Hi Dave, On 19/03/2019 17:52, Dave Martin wrote: > In preparation for adding logic to filter out some KVM_REG_ARM_CORE > registers from the KVM_GET_REG_LIST output, this patch factors out > the core register enumeration into a separate function and rebuilds > num_core_regs() on top of it. > > This may be a little more expensive (depending on how good a job > the compiler does of specialising the code), but KVM_GET_REG_LIST > is not a hot path. > > This will make it easier to consolidate ID filtering code in one > place. > > No functional change. > > Signed-off-by: Dave Martin <[email protected]> >
Reviewed-by: Julien Thierry <[email protected]> Cheers, Julien > --- > > Changes since v5: > > * New patch. > > This reimplements part of the separately-posted patch "KVM: arm64: > Factor out KVM_GET_REG_LIST core register enumeration", minus aspects > that potentially break the ABI. > > As a result, the opportunity to truly consolidate all the ID reg > filtering in one place is deliberately left on the floor, for now. > This will be addressed in a separate series later on. > --- > arch/arm64/kvm/guest.c | 33 +++++++++++++++++++++++++-------- > 1 file changed, 25 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c > index 3e38eb2..a391a61 100644 > --- a/arch/arm64/kvm/guest.c > +++ b/arch/arm64/kvm/guest.c > @@ -23,6 +23,7 @@ > #include <linux/err.h> > #include <linux/kvm_host.h> > #include <linux/module.h> > +#include <linux/stddef.h> > #include <linux/string.h> > #include <linux/vmalloc.h> > #include <linux/fs.h> > @@ -194,9 +195,28 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, > struct kvm_regs *regs) > return -EINVAL; > } > > +static int kvm_arm_copy_core_reg_indices(u64 __user *uindices) > +{ > + unsigned int i; > + int n = 0; > + const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | > KVM_REG_ARM_CORE; > + > + for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) { > + if (uindices) { > + if (put_user(core_reg | i, uindices)) > + return -EFAULT; > + uindices++; > + } > + > + n++; > + } > + > + return n; > +} > + > static unsigned long num_core_regs(void) > { > - return sizeof(struct kvm_regs) / sizeof(__u32); > + return kvm_arm_copy_core_reg_indices(NULL); > } > > /** > @@ -276,15 +296,12 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu) > */ > int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) > { > - unsigned int i; > - const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | > KVM_REG_ARM_CORE; > int ret; > > - for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) { > - if (put_user(core_reg | i, uindices)) > - return -EFAULT; > - uindices++; > - } > + ret = kvm_arm_copy_core_reg_indices(uindices); > + if (ret) > + return ret; > + uindices += ret; > > ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices); > if (ret) > -- Julien Thierry _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
