Re: [PATCH v2] kvm_host: unify VM_STAT and VCPU_STAT definitions in a single place

[Emanuele Giuseppe Esposito <eesposit@xxxxxxxxxx>]

On 4/15/20 8:36 AM, Philippe Mathieu-Daudé wrote:
> On 4/14/20 5:56 PM, Emanuele Giuseppe Esposito wrote:
> > The macros VM_STAT and VCPU_STAT are redundantly implemented in multiple
> > files, each used by a different architecure to initialize the debugfs
> > entries for statistics. Since they all have the same purpose, they can be
> > unified in a single common definition in include/linux/kvm_host.h
> >
> > Signed-off-by: Emanuele Giuseppe Esposito <eesposit@xxxxxxxxxx>
> > ---
> >   arch/arm64/kvm/guest.c    |  23 ++---
> >   arch/mips/kvm/mips.c      |  61 ++++++------
> >   arch/powerpc/kvm/book3s.c |  61 ++++++------
> >   arch/powerpc/kvm/booke.c  |  41 ++++----
> >   arch/s390/kvm/kvm-s390.c  | 203 +++++++++++++++++++-------------------
> >   arch/x86/kvm/x86.c        |  80 +++++++--------
> >   include/linux/kvm_host.h  |   5 +
> >   7 files changed, 231 insertions(+), 243 deletions(-)
> >
> > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> > index 23ebe51410f0..8417b200bec9 100644
> > --- a/arch/arm64/kvm/guest.c
> > +++ b/arch/arm64/kvm/guest.c
> > @@ -29,20 +29,17 @@
> >   
> >   #include "trace.h"
> >   
> > -#define VM_STAT(x) { #x, offsetof(struct kvm, stat.x), KVM_STAT_VM }
> > -#define VCPU_STAT(x) { #x, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU }
> > -
> >   struct kvm_stats_debugfs_item debugfs_entries[] = {
> > -	VCPU_STAT(halt_successful_poll),
> > -	VCPU_STAT(halt_attempted_poll),
> > -	VCPU_STAT(halt_poll_invalid),
> > -	VCPU_STAT(halt_wakeup),
> > -	VCPU_STAT(hvc_exit_stat),
> > -	VCPU_STAT(wfe_exit_stat),
> > -	VCPU_STAT(wfi_exit_stat),
> > -	VCPU_STAT(mmio_exit_user),
> > -	VCPU_STAT(mmio_exit_kernel),
> > -	VCPU_STAT(exits),
> > +	VCPU_STAT("halt_successful_poll", halt_successful_poll),
> > +	VCPU_STAT("halt_attempted_poll", halt_attempted_poll),
> > +	VCPU_STAT("halt_poll_invalid", halt_poll_invalid),
> > +	VCPU_STAT("halt_wakeup", halt_wakeup),
> > +	VCPU_STAT("hvc_exit_stat", hvc_exit_stat),
> > +	VCPU_STAT("wfe_exit_stat", wfe_exit_stat),
> > +	VCPU_STAT("wfi_exit_stat", wfi_exit_stat),
> > +	VCPU_STAT("mmio_exit_user", mmio_exit_user),
> > +	VCPU_STAT("mmio_exit_kernel", mmio_exit_kernel),
> > +	VCPU_STAT("exits", exits),
> >   	{ NULL }
> >   };
>
> Patch easily reviewed with --word-diff.
>
> [...]
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index 6d58beb65454..2e6ead872957 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -1130,6 +1130,11 @@ struct kvm_stats_debugfs_item {
> >   #define KVM_DBGFS_GET_MODE(dbgfs_item)                                         \
> >   	((dbgfs_item)->mode ? (dbgfs_item)->mode : 0644)
> >   
> > +#define VM_STAT(n, x, ...) 													   \
> > +	{ n, offsetof(struct kvm, stat.x), KVM_STAT_VM, ## __VA_ARGS__ }
> > +#define VCPU_STAT(n, x, ...)												   \
>
> Not sure while you use so many whitespaces here... (maybe Paolo can
> strip some when applying?).

I honestly am not sure why it added few more spaces than I wanted, but 
the idea was to follow the KVM_DBGFS_GET_MODE macro above and put the 
backslash at the end of the line (80th char).

> Otherwise it looks nicer that v1, thanks.
>
> Reviewed-by: Philippe Mathieu-Daudé <f4bug@xxxxxxxxx>
>
> > +	{ n, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU, ## __VA_ARGS__ }
> > +
> >   extern struct kvm_stats_debugfs_item debugfs_entries[];
> >   extern struct dentry *kvm_debugfs_dir;
> >