Re: [Qemu-devel] [PATCH 04/11] Add KVM support for S390x

[Alexander Graf]

On 02.12.2009, at 09:12, Aurelien Jarno wrote:

> On Mon, Nov 30, 2009 at 11:25:03PM +0100, Alexander Graf wrote:
>> 
>> On 30.11.2009, at 19:18, Aurelien Jarno wrote:
>> 
>>> On Thu, Nov 26, 2009 at 02:23:13PM +0100, Alexander Graf wrote:
>>>> S390x was one of the first platforms that received support for KVM back in 
>>>> the
>>>> day. Unfortunately until now there hasn't been a qemu implementation that 
>>>> would
>>>> enable users to actually run guests.
>>>> 
>>>> So let's include support for KVM S390x in qemu!
>>> 
>>> Please find the comments below.
>>> 
>>>> Signed-off-by: Alexander Graf <address@hidden>
>>>> ---
>>>> configure          |    4 +-
>>>> target-s390x/kvm.c |  463 
>>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>> 2 files changed, 466 insertions(+), 1 deletions(-)
>>>> create mode 100644 target-s390x/kvm.c
>>>> 
>>>> diff --git a/configure b/configure
>>>> index b616e1a..cf466ec 100755
>>>> --- a/configure
>>>> +++ b/configure
>>>> @@ -1348,6 +1348,8 @@ EOF
>>>>            kvm_cflags="$kvm_cflags -I$kerneldir/arch/x86/include"
>>>>    elif test "$cpu" = "ppc" -a -d "$kerneldir/arch/powerpc/include" ; then
>>>>        kvm_cflags="$kvm_cflags -I$kerneldir/arch/powerpc/include"
>>>> +  elif test "$cpu" = "s390x" -a -d "$kerneldir/arch/s390/include" ; then
>>>> +      kvm_cflags="$kvm_cflags -I$kerneldir/arch/s390/include"
>>>>        elif test -d "$kerneldir/arch/$cpu/include" ; then
>>>>            kvm_cflags="$kvm_cflags -I$kerneldir/arch/$cpu/include"
>>>>      fi
>>>> @@ -2360,7 +2362,7 @@ case "$target_arch2" in
>>>>    fi
>>>> esac
>>>> case "$target_arch2" in
>>>> -  i386|x86_64|ppcemb|ppc|ppc64)
>>>> +  i386|x86_64|ppcemb|ppc|ppc64|s390x)
>>>>    # Make sure the target and host cpus are compatible
>>>>    if test "$kvm" = "yes" -a "$target_softmmu" = "yes" -a \
>>>>      \( "$target_arch2" = "$cpu" -o \
>>>> diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
>>>> new file mode 100644
>>>> index 0000000..d477664
>>>> --- /dev/null
>>>> +++ b/target-s390x/kvm.c
>>>> @@ -0,0 +1,463 @@
>>>> +/*
>>>> + * QEMU S390x KVM implementation
>>>> + *
>>>> + * Copyright (c) 2009 Alexander Graf <address@hidden>
>>>> + *
>>>> + * 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 <sys/types.h>
>>>> +#include <sys/ioctl.h>
>>>> +#include <sys/mman.h>
>>>> +
>>>> +#include <linux/kvm.h>
>>>> +#include <asm/ptrace.h>
>>>> +
>>>> +#include "qemu-common.h"
>>>> +#include "qemu-timer.h"
>>>> +#include "sysemu.h"
>>>> +#include "kvm.h"
>>>> +#include "cpu.h"
>>>> +#include "device_tree.h"
>>>> +
>>>> +/* #define DEBUG_KVM */
>>>> +
>>>> +#ifdef DEBUG_KVM
>>>> +#define dprintf(fmt, ...) \
>>>> +    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
>>>> +#else
>>>> +#define dprintf(fmt, ...) \
>>>> +    do { } while (0)
>>>> +#endif
>>>> +
>>>> +#define IPA0_DIAG               0x8300
>>>> +#define IPA0_SIGP               0xae00
>>>> +#define IPA0_PRIV               0xb200
>>>> +
>>>> +#define PRIV_SCLP_CALL          0x20
>>>> +#define DIAG_KVM_HYPERCALL      0x500
>>>> +#define DIAG_KVM_BREAKPOINT     0x501
>>>> +
>>>> +#define SCP_LENGTH              0x00
>>>> +#define SCP_FUNCTION_CODE       0x02
>>>> +#define SCP_CONTROL_MASK        0x03
>>>> +#define SCP_RESPONSE_CODE       0x06
>>>> +#define SCP_MEM_CODE            0x08
>>>> +#define SCP_INCREMENT           0x0a
>>>> +
>>>> +#define ICPT_INSTRUCTION        0x04
>>>> +#define ICPT_WAITPSW            0x1c
>>>> +#define ICPT_SOFT_INTERCEPT     0x24
>>>> +#define ICPT_CPU_STOP           0x28
>>>> +#define ICPT_IO                 0x40
>>>> +
>>>> +#define SIGP_RESTART            0x06
>>>> +#define SIGP_INITIAL_CPU_RESET  0x0b
>>>> +#define SIGP_STORE_STATUS_ADDR  0x0e
>>>> +#define SIGP_SET_ARCH           0x12
>>>> +
>>>> +
>>>> +int kvm_arch_init(KVMState *s, int smp_cpus)
>>>> +{
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +int kvm_arch_init_vcpu(CPUState *env)
>>>> +{
>>>> +    int ret = 0;
>>>> +
>>>> +    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL) < 0)
>>>> +        perror("cannot init reset vcpu");
>>> 
>>> coding style.
>>> 
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +void kvm_arch_reset_vcpu(CPUState *env)
>>>> +{
>>>> +}
>>> 
>>> Is there really nothing to do? If some code has to be added later, it
>>> may be worth adding a comment.
>> 
>> As you have probably realized by now, all reset code is missing. In fact, we 
>> don't even ever call the qemu reset functions to actually do a reset.
> 
> Can you make it clean with an abort?
> 
>>>> +
>>>> +static void _kvm_s390_interrupt(CPUState *env, int type, uint32_t parm, 
>>>> uint64_t parm64, int vm)
>>>> +{
>>> 
>>> Why such a name starting with an underscore?
>> 
>> Because that's the internal function that gets used by the exported, 
>> properly named ones. Are there any conventions on how to declare private 
>> functions?
> 
> I don't think there is any convention, but I know malc always complains
> about not introducing names starting with an underscore.

Hm - I just wanted to clearly show that this is an internal API, nobody should 
really have to call directly. But I'm open for other naming suggestions.

Alex