Re: [Qemu-devel] [PATCH 1/2] Move KVM init to arch_init.c, compile vl.c once

[Blue Swirl]

On 4/1/10, Anthony Liguori <address@hidden> wrote:
> On 04/01/2010 03:07 PM, Blue Swirl wrote:
>
> > Remove dependency of vl.c to KVM, then we can partially revert
> > b33612d03540fda7fa67485f1c20395beb7a2bf0.
> >
> > Signed-off-by: Blue Swirl<address@hidden>
> > ---
> >  Makefile.objs   |    2 +-
> >  Makefile.target |    2 +-
> >  arch_init.c     |   20 ++++++++++++++++++++
> >  arch_init.h     |    2 ++
> >  vl.c            |   14 ++------------
> >  5 files changed, 26 insertions(+), 14 deletions(-)
> >
> > diff --git a/Makefile.objs b/Makefile.objs
> > index 74d7a3d..4cc8ea6 100644
> > --- a/Makefile.objs
> > +++ b/Makefile.objs
> > @@ -128,7 +128,7 @@ user-obj-y += cutils.o cache-utils.o
> >  # libhw
> >
> >  hw-obj-y =
> > -hw-obj-y += loader.o
> > +hw-obj-y += vl.o loader.o
> >  hw-obj-y += virtio.o virtio-console.o
> >  hw-obj-y += fw_cfg.o pci.o pci_host.o pcie_host.o
> >  hw-obj-y += watchdog.o
> > diff --git a/Makefile.target b/Makefile.target
> > index 167fc8d..2aa02f5 100644
> > --- a/Makefile.target
> > +++ b/Makefile.target
> > @@ -161,7 +161,7 @@ endif #CONFIG_BSD_USER
> >  # System emulator target
> >  ifdef CONFIG_SOFTMMU
> >
> > -obj-y = arch_init.o cpus.o monitor.o machine.o gdbstub.o vl.o
> > +obj-y = arch_init.o cpus.o monitor.o machine.o gdbstub.o
> >  # virtio has to be here due to weird dependency between PCI and
> virtio-net.
> >  # need to fix this properly
> >  obj-y += virtio-blk.o virtio-balloon.o virtio-net.o virtio-pci.o
> > virtio-serial-bus.o
> > diff --git a/arch_init.c b/arch_init.c
> > index cfc03ea..001c560 100644
> > --- a/arch_init.c
> > +++ b/arch_init.c
> > @@ -41,6 +41,8 @@
> >  #include "gdbstub.h"
> >  #include "hw/smbios.h"
> >
> > +int kvm_allowed = 0;
> > +
> >  #ifdef TARGET_SPARC
> >  int graphic_width = 1024;
> >  int graphic_height = 768;
> > @@ -508,3 +510,21 @@ int xen_available(void)
> >      return 0;
> >  #endif
> >  }
> > +
> > +void enable_kvm(void)
> > +{
> > +    kvm_allowed = 1;
> > +}
> >
> >
>
>  Can we get away with keeping a local to vl.c use_kvm flag and then call
> kvm_init() if use_kvm in vl.c?

It will not be safe to use kvm_enabled() in vl.c, so there needs to be
a target dependent helper. The call to kvm_init could remain in vl.c,
likewise it's not strictly needed to move kvm_allowed to arch_init.c.
They just caused problems with the poisoning check in patch 2/2. But
with this approach, because kvm.h is no longer included, there will
not be any problems.

>
>  We can stick a stub kvm_init() in arch_init.c if !CONFIG_KVM.
>
>  Regards,
>
>  Anthony LIguori
>
>
>
> > +void kvm_maybe_init(int smp_cpus)
> > +{
> > +    if (kvm_enabled()) {
> > +        int ret;
> > +
> > +        ret = kvm_init(smp_cpus);
> > +        if (ret<  0) {
> > +            fprintf(stderr, "failed to initialize KVM\n");
> > +            exit(1);
> > +        }
> > +    }
> > +}
> > diff --git a/arch_init.h b/arch_init.h
> > index 682890c..dde4309 100644
> > --- a/arch_init.h
> > +++ b/arch_init.h
> > @@ -29,5 +29,7 @@ void cpudef_init(void);
> >  int audio_available(void);
> >  int kvm_available(void);
> >  int xen_available(void);
> > +void enable_kvm(void);
> > +void kvm_maybe_init(int smp_cpus);
> >
> >  #endif
> > diff --git a/vl.c b/vl.c
> > index 03fccbf..cc214dd 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -145,7 +145,6 @@ int main(int argc, char **argv)
> >  #include "dma.h"
> >  #include "audio/audio.h"
> >  #include "migration.h"
> > -#include "kvm.h"
> >  #include "balloon.h"
> >  #include "qemu-option.h"
> >  #include "qemu-config.h"
> > @@ -241,7 +240,6 @@ uint8_t qemu_uuid[16];
> >  static QEMUBootSetHandler *boot_set_handler;
> >  static void *boot_set_opaque;
> >
> > -int kvm_allowed = 0;
> >  uint32_t xen_domid;
> >  enum xen_mode xen_mode = XEN_EMULATE;
> >
> > @@ -3228,7 +3226,7 @@ int main(int argc, char **argv, char **envp)
> >                      printf("Option %s not supported for this
> > target\n", popt->name);
> >                      exit(1);
> >                  }
> > -                kvm_allowed = 1;
> > +                enable_kvm();
> >                  break;
> >              case QEMU_OPTION_usb:
> >                  usb_enabled = 1;
> > @@ -3574,15 +3572,7 @@ int main(int argc, char **argv, char **envp)
> >          exit(1);
> >      }
> >
> > -    if (kvm_enabled()) {
> > -        int ret;
> > -
> > -        ret = kvm_init(smp_cpus);
> > -        if (ret<  0) {
> > -            fprintf(stderr, "failed to initialize KVM\n");
> > -            exit(1);
> > -        }
> > -    }
> > +    kvm_maybe_init(smp_cpus);
> >
> >      if (qemu_init_main_loop()) {
> >          fprintf(stderr, "qemu_init_main_loop failed\n");
> >
> >
>
>