On 30.11.2009, at 19:18, Aurelien Jarno wrote:
> 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.
Historical reasons. To keep Uli's stripped down version separate from my code.
>
>> Signed-off-by: Alexander Graf <ag...@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 ?).
I can't imagine any hardware using the CPU's MMU to write to RAM. That's what
IOMMUs are for.
The only 2 consumers are:
1) tcg
2) gdb / monitor
With 2) being broken, because we can't resolve virtual addresses to physical
addresses. But that won't change until someone implements the softmmu emulation
target for real.
