On Wed, Jul 25, 2018 at 03:12:15PM +0100, Alex Bennée wrote: > > Dave Martin <Dave.Martin@xxxxxxx> writes: > > > Some system registers may or may not logically exist for a vcpu > > depending on whether certain architectural features are enabled for > > the vcpu. > > > > In order to avoid spuriously emulating access to these registers > > when they should not exist, or allowing the registers to be > > spuriously enumerated or saved/restored through the ioctl > > interface, a means is needed to allow registers to be hidden > > depending on the vcpu configuration. > > > > In order to support this in a flexible way, this patch adds a > > check_present() method to struct sys_reg_desc, and updates the > > generic system register access and enumeration code to be aware of > > it: if check_present() returns false, the code behaves as if the > > register did not exist. > > > > For convenience, the complete check is wrapped up in a new helper > > sys_reg_present(). > > > > An attempt has been made to hook the new check into the generic > > accessors for trapped system registers. This should reduce the > > potential for future surprises, although the redundant check will > > add a small cost. No system register depends on this functionality > > yet, and some paths needing the check may also need attention. > > > > Naturally, this facility makes sense only for registers that are > > trapped. > > > > Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> > > --- > > arch/arm64/kvm/sys_regs.c | 20 +++++++++++++++----- > > arch/arm64/kvm/sys_regs.h | 11 +++++++++++ > > 2 files changed, 26 insertions(+), 5 deletions(-) [...] > > diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h > > index cd710f8..dfbb342 100644 > > --- a/arch/arm64/kvm/sys_regs.h > > +++ b/arch/arm64/kvm/sys_regs.h > > @@ -22,6 +22,9 @@ > > #ifndef __ARM64_KVM_SYS_REGS_LOCAL_H__ > > #define __ARM64_KVM_SYS_REGS_LOCAL_H__ > > > > +#include <linux/compiler.h> > > +#include <linux/types.h> > > I can see why you want compiler.h, but why types.h? For bool (though it felt a bit pedantic). Cheers ---Dave _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
