], env->spr[SPR_SRR1]);
> +
> +        qemu_fprintf(f, "  TCR " TARGET_FMT_lx "   TSR " TARGET_FMT_lx
> +                     "    ISR " TARGET_FMT_lx "   EDR " TARGET_FMT_lx "\n",
> +                     env->spr[SPR_PPE42_TCR], env->spr[SPR_PPE42_TSR],
> +                     env->spr[SPR_PPE42_ISR], env->spr[SPR_PPE42_EDR]);
> +
> +        qemu_fprintf(f, "  PIR " TARGET_FMT_lx "   IVPR " TARGET_FMT_lx "\n",
> +                     env->spr[SPR_PPE42_PIR], env->spr[SPR_PPE42_IVPR]);
> +        break;
>       case POWERPC_EXCP_40x:
>           qemu_fprintf(f, "  TCR " TARGET_FMT_lx "   TSR " TARGET_FMT_lx
>                        "    ESR " TARGET_FMT_lx "   DEAR " TARGET_FMT_lx "\n",
> diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
> index 1efdc4066e..2e35e63826 100644
> --- a/target/ppc/excp_helper.c
> +++ b/target/ppc/excp_helper.c
> @@ -949,6 +949,133 @@ static void powerpc_excp_74xx(PowerPCCPU *cpu, int excp)
>       powerpc_set_excp_state(cpu, vector, new_msr);
>   }
>   
> +#define ISR_MCS_INSTRUCTION             0
> +#define ISR_MCS_DATA_LOAD               1
> +#define ISR_MCS_DATA_PRECISE_STORE      2
> +#define ISR_MCS_DATA_IMPRECISE_STORE    3
> +#define ISR_MCS_PROGRAM                 4
> +#define ISR_MCS_ISI                     5
> +#define ISR_MCS_ALIGNMENT               6
> +#define ISR_MCS_DSI                     7

Should these have a PPE42_ prefix?
Also, may better be kept in cpu.h alongwith other PPE42 ISR bits ?

> +static void powerpc_excp_ppe42(PowerPCCPU *cpu, int excp)
> +{
> +    CPUPPCState *env = &cpu->env;
> +    target_ulong msr, new_msr, vector;
> +    target_ulong mcs = ISR_MCS_INSTRUCTION;
> +    bool promote_unmaskable;
> +
> +    msr = env->msr;
> +
> +    /*
> +     * New interrupt handler msr preserves SIBRC and ME unless explicitly
> +     * overridden by the exception.  All other MSR bits are zeroed out.
> +     */
> +    new_msr = env->msr & (((target_ulong)1 << MSR_ME) | R_MSR_SIBRC_MASK);
> +
> +    /* HV emu assistance interrupt only exists on server arch 2.05 or later */
> +    if (excp == POWERPC_EXCP_HV_EMU) {
> +        excp = POWERPC_EXCP_PROGRAM;
> +    }
> +
> +    /*
> +     * Unmaskable interrupts (Program, ISI, Alignment and DSI) are promoted to
> +     * machine check if MSR_UIE is 0.
> +     */
> +    promote_unmaskable = !(msr & ((target_ulong)1 << MSR_UIE));
> +
> +
> +    switch (excp) {
> +    case POWERPC_EXCP_MCHECK:    /* Machine check exception                  */
> +        break;
> +    case POWERPC_EXCP_DSI:       /* Data storage exception                   */
> +        trace_ppc_excp_dsi(env->spr[SPR_PPE42_ISR], env->spr[SPR_PPE42_EDR]);
> +        if (promote_unmaskable) {
> +            excp = POWERPC_EXCP_MCHECK;
> +            mcs = ISR_MCS_DSI;
> +        }
> +        break;
> +    case POWERPC_EXCP_ISI:       /* Instruction storage exception            */
> +        trace_ppc_excp_isi(msr, env->nip);
> +        if (promote_unmaskable) {
> +            excp = POWERPC_EXCP_MCHECK;
> +            mcs = ISR_MCS_ISI;
> +        }
> +        break;
> +    case POWERPC_EXCP_EXTERNAL:  /* External input                           */
> +        break;
> +    case POWERPC_EXCP_ALIGN:     /* Alignment exception                      */
> +        if (promote_unmaskable) {
> +            excp = POWERPC_EXCP_MCHECK;
> +            mcs = ISR_MCS_ALIGNMENT;
> +        }
> +        break;
> +    case POWERPC_EXCP_PROGRAM:   /* Program exception                        */
> +        if (promote_unmaskable) {
> +            excp = POWERPC_EXCP_MCHECK;
> +            mcs = ISR_MCS_PROGRAM;
> +        }
> +        switch (env->error_code & ~0xF) {
> +        case POWERPC_EXCP_INVAL:
> +            trace_ppc_excp_inval(env->nip);
> +            env->spr[SPR_PPE42_ISR] &= ~((target_ulong)1 << ISR_PTR);
> +            break;
> +        case POWERPC_EXCP_TRAP:
> +            env->spr[SPR_PPE42_ISR] |= ((target_ulong)1 << ISR_PTR);
> +            break;
> +        default:
> +            /* Should never occur */
> +            cpu_abort(env_cpu(env), "Invalid program exception %d. Aborting\n",
> +                      env->error_code);
> +            break;
> +        }
> +#ifdef CONFIG_TCG
> +        env->spr[SPR_PPE42_EDR] = ppc_ldl_code(env, env->nip);
> +#endif
> +        break;
> +    case POWERPC_EXCP_DECR:      /* Decrementer exception                    */
> +        break;
> +    case POWERPC_EXCP_FIT:       /* Fixed-interval timer interrupt           */
> +        trace_ppc_excp_print("FIT");
> +        break;
> +    case POWERPC_EXCP_WDT:       /* Watchdog timer interrupt                 */
> +        trace_ppc_excp_print("WDT");
> +        break;
> +    case POWERPC_EXCP_RESET:     /* System reset exception                   */
> +        /* reset exceptions don't have ME set */
> +        new_msr &= ~((target_ulong)1 << MSR_ME);
> +        break;
> +    default:
> +        cpu_abort(env_cpu(env), "Invalid PPE42 exception %d. Aborting\n",
> +                  excp);
> +        break;
> +    }
> +
> +    env->spr[SPR_SRR0] = env->nip;
> +    env->spr[SPR_SRR1] = msr;
> +
> +    vector = env->excp_vectors[excp];
> +    if (vector == (target_ulong)-1ULL) {
> +        cpu_abort(env_cpu(env),
> +                  "Raised an exception without defined vector %d\n", excp);
> +    }
> +    vector |= env->spr[SPR_PPE42_IVPR];
> +
> +    if (excp == POWERPC_EXCP_MCHECK) {
> +        /* Also set the Machine Check Status (MCS) */
> +        env->spr[SPR_PPE42_ISR] &= ~R_ISR_MCS_MASK;
> +        env->spr[SPR_PPE42_ISR] |= (mcs & R_ISR_MCS_MASK);
> +        env->spr[SPR_PPE42_ISR] &= ~((target_ulong)1 << ISR_MFE);
> +
> +        /* Machine checks halt execution if MSR_ME is 0 */
> +        powerpc_mcheck_checkstop(env);
> +
> +        /* machine check exceptions don't have ME set */
> +        new_msr &= ~((target_ulong)1 << MSR_ME);
> +    }
> +
> +    powerpc_set_excp_state(cpu, vector, new_msr);
> +}
> +
>   static void powerpc_excp_booke(PowerPCCPU *cpu, int excp)
>   {
>       CPUPPCState *env = &cpu->env;
> @@ -1589,6 +1716,9 @@ void powerpc_excp(PowerPCCPU *cpu, int excp)
>       case POWERPC_EXCP_POWER11:
>           powerpc_excp_books(cpu, excp);
>           break;
> +    case POWERPC_EXCP_PPE42:
> +        powerpc_excp_ppe42(cpu, excp);
> +        break;
>       default:
>           g_assert_not_reached();
>       }
> @@ -1945,6 +2075,43 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env,
>   }
>   #endif /* TARGET_PPC64 */
>   
> +static int ppe42_next_unmasked_interrupt(CPUPPCState *env)
> +{
> +    bool async_deliver;
> +
> +    /* External reset */
> +    if (env->pending_interrupts & PPC_INTERRUPT_RESET) {
> +        return PPC_INTERRUPT_RESET;
> +    }
> +    /* Machine check exception */
> +    if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
> +        return PPC_INTERRUPT_MCK;
> +    }
> +
> +    async_deliver = FIELD_EX64(env->msr, MSR, EE);
> +
> +    if (async_deliver != 0) {
> +        /* Watchdog timer */
> +        if (env->pending_interrupts & PPC_INTERRUPT_WDT) {
> +            return PPC_INTERRUPT_WDT;
> +        }
> +        /* External Interrupt */
> +        if (env->pending_interrupts & PPC_INTERRUPT_EXT) {
> +            return PPC_INTERRUPT_EXT;
> +        }
> +        /* Fixed interval timer */
> +        if (env->pending_interrupts & PPC_INTERRUPT_FIT) {
> +            return PPC_INTERRUPT_FIT;
> +        }
> +        /* Decrementer exception */
> +        if (env->pending_interrupts & PPC_INTERRUPT_DECR) {
> +            return PPC_INTERRUPT_DECR;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
>   static int ppc_next_unmasked_interrupt(CPUPPCState *env)
>   {
>       uint32_t pending_interrupts = env->pending_interrupts;
> @@ -1970,6 +2137,10 @@ static int ppc_next_unmasked_interrupt(CPUPPCState *env)
>       }
>   #endif
>   
> +    if (env->excp_model == POWERPC_EXCP_PPE42) {
> +        return ppe42_next_unmasked_interrupt(env);
> +    }
> +
>       /* External reset */
>       if (pending_interrupts & PPC_INTERRUPT_RESET) {
>           return PPC_INTERRUPT_RESET;
> diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c
> index 7e5726871e..7be00f5bbe 100644
> --- a/target/ppc/helper_regs.c
> +++ b/target/ppc/helper_regs.c
> @@ -186,6 +186,10 @@ static uint32_t hreg_compute_hflags_value(CPUPPCState *env)
>       if (env->spr[SPR_LPCR] & LPCR_HR) {
>           hflags |= 1 << HFLAGS_HR;
>       }
> +    if (ppc_flags & POWERPC_FLAG_PPE42) {
> +        /* PPE42 has a single address space and no problem state */
> +        msr = 0;
> +    }

We really dont want this to be checked on PPC64 machines, hence 
!TARGET_PPC64 needed.

>   
>   #ifndef CONFIG_USER_ONLY
>       if (!env->has_hv_mode || (msr & (1ull << MSR_HV))) {
> @@ -306,9 +310,6 @@ int hreg_store_msr(CPUPPCState *env, target_ulong value, int alter_hv)
>           value &= ~(1 << MSR_ME);
>           value |= env->msr & (1 << MSR_ME);
>       }
> -    if ((value ^ env->msr) & (R_MSR_IR_MASK | R_MSR_DR_MASK)) {
> -        cpu_interrupt_exittb(cs);
> -    }
>       if ((env->mmu_model == POWERPC_MMU_BOOKE ||
>            env->mmu_model == POWERPC_MMU_BOOKE206) &&
>           ((value ^ env->msr) & R_MSR_GS_MASK)) {
> @@ -319,8 +320,14 @@ int hreg_store_msr(CPUPPCState *env, target_ulong value, int alter_hv)
>           /* Swap temporary saved registers with GPRs */
>           hreg_swap_gpr_tgpr(env);
>       }
> -    if (unlikely((value ^ env->msr) & R_MSR_EP_MASK)) {
> -        env->excp_prefix = FIELD_EX64(value, MSR, EP) * 0xFFF00000;
> +    /* PPE42 MSR has bits overlapping with others */
> +    if (!(env->flags & POWERPC_FLAG_PPE42)) {
> +        if ((value ^ env->msr) & (R_MSR_IR_MASK | R_MSR_DR_MASK)) {
> +            cpu_interrupt_exittb(cs);
> +        }
> +        if (unlikely((value ^ env->msr) & R_MSR_EP_MASK)) {
> +            env->excp_prefix = FIELD_EX64(value, MSR, EP) * 0xFFF00000;
> +        }
>       }
>       /*
>        * If PR=1 then EE, IR and DR must be 1
> @@ -462,6 +469,17 @@ void register_generic_sprs(PowerPCCPU *cpu)
>                    SPR_NOACCESS, SPR_NOACCESS,
>                    &spr_read_generic, &spr_write_generic,
>                    0x00000000);
> +
> +    if (env->insns_flags2 & PPC2_PPE42) {
> +        spr_register(env, SPR_PVR, "PVR",
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, SPR_NOACCESS,
> +                 pcc->pvr);
> +
> +        /* PPE42 doesn't support additional SPRG regs or timebase */
> +        return;
> +    }
> +
>       spr_register(env, SPR_SPRG1, "SPRG1",
>                    SPR_NOACCESS, SPR_NOACCESS,
>                    &spr_read_generic, &spr_write_generic,
> diff --git a/target/ppc/tcg-excp_helper.c b/target/ppc/tcg-excp_helper.c
> index f835be5156..14f3ad92fe 100644
> --- a/target/ppc/tcg-excp_helper.c
> +++ b/target/ppc/tcg-excp_helper.c
> @@ -229,6 +229,18 @@ void ppc_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr,
>       case POWERPC_MMU_BOOKE206:
>           env->spr[SPR_BOOKE_DEAR] = vaddr;
>           break;
> +    case POWERPC_MMU_REAL:
> +        if (env->flags & POWERPC_FLAG_PPE42) {
> +            env->spr[SPR_PPE42_EDR] = vaddr;
> +            if (access_type == MMU_DATA_STORE) {
> +                env->spr[SPR_PPE42_ISR] |= ISR_ST;
> +            } else {
> +                env->spr[SPR_PPE42_ISR] &= ~ISR_ST;
> +            }
> +        } else {
> +            env->spr[SPR_DAR] = vaddr;
> +        }
> +        break;
>       default:
>           env->spr[SPR_DAR] = vaddr;
>           break;
> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> index 27f90c3cc5..b4f4d10384 100644
> --- a/target/ppc/translate.c
> +++ b/target/ppc/translate.c
> @@ -4264,8 +4264,10 @@ static void gen_mtmsr(DisasContext *ctx)
>           /* L=1 form only updates EE and RI */
>           mask &= (1ULL << MSR_RI) | (1ULL << MSR_EE);
>       } else {
> -        /* mtmsr does not alter S, ME, or LE */
> -        mask &= ~((1ULL << MSR_LE) | (1ULL << MSR_ME) | (1ULL << MSR_S));
> +        if (!(ctx->insns_flags2 & PPC2_PPE42)) {

you may want to use likely() in above check?
Also check other instances wherever applicable.

Thanks
Harsh

> +            /* mtmsr does not alter S, ME, or LE */
> +            mask &= ~((1ULL << MSR_LE) | (1ULL << MSR_ME) | (1ULL << MSR_S));
> +        }
>   
>           /*
>            * XXX: we need to update nip before the store if we enter


^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 11:24   ` Harsh Prateek Bora
@ 2025-08-25 11:34     ` Thomas Huth
  2025-08-25 11:46       ` Harsh Prateek Bora
  2025-08-25 16:56     ` Miles Glenn
  1 sibling, 1 reply; 19+ messages in thread
From: Thomas Huth @ 2025-08-25 11:34 UTC (permalink / raw)
  To: Harsh Prateek Bora, Glenn Miles, qemu-devel
  Cc: qemu-ppc, clg, npiggin, rathc, richard.henderson,
	Philippe Mathieu-Daudé, Pierrick Bouvier

On 25/08/2025 13.24, Harsh Prateek Bora wrote:
> Hi Glenn,
> 
> This seems significant work. Thanks for upstreaming.
> 
> On 8/20/25 02:58, Glenn Miles wrote:
>> Adds the IBM PPE42 family of processors supporting the
> 
> family of 32-bit processors ?
> 
>> PPE42, PPE42X and PPE42XM processor versions.  These
>> processors are used as embedded processors in the IBM
>> Power9, Power10 and Power12 processors for various
>> tasks.  It is basically a stripped down version of the
>> IBM PowerPC 405 processor, with some added instructions
>> for handling 64-bit loads and stores.
>>
>> For more information on the PPE 42 processor please visit:
>>
>> https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf
>>
>> Supports PPE42 SPR's (Including the MSR) and  Exceptions.
>>
>> Does not yet support new PPE42 instructions and does not
>> prevent access to some invalid instructions and registers
>> (currently allows for access to invalid GPR's and CR fields).
>>
>> Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
>> ---
>>   target/ppc/cpu-models.c      |   7 +
>>   target/ppc/cpu-models.h      |   4 +
>>   target/ppc/cpu.h             |  66 +++++++-
>>   target/ppc/cpu_init.c        | 286 ++++++++++++++++++++++++++++++-----
>>   target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
>>   target/ppc/helper_regs.c     |  28 +++-
>>   target/ppc/tcg-excp_helper.c |  12 ++
>>   target/ppc/translate.c       |   6 +-
>>   8 files changed, 535 insertions(+), 45 deletions(-)
>>
>> diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
>> index ea86ea202a..09f73e23a8 100644
>> --- a/target/ppc/cpu-models.c
>> +++ b/target/ppc/cpu-models.c
>> @@ -116,6 +116,13 @@
>>                   NULL)
>>       POWERPC_DEF("x2vp20",        CPU_POWERPC_X2VP20,                 405,
>>                   NULL)
>> +    /* PPE42 Embedded 
>> Controllers                                            */
>> +    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42,                  ppe42,
>> +                "Generic PPE 42")
>> +    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X,                 ppe42x,
>> +                "Generic PPE 42X")
>> +    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM,                
>> ppe42xm,
>> +                "Generic PPE 42XM")
> 
> Can all the PPE42 specific code be conditionally compiled only for
> !TARGET_PPC64 (and !CONFIG_USER_ONLY wherever possible)?
> Not only to reduce the bloating size of respective binaries, but also to
> avoid some code being added to hot path routines like 
> hreg_compute_hflags_value().

qemu-system-ppc64 is a superset of qemu-system-ppc, and there are even 
efforts to unify all system functionality into a singly binary, so excluding 
a 32-bit feature from qemu-system-ppc64 sounds like a step into the wrong 
direction to me right now...?

  Thomas



^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 11:34     ` Thomas Huth
@ 2025-08-25 11:46       ` Harsh Prateek Bora
  2025-08-25 11:58         ` Thomas Huth
  0 siblings, 1 reply; 19+ messages in thread
From: Harsh Prateek Bora @ 2025-08-25 11:46 UTC (permalink / raw)
  To: Thomas Huth, Glenn Miles, qemu-devel
  Cc: qemu-ppc, clg, npiggin, rathc, richard.henderson,
	Philippe Mathieu-Daudé, Pierrick Bouvier

Hi Thomas,

On 8/25/25 17:04, Thomas Huth wrote:
> On 25/08/2025 13.24, Harsh Prateek Bora wrote:
>> Hi Glenn,
>>
>> This seems significant work. Thanks for upstreaming.
>>
>> On 8/20/25 02:58, Glenn Miles wrote:
>>> Adds the IBM PPE42 family of processors supporting the
>>
>> family of 32-bit processors ?
>>
>>> PPE42, PPE42X and PPE42XM processor versions.  These
>>> processors are used as embedded processors in the IBM
>>> Power9, Power10 and Power12 processors for various
>>> tasks.  It is basically a stripped down version of the
>>> IBM PowerPC 405 processor, with some added instructions
>>> for handling 64-bit loads and stores.
>>>
>>> For more information on the PPE 42 processor please visit:
>>>
>>> https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf
>>>
>>> Supports PPE42 SPR's (Including the MSR) and  Exceptions.
>>>
>>> Does not yet support new PPE42 instructions and does not
>>> prevent access to some invalid instructions and registers
>>> (currently allows for access to invalid GPR's and CR fields).
>>>
>>> Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
>>> ---
>>>   target/ppc/cpu-models.c      |   7 +
>>>   target/ppc/cpu-models.h      |   4 +
>>>   target/ppc/cpu.h             |  66 +++++++-
>>>   target/ppc/cpu_init.c        | 286 ++++++++++++++++++++++++++++++-----
>>>   target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
>>>   target/ppc/helper_regs.c     |  28 +++-
>>>   target/ppc/tcg-excp_helper.c |  12 ++
>>>   target/ppc/translate.c       |   6 +-
>>>   8 files changed, 535 insertions(+), 45 deletions(-)
>>>
>>> diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
>>> index ea86ea202a..09f73e23a8 100644
>>> --- a/target/ppc/cpu-models.c
>>> +++ b/target/ppc/cpu-models.c
>>> @@ -116,6 +116,13 @@
>>>                   NULL)
>>>       POWERPC_DEF("x2vp20",        
>>> CPU_POWERPC_X2VP20,                 405,
>>>                   NULL)
>>> +    /* PPE42 Embedded 
>>> Controllers                                            */
>>> +    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42,                  
>>> ppe42,
>>> +                "Generic PPE 42")
>>> +    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X,                 
>>> ppe42x,
>>> +                "Generic PPE 42X")
>>> +    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM, ppe42xm,
>>> +                "Generic PPE 42XM")
>>
>> Can all the PPE42 specific code be conditionally compiled only for
>> !TARGET_PPC64 (and !CONFIG_USER_ONLY wherever possible)?
>> Not only to reduce the bloating size of respective binaries, but also to
>> avoid some code being added to hot path routines like 
>> hreg_compute_hflags_value().
> 
> qemu-system-ppc64 is a superset of qemu-system-ppc, and there are even 
> efforts to unify all system functionality into a singly binary, so 
> excluding a 32-bit feature from qemu-system-ppc64 sounds like a step 
> into the wrong direction to me right now...?

We do have existing code getting conditionally compiled for TARGET_PPC64
which I guess gets enabled with:
  --configure target-list=<ppc64|ppc>-softmmu
I understand the efforts are towards having a single binary to support
both, but what gets built-in is still decided with configure choice?

Please correct/clarify with above understanding.

regards,
Harsh
> 
>   Thomas
> 


^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 11:46       ` Harsh Prateek Bora
@ 2025-08-25 11:58         ` Thomas Huth
  2025-08-25 12:08           ` Harsh Prateek Bora
  0 siblings, 1 reply; 19+ messages in thread
From: Thomas Huth @ 2025-08-25 11:58 UTC (permalink / raw)
  To: Harsh Prateek Bora, Glenn Miles, qemu-devel
  Cc: qemu-ppc, clg, npiggin, rathc, richard.henderson,
	Philippe Mathieu-Daudé, Pierrick Bouvier

On 25/08/2025 13.46, Harsh Prateek Bora wrote:
> Hi Thomas,
> 
> On 8/25/25 17:04, Thomas Huth wrote:
>> On 25/08/2025 13.24, Harsh Prateek Bora wrote:
>>> Hi Glenn,
>>>
>>> This seems significant work. Thanks for upstreaming.
>>>
>>> On 8/20/25 02:58, Glenn Miles wrote:
>>>> Adds the IBM PPE42 family of processors supporting the
>>>
>>> family of 32-bit processors ?
>>>
>>>> PPE42, PPE42X and PPE42XM processor versions.  These
>>>> processors are used as embedded processors in the IBM
>>>> Power9, Power10 and Power12 processors for various
>>>> tasks.  It is basically a stripped down version of the
>>>> IBM PowerPC 405 processor, with some added instructions
>>>> for handling 64-bit loads and stores.
>>>>
>>>> For more information on the PPE 42 processor please visit:
>>>>
>>>> https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf
>>>>
>>>> Supports PPE42 SPR's (Including the MSR) and  Exceptions.
>>>>
>>>> Does not yet support new PPE42 instructions and does not
>>>> prevent access to some invalid instructions and registers
>>>> (currently allows for access to invalid GPR's and CR fields).
>>>>
>>>> Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
>>>> ---
>>>>   target/ppc/cpu-models.c      |   7 +
>>>>   target/ppc/cpu-models.h      |   4 +
>>>>   target/ppc/cpu.h             |  66 +++++++-
>>>>   target/ppc/cpu_init.c        | 286 ++++++++++++++++++++++++++++++-----
>>>>   target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
>>>>   target/ppc/helper_regs.c     |  28 +++-
>>>>   target/ppc/tcg-excp_helper.c |  12 ++
>>>>   target/ppc/translate.c       |   6 +-
>>>>   8 files changed, 535 insertions(+), 45 deletions(-)
>>>>
>>>> diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
>>>> index ea86ea202a..09f73e23a8 100644
>>>> --- a/target/ppc/cpu-models.c
>>>> +++ b/target/ppc/cpu-models.c
>>>> @@ -116,6 +116,13 @@
>>>>                   NULL)
>>>>       POWERPC_DEF("x2vp20", CPU_POWERPC_X2VP20,                 405,
>>>>                   NULL)
>>>> +    /* PPE42 Embedded 
>>>> Controllers                                            */
>>>> +    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42, ppe42,
>>>> +                "Generic PPE 42")
>>>> +    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X, ppe42x,
>>>> +                "Generic PPE 42X")
>>>> +    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM, ppe42xm,
>>>> +                "Generic PPE 42XM")
>>>
>>> Can all the PPE42 specific code be conditionally compiled only for
>>> !TARGET_PPC64 (and !CONFIG_USER_ONLY wherever possible)?
>>> Not only to reduce the bloating size of respective binaries, but also to
>>> avoid some code being added to hot path routines like 
>>> hreg_compute_hflags_value().
>>
>> qemu-system-ppc64 is a superset of qemu-system-ppc, and there are even 
>> efforts to unify all system functionality into a singly binary, so 
>> excluding a 32-bit feature from qemu-system-ppc64 sounds like a step into 
>> the wrong direction to me right now...?
> 
> We do have existing code getting conditionally compiled for TARGET_PPC64
> which I guess gets enabled with:
>   --configure target-list=<ppc64|ppc>-softmmu
> I understand the efforts are towards having a single binary to support
> both, but what gets built-in is still decided with configure choice?
> 
> Please correct/clarify with above understanding.

As I said, qemu-system-ppc64 is currently a full superset of 
qemu-system-ppc. The ppc64 binary contains all the 32-bit code, you can 
perfectly run a "g3beige" or "bamboo" machine with qemu-system-ppc64, too. 
By disabling the ppe42 code in the ppc64 binary, this would now introduce an 
execption to that unwritten rule, so I'd expect that we'd not rather want to 
do this now.

  Thomas



^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 11:58         ` Thomas Huth
@ 2025-08-25 12:08           ` Harsh Prateek Bora
  2025-08-25 12:22             ` Thomas Huth
  0 siblings, 1 reply; 19+ messages in thread
From: Harsh Prateek Bora @ 2025-08-25 12:08 UTC (permalink / raw)
  To: Thomas Huth, Glenn Miles, qemu-devel
  Cc: qemu-ppc, clg, npiggin, rathc, richard.henderson,
	Philippe Mathieu-Daudé, Pierrick Bouvier



On 8/25/25 17:28, Thomas Huth wrote:
> On 25/08/2025 13.46, Harsh Prateek Bora wrote:
>> Hi Thomas,
>>
>> On 8/25/25 17:04, Thomas Huth wrote:
>>> On 25/08/2025 13.24, Harsh Prateek Bora wrote:
>>>> Hi Glenn,
>>>>
>>>> This seems significant work. Thanks for upstreaming.
>>>>
>>>> On 8/20/25 02:58, Glenn Miles wrote:
>>>>> Adds the IBM PPE42 family of processors supporting the
>>>>
>>>> family of 32-bit processors ?
>>>>
>>>>> PPE42, PPE42X and PPE42XM processor versions.  These
>>>>> processors are used as embedded processors in the IBM
>>>>> Power9, Power10 and Power12 processors for various
>>>>> tasks.  It is basically a stripped down version of the
>>>>> IBM PowerPC 405 processor, with some added instructions
>>>>> for handling 64-bit loads and stores.
>>>>>
>>>>> For more information on the PPE 42 processor please visit:
>>>>>
>>>>> https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf
>>>>>
>>>>> Supports PPE42 SPR's (Including the MSR) and  Exceptions.
>>>>>
>>>>> Does not yet support new PPE42 instructions and does not
>>>>> prevent access to some invalid instructions and registers
>>>>> (currently allows for access to invalid GPR's and CR fields).
>>>>>
>>>>> Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
>>>>> ---
>>>>>   target/ppc/cpu-models.c      |   7 +
>>>>>   target/ppc/cpu-models.h      |   4 +
>>>>>   target/ppc/cpu.h             |  66 +++++++-
>>>>>   target/ppc/cpu_init.c        | 286 
>>>>> ++++++++++++++++++++++++++++++-----
>>>>>   target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
>>>>>   target/ppc/helper_regs.c     |  28 +++-
>>>>>   target/ppc/tcg-excp_helper.c |  12 ++
>>>>>   target/ppc/translate.c       |   6 +-
>>>>>   8 files changed, 535 insertions(+), 45 deletions(-)
>>>>>
>>>>> diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
>>>>> index ea86ea202a..09f73e23a8 100644
>>>>> --- a/target/ppc/cpu-models.c
>>>>> +++ b/target/ppc/cpu-models.c
>>>>> @@ -116,6 +116,13 @@
>>>>>                   NULL)
>>>>>       POWERPC_DEF("x2vp20", CPU_POWERPC_X2VP20,                 405,
>>>>>                   NULL)
>>>>> +    /* PPE42 Embedded 
>>>>> Controllers                                            */
>>>>> +    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42, ppe42,
>>>>> +                "Generic PPE 42")
>>>>> +    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X, ppe42x,
>>>>> +                "Generic PPE 42X")
>>>>> +    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM, ppe42xm,
>>>>> +                "Generic PPE 42XM")
>>>>
>>>> Can all the PPE42 specific code be conditionally compiled only for
>>>> !TARGET_PPC64 (and !CONFIG_USER_ONLY wherever possible)?
>>>> Not only to reduce the bloating size of respective binaries, but 
>>>> also to
>>>> avoid some code being added to hot path routines like 
>>>> hreg_compute_hflags_value().
>>>
>>> qemu-system-ppc64 is a superset of qemu-system-ppc, and there are 
>>> even efforts to unify all system functionality into a singly binary, 
>>> so excluding a 32-bit feature from qemu-system-ppc64 sounds like a 
>>> step into the wrong direction to me right now...?
>>
>> We do have existing code getting conditionally compiled for TARGET_PPC64
>> which I guess gets enabled with:
>>   --configure target-list=<ppc64|ppc>-softmmu
>> I understand the efforts are towards having a single binary to support
>> both, but what gets built-in is still decided with configure choice?
>>
>> Please correct/clarify with above understanding.
> 
> As I said, qemu-system-ppc64 is currently a full superset of 
> qemu-system-ppc. The ppc64 binary contains all the 32-bit code, you can 
> perfectly run a "g3beige" or "bamboo" machine with qemu-system-ppc64, 
> too. By disabling the ppe42 code in the ppc64 binary, this would now 
> introduce an execption to that unwritten rule, so I'd expect that we'd 
> not rather want to do this now.

My understanding is that above holds true only for default builds which
builds all targets. We certainly do not build 32 bit ppc code when using
--configure target-list=ppc64-softmmu. (we have ppc-softmmu for 32 bit 
though)

Could you please add respective folks to this thread who are working on
unifying builds to clarify more on this. We certainly dont want 32-bit
specific code to be running on a 64-bit machine, specially in hot paths.

regards,
Harsh
> 
>   Thomas
> 


^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 12:08           ` Harsh Prateek Bora
@ 2025-08-25 12:22             ` Thomas Huth
  2025-08-25 12:36               ` Harsh Prateek Bora
  0 siblings, 1 reply; 19+ messages in thread
From: Thomas Huth @ 2025-08-25 12:22 UTC (permalink / raw)
  To: Harsh Prateek Bora, Glenn Miles, qemu-devel
  Cc: qemu-ppc, clg, npiggin, rathc, richard.henderson,
	Philippe Mathieu-Daudé, Pierrick Bouvier

On 25/08/2025 14.08, Harsh Prateek Bora wrote:
> 
> 
> On 8/25/25 17:28, Thomas Huth wrote:
>> On 25/08/2025 13.46, Harsh Prateek Bora wrote:
>>> Hi Thomas,
>>>
>>> On 8/25/25 17:04, Thomas Huth wrote:
>>>> On 25/08/2025 13.24, Harsh Prateek Bora wrote:
>>>>> Hi Glenn,
>>>>>
>>>>> This seems significant work. Thanks for upstreaming.
>>>>>
>>>>> On 8/20/25 02:58, Glenn Miles wrote:
>>>>>> Adds the IBM PPE42 family of processors supporting the
>>>>>
>>>>> family of 32-bit processors ?
>>>>>
>>>>>> PPE42, PPE42X and PPE42XM processor versions.  These
>>>>>> processors are used as embedded processors in the IBM
>>>>>> Power9, Power10 and Power12 processors for various
>>>>>> tasks.  It is basically a stripped down version of the
>>>>>> IBM PowerPC 405 processor, with some added instructions
>>>>>> for handling 64-bit loads and stores.
>>>>>>
>>>>>> For more information on the PPE 42 processor please visit:
>>>>>>
>>>>>> https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf
>>>>>>
>>>>>> Supports PPE42 SPR's (Including the MSR) and  Exceptions.
>>>>>>
>>>>>> Does not yet support new PPE42 instructions and does not
>>>>>> prevent access to some invalid instructions and registers
>>>>>> (currently allows for access to invalid GPR's and CR fields).
>>>>>>
>>>>>> Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
>>>>>> ---
>>>>>>   target/ppc/cpu-models.c      |   7 +
>>>>>>   target/ppc/cpu-models.h      |   4 +
>>>>>>   target/ppc/cpu.h             |  66 +++++++-
>>>>>>   target/ppc/cpu_init.c        | 286 ++++++++++++++++++++++++++++++-----
>>>>>>   target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
>>>>>>   target/ppc/helper_regs.c     |  28 +++-
>>>>>>   target/ppc/tcg-excp_helper.c |  12 ++
>>>>>>   target/ppc/translate.c       |   6 +-
>>>>>>   8 files changed, 535 insertions(+), 45 deletions(-)
>>>>>>
>>>>>> diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
>>>>>> index ea86ea202a..09f73e23a8 100644
>>>>>> --- a/target/ppc/cpu-models.c
>>>>>> +++ b/target/ppc/cpu-models.c
>>>>>> @@ -116,6 +116,13 @@
>>>>>>                   NULL)
>>>>>>       POWERPC_DEF("x2vp20", CPU_POWERPC_X2VP20,                 405,
>>>>>>                   NULL)
>>>>>> +    /* PPE42 Embedded 
>>>>>> Controllers                                            */
>>>>>> +    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42, ppe42,
>>>>>> +                "Generic PPE 42")
>>>>>> +    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X, ppe42x,
>>>>>> +                "Generic PPE 42X")
>>>>>> +    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM, ppe42xm,
>>>>>> +                "Generic PPE 42XM")
>>>>>
>>>>> Can all the PPE42 specific code be conditionally compiled only for
>>>>> !TARGET_PPC64 (and !CONFIG_USER_ONLY wherever possible)?
>>>>> Not only to reduce the bloating size of respective binaries, but also to
>>>>> avoid some code being added to hot path routines like 
>>>>> hreg_compute_hflags_value().
>>>>
>>>> qemu-system-ppc64 is a superset of qemu-system-ppc, and there are even 
>>>> efforts to unify all system functionality into a singly binary, so 
>>>> excluding a 32-bit feature from qemu-system-ppc64 sounds like a step 
>>>> into the wrong direction to me right now...?
>>>
>>> We do have existing code getting conditionally compiled for TARGET_PPC64
>>> which I guess gets enabled with:
>>>   --configure target-list=<ppc64|ppc>-softmmu
>>> I understand the efforts are towards having a single binary to support
>>> both, but what gets built-in is still decided with configure choice?
>>>
>>> Please correct/clarify with above understanding.
>>
>> As I said, qemu-system-ppc64 is currently a full superset of qemu-system- 
>> ppc. The ppc64 binary contains all the 32-bit code, you can perfectly run 
>> a "g3beige" or "bamboo" machine with qemu-system-ppc64, too. By disabling 
>> the ppe42 code in the ppc64 binary, this would now introduce an execption 
>> to that unwritten rule, so I'd expect that we'd not rather want to do this 
>> now.
> 
> My understanding is that above holds true only for default builds which
> builds all targets. We certainly do not build 32 bit ppc code when using
> --configure target-list=ppc64-softmmu. (we have ppc-softmmu for 32 bit though)

Just give it a try:

  ./configure --target-list=ppc64-softmmu --disable-docs
  make -j$(nproc)
  ./qemu-system-ppc64 -M g3beige

... works perfectly fine for me.

AFAIK we don't have a switch to disable 32-bit code in the ppc64 binary.

  Thomas



^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 12:22             ` Thomas Huth
@ 2025-08-25 12:36               ` Harsh Prateek Bora
  2025-08-25 14:33                 ` BALATON Zoltan
  0 siblings, 1 reply; 19+ messages in thread
From: Harsh Prateek Bora @ 2025-08-25 12:36 UTC (permalink / raw)
  To: Thomas Huth, Glenn Miles, qemu-devel
  Cc: qemu-ppc, clg, npiggin, rathc, richard.henderson,
	Philippe Mathieu-Daudé, Pierrick Bouvier



On 8/25/25 17:52, Thomas Huth wrote:
> On 25/08/2025 14.08, Harsh Prateek Bora wrote:
>>
>>
>> On 8/25/25 17:28, Thomas Huth wrote:
>>> On 25/08/2025 13.46, Harsh Prateek Bora wrote:
>>>> Hi Thomas,
>>>>
>>>> On 8/25/25 17:04, Thomas Huth wrote:
>>>>> On 25/08/2025 13.24, Harsh Prateek Bora wrote:
>>>>>> Hi Glenn,
>>>>>>
>>>>>> This seems significant work. Thanks for upstreaming.
>>>>>>
>>>>>> On 8/20/25 02:58, Glenn Miles wrote:
>>>>>>> Adds the IBM PPE42 family of processors supporting the
>>>>>>
>>>>>> family of 32-bit processors ?
>>>>>>
>>>>>>> PPE42, PPE42X and PPE42XM processor versions.  These
>>>>>>> processors are used as embedded processors in the IBM
>>>>>>> Power9, Power10 and Power12 processors for various
>>>>>>> tasks.  It is basically a stripped down version of the
>>>>>>> IBM PowerPC 405 processor, with some added instructions
>>>>>>> for handling 64-bit loads and stores.
>>>>>>>
>>>>>>> For more information on the PPE 42 processor please visit:
>>>>>>>
>>>>>>> https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf
>>>>>>>
>>>>>>> Supports PPE42 SPR's (Including the MSR) and  Exceptions.
>>>>>>>
>>>>>>> Does not yet support new PPE42 instructions and does not
>>>>>>> prevent access to some invalid instructions and registers
>>>>>>> (currently allows for access to invalid GPR's and CR fields).
>>>>>>>
>>>>>>> Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
>>>>>>> ---
>>>>>>>   target/ppc/cpu-models.c      |   7 +
>>>>>>>   target/ppc/cpu-models.h      |   4 +
>>>>>>>   target/ppc/cpu.h             |  66 +++++++-
>>>>>>>   target/ppc/cpu_init.c        | 286 
>>>>>>> ++++++++++++++++++++++++++++++-----
>>>>>>>   target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
>>>>>>>   target/ppc/helper_regs.c     |  28 +++-
>>>>>>>   target/ppc/tcg-excp_helper.c |  12 ++
>>>>>>>   target/ppc/translate.c       |   6 +-
>>>>>>>   8 files changed, 535 insertions(+), 45 deletions(-)
>>>>>>>
>>>>>>> diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
>>>>>>> index ea86ea202a..09f73e23a8 100644
>>>>>>> --- a/target/ppc/cpu-models.c
>>>>>>> +++ b/target/ppc/cpu-models.c
>>>>>>> @@ -116,6 +116,13 @@
>>>>>>>                   NULL)
>>>>>>>       POWERPC_DEF("x2vp20", CPU_POWERPC_X2VP20,                 405,
>>>>>>>                   NULL)
>>>>>>> +    /* PPE42 Embedded 
>>>>>>> Controllers                                            */
>>>>>>> +    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42, ppe42,
>>>>>>> +                "Generic PPE 42")
>>>>>>> +    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X, ppe42x,
>>>>>>> +                "Generic PPE 42X")
>>>>>>> +    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM, ppe42xm,
>>>>>>> +                "Generic PPE 42XM")
>>>>>>
>>>>>> Can all the PPE42 specific code be conditionally compiled only for
>>>>>> !TARGET_PPC64 (and !CONFIG_USER_ONLY wherever possible)?
>>>>>> Not only to reduce the bloating size of respective binaries, but 
>>>>>> also to
>>>>>> avoid some code being added to hot path routines like 
>>>>>> hreg_compute_hflags_value().
>>>>>
>>>>> qemu-system-ppc64 is a superset of qemu-system-ppc, and there are 
>>>>> even efforts to unify all system functionality into a singly 
>>>>> binary, so excluding a 32-bit feature from qemu-system-ppc64 sounds 
>>>>> like a step into the wrong direction to me right now...?
>>>>
>>>> We do have existing code getting conditionally compiled for 
>>>> TARGET_PPC64
>>>> which I guess gets enabled with:
>>>>   --configure target-list=<ppc64|ppc>-softmmu
>>>> I understand the efforts are towards having a single binary to support
>>>> both, but what gets built-in is still decided with configure choice?
>>>>
>>>> Please correct/clarify with above understanding.
>>>
>>> As I said, qemu-system-ppc64 is currently a full superset of 
>>> qemu-system- ppc. The ppc64 binary contains all the 32-bit code, you 
>>> can perfectly run a "g3beige" or "bamboo" machine with 
>>> qemu-system-ppc64, too. By disabling the ppe42 code in the ppc64 
>>> binary, this would now introduce an execption to that unwritten rule, 
>>> so I'd expect that we'd not rather want to do this now.
>>
>> My understanding is that above holds true only for default builds which
>> builds all targets. We certainly do not build 32 bit ppc code when using
>> --configure target-list=ppc64-softmmu. (we have ppc-softmmu for 32 bit 
>> though)
> 
> Just give it a try:
> 
>   ./configure --target-list=ppc64-softmmu --disable-docs
>   make -j$(nproc)
>   ./qemu-system-ppc64 -M g3beige
> 
> ... works perfectly fine for me.
> 
This would work because the respective code is not restricted with 
#ifndef TARGET_PPC64.

However, there are instance like below in hw/ppc/mac_oldworld.c:

static void heathrow_class_init(ObjectClass *oc, const void *data)
{
     MachineClass *mc = MACHINE_CLASS(oc);
     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(oc);

     mc->desc = "Heathrow based PowerMac";
     mc->init = ppc_heathrow_init;
     mc->block_default_type = IF_IDE;
     /* SMP is not supported currently */
     mc->max_cpus = 1;
#ifndef TARGET_PPC64
     mc->is_default = true;
#endif

Similarly, we have multiple instances with #else block for #ifdef
TARGET_PPC64 which doesnt get compiled with ppc64-softmmu, but only with
ppc-softmmu meant for 32-bit targets. See target/ppc/excp_helper.c for 
example.

regards,
Harsh

> AFAIK we don't have a switch to disable 32-bit code in the ppc64 binary.
> 
>   Thomas
> 


^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 12:36               ` Harsh Prateek Bora
@ 2025-08-25 14:33                 ` BALATON Zoltan
  2025-08-26  4:54                   ` Harsh Prateek Bora
  0 siblings, 1 reply; 19+ messages in thread
From: BALATON Zoltan @ 2025-08-25 14:33 UTC (permalink / raw)
  To: Harsh Prateek Bora
  Cc: Thomas Huth, Glenn Miles, qemu-devel, qemu-ppc, clg, npiggin,
	rathc, richard.henderson, Philippe Mathieu-Daudé,
	Pierrick Bouvier

[-- Attachment #1: Type: text/plain, Size: 3375 bytes --]

On Mon, 25 Aug 2025, Harsh Prateek Bora wrote:
> On 8/25/25 17:52, Thomas Huth wrote:
>> On 25/08/2025 14.08, Harsh Prateek Bora wrote:
>>> On 8/25/25 17:28, Thomas Huth wrote:
>>>> As I said, qemu-system-ppc64 is currently a full superset of qemu-system- 
>>>> ppc. The ppc64 binary contains all the 32-bit code, you can perfectly run 
>>>> a "g3beige" or "bamboo" machine with qemu-system-ppc64, too. By disabling 
>>>> the ppe42 code in the ppc64 binary, this would now introduce an execption 
>>>> to that unwritten rule, so I'd expect that we'd not rather want to do 
>>>> this now.
>>> 
>>> My understanding is that above holds true only for default builds which
>>> builds all targets. We certainly do not build 32 bit ppc code when using
>>> --configure target-list=ppc64-softmmu. (we have ppc-softmmu for 32 bit 
>>> though)

We do build 32-bit machines in ppc64-softmmu but leave out 64-bit from 
ppc-softmmu so it's only one way.

>> Just give it a try:
>>
>>   ./configure --target-list=ppc64-softmmu --disable-docs
>>   make -j$(nproc)
>>   ./qemu-system-ppc64 -M g3beige
>> 
>> ... works perfectly fine for me.
>> 
> This would work because the respective code is not restricted with #ifndef 
> TARGET_PPC64.
>
> However, there are instance like below in hw/ppc/mac_oldworld.c:
>
> static void heathrow_class_init(ObjectClass *oc, const void *data)
> {
>    MachineClass *mc = MACHINE_CLASS(oc);
>    FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(oc);
>
>    mc->desc = "Heathrow based PowerMac";
>    mc->init = ppc_heathrow_init;
>    mc->block_default_type = IF_IDE;
>    /* SMP is not supported currently */
>    mc->max_cpus = 1;
> #ifndef TARGET_PPC64
>    mc->is_default = true;
> #endif

This is only because the default machine for ppc64-softmmu is different 
than for ppc-softmmu as the 64-bit machines don't exist in ppc-softmmu but 
ppc64-softmmu had different default machine before machines from 
qemu-system-ppc got included in qemu-system-ppc64 so it kept that. (Looks 
like the default used to be mac_newworld before commit 159f8286b760dea but 
wasn't changed to match but to something else.) The default machines are 
arbitrary, we could make "none" the default and always require users to 
supply -machine but that would break existing command lines so this wasn't 
done.

> Similarly, we have multiple instances with #else block for #ifdef
> TARGET_PPC64 which doesnt get compiled with ppc64-softmmu, but only with
> ppc-softmmu meant for 32-bit targets. See target/ppc/excp_helper.c for 
> example.

This is again leaving out 64-bit code from ppc-softmmu but as Thomas says 
32-bit machines are always included in qemu-softmmu-ppc64. I can't find 
the commit which changed this, previously we had these to be separate and 
since some types are different in ppc64-softmmu it wasn't clear if that 
could cause any problems for 32-bit CPUs and machines so ppc-softmmu was 
kept until that's cleaned up which never happened. There are also some 
pecularities in some machines like mac_newworld that behaves differently 
in qemu-system-ppc and qemu-system-ppc64 and the potentially lower 
performance of qemu-system-ppc64 in emulating 32-bit machines which is why 
we still have ppc-softmmu.

Regards,
BALATON Zoltan

> regards,
> Harsh
>
>> AFAIK we don't have a switch to disable 32-bit code in the ppc64 binary.
>>
>>   Thomas
>> 
>
>

^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 11:24   ` Harsh Prateek Bora
  2025-08-25 11:34     ` Thomas Huth
@ 2025-08-25 16:56     ` Miles Glenn
  2025-08-26  5:30       ` Harsh Prateek Bora
  1 sibling, 1 reply; 19+ messages in thread
From: Miles Glenn @ 2025-08-25 16:56 UTC (permalink / raw)
  To: Harsh Prateek Bora, qemu-devel
  Cc: qemu-ppc, clg, npiggin, thuth, rathc, richard.henderson

Hi Harsh, Thanks for taking a look!  Please see inline responses below.


On Mon, 2025-08-25 at 16:54 +0530, Harsh Prateek Bora wrote:
> Hi Glenn,
> 
> This seems significant work. Thanks for upstreaming.
> 
> On 8/20/25 02:58, Glenn Miles wrote:
> > Adds the IBM PPE42 family of processors supporting the
> 
> family of 32-bit processors ?

Sure, I can add that to the commit message.

> 
> > PPE42, PPE42X and PPE42XM processor versions.  These
> > processors are used as embedded processors in the IBM
> > Power9, Power10 and Power12 processors for various
> > tasks.  It is basically a stripped down version of the
> > IBM PowerPC 405 processor, with some added instructions
> > for handling 64-bit loads and stores.
> > 
> > For more information on the PPE 42 processor please visit:
> > 
> > https://wiki.raptorcs.com/w/images/a/a3/PPE_42X_Core_Users_Manual.pdf
> > 
> > Supports PPE42 SPR's (Including the MSR) and  Exceptions.
> > 
> > Does not yet support new PPE42 instructions and does not
> > prevent access to some invalid instructions and registers
> > (currently allows for access to invalid GPR's and CR fields).
> > 
> > Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
> > ---
> >   target/ppc/cpu-models.c      |   7 +
> >   target/ppc/cpu-models.h      |   4 +
> >   target/ppc/cpu.h             |  66 +++++++-
> >   target/ppc/cpu_init.c        | 286 ++++++++++++++++++++++++++++++-----
> >   target/ppc/excp_helper.c     | 171 +++++++++++++++++++++
> >   target/ppc/helper_regs.c     |  28 +++-
> >   target/ppc/tcg-excp_helper.c |  12 ++
> >   target/ppc/translate.c       |   6 +-
> >   8 files changed, 535 insertions(+), 45 deletions(-)
> > 
> > diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
> > index ea86ea202a..09f73e23a8 100644
> > --- a/target/ppc/cpu-models.c
> > +++ b/target/ppc/cpu-models.c
> > @@ -116,6 +116,13 @@
> >                   NULL)
> >       POWERPC_DEF("x2vp20",        CPU_POWERPC_X2VP20,                 405,
> >                   NULL)
> > +    /* PPE42 Embedded Controllers                                            */
> > +    POWERPC_DEF("PPE42",         CPU_POWERPC_PPE42,                  ppe42,
> > +                "Generic PPE 42")
> > +    POWERPC_DEF("PPE42X",        CPU_POWERPC_PPE42X,                 ppe42x,
> > +                "Generic PPE 42X")
> > +    POWERPC_DEF("PPE42XM",       CPU_POWERPC_PPE42XM,                ppe42xm,
> > +                "Generic PPE 42XM")
> 
> Can all the PPE42 specific code be conditionally compiled only for
> !TARGET_PPC64 (and !CONFIG_USER_ONLY wherever possible)?
> Not only to reduce the bloating size of respective binaries, but also to
> avoid some code being added to hot path routines like 
> hreg_compute_hflags_value().
> 

Harsh, it sounds like there is a desire to keep the 32-bit CPU support
enabled even for the 64-bit executable, so I will keep it in for now
and I will audit the code for adding more likely/unlikely statements to
conditionals where it makes sense to do so.  Would that be acceptable?


> >       /* PowerPC 440 family                                                    */
> >   #if defined(TODO_USER_ONLY)
> >       POWERPC_DEF("440",           CPU_POWERPC_440,                    440GP,
> > diff --git a/target/ppc/cpu-models.h b/target/ppc/cpu-models.h
> > index 72ad31ba50..c6cd27f390 100644
> > --- a/target/ppc/cpu-models.h
> > +++ b/target/ppc/cpu-models.h
> > @@ -69,6 +69,10 @@ enum {
> >       /* Xilinx cores */
> >       CPU_POWERPC_X2VP4              = 0x20010820,
> >       CPU_POWERPC_X2VP20             = 0x20010860,
> > +    /* IBM PPE42 Family */
> > +    CPU_POWERPC_PPE42              = 0x42000000,
> > +    CPU_POWERPC_PPE42X             = 0x42100000,
> > +    CPU_POWERPC_PPE42XM            = 0x42200000,
> >       /* PowerPC 440 family */
> >       /* Generic PowerPC 440 */
> >   #define CPU_POWERPC_440              CPU_POWERPC_440GXf
> > diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> > index 6b90543811..f2fc84f384 100644
> > --- a/target/ppc/cpu.h
> > +++ b/target/ppc/cpu.h
> > @@ -220,6 +220,8 @@ typedef enum powerpc_excp_t {
> >       POWERPC_EXCP_POWER10,
> >       /* POWER11 exception model           */
> >       POWERPC_EXCP_POWER11,
> > +    /* PPE42 exception model            */
> > +    POWERPC_EXCP_PPE42,
> >   } powerpc_excp_t;
> >   
> >   /*****************************************************************************/
> > @@ -282,6 +284,8 @@ typedef enum powerpc_input_t {
> >       PPC_FLAGS_INPUT_POWER9,
> >       /* Freescale RCPU bus               */
> >       PPC_FLAGS_INPUT_RCPU,
> > +    /* PPE42 bus                        */
> > +    PPC_FLAGS_INPUT_PPE42,
> >   } powerpc_input_t;
> >   
> >   #define PPC_INPUT(env) ((env)->bus_model)
> > @@ -433,39 +437,64 @@ typedef enum {
> >   #define MSR_TM   PPC_BIT_NR(31) /* Transactional Memory Available (Book3s)   */
> >   #define MSR_CM   PPC_BIT_NR(32) /* Computation mode for BookE         hflags */
> >   #define MSR_ICM  PPC_BIT_NR(33) /* Interrupt computation mode for BookE      */
> > +#define MSR_SEM0 PPC_BIT_NR(33) /* SIB Error Mask Bit 0 (PPE42)              */
> > +#define MSR_SEM1 PPC_BIT_NR(34) /* SIB Error Mask Bit 1 (PPE42)              */
> > +#define MSR_SEM2 PPC_BIT_NR(35) /* SIB Error Mask Bit 2 (PPE42)              */
> >   #define MSR_GS   PPC_BIT_NR(35) /* guest state for BookE                     */
> > +#define MSR_SEM3 PPC_BIT_NR(36) /* SIB Error Mask Bit 3 (PPE42)              */
> > +#define MSR_SEM4 PPC_BIT_NR(37) /* SIB Error Mask Bit 4 (PPE42)              */
> >   #define MSR_UCLE PPC_BIT_NR(37) /* User-mode cache lock enable for BookE     */
> >   #define MSR_VR   PPC_BIT_NR(38) /* altivec available                x hflags */
> >   #define MSR_SPE  PPC_BIT_NR(38) /* SPE enable for BookE             x hflags */
> > +#define MSR_SEM5 PPC_BIT_NR(38) /* SIB Error Mask Bit 5 (PPE42)              */
> > +#define MSR_SEM6 PPC_BIT_NR(39) /* SIB Error Mask Bit 6 (PPE42)              */
> >   #define MSR_VSX  PPC_BIT_NR(40) /* Vector Scalar Extension (>= 2.06)x hflags */
> > +#define MSR_IS0  PPC_BIT_NR(40) /* Instance Specific Bit 0 (PPE42)           */
> >   #define MSR_S    PPC_BIT_NR(41) /* Secure state                              */
> > +#define MSR_SIBRC0 PPC_BIT_NR(41) /* Last SIB return code Bit 0 (PPE42)      */
> > +#define MSR_SIBRC1 PPC_BIT_NR(42) /* Last SIB return code Bit 1 (PPE42)      */
> > +#define MSR_SIBRC2 PPC_BIT_NR(43) /* Last SIB return code Bit 2 (PPE42)      */
> > +#define MSR_LP   PPC_BIT_NR(44) /* Low Priority (PPE42)                      */
> >   #define MSR_KEY  PPC_BIT_NR(44) /* key bit on 603e                           */
> >   #define MSR_POW  PPC_BIT_NR(45) /* Power management                          */
> >   #define MSR_WE   PPC_BIT_NR(45) /* Wait State Enable on 405                  */
> > +#define MSR_IS1  PPC_BIT_NR(46) /* Instance Specific Bit 1 (PPE42)           */
> >   #define MSR_TGPR PPC_BIT_NR(46) /* TGPR usage on 602/603            x        */
> >   #define MSR_CE   PPC_BIT_NR(46) /* Critical int. enable on embedded PPC x    */
> >   #define MSR_ILE  PPC_BIT_NR(47) /* Interrupt little-endian mode              */
> > +#define MSR_UIE  PPC_BIT_NR(47) /* Unmaskable Interrupt Enable (PPE42)       */
> >   #define MSR_EE   PPC_BIT_NR(48) /* External interrupt enable                 */
> >   #define MSR_PR   PPC_BIT_NR(49) /* Problem state                      hflags */
> >   #define MSR_FP   PPC_BIT_NR(50) /* Floating point available           hflags */
> >   #define MSR_ME   PPC_BIT_NR(51) /* Machine check interrupt enable            */
> >   #define MSR_FE0  PPC_BIT_NR(52) /* Floating point exception mode 0           */
> > +#define MSR_IS2  PPC_BIT_NR(52) /* Instance Specific Bit 2 (PPE42)           */
> > +#define MSR_IS3  PPC_BIT_NR(53) /* Instance Specific Bit 3 (PPE42)           */
> >   #define MSR_SE   PPC_BIT_NR(53) /* Single-step trace enable         x hflags */
> >   #define MSR_DWE  PPC_BIT_NR(53) /* Debug wait enable on 405         x        */
> >   #define MSR_UBLE PPC_BIT_NR(53) /* User BTB lock enable on e500     x        */
> >   #define MSR_BE   PPC_BIT_NR(54) /* Branch trace enable              x hflags */
> >   #define MSR_DE   PPC_BIT_NR(54) /* Debug int. enable on embedded PPC   x     */
> >   #define MSR_FE1  PPC_BIT_NR(55) /* Floating point exception mode 1           */
> > +#define MSR_IPE  PPC_BIT_NR(55) /* Imprecise Mode Enable (PPE42)             */
> >   #define MSR_AL   PPC_BIT_NR(56) /* AL bit on POWER                           */
> > +#define MSR_SIBRCA0 PPC_BIT_NR(56) /* SIB Return Code Accumulator bit0 (PPE42) */
> > +#define MSR_SIBRCA1 PPC_BIT_NR(57) /* SIB Return Code Accumulator bit1 (PPE42) */
> >   #define MSR_EP   PPC_BIT_NR(57) /* Exception prefix on 601                   */
> >   #define MSR_IR   PPC_BIT_NR(58) /* Instruction relocate                      */
> >   #define MSR_IS   PPC_BIT_NR(58) /* Instruction address space (BookE)         */
> > +#define MSR_SIBRCA2 PPC_BIT_NR(58) /* SIB Return Code Accumulator bit2 (PPE42) */
> > +#define MSR_SIBRCA3 PPC_BIT_NR(59) /* SIB Return Code Accumulator bit3 (PPE42) */
> >   #define MSR_DR   PPC_BIT_NR(59) /* Data relocate                             */
> >   #define MSR_DS   PPC_BIT_NR(59) /* Data address space (BookE)                */
> >   #define MSR_PE   PPC_BIT_NR(60) /* Protection enable on 403                  */
> > +#define MSR_SIBRCA4 PPC_BIT_NR(60) /* SIB Return Code Accumulator bit4 (PPE42) */
> > +#define MSR_SIBRCA5 PPC_BIT_NR(61) /* SIB Return Code Accumulator bit5 (PPE42) */
> >   #define MSR_PX   PPC_BIT_NR(61) /* Protection exclusive on 403        x      */
> >   #define MSR_PMM  PPC_BIT_NR(61) /* Performance monitor mark on POWER  x      */
> >   #define MSR_RI   PPC_BIT_NR(62) /* Recoverable interrupt            1        */
> > +#define MSR_SIBRCA6 PPC_BIT_NR(62) /* SIB Return Code Accumulator bit6 (PPE42) */
> > +#define MSR_SIBRCA7 PPC_BIT_NR(63) /* SIB Return Code Accumulator bit7 (PPE42) */
> >   #define MSR_LE   PPC_BIT_NR(63) /* Little-endian mode               1 hflags */
> >   
> 
> You may keep PPE42 bits together for easier review/maintenance with
> conditional compilation getting enabled, but I am ok with either.
> 

Yeah, I went back and forth on this, but ultimately landed with keeping
it in numberical order with the other definitions.  I think this makes
it more clear on which bits overlap between CPUs.

> >   FIELD(MSR, SF, MSR_SF, 1)
> > @@ -517,6 +546,9 @@ FIELD(MSR, PX, MSR_PX, 1)
> >   FIELD(MSR, PMM, MSR_PMM, 1)
> >   FIELD(MSR, RI, MSR_RI, 1)
> >   FIELD(MSR, LE, MSR_LE, 1)
> > +FIELD(MSR, SEM, MSR_SEM6, 7)
> > +FIELD(MSR, SIBRC, MSR_SIBRC2, 3)
> > +FIELD(MSR, SIBRCA, MSR_SIBRCA7, 8)
> >   
> >   /*
> >    * FE0 and FE1 bits are not side-by-side
> > @@ -730,6 +762,21 @@ FIELD(MSR, LE, MSR_LE, 1)
> >   #define ESR_VLEMI PPC_BIT(58) /* VLE operation                          */
> >   #define ESR_MIF   PPC_BIT(62) /* Misaligned instruction (VLE)           */
> >   
> > +/* PPE42 Interrupt Status Register bits                                 */
> > +#define ISR_SRSMS0  PPC_BIT_NR(48) /* System Reset State Machine State 0   */
> > +#define ISR_SRSMS1  PPC_BIT_NR(49) /* System Reset State Machine State 1   */
> > +#define ISR_SRSMS2  PPC_BIT_NR(50) /* System Reset State Machine State 2   */
> > +#define ISR_SRSMS3  PPC_BIT_NR(51) /* System Reset State Machine State 3   */
> > +#define ISR_EP      PPC_BIT_NR(53) /* MSR[EE] Maskable Event Pending       */
> > +#define ISR_PTR     PPC_BIT_NR(56) /* Program Interrupt from trap          */
> > +#define ISR_ST      PPC_BIT_NR(57) /* Data Interrupt caused by store       */
> > +#define ISR_MFE     PPC_BIT_NR(60) /* Multiple Fault Error                 */
> > +#define ISR_MCS0    PPC_BIT_NR(61) /* Machine Check Status bit0            */
> > +#define ISR_MCS1    PPC_BIT_NR(62) /* Machine Check Status bit1            */
> > +#define ISR_MCS2    PPC_BIT_NR(63) /* Machine Check Status bit2            */
> 
> Better to have PPE42_ prefix ?
> 

Sure, I'll add the prefix.

> > +FIELD(ISR, SRSMS, ISR_SRSMS3, 4)
> > +FIELD(ISR, MCS, ISR_MCS2, 3)
> > +
> >   /* Transaction EXception And Summary Register bits                           */
> >   #define TEXASR_FAILURE_PERSISTENT                (63 - 7)
> >   #define TEXASR_DISALLOWED                        (63 - 8)
> > @@ -785,6 +832,8 @@ enum {
> >       POWERPC_FLAG_SMT_1LPAR = 0x00800000,
> >       /* Has BHRB */
> >       POWERPC_FLAG_BHRB      = 0x01000000,
> > +    /* Use PPE42-specific behavior                                           */
> > +    POWERPC_FLAG_PPE42     = 0x02000000,
> >   };
> >   
> >   /*
> > @@ -1750,9 +1799,12 @@ void ppc_compat_add_property(Object *obj, const char *name,
> >   #define SPR_BOOKE_CSRR0       (0x03A)
> >   #define SPR_BOOKE_CSRR1       (0x03B)
> >   #define SPR_BOOKE_DEAR        (0x03D)
> > +#define SPR_PPE42_EDR         (0x03D)
> >   #define SPR_IAMR              (0x03D)
> >   #define SPR_BOOKE_ESR         (0x03E)
> > +#define SPR_PPE42_ISR         (0x03E)
> >   #define SPR_BOOKE_IVPR        (0x03F)
> > +#define SPR_PPE42_IVPR        (0x03F)
> >   #define SPR_MPC_EIE           (0x050)
> >   #define SPR_MPC_EID           (0x051)
> >   #define SPR_MPC_NRI           (0x052)
> > @@ -1818,6 +1870,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
> >   #define SPR_TBU40             (0x11E)
> >   #define SPR_SVR               (0x11E)
> >   #define SPR_BOOKE_PIR         (0x11E)
> > +#define SPR_PPE42_PIR         (0x11E)
> >   #define SPR_PVR               (0x11F)
> >   #define SPR_HSPRG0            (0x130)
> >   #define SPR_BOOKE_DBSR        (0x130)
> > @@ -1827,6 +1880,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
> >   #define SPR_BOOKE_EPCR        (0x133)
> >   #define SPR_SPURR             (0x134)
> >   #define SPR_BOOKE_DBCR0       (0x134)
> > +#define SPR_PPE42_DBCR        (0x134)
> >   #define SPR_IBCR              (0x135)
> >   #define SPR_PURR              (0x135)
> >   #define SPR_BOOKE_DBCR1       (0x135)
> > @@ -1844,6 +1898,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
> >   #define SPR_HSRR1             (0x13B)
> >   #define SPR_BOOKE_IAC4        (0x13B)
> >   #define SPR_BOOKE_DAC1        (0x13C)
> > +#define SPR_PPE42_DACR        (0x13C)
> >   #define SPR_MMCRH             (0x13C)
> >   #define SPR_DABR2             (0x13D)
> >   #define SPR_BOOKE_DAC2        (0x13D)
> > @@ -1853,12 +1908,14 @@ void ppc_compat_add_property(Object *obj, const char *name,
> >   #define SPR_BOOKE_DVC2        (0x13F)
> >   #define SPR_LPIDR             (0x13F)
> >   #define SPR_BOOKE_TSR         (0x150)
> > +#define SPR_PPE42_TSR         (0x150)
> >   #define SPR_HMER              (0x150)
> >   #define SPR_HMEER             (0x151)
> >   #define SPR_PCR               (0x152)
> >   #define SPR_HEIR              (0x153)
> >   #define SPR_BOOKE_LPIDR       (0x152)
> >   #define SPR_BOOKE_TCR         (0x154)
> > +#define SPR_PPE42_TCR         (0x154)
> >   #define SPR_BOOKE_TLB0PS      (0x158)
> >   #define SPR_BOOKE_TLB1PS      (0x159)
> >   #define SPR_BOOKE_TLB2PS      (0x15A)
> > @@ -2528,6 +2585,12 @@ enum {
> >       PPC2_MEM_LWSYNC    = 0x0000000000200000ULL,
> >       /* ISA 2.06 BCD assist instructions                                      */
> >       PPC2_BCDA_ISA206   = 0x0000000000400000ULL,
> > +    /* PPE42 instructions                                                    */
> > +    PPC2_PPE42         = 0x0000000000800000ULL,
> > +    /* PPE42X instructions                                                   */
> > +    PPC2_PPE42X        = 0x0000000001000000ULL,
> > +    /* PPE42XM instructions                                                  */
> > +    PPC2_PPE42XM       = 0x0000000002000000ULL,
> >   
> >   #define PPC_TCG_INSNS2 (PPC2_BOOKE206 | PPC2_VSX | PPC2_PRCNTL | PPC2_DBRX | \
> >                           PPC2_ISA205 | PPC2_VSX207 | PPC2_PERM_ISA206 | \
> > @@ -2537,7 +2600,8 @@ enum {
> >                           PPC2_ALTIVEC_207 | PPC2_ISA207S | PPC2_DFP | \
> >                           PPC2_FP_CVT_S64 | PPC2_TM | PPC2_PM_ISA206 | \
> >                           PPC2_ISA300 | PPC2_ISA310 | PPC2_MEM_LWSYNC | \
> > -                        PPC2_BCDA_ISA206)
> > +                        PPC2_BCDA_ISA206 | PPC2_PPE42 | PPC2_PPE42X | \
> > +                        PPC2_PPE42XM)
> >   };
> >   
> >   /*****************************************************************************/
> > diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
> > index a0e77f2673..317670a96b 100644
> > --- a/target/ppc/cpu_init.c
> > +++ b/target/ppc/cpu_init.c
> > @@ -1653,6 +1653,47 @@ static void register_8xx_sprs(CPUPPCState *env)
> >    * ... and more (thermal management, performance counters, ...)
> >    */
> >   
> > +static void register_ppe42_sprs(CPUPPCState *env)
> > +{
> > +    spr_register(env, SPR_PPE42_EDR, "EDR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, &spr_write_generic,
> > +                 0x00000000);
> > +    spr_register(env, SPR_PPE42_ISR, "ISR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, &spr_write_generic,
> > +                 0x00000000);
> > +    spr_register(env, SPR_PPE42_IVPR, "IVPR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, SPR_NOACCESS,
> > +                 0xfff80000);
> > +    spr_register(env, SPR_PPE42_PIR, "PIR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, &spr_write_pir,
> > +                 0x00000000);
> > +    spr_register(env, SPR_PPE42_DBCR, "DBCR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, &spr_write_40x_dbcr0,
> > +                 0x00000000);
> > +    spr_register(env, SPR_PPE42_DACR, "DACR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, &spr_write_generic,
> > +                 0x00000000);
> > +    /* Timer */
> > +    spr_register(env, SPR_DECR, "DECR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_decr, &spr_write_decr,
> > +                 0x00000000);
> > +    spr_register(env, SPR_PPE42_TSR, "TSR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, &spr_write_booke_tsr,
> > +                 0x00000000);
> > +    spr_register(env, SPR_BOOKE_TCR, "TCR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, &spr_write_booke_tcr,
> > +                 0x00000000);
> > +}
> > +
> >   /*****************************************************************************/
> >   /* Exception vectors models                                                  */
> >   static void init_excp_4xx(CPUPPCState *env)
> > @@ -1679,6 +1720,30 @@ static void init_excp_4xx(CPUPPCState *env)
> >   #endif
> >   }
> >   
> > +static void init_excp_ppe42(CPUPPCState *env)
> > +{
> > +#if !defined(CONFIG_USER_ONLY)
> > +    /* Machine Check vector changed after version 0 */
> > +    if (((env->spr[SPR_PVR] & 0xf00000ul) >> 20) == 0) {
> > +        env->excp_vectors[POWERPC_EXCP_MCHECK]   = 0x00000000;
> > +    } else {
> > +        env->excp_vectors[POWERPC_EXCP_MCHECK]   = 0x00000020;
> > +    }
> > +    env->excp_vectors[POWERPC_EXCP_RESET]    = 0x00000040;
> > +    env->excp_vectors[POWERPC_EXCP_DSI]      = 0x00000060;
> > +    env->excp_vectors[POWERPC_EXCP_ISI]      = 0x00000080;
> > +    env->excp_vectors[POWERPC_EXCP_EXTERNAL] = 0x000000A0;
> > +    env->excp_vectors[POWERPC_EXCP_ALIGN]    = 0x000000C0;
> > +    env->excp_vectors[POWERPC_EXCP_PROGRAM]  = 0x000000E0;
> > +    env->excp_vectors[POWERPC_EXCP_DECR]     = 0x00000100;
> > +    env->excp_vectors[POWERPC_EXCP_FIT]      = 0x00000120;
> > +    env->excp_vectors[POWERPC_EXCP_WDT]      = 0x00000140;
> > +    env->ivpr_mask = 0xFFFFFE00UL;
> > +    /* Hardware reset vector */
> > +    env->hreset_vector = 0x00000040UL;
> > +#endif
> > +}
> > +
> >   static void init_excp_MPC5xx(CPUPPCState *env)
> >   {
> >   #if !defined(CONFIG_USER_ONLY)
> > @@ -2200,6 +2265,125 @@ POWERPC_FAMILY(405)(ObjectClass *oc, const void *data)
> >                    POWERPC_FLAG_DE | POWERPC_FLAG_BUS_CLK;
> >   }
> >   
> > +static void init_proc_ppe42(CPUPPCState *env)
> > +{
> > +    register_ppe42_sprs(env);
> > +
> > +    init_excp_ppe42(env);
> > +    env->dcache_line_size = 32;
> > +    env->icache_line_size = 32;
> > +    /* Allocate hardware IRQ controller */
> > +    ppc40x_irq_init(env_archcpu(env));
> > +
> > +    SET_FIT_PERIOD(8, 12, 16, 20);
> > +    SET_WDT_PERIOD(16, 20, 24, 28);
> > +}
> > +
> > +POWERPC_FAMILY(ppe42)(ObjectClass *oc, const void *data)
> > +{
> > +    DeviceClass *dc = DEVICE_CLASS(oc);
> > +    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> > +
> > +    dc->desc = "PPE 42";
> > +    pcc->init_proc = init_proc_ppe42;
> > +    pcc->check_pow = check_pow_nocheck;
> > +    pcc->check_attn = check_attn_none;
> > +    pcc->insns_flags = PPC_INSNS_BASE |
> > +                       PPC_WRTEE |
> > +                       PPC_CACHE |
> > +                       PPC_CACHE_DCBZ |
> > +                       PPC_MEM_SYNC;
> > +    pcc->insns_flags2 = PPC2_PPE42;
> > +    pcc->msr_mask = R_MSR_SEM_MASK |
> > +                    (1ull << MSR_IS0) |
> > +                    R_MSR_SIBRC_MASK |
> > +                    (1ull << MSR_LP) |
> > +                    (1ull << MSR_WE) |
> > +                    (1ull << MSR_IS1) |
> > +                    (1ull << MSR_UIE) |
> > +                    (1ull << MSR_EE) |
> > +                    (1ull << MSR_ME) |
> > +                    (1ull << MSR_IS2) |
> > +                    (1ull << MSR_IS3) |
> > +                    (1ull << MSR_IPE) |
> > +                    R_MSR_SIBRCA_MASK;
> > +    pcc->mmu_model = POWERPC_MMU_REAL;
> > +    pcc->excp_model = POWERPC_EXCP_PPE42;
> > +    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
> > +    pcc->bfd_mach = bfd_mach_ppc_403;
> > +    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;
> 
> This shares common code with ppe42x and ppe42xm variants.
> Could this be re-used from a common routine?
> 

Yes, I'll move the common code into a common function.

> > +}
> > +
> > +POWERPC_FAMILY(ppe42x)(ObjectClass *oc, const void *data)
> > +{
> > +    DeviceClass *dc = DEVICE_CLASS(oc);
> > +    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> > +
> > +    dc->desc = "PPE 42X";
> > +    pcc->init_proc = init_proc_ppe42;
> > +    pcc->check_pow = check_pow_nocheck;
> > +    pcc->check_attn = check_attn_none;
> > +    pcc->insns_flags = PPC_INSNS_BASE |
> > +                       PPC_WRTEE |
> > +                       PPC_CACHE |
> > +                       PPC_CACHE_DCBZ |
> > +                       PPC_MEM_SYNC;
> > +    pcc->insns_flags2 = PPC2_PPE42 | PPC2_PPE42X;
> > +    pcc->msr_mask = R_MSR_SEM_MASK |
> > +                    (1ull << MSR_IS0) |
> > +                    R_MSR_SIBRC_MASK |
> > +                    (1ull << MSR_LP) |
> > +                    (1ull << MSR_WE) |
> > +                    (1ull << MSR_IS1) |
> > +                    (1ull << MSR_UIE) |
> > +                    (1ull << MSR_EE) |
> > +                    (1ull << MSR_ME) |
> > +                    (1ull << MSR_IS2) |
> > +                    (1ull << MSR_IS3) |
> > +                    (1ull << MSR_IPE) |
> > +                    R_MSR_SIBRCA_MASK;
> > +    pcc->mmu_model = POWERPC_MMU_REAL;
> > +    pcc->excp_model = POWERPC_EXCP_PPE42;
> > +    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
> > +    pcc->bfd_mach = bfd_mach_ppc_403;
> > +    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;
> > +}
> > +
> > +POWERPC_FAMILY(ppe42xm)(ObjectClass *oc, const void *data)
> > +{
> > +    DeviceClass *dc = DEVICE_CLASS(oc);
> > +    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> > +
> > +    dc->desc = "PPE 42XM";
> > +    pcc->init_proc = init_proc_ppe42;
> > +    pcc->check_pow = check_pow_nocheck;
> > +    pcc->check_attn = check_attn_none;
> > +    pcc->insns_flags = PPC_INSNS_BASE |
> > +                       PPC_WRTEE |
> > +                       PPC_CACHE |
> > +                       PPC_CACHE_DCBZ |
> > +                       PPC_MEM_SYNC;
> > +    pcc->insns_flags2 = PPC2_PPE42 | PPC2_PPE42X | PPC2_PPE42XM;
> > +    pcc->msr_mask = R_MSR_SEM_MASK |
> > +                    (1ull << MSR_IS0) |
> > +                    R_MSR_SIBRC_MASK |
> > +                    (1ull << MSR_LP) |
> > +                    (1ull << MSR_WE) |
> > +                    (1ull << MSR_IS1) |
> > +                    (1ull << MSR_UIE) |
> > +                    (1ull << MSR_EE) |
> > +                    (1ull << MSR_ME) |
> > +                    (1ull << MSR_IS2) |
> > +                    (1ull << MSR_IS3) |
> > +                    (1ull << MSR_IPE) |
> > +                    R_MSR_SIBRCA_MASK;
> > +    pcc->mmu_model = POWERPC_MMU_REAL;
> > +    pcc->excp_model = POWERPC_EXCP_PPE42;
> > +    pcc->bus_model = PPC_FLAGS_INPUT_PPE42;   // Could be used in the future, but not yet for ppe
> > +    pcc->bfd_mach = bfd_mach_ppc_403;
> > +    pcc->flags = POWERPC_FLAG_PPE42 | POWERPC_FLAG_BUS_CLK;
> > +}
> > +
> >   static void init_proc_440EP(CPUPPCState *env)
> >   {
> >       register_BookE_sprs(env, 0x000000000000FFFFULL);
> > @@ -6802,53 +6986,63 @@ static void init_ppc_proc(PowerPCCPU *cpu)
> >   
> >       /* MSR bits & flags consistency checks */
> >       if (env->msr_mask & (1 << 25)) {
> > -        switch (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE)) {
> > +        switch (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE |
> > +                              POWERPC_FLAG_PPE42)) {
> >           case POWERPC_FLAG_SPE:
> >           case POWERPC_FLAG_VRE:
> > +        case POWERPC_FLAG_PPE42:
> >               break;
> >           default:
> >               fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> > -                    "Should define POWERPC_FLAG_SPE or POWERPC_FLAG_VRE\n");
> > +                    "Should define POWERPC_FLAG_SPE or POWERPC_FLAG_VRE\n"
> > +                    "or POWERPC_FLAG_PPE42\n");
> >               exit(1);
> >           }
> >       } else if (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE)) {
> >           fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> > -                "Should not define POWERPC_FLAG_SPE nor POWERPC_FLAG_VRE\n");
> > +                "Should not define POWERPC_FLAG_SPE nor POWERPC_FLAG_VRE\n"
> > +                "nor POWERPC_FLAG_PPE42\n");
> >           exit(1);
> >       }
> >       if (env->msr_mask & (1 << 17)) {
> > -        switch (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE)) {
> > +        switch (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE |
> > +                              POWERPC_FLAG_PPE42)) {
> >           case POWERPC_FLAG_TGPR:
> >           case POWERPC_FLAG_CE:
> > +        case POWERPC_FLAG_PPE42:
> >               break;
> >           default:
> >               fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> > -                    "Should define POWERPC_FLAG_TGPR or POWERPC_FLAG_CE\n");
> > +                    "Should define POWERPC_FLAG_TGPR or POWERPC_FLAG_CE\n"
> > +                    "or POWERPC_FLAG_PPE42\n");
> >               exit(1);
> >           }
> > -    } else if (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE)) {
> > +    } else if (env->flags & (POWERPC_FLAG_TGPR | POWERPC_FLAG_CE |
> > +                             POWERPC_FLAG_PPE42)) {
> >           fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> > -                "Should not define POWERPC_FLAG_TGPR nor POWERPC_FLAG_CE\n");
> > +                "Should not define POWERPC_FLAG_TGPR nor POWERPC_FLAG_CE\n"
> > +                "nor POWERPC_FLAG_PPE42\n");
> >           exit(1);
> >       }
> >       if (env->msr_mask & (1 << 10)) {
> >           switch (env->flags & (POWERPC_FLAG_SE | POWERPC_FLAG_DWE |
> > -                              POWERPC_FLAG_UBLE)) {
> > +                              POWERPC_FLAG_UBLE | POWERPC_FLAG_PPE42)) {
> >           case POWERPC_FLAG_SE:
> >           case POWERPC_FLAG_DWE:
> >           case POWERPC_FLAG_UBLE:
> > +        case POWERPC_FLAG_PPE42:
> >               break;
> >           default:
> >               fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> >                       "Should define POWERPC_FLAG_SE or POWERPC_FLAG_DWE or "
> > -                    "POWERPC_FLAG_UBLE\n");
> > +                    "POWERPC_FLAG_UBLE or POWERPC_FLAG_PPE42\n");
> >               exit(1);
> >           }
> >       } else if (env->flags & (POWERPC_FLAG_SE | POWERPC_FLAG_DWE |
> > -                             POWERPC_FLAG_UBLE)) {
> > +                             POWERPC_FLAG_UBLE | POWERPC_FLAG_PPE42)) {
> >           fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> >                   "Should not define POWERPC_FLAG_SE nor POWERPC_FLAG_DWE nor "
> > -                "POWERPC_FLAG_UBLE\n");
> > +                "POWERPC_FLAG_UBLE nor POWERPC_FLAG_PPE42\n");
> >               exit(1);
> >       }
> >       if (env->msr_mask & (1 << 9)) {
> > @@ -6867,18 +7061,23 @@ static void init_ppc_proc(PowerPCCPU *cpu)
> >           exit(1);
> >       }
> >       if (env->msr_mask & (1 << 2)) {
> > -        switch (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM)) {
> > +        switch (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM |
> > +                              POWERPC_FLAG_PPE42)) {
> >           case POWERPC_FLAG_PX:
> >           case POWERPC_FLAG_PMM:
> > +        case POWERPC_FLAG_PPE42:
> >               break;
> >           default:
> >               fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> > -                    "Should define POWERPC_FLAG_PX or POWERPC_FLAG_PMM\n");
> > +                    "Should define POWERPC_FLAG_PX or POWERPC_FLAG_PMM\n"
> > +                    "or POWERPC_FLAG_PPE42\n");
> >               exit(1);
> >           }
> > -    } else if (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM)) {
> > +    } else if (env->flags & (POWERPC_FLAG_PX | POWERPC_FLAG_PMM |
> > +                             POWERPC_FLAG_PPE42)) {
> >           fprintf(stderr, "PowerPC MSR definition inconsistency\n"
> > -                "Should not define POWERPC_FLAG_PX nor POWERPC_FLAG_PMM\n");
> > +                "Should not define POWERPC_FLAG_PX nor POWERPC_FLAG_PMM\n"
> > +                "nor POWERPC_FLAG_PPE42\n");
> >           exit(1);
> >       }
> >       if ((env->flags & POWERPC_FLAG_BUS_CLK) == 0) {
> > @@ -7243,39 +7442,40 @@ static void ppc_cpu_reset_hold(Object *obj, ResetType type)
> >       }
> >   
> >       msr = (target_ulong)0;
> > -    msr |= (target_ulong)MSR_HVB;
> > -    msr |= (target_ulong)1 << MSR_EP;
> > +    if (!(env->flags & POWERPC_FLAG_PPE42)) {
> > +        msr |= (target_ulong)MSR_HVB;
> > +        msr |= (target_ulong)1 << MSR_EP;
> >   #if defined(DO_SINGLE_STEP) && 0
> > -    /* Single step trace mode */
> > -    msr |= (target_ulong)1 << MSR_SE;
> > -    msr |= (target_ulong)1 << MSR_BE;
> > +        /* Single step trace mode */
> > +        msr |= (target_ulong)1 << MSR_SE;
> > +        msr |= (target_ulong)1 << MSR_BE;
> >   #endif
> >   #if defined(CONFIG_USER_ONLY)
> > -    msr |= (target_ulong)1 << MSR_FP; /* Allow floating point usage */
> > -    msr |= (target_ulong)1 << MSR_FE0; /* Allow floating point exceptions */
> > -    msr |= (target_ulong)1 << MSR_FE1;
> > -    msr |= (target_ulong)1 << MSR_VR; /* Allow altivec usage */
> > -    msr |= (target_ulong)1 << MSR_VSX; /* Allow VSX usage */
> > -    msr |= (target_ulong)1 << MSR_SPE; /* Allow SPE usage */
> > -    msr |= (target_ulong)1 << MSR_PR;
> > +        msr |= (target_ulong)1 << MSR_FP; /* Allow floating point usage */
> > +        msr |= (target_ulong)1 << MSR_FE0; /* Allow floating point exceptions */
> > +        msr |= (target_ulong)1 << MSR_FE1;
> > +        msr |= (target_ulong)1 << MSR_VR; /* Allow altivec usage */
> > +        msr |= (target_ulong)1 << MSR_VSX; /* Allow VSX usage */
> > +        msr |= (target_ulong)1 << MSR_SPE; /* Allow SPE usage */
> > +        msr |= (target_ulong)1 << MSR_PR;
> >   #if defined(TARGET_PPC64)
> > -    msr |= (target_ulong)1 << MSR_TM; /* Transactional memory */
> > +        msr |= (target_ulong)1 << MSR_TM; /* Transactional memory */
> >   #endif
> >   #if !TARGET_BIG_ENDIAN
> > -    msr |= (target_ulong)1 << MSR_LE; /* Little-endian user mode */
> > -    if (!((env->msr_mask >> MSR_LE) & 1)) {
> > -        fprintf(stderr, "Selected CPU does not support little-endian.\n");
> > -        exit(1);
> > -    }
> > +        msr |= (target_ulong)1 << MSR_LE; /* Little-endian user mode */
> > +        if (!((env->msr_mask >> MSR_LE) & 1)) {
> > +            fprintf(stderr, "Selected CPU does not support little-endian.\n");
> > +            exit(1);
> > +        }
> >   #endif
> >   #endif
> >   
> >   #if defined(TARGET_PPC64)
> > -    if (mmu_is_64bit(env->mmu_model)) {
> > -        msr |= (1ULL << MSR_SF);
> > -    }
> > +        if (mmu_is_64bit(env->mmu_model)) {
> > +            msr |= (1ULL << MSR_SF);
> > +        }
> >   #endif
> > -
> > +    }
> >       hreg_store_msr(env, msr, 1);
> >   
> >   #if !defined(CONFIG_USER_ONLY)
> > @@ -7725,6 +7925,18 @@ void ppc_cpu_dump_state(CPUState *cs, FILE *f, int flags)
> >            * they can be read with "p $ivor0", "p $ivor1", etc.
> >            */
> >           break;
> > +    case POWERPC_EXCP_PPE42:
> > +        qemu_fprintf(f, "SRR0 " TARGET_FMT_lx " SRR1 " TARGET_FMT_lx "\n",
> > +                     env->spr[SPR_SRR0], env->spr[SPR_SRR1]);
> > +
> > +        qemu_fprintf(f, "  TCR " TARGET_FMT_lx "   TSR " TARGET_FMT_lx
> > +                     "    ISR " TARGET_FMT_lx "   EDR " TARGET_FMT_lx "\n",
> > +                     env->spr[SPR_PPE42_TCR], env->spr[SPR_PPE42_TSR],
> > +                     env->spr[SPR_PPE42_ISR], env->spr[SPR_PPE42_EDR]);
> > +
> > +        qemu_fprintf(f, "  PIR " TARGET_FMT_lx "   IVPR " TARGET_FMT_lx "\n",
> > +                     env->spr[SPR_PPE42_PIR], env->spr[SPR_PPE42_IVPR]);
> > +        break;
> >       case POWERPC_EXCP_40x:
> >           qemu_fprintf(f, "  TCR " TARGET_FMT_lx "   TSR " TARGET_FMT_lx
> >                        "    ESR " TARGET_FMT_lx "   DEAR " TARGET_FMT_lx "\n",
> > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
> > index 1efdc4066e..2e35e63826 100644
> > --- a/target/ppc/excp_helper.c
> > +++ b/target/ppc/excp_helper.c
> > @@ -949,6 +949,133 @@ static void powerpc_excp_74xx(PowerPCCPU *cpu, int excp)
> >       powerpc_set_excp_state(cpu, vector, new_msr);
> >   }
> >   
> > +#define ISR_MCS_INSTRUCTION             0
> > +#define ISR_MCS_DATA_LOAD               1
> > +#define ISR_MCS_DATA_PRECISE_STORE      2
> > +#define ISR_MCS_DATA_IMPRECISE_STORE    3
> > +#define ISR_MCS_PROGRAM                 4
> > +#define ISR_MCS_ISI                     5
> > +#define ISR_MCS_ALIGNMENT               6
> > +#define ISR_MCS_DSI                     7
> 
> Should these have a PPE42_ prefix?
> Also, may better be kept in cpu.h alongwith other PPE42 ISR bits ?
> 

Will do.

> > +static void powerpc_excp_ppe42(PowerPCCPU *cpu, int excp)
> > +{
> > +    CPUPPCState *env = &cpu->env;
> > +    target_ulong msr, new_msr, vector;
> > +    target_ulong mcs = ISR_MCS_INSTRUCTION;
> > +    bool promote_unmaskable;
> > +
> > +    msr = env->msr;
> > +
> > +    /*
> > +     * New interrupt handler msr preserves SIBRC and ME unless explicitly
> > +     * overridden by the exception.  All other MSR bits are zeroed out.
> > +     */
> > +    new_msr = env->msr & (((target_ulong)1 << MSR_ME) | R_MSR_SIBRC_MASK);
> > +
> > +    /* HV emu assistance interrupt only exists on server arch 2.05 or later */
> > +    if (excp == POWERPC_EXCP_HV_EMU) {
> > +        excp = POWERPC_EXCP_PROGRAM;
> > +    }
> > +
> > +    /*
> > +     * Unmaskable interrupts (Program, ISI, Alignment and DSI) are promoted to
> > +     * machine check if MSR_UIE is 0.
> > +     */
> > +    promote_unmaskable = !(msr & ((target_ulong)1 << MSR_UIE));
> > +
> > +
> > +    switch (excp) {
> > +    case POWERPC_EXCP_MCHECK:    /* Machine check exception                  */
> > +        break;
> > +    case POWERPC_EXCP_DSI:       /* Data storage exception                   */
> > +        trace_ppc_excp_dsi(env->spr[SPR_PPE42_ISR], env->spr[SPR_PPE42_EDR]);
> > +        if (promote_unmaskable) {
> > +            excp = POWERPC_EXCP_MCHECK;
> > +            mcs = ISR_MCS_DSI;
> > +        }
> > +        break;
> > +    case POWERPC_EXCP_ISI:       /* Instruction storage exception            */
> > +        trace_ppc_excp_isi(msr, env->nip);
> > +        if (promote_unmaskable) {
> > +            excp = POWERPC_EXCP_MCHECK;
> > +            mcs = ISR_MCS_ISI;
> > +        }
> > +        break;
> > +    case POWERPC_EXCP_EXTERNAL:  /* External input                           */
> > +        break;
> > +    case POWERPC_EXCP_ALIGN:     /* Alignment exception                      */
> > +        if (promote_unmaskable) {
> > +            excp = POWERPC_EXCP_MCHECK;
> > +            mcs = ISR_MCS_ALIGNMENT;
> > +        }
> > +        break;
> > +    case POWERPC_EXCP_PROGRAM:   /* Program exception                        */
> > +        if (promote_unmaskable) {
> > +            excp = POWERPC_EXCP_MCHECK;
> > +            mcs = ISR_MCS_PROGRAM;
> > +        }
> > +        switch (env->error_code & ~0xF) {
> > +        case POWERPC_EXCP_INVAL:
> > +            trace_ppc_excp_inval(env->nip);
> > +            env->spr[SPR_PPE42_ISR] &= ~((target_ulong)1 << ISR_PTR);
> > +            break;
> > +        case POWERPC_EXCP_TRAP:
> > +            env->spr[SPR_PPE42_ISR] |= ((target_ulong)1 << ISR_PTR);
> > +            break;
> > +        default:
> > +            /* Should never occur */
> > +            cpu_abort(env_cpu(env), "Invalid program exception %d. Aborting\n",
> > +                      env->error_code);
> > +            break;
> > +        }
> > +#ifdef CONFIG_TCG
> > +        env->spr[SPR_PPE42_EDR] = ppc_ldl_code(env, env->nip);
> > +#endif
> > +        break;
> > +    case POWERPC_EXCP_DECR:      /* Decrementer exception                    */
> > +        break;
> > +    case POWERPC_EXCP_FIT:       /* Fixed-interval timer interrupt           */
> > +        trace_ppc_excp_print("FIT");
> > +        break;
> > +    case POWERPC_EXCP_WDT:       /* Watchdog timer interrupt                 */
> > +        trace_ppc_excp_print("WDT");
> > +        break;
> > +    case POWERPC_EXCP_RESET:     /* System reset exception                   */
> > +        /* reset exceptions don't have ME set */
> > +        new_msr &= ~((target_ulong)1 << MSR_ME);
> > +        break;
> > +    default:
> > +        cpu_abort(env_cpu(env), "Invalid PPE42 exception %d. Aborting\n",
> > +                  excp);
> > +        break;
> > +    }
> > +
> > +    env->spr[SPR_SRR0] = env->nip;
> > +    env->spr[SPR_SRR1] = msr;
> > +
> > +    vector = env->excp_vectors[excp];
> > +    if (vector == (target_ulong)-1ULL) {
> > +        cpu_abort(env_cpu(env),
> > +                  "Raised an exception without defined vector %d\n", excp);
> > +    }
> > +    vector |= env->spr[SPR_PPE42_IVPR];
> > +
> > +    if (excp == POWERPC_EXCP_MCHECK) {
> > +        /* Also set the Machine Check Status (MCS) */
> > +        env->spr[SPR_PPE42_ISR] &= ~R_ISR_MCS_MASK;
> > +        env->spr[SPR_PPE42_ISR] |= (mcs & R_ISR_MCS_MASK);
> > +        env->spr[SPR_PPE42_ISR] &= ~((target_ulong)1 << ISR_MFE);
> > +
> > +        /* Machine checks halt execution if MSR_ME is 0 */
> > +        powerpc_mcheck_checkstop(env);
> > +
> > +        /* machine check exceptions don't have ME set */
> > +        new_msr &= ~((target_ulong)1 << MSR_ME);
> > +    }
> > +
> > +    powerpc_set_excp_state(cpu, vector, new_msr);
> > +}
> > +
> >   static void powerpc_excp_booke(PowerPCCPU *cpu, int excp)
> >   {
> >       CPUPPCState *env = &cpu->env;
> > @@ -1589,6 +1716,9 @@ void powerpc_excp(PowerPCCPU *cpu, int excp)
> >       case POWERPC_EXCP_POWER11:
> >           powerpc_excp_books(cpu, excp);
> >           break;
> > +    case POWERPC_EXCP_PPE42:
> > +        powerpc_excp_ppe42(cpu, excp);
> > +        break;
> >       default:
> >           g_assert_not_reached();
> >       }
> > @@ -1945,6 +2075,43 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env,
> >   }
> >   #endif /* TARGET_PPC64 */
> >   
> > +static int ppe42_next_unmasked_interrupt(CPUPPCState *env)
> > +{
> > +    bool async_deliver;
> > +
> > +    /* External reset */
> > +    if (env->pending_interrupts & PPC_INTERRUPT_RESET) {
> > +        return PPC_INTERRUPT_RESET;
> > +    }
> > +    /* Machine check exception */
> > +    if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
> > +        return PPC_INTERRUPT_MCK;
> > +    }
> > +
> > +    async_deliver = FIELD_EX64(env->msr, MSR, EE);
> > +
> > +    if (async_deliver != 0) {
> > +        /* Watchdog timer */
> > +        if (env->pending_interrupts & PPC_INTERRUPT_WDT) {
> > +            return PPC_INTERRUPT_WDT;
> > +        }
> > +        /* External Interrupt */
> > +        if (env->pending_interrupts & PPC_INTERRUPT_EXT) {
> > +            return PPC_INTERRUPT_EXT;
> > +        }
> > +        /* Fixed interval timer */
> > +        if (env->pending_interrupts & PPC_INTERRUPT_FIT) {
> > +            return PPC_INTERRUPT_FIT;
> > +        }
> > +        /* Decrementer exception */
> > +        if (env->pending_interrupts & PPC_INTERRUPT_DECR) {
> > +            return PPC_INTERRUPT_DECR;
> > +        }
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> >   static int ppc_next_unmasked_interrupt(CPUPPCState *env)
> >   {
> >       uint32_t pending_interrupts = env->pending_interrupts;
> > @@ -1970,6 +2137,10 @@ static int ppc_next_unmasked_interrupt(CPUPPCState *env)
> >       }
> >   #endif
> >   
> > +    if (env->excp_model == POWERPC_EXCP_PPE42) {
> > +        return ppe42_next_unmasked_interrupt(env);
> > +    }
> > +
> >       /* External reset */
> >       if (pending_interrupts & PPC_INTERRUPT_RESET) {
> >           return PPC_INTERRUPT_RESET;
> > diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c
> > index 7e5726871e..7be00f5bbe 100644
> > --- a/target/ppc/helper_regs.c
> > +++ b/target/ppc/helper_regs.c
> > @@ -186,6 +186,10 @@ static uint32_t hreg_compute_hflags_value(CPUPPCState *env)
> >       if (env->spr[SPR_LPCR] & LPCR_HR) {
> >           hflags |= 1 << HFLAGS_HR;
> >       }
> > +    if (ppc_flags & POWERPC_FLAG_PPE42) {
> > +        /* PPE42 has a single address space and no problem state */
> > +        msr = 0;
> > +    }
> 
> We really dont want this to be checked on PPC64 machines, hence 
> !TARGET_PPC64 needed.
> 

This is related to the issue of whether we want to continue supporting
32-bit CPUs inside the 64-bit executable.  It seems that the community
is saying that we should continue to do that, so I'd like to keep this
in even for PPC64 machines, but I will go ahead and add an 'unlikely'
here in order to possibly lessen the impact.

> >   
> >   #ifndef CONFIG_USER_ONLY
> >       if (!env->has_hv_mode || (msr & (1ull << MSR_HV))) {
> > @@ -306,9 +310,6 @@ int hreg_store_msr(CPUPPCState *env, target_ulong value, int alter_hv)
> >           value &= ~(1 << MSR_ME);
> >           value |= env->msr & (1 << MSR_ME);
> >       }
> > -    if ((value ^ env->msr) & (R_MSR_IR_MASK | R_MSR_DR_MASK)) {
> > -        cpu_interrupt_exittb(cs);
> > -    }
> >       if ((env->mmu_model == POWERPC_MMU_BOOKE ||
> >            env->mmu_model == POWERPC_MMU_BOOKE206) &&
> >           ((value ^ env->msr) & R_MSR_GS_MASK)) {
> > @@ -319,8 +320,14 @@ int hreg_store_msr(CPUPPCState *env, target_ulong value, int alter_hv)
> >           /* Swap temporary saved registers with GPRs */
> >           hreg_swap_gpr_tgpr(env);
> >       }
> > -    if (unlikely((value ^ env->msr) & R_MSR_EP_MASK)) {
> > -        env->excp_prefix = FIELD_EX64(value, MSR, EP) * 0xFFF00000;
> > +    /* PPE42 MSR has bits overlapping with others */
> > +    if (!(env->flags & POWERPC_FLAG_PPE42)) {
> > +        if ((value ^ env->msr) & (R_MSR_IR_MASK | R_MSR_DR_MASK)) {
> > +            cpu_interrupt_exittb(cs);
> > +        }
> > +        if (unlikely((value ^ env->msr) & R_MSR_EP_MASK)) {
> > +            env->excp_prefix = FIELD_EX64(value, MSR, EP) * 0xFFF00000;
> > +        }
> >       }
> >       /*
> >        * If PR=1 then EE, IR and DR must be 1
> > @@ -462,6 +469,17 @@ void register_generic_sprs(PowerPCCPU *cpu)
> >                    SPR_NOACCESS, SPR_NOACCESS,
> >                    &spr_read_generic, &spr_write_generic,
> >                    0x00000000);
> > +
> > +    if (env->insns_flags2 & PPC2_PPE42) {
> > +        spr_register(env, SPR_PVR, "PVR",
> > +                 SPR_NOACCESS, SPR_NOACCESS,
> > +                 &spr_read_generic, SPR_NOACCESS,
> > +                 pcc->pvr);
> > +
> > +        /* PPE42 doesn't support additional SPRG regs or timebase */
> > +        return;
> > +    }
> > +
> >       spr_register(env, SPR_SPRG1, "SPRG1",
> >                    SPR_NOACCESS, SPR_NOACCESS,
> >                    &spr_read_generic, &spr_write_generic,
> > diff --git a/target/ppc/tcg-excp_helper.c b/target/ppc/tcg-excp_helper.c
> > index f835be5156..14f3ad92fe 100644
> > --- a/target/ppc/tcg-excp_helper.c
> > +++ b/target/ppc/tcg-excp_helper.c
> > @@ -229,6 +229,18 @@ void ppc_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr,
> >       case POWERPC_MMU_BOOKE206:
> >           env->spr[SPR_BOOKE_DEAR] = vaddr;
> >           break;
> > +    case POWERPC_MMU_REAL:
> > +        if (env->flags & POWERPC_FLAG_PPE42) {
> > +            env->spr[SPR_PPE42_EDR] = vaddr;
> > +            if (access_type == MMU_DATA_STORE) {
> > +                env->spr[SPR_PPE42_ISR] |= ISR_ST;
> > +            } else {
> > +                env->spr[SPR_PPE42_ISR] &= ~ISR_ST;
> > +            }
> > +        } else {
> > +            env->spr[SPR_DAR] = vaddr;
> > +        }
> > +        break;
> >       default:
> >           env->spr[SPR_DAR] = vaddr;
> >           break;
> > diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> > index 27f90c3cc5..b4f4d10384 100644
> > --- a/target/ppc/translate.c
> > +++ b/target/ppc/translate.c
> > @@ -4264,8 +4264,10 @@ static void gen_mtmsr(DisasContext *ctx)
> >           /* L=1 form only updates EE and RI */
> >           mask &= (1ULL << MSR_RI) | (1ULL << MSR_EE);
> >       } else {
> > -        /* mtmsr does not alter S, ME, or LE */
> > -        mask &= ~((1ULL << MSR_LE) | (1ULL << MSR_ME) | (1ULL << MSR_S));
> > +        if (!(ctx->insns_flags2 & PPC2_PPE42)) {
> 
> you may want to use likely() in above check?
> Also check other instances wherever applicable.
> 

Yes, I think it does make sense to add it here.

> Thanks
> Harsh
> 
> > +            /* mtmsr does not alter S, ME, or LE */
> > +            mask &= ~((1ULL << MSR_LE) | (1ULL << MSR_ME) | (1ULL << MSR_S));
> > +        }
> >   
> >           /*
> >            * XXX: we need to update nip before the store if we enter



^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 14:33                 ` BALATON Zoltan
@ 2025-08-26  4:54                   ` Harsh Prateek Bora
  2025-08-26 12:12                     ` BALATON Zoltan
  0 siblings, 1 reply; 19+ messages in thread
From: Harsh Prateek Bora @ 2025-08-26  4:54 UTC (permalink / raw)
  To: BALATON Zoltan
  Cc: Thomas Huth, Glenn Miles, qemu-devel, qemu-ppc, clg, npiggin,
	rathc, richard.henderson, Philippe Mathieu-Daudé,
	Pierrick Bouvier



On 8/25/25 20:03, BALATON Zoltan wrote:
> On Mon, 25 Aug 2025, Harsh Prateek Bora wrote:
>> On 8/25/25 17:52, Thomas Huth wrote:
>>> On 25/08/2025 14.08, Harsh Prateek Bora wrote:
>>>> On 8/25/25 17:28, Thomas Huth wrote:
>>>>> As I said, qemu-system-ppc64 is currently a full superset of 
>>>>> qemu-system- ppc. The ppc64 binary contains all the 32-bit code, 
>>>>> you can perfectly run a "g3beige" or "bamboo" machine with 
>>>>> qemu-system-ppc64, too. By disabling the ppe42 code in the ppc64 
>>>>> binary, this would now introduce an execption to that unwritten 
>>>>> rule, so I'd expect that we'd not rather want to do this now.
>>>>
>>>> My understanding is that above holds true only for default builds which
>>>> builds all targets. We certainly do not build 32 bit ppc code when 
>>>> using
>>>> --configure target-list=ppc64-softmmu. (we have ppc-softmmu for 32 
>>>> bit though)
> 
> We do build 32-bit machines in ppc64-softmmu but leave out 64-bit from 
> ppc-softmmu so it's only one way.
> 
>>> Just give it a try:
>>>
>>>   ./configure --target-list=ppc64-softmmu --disable-docs
>>>   make -j$(nproc)
>>>   ./qemu-system-ppc64 -M g3beige
>>>
>>> ... works perfectly fine for me.
>>>
>> This would work because the respective code is not restricted with 
>> #ifndef TARGET_PPC64.
>>
>> However, there are instance like below in hw/ppc/mac_oldworld.c:
>>
>> static void heathrow_class_init(ObjectClass *oc, const void *data)
>> {
>>    MachineClass *mc = MACHINE_CLASS(oc);
>>    FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(oc);
>>
>>    mc->desc = "Heathrow based PowerMac";
>>    mc->init = ppc_heathrow_init;
>>    mc->block_default_type = IF_IDE;
>>    /* SMP is not supported currently */
>>    mc->max_cpus = 1;
>> #ifndef TARGET_PPC64
>>    mc->is_default = true;
>> #endif
> 
> This is only because the default machine for ppc64-softmmu is different 
> than for ppc-softmmu as the 64-bit machines don't exist in ppc-softmmu 
> but ppc64-softmmu had different default machine before machines from 
> qemu-system-ppc got included in qemu-system-ppc64 so it kept that. 
> (Looks like the default used to be mac_newworld before commit 
> 159f8286b760dea but wasn't changed to match but to something else.) The 
> default machines are arbitrary, we could make "none" the default and 
> always require users to supply -machine but that would break existing 
> command lines so this wasn't done.
> 
>> Similarly, we have multiple instances with #else block for #ifdef
>> TARGET_PPC64 which doesnt get compiled with ppc64-softmmu, but only with
>> ppc-softmmu meant for 32-bit targets. See target/ppc/excp_helper.c for 
>> example.
> 
> This is again leaving out 64-bit code from ppc-softmmu but as Thomas 
> says 32-bit machines are always included in qemu-softmmu-ppc64. I can't 
> find the commit which changed this, previously we had these to be 
> separate and since some types are different in ppc64-softmmu it wasn't 
> clear if that could cause any problems for 32-bit CPUs and machines so 
> ppc-softmmu was kept until that's cleaned up which never happened. There 
> are also some pecularities in some machines like mac_newworld that 
> behaves differently in qemu-system-ppc and qemu-system-ppc64 and the 
> potentially lower performance of qemu-system-ppc64 in emulating 32-bit 
> machines which is why we still have ppc-softmmu.
> 

Ok, I see. So, if we wish to keep the 32-bit machines supported with 
qemu-system-ppc64, we will have them co-exist with run-time checks for 
!ppc64 and/or "unlikely" operations in the hot path routines, which 
wouldnt be needed otherwise. I hope we can deal with run-time checks for 
!ppc64 if such ops increase.

Thanks to Thomas and you for clarifying this.

regards,
Harsh

> Regards,
> BALATON Zoltan
> 
>> regards,
>> Harsh
>>
>>> AFAIK we don't have a switch to disable 32-bit code in the ppc64 binary.
>>>
>>>   Thomas
>>>
>>
>>


^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-25 16:56     ` Miles Glenn
@ 2025-08-26  5:30       ` Harsh Prateek Bora
  0 siblings, 0 replies; 19+ messages in thread
From: Harsh Prateek Bora @ 2025-08-26  5:30 UTC (permalink / raw)
  To: milesg, qemu-devel
  Cc: qemu-ppc, clg, npiggin, thuth, rathc, richard.henderson



On 8/25/25 22:26, Miles Glenn wrote:
>>> @@ -186,6 +186,10 @@ static uint32_t hreg_compute_hflags_value(CPUPPCState *env)
>>>        if (env->spr[SPR_LPCR] & LPCR_HR) {
>>>            hflags |= 1 << HFLAGS_HR;
>>>        }
>>> +    if (ppc_flags & POWERPC_FLAG_PPE42) {
>>> +        /* PPE42 has a single address space and no problem state */
>>> +        msr = 0;
>>> +    }
>> We really dont want this to be checked on PPC64 machines, hence
>> !TARGET_PPC64 needed.
>>
> This is related to the issue of whether we want to continue supporting
> 32-bit CPUs inside the 64-bit executable.  It seems that the community
> is saying that we should continue to do that, so I'd like to keep this
> in even for PPC64 machines, but I will go ahead and add an 'unlikely'
> here in order to possibly lessen the impact.

Yeh, sure, that should suffice for now.

Thanks
Harsh


^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-26  4:54                   ` Harsh Prateek Bora
@ 2025-08-26 12:12                     ` BALATON Zoltan
  2025-08-28 14:48                       ` Pierrick Bouvier
  0 siblings, 1 reply; 19+ messages in thread
From: BALATON Zoltan @ 2025-08-26 12:12 UTC (permalink / raw)
  To: Harsh Prateek Bora
  Cc: Thomas Huth, Glenn Miles, qemu-devel, qemu-ppc, clg, npiggin,
	rathc, richard.henderson, Philippe Mathieu-Daudé,
	Pierrick Bouvier

[-- Attachment #1: Type: text/plain, Size: 4700 bytes --]

On Tue, 26 Aug 2025, Harsh Prateek Bora wrote:
> On 8/25/25 20:03, BALATON Zoltan wrote:
>> On Mon, 25 Aug 2025, Harsh Prateek Bora wrote:
>>> On 8/25/25 17:52, Thomas Huth wrote:
>>>> On 25/08/2025 14.08, Harsh Prateek Bora wrote:
>>>>> On 8/25/25 17:28, Thomas Huth wrote:
>>>>>> As I said, qemu-system-ppc64 is currently a full superset of 
>>>>>> qemu-system- ppc. The ppc64 binary contains all the 32-bit code, you 
>>>>>> can perfectly run a "g3beige" or "bamboo" machine with 
>>>>>> qemu-system-ppc64, too. By disabling the ppe42 code in the ppc64 
>>>>>> binary, this would now introduce an execption to that unwritten rule, 
>>>>>> so I'd expect that we'd not rather want to do this now.
>>>>> 
>>>>> My understanding is that above holds true only for default builds which
>>>>> builds all targets. We certainly do not build 32 bit ppc code when using
>>>>> --configure target-list=ppc64-softmmu. (we have ppc-softmmu for 32 bit 
>>>>> though)
>> 
>> We do build 32-bit machines in ppc64-softmmu but leave out 64-bit from 
>> ppc-softmmu so it's only one way.
>> 
>>>> Just give it a try:
>>>> 
>>>>   ./configure --target-list=ppc64-softmmu --disable-docs
>>>>   make -j$(nproc)
>>>>   ./qemu-system-ppc64 -M g3beige
>>>> 
>>>> ... works perfectly fine for me.
>>>> 
>>> This would work because the respective code is not restricted with #ifndef 
>>> TARGET_PPC64.
>>> 
>>> However, there are instance like below in hw/ppc/mac_oldworld.c:
>>> 
>>> static void heathrow_class_init(ObjectClass *oc, const void *data)
>>> {
>>>    MachineClass *mc = MACHINE_CLASS(oc);
>>>    FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(oc);
>>> 
>>>    mc->desc = "Heathrow based PowerMac";
>>>    mc->init = ppc_heathrow_init;
>>>    mc->block_default_type = IF_IDE;
>>>    /* SMP is not supported currently */
>>>    mc->max_cpus = 1;
>>> #ifndef TARGET_PPC64
>>>    mc->is_default = true;
>>> #endif
>> 
>> This is only because the default machine for ppc64-softmmu is different 
>> than for ppc-softmmu as the 64-bit machines don't exist in ppc-softmmu but 
>> ppc64-softmmu had different default machine before machines from 
>> qemu-system-ppc got included in qemu-system-ppc64 so it kept that. (Looks 
>> like the default used to be mac_newworld before commit 159f8286b760dea but 
>> wasn't changed to match but to something else.) The default machines are 
>> arbitrary, we could make "none" the default and always require users to 
>> supply -machine but that would break existing command lines so this wasn't 
>> done.
>> 
>>> Similarly, we have multiple instances with #else block for #ifdef
>>> TARGET_PPC64 which doesnt get compiled with ppc64-softmmu, but only with
>>> ppc-softmmu meant for 32-bit targets. See target/ppc/excp_helper.c for 
>>> example.
>> 
>> This is again leaving out 64-bit code from ppc-softmmu but as Thomas says 
>> 32-bit machines are always included in qemu-softmmu-ppc64. I can't find the 
>> commit which changed this, previously we had these to be separate and since 
>> some types are different in ppc64-softmmu it wasn't clear if that could 
>> cause any problems for 32-bit CPUs and machines so ppc-softmmu was kept 
>> until that's cleaned up which never happened. There are also some 
>> pecularities in some machines like mac_newworld that behaves differently in 
>> qemu-system-ppc and qemu-system-ppc64 and the potentially lower performance 
>> of qemu-system-ppc64 in emulating 32-bit machines which is why we still 
>> have ppc-softmmu.
>> 
>
> Ok, I see. So, if we wish to keep the 32-bit machines supported with 
> qemu-system-ppc64, we will have them co-exist with run-time checks for !ppc64 
> and/or "unlikely" operations in the hot path routines, which wouldnt be 
> needed otherwise. I hope we can deal with run-time checks for !ppc64 if such 
> ops increase.

I guess this will only get worse with the single binary that will also add 
if target == checks and removes some of the optimisations that assumed 
endianness and word size. It would be good if somebody could do some tests 
to check performance issues which could be made part of the test suite so 
we at least notice these changes. I'm not sure what would be a good set of 
benchmarks, I've used STREAM to check memory access and exceptions/MMU and 
lame some.waw some.mp3 to check FPU and vector instructions speed before 
but maybe there are better tools.

I've also tried adding function pointers to CPU class for different 
exception models to remove the switch from the beginning of excp handling 
functions that call out to PPC64 specific versions but I found that to be 
slower than the current switch at least on x86_64 host.

Regards,
BALATON Zoltan

^ permalink raw reply	[flat|nested] 19+ messages in thread

* Re: [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors
  2025-08-26 12:12                     ` BALATON Zoltan
@ 2025-08-28 14:48                       ` Pierrick Bouvier
  0 siblings, 0 replies; 19+ messages in thread
From: Pierrick Bouvier @ 2025-08-28 14:48 UTC (permalink / raw)
  To: BALATON Zoltan, Harsh Prateek Bora
  Cc: Thomas Huth, Glenn Miles, qemu-devel, qemu-ppc, clg, npiggin,
	rathc, richard.henderson, Philippe Mathieu-Daudé

On 2025-08-26 14:12, BALATON Zoltan wrote:
> On Tue, 26 Aug 2025, Harsh Prateek Bora wrote:
>> On 8/25/25 20:03, BALATON Zoltan wrote:
>>> On Mon, 25 Aug 2025, Harsh Prateek Bora wrote:
>>>> On 8/25/25 17:52, Thomas Huth wrote:
>>>>> On 25/08/2025 14.08, Harsh Prateek Bora wrote:
>>>>>> On 8/25/25 17:28, Thomas Huth wrote:
>>>>>>> As I said, qemu-system-ppc64 is currently a full superset of
>>>>>>> qemu-system- ppc. The ppc64 binary contains all the 32-bit code, you
>>>>>>> can perfectly run a "g3beige" or "bamboo" machine with
>>>>>>> qemu-system-ppc64, too. By disabling the ppe42 code in the ppc64
>>>>>>> binary, this would now introduce an execption to that unwritten rule,
>>>>>>> so I'd expect that we'd not rather want to do this now.
>>>>>>
>>>>>> My understanding is that above holds true only for default builds which
>>>>>> builds all targets. We certainly do not build 32 bit ppc code when using
>>>>>> --configure target-list=ppc64-softmmu. (we have ppc-softmmu for 32 bit
>>>>>> though)
>>>
>>> We do build 32-bit machines in ppc64-softmmu but leave out 64-bit from
>>> ppc-softmmu so it's only one way.
>>>
>>>>> Just give it a try:
>>>>>
>>>>>    ./configure --target-list=ppc64-softmmu --disable-docs
>>>>>    make -j$(nproc)
>>>>>    ./qemu-system-ppc64 -M g3beige
>>>>>
>>>>> ... works perfectly fine for me.
>>>>>
>>>> This would work because the respective code is not restricted with #ifndef
>>>> TARGET_PPC64.
>>>>
>>>> However, there are instance like below in hw/ppc/mac_oldworld.c:
>>>>
>>>> static void heathrow_class_init(ObjectClass *oc, const void *data)
>>>> {
>>>>     MachineClass *mc = MACHINE_CLASS(oc);
>>>>     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(oc);
>>>>
>>>>     mc->desc = "Heathrow based PowerMac";
>>>>     mc->init = ppc_heathrow_init;
>>>>     mc->block_default_type = IF_IDE;
>>>>     /* SMP is not supported currently */
>>>>     mc->max_cpus = 1;
>>>> #ifndef TARGET_PPC64
>>>>     mc->is_default = true;
>>>> #endif
>>>
>>> This is only because the default machine for ppc64-softmmu is different
>>> than for ppc-softmmu as the 64-bit machines don't exist in ppc-softmmu but
>>> ppc64-softmmu had different default machine before machines from
>>> qemu-system-ppc got included in qemu-system-ppc64 so it kept that. (Looks
>>> like the default used to be mac_newworld before commit 159f8286b760dea but
>>> wasn't changed to match but to something else.) The default machines are
>>> arbitrary, we could make "none" the default and always require users to
>>> supply -machine but that would break existing command lines so this wasn't
>>> done.
>>>
>>>> Similarly, we have multiple instances with #else block for #ifdef
>>>> TARGET_PPC64 which doesnt get compiled with ppc64-softmmu, but only with
>>>> ppc-softmmu meant for 32-bit targets. See target/ppc/excp_helper.c for
>>>> example.
>>>
>>> This is again leaving out 64-bit code from ppc-softmmu but as Thomas says
>>> 32-bit machines are always included in qemu-softmmu-ppc64. I can't find the
>>> commit which changed this, previously we had these to be separate and since
>>> some types are different in ppc64-softmmu it wasn't clear if that could
>>> cause any problems for 32-bit CPUs and machines so ppc-softmmu was kept
>>> until that's cleaned up which never happened. There are also some
>>> pecularities in some machines like mac_newworld that behaves differently in
>>> qemu-system-ppc and qemu-system-ppc64 and the potentially lower performance
>>> of qemu-system-ppc64 in emulating 32-bit machines which is why we still
>>> have ppc-softmmu.
>>>
>>
>> Ok, I see. So, if we wish to keep the 32-bit machines supported with
>> qemu-system-ppc64, we will have them co-exist with run-time checks for !ppc64
>> and/or "unlikely" operations in the hot path routines, which wouldnt be
>> needed otherwise. I hope we can deal with run-time checks for !ppc64 if such
>> ops increase.
> 
> I guess this will only get worse with the single binary that will also add
> if target == checks and removes some of the optimisations that assumed
> endianness and word size. It would be good if somebody could do some tests
> to check performance issues which could be made part of the test suite so
> we at least notice these changes. I'm not sure what would be a good set of
> benchmarks, I've used STREAM to check memory access and exceptions/MMU and
> lame some.waw some.mp3 to check FPU and vector instructions speed before
> but maybe there are better tools.
> 
> I've also tried adding function pointers to CPU class for different
> exception models to remove the switch from the beginning of excp handling
> functions that call out to PPC64 specific versions but I found that to be
> slower than the current switch at least on x86_64 host.
>

Having performance tests would be a great addition to the QEMU test 
suite, whether it's for the single binary or any other change.

Concerning the single binary, we have no plan to modify ppc target code 
for now. As well, most of other architecture already handle 32 vs 64bits 
and endianness with runtime paths, and it has not been a problem so far.

I still think it's better to write proper code and eventually optimize 
parts identified by proper profiling. But impacting architecture and use 
preprocessor heavily before any proof that is needed has been found is 
premature optimization IMHO.

Regards,
Pierrick


^ permalink raw reply	[flat|nested] 19+ messages in thread

end of thread, other threads:[~2025-08-28 17:26 UTC | newest]

Thread overview: 19+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-08-19 21:28 [PATCH 0/4] Add IBM PPE42 CPU support Glenn Miles
2025-08-19 21:28 ` [PATCH 1/4] target/ppc: Add IBM PPE42 family of processors Glenn Miles
2025-08-25 11:24   ` Harsh Prateek Bora
2025-08-25 11:34     ` Thomas Huth
2025-08-25 11:46       ` Harsh Prateek Bora
2025-08-25 11:58         ` Thomas Huth
2025-08-25 12:08           ` Harsh Prateek Bora
2025-08-25 12:22             ` Thomas Huth
2025-08-25 12:36               ` Harsh Prateek Bora
2025-08-25 14:33                 ` BALATON Zoltan
2025-08-26  4:54                   ` Harsh Prateek Bora
2025-08-26 12:12                     ` BALATON Zoltan
2025-08-28 14:48                       ` Pierrick Bouvier
2025-08-25 16:56     ` Miles Glenn
2025-08-26  5:30       ` Harsh Prateek Bora
2025-08-19 21:28 ` [PATCH 2/4] target/ppc: Add IBM PPE42 special instructions Glenn Miles
2025-08-19 21:28 ` [PATCH 3/4] hw/ppc: Add a test machine for the IBM PPE42 CPU Glenn Miles
2025-08-19 21:28 ` [PATCH 4/4] tests/functional: Add test for IBM PPE42 instructions Glenn Miles
2025-08-25  9:10   ` Thomas Huth

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