Re: [Qemu-devel] [PATCH 06/11] Add support for S390x system emulation

[Aurelien Jarno <aurelien@aurel32.net>]

On Thu, Nov 26, 2009 at 02:23:15PM +0100, Alexander Graf wrote:
> Let's enable the basics for system emulation so we can run virtual machines
> with KVM!

I don't really understand while this whole patch is not merged in patch
number 1. Otherwise, please find the comments below.

> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  target-s390x/cpu.h                |  153 ++++++++++++++++++++++++++++++++++++-
>  target-s390x/exec.h               |    5 +
>  target-s390x/helper.c             |   22 +++++
>  target-s390x/machine.c            |   30 +++++++
>  4 files changed, 208 insertions(+), 2 deletions(-)
>  create mode 100644 default-configs/s390x-softmmu.mak
>  create mode 100644 target-s390x/machine.c
> 
> diff --git a/default-configs/s390x-softmmu.mak b/default-configs/s390x-softmmu.mak
> new file mode 100644
> index 0000000..e69de29
> diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
> index f45b00c..a74745c 100644
> --- a/target-s390x/cpu.h
> +++ b/target-s390x/cpu.h
> @@ -30,8 +30,7 @@
>  
>  #include "softfloat.h"
>  
> -#define NB_MMU_MODES 2 // guess
> -#define MMU_USER_IDX 0 // guess
> +#define NB_MMU_MODES 2
>  
>  typedef union FPReg {
>      struct {
> @@ -77,6 +76,15 @@ static inline void cpu_clone_regs(CPUState *env, target_ulong newsp)
>  }
>  #endif
>  
> +#define MMU_MODE0_SUFFIX _kernel
> +#define MMU_MODE1_SUFFIX _user
> +#define MMU_USER_IDX 1
> +static inline int cpu_mmu_index (CPUState *env)
> +{
> +    /* XXX: Currently we don't implement virtual memory */
> +    return 0;

Is it correct? It means that memory access will aways be kernel memory
accesses. IIRC, even with KVM enabled, softmmu accesses are possible in
some cases (devices ?).

> +}
> +
>  CPUS390XState *cpu_s390x_init(const char *cpu_model);
>  int cpu_s390x_exec(CPUS390XState *s);
>  void cpu_s390x_close(CPUS390XState *s);
> @@ -92,6 +100,13 @@ int cpu_s390x_handle_mmu_fault (CPUS390XState *env, target_ulong address, int rw
>  
>  #define TARGET_PAGE_BITS 12
>  
> +#ifndef CONFIG_USER_ONLY
> +extern int s390_virtio_hypercall(CPUState *env);
> +extern void kvm_s390_virtio_irq(CPUState *env, int config_change, uint64_t token);
> +extern CPUState *s390_cpu_addr2state(uint16_t cpu_addr);
> +#endif
> +
> +
>  #define cpu_init cpu_s390x_init
>  #define cpu_exec cpu_s390x_exec
>  #define cpu_gen_code cpu_s390x_gen_code
> @@ -116,4 +131,138 @@ static inline void cpu_get_tb_cpu_state(CPUState* env, target_ulong *pc,
>      *cs_base = 0;
>      *flags = env->psw.mask; // guess
>  }
> +
> +/* Program Status Word.  */
> +#define S390_PSWM_REGNUM 0
> +#define S390_PSWA_REGNUM 1
> +/* General Purpose Registers.  */
> +#define S390_R0_REGNUM 2
> +#define S390_R1_REGNUM 3
> +#define S390_R2_REGNUM 4
> +#define S390_R3_REGNUM 5
> +#define S390_R4_REGNUM 6
> +#define S390_R5_REGNUM 7
> +#define S390_R6_REGNUM 8
> +#define S390_R7_REGNUM 9
> +#define S390_R8_REGNUM 10
> +#define S390_R9_REGNUM 11
> +#define S390_R10_REGNUM 12
> +#define S390_R11_REGNUM 13
> +#define S390_R12_REGNUM 14
> +#define S390_R13_REGNUM 15
> +#define S390_R14_REGNUM 16
> +#define S390_R15_REGNUM 17
> +/* Access Registers.  */
> +#define S390_A0_REGNUM 18
> +#define S390_A1_REGNUM 19
> +#define S390_A2_REGNUM 20
> +#define S390_A3_REGNUM 21
> +#define S390_A4_REGNUM 22
> +#define S390_A5_REGNUM 23
> +#define S390_A6_REGNUM 24
> +#define S390_A7_REGNUM 25
> +#define S390_A8_REGNUM 26
> +#define S390_A9_REGNUM 27
> +#define S390_A10_REGNUM 28
> +#define S390_A11_REGNUM 29
> +#define S390_A12_REGNUM 30
> +#define S390_A13_REGNUM 31
> +#define S390_A14_REGNUM 32
> +#define S390_A15_REGNUM 33
> +/* Floating Point Control Word.  */
> +#define S390_FPC_REGNUM 34
> +/* Floating Point Registers.  */
> +#define S390_F0_REGNUM 35
> +#define S390_F1_REGNUM 36
> +#define S390_F2_REGNUM 37
> +#define S390_F3_REGNUM 38
> +#define S390_F4_REGNUM 39
> +#define S390_F5_REGNUM 40
> +#define S390_F6_REGNUM 41
> +#define S390_F7_REGNUM 42
> +#define S390_F8_REGNUM 43
> +#define S390_F9_REGNUM 44
> +#define S390_F10_REGNUM 45
> +#define S390_F11_REGNUM 46
> +#define S390_F12_REGNUM 47
> +#define S390_F13_REGNUM 48
> +#define S390_F14_REGNUM 49
> +#define S390_F15_REGNUM 50
> +/* Total.  */
> +#define S390_NUM_REGS 51
> +
> +/* Pseudo registers -- PC and condition code.  */
> +#define S390_PC_REGNUM S390_NUM_REGS
> +#define S390_CC_REGNUM (S390_NUM_REGS+1)
> +#define S390_NUM_PSEUDO_REGS 2
> +#define S390_NUM_TOTAL_REGS (S390_NUM_REGS+2)
> +
> +
> +
> +/* Program Status Word.  */
> +#define S390_PSWM_REGNUM 0
> +#define S390_PSWA_REGNUM 1
> +/* General Purpose Registers.  */
> +#define S390_R0_REGNUM 2
> +#define S390_R1_REGNUM 3
> +#define S390_R2_REGNUM 4
> +#define S390_R3_REGNUM 5
> +#define S390_R4_REGNUM 6
> +#define S390_R5_REGNUM 7
> +#define S390_R6_REGNUM 8
> +#define S390_R7_REGNUM 9
> +#define S390_R8_REGNUM 10
> +#define S390_R9_REGNUM 11
> +#define S390_R10_REGNUM 12
> +#define S390_R11_REGNUM 13
> +#define S390_R12_REGNUM 14
> +#define S390_R13_REGNUM 15
> +#define S390_R14_REGNUM 16
> +#define S390_R15_REGNUM 17
> +/* Access Registers.  */
> +#define S390_A0_REGNUM 18
> +#define S390_A1_REGNUM 19
> +#define S390_A2_REGNUM 20
> +#define S390_A3_REGNUM 21
> +#define S390_A4_REGNUM 22
> +#define S390_A5_REGNUM 23
> +#define S390_A6_REGNUM 24
> +#define S390_A7_REGNUM 25
> +#define S390_A8_REGNUM 26
> +#define S390_A9_REGNUM 27
> +#define S390_A10_REGNUM 28
> +#define S390_A11_REGNUM 29
> +#define S390_A12_REGNUM 30
> +#define S390_A13_REGNUM 31
> +#define S390_A14_REGNUM 32
> +#define S390_A15_REGNUM 33
> +/* Floating Point Control Word.  */
> +#define S390_FPC_REGNUM 34
> +/* Floating Point Registers.  */
> +#define S390_F0_REGNUM 35
> +#define S390_F1_REGNUM 36
> +#define S390_F2_REGNUM 37
> +#define S390_F3_REGNUM 38
> +#define S390_F4_REGNUM 39
> +#define S390_F5_REGNUM 40
> +#define S390_F6_REGNUM 41
> +#define S390_F7_REGNUM 42
> +#define S390_F8_REGNUM 43
> +#define S390_F9_REGNUM 44
> +#define S390_F10_REGNUM 45
> +#define S390_F11_REGNUM 46
> +#define S390_F12_REGNUM 47
> +#define S390_F13_REGNUM 48
> +#define S390_F14_REGNUM 49
> +#define S390_F15_REGNUM 50
> +/* Total.  */
> +#define S390_NUM_REGS 51
> +
> +/* Pseudo registers -- PC and condition code.  */
> +#define S390_PC_REGNUM S390_NUM_REGS
> +#define S390_CC_REGNUM (S390_NUM_REGS+1)
> +#define S390_NUM_PSEUDO_REGS 2
> +#define S390_NUM_TOTAL_REGS (S390_NUM_REGS+2)
> +
> +
>  #endif
> diff --git a/target-s390x/exec.h b/target-s390x/exec.h
> index 5198359..13dc7dd 100644
> --- a/target-s390x/exec.h
> +++ b/target-s390x/exec.h
> @@ -22,9 +22,14 @@
>  
>  register struct CPUS390XState *env asm(AREG0);
>  
> +#include "config.h"
>  #include "cpu.h"
>  #include "exec-all.h"
>  
> +#if !defined(CONFIG_USER_ONLY)
> +#include "softmmu_exec.h"
> +#endif /* !defined(CONFIG_USER_ONLY) */
> +
>  static inline int cpu_has_work(CPUState *env)
>  {
>      return env->interrupt_request & CPU_INTERRUPT_HARD; // guess
> diff --git a/target-s390x/helper.c b/target-s390x/helper.c
> index 0e222e3..f4c4e04 100644
> --- a/target-s390x/helper.c
> +++ b/target-s390x/helper.c
> @@ -27,6 +27,9 @@
>  #include "gdbstub.h"
>  #include "qemu-common.h"
>  
> +#include <linux/kvm.h>
> +#include "kvm.h"
> +
>  CPUS390XState *cpu_s390x_init(const char *cpu_model)
>  {
>      CPUS390XState *env;
> @@ -60,3 +63,22 @@ void cpu_reset(CPUS390XState *env)
>      /* FIXME: reset vector? */
>      tlb_flush(env, 1);
>  }
> +
> +#ifndef CONFIG_USER_ONLY
> +
> +int cpu_s390x_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
> +                                int mmu_idx, int is_softmmu)
> +{
> +    target_ulong phys;
> +    int prot;
> +
> +    /* XXX: implement mmu */
> +
> +    phys = address;
> +    prot = PAGE_READ | PAGE_WRITE;
> +
> +    return tlb_set_page(env, address & TARGET_PAGE_MASK,
> +                        phys & TARGET_PAGE_MASK, prot,
> +                        mmu_idx, is_softmmu);

Same as previous comment, if softmmu accesses are possible, this
function should be written correctly.

> +}
> +#endif /* CONFIG_USER_ONLY */
> diff --git a/target-s390x/machine.c b/target-s390x/machine.c
> new file mode 100644
> index 0000000..3e79be6
> --- /dev/null
> +++ b/target-s390x/machine.c
> @@ -0,0 +1,30 @@
> +/*
> + * QEMU S390x machine definitions
> + *
> + * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
/> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "hw/hw.h"
> +#include "hw/boards.h"
> +
> +void cpu_save(QEMUFile *f, void *opaque)
> +{
> +}
> +
> +int cpu_load(QEMUFile *f, void *opaque, int version_id)
> +{
> +    return 0;
> +}
> -- 
> 1.6.0.2
> 
> 
> 
> 

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net