On Thu, 30 May 2019 16:13:12 +0100 Dave Martin <dave.mar...@arm.com> wrote:
> To help the user understand what is going on, amend ptrauth > configuration diagnostic messages to refer to command line options > by the exact name used on the command line. > > Also, provide a clean diagnostic when ptrauth is requested, but not > availble. The generic "Unable to initialise vcpu" message is > rather cryptic for this case. Again I don't see much value in having this as a separate patch, as it basically just touches code introduced two patches earlier. I think it should be merged into 5/9. > Since we now don't attempt to enable ptrauth at all unless KVM > reports the relevant capabilities, remove the error message for > that case too: in any case, we can't diagnose precisely why > KVM_ARM_VCPU_INIT failed, so the message may be misleading. So this leaves the only point where we use .enable_ptrauth to that error message about the host not supporting it. Not sure if that's worth this separate option? Cheers, Andre. > Signed-off-by: Dave Martin <dave.mar...@arm.com> > --- > arm/aarch64/include/kvm/kvm-config-arch.h | 4 ++-- > arm/aarch64/kvm-cpu.c | 15 +++++++++++---- > arm/kvm-cpu.c | 8 ++------ > 3 files changed, 15 insertions(+), 12 deletions(-) > > diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h > b/arm/aarch64/include/kvm/kvm-config-arch.h > index 0279b13..fe1699d 100644 > --- a/arm/aarch64/include/kvm/kvm-config-arch.h > +++ b/arm/aarch64/include/kvm/kvm-config-arch.h > @@ -10,9 +10,9 @@ > "Specify random seed for Kernel Address Space " \ > "Layout Randomization (KASLR)"), \ > OPT_BOOLEAN('\0', "enable-ptrauth", &(cfg)->enable_ptrauth, \ > - "Enables pointer authentication"), \ > + "Enable pointer authentication for the guest"), \ > OPT_BOOLEAN('\0', "disable-ptrauth", &(cfg)->disable_ptrauth, \ > - "Disables pointer authentication"), > + "Disable pointer authentication for the guest"), > > #include "arm-common/kvm-config-arch.h" > > diff --git a/arm/aarch64/kvm-cpu.c b/arm/aarch64/kvm-cpu.c > index d3c32e0..08e4fd5 100644 > --- a/arm/aarch64/kvm-cpu.c > +++ b/arm/aarch64/kvm-cpu.c > @@ -130,16 +130,23 @@ static void reset_vcpu_aarch64(struct kvm_cpu *vcpu) > > static void select_ptrauth_feature(struct kvm *kvm, struct kvm_vcpu_init > *init) > { > + bool supported; > + > /* Check Pointer Authentication command line arguments. */ > if (kvm->cfg.arch.enable_ptrauth && kvm->cfg.arch.disable_ptrauth) > - die("Both enable-ptrauth and disable-ptrauth option cannot be > present"); > + die("--enable-ptrauth conflicts with --disable-ptrauth"); > + > + supported = kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) && > + kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC); > + > + if (kvm->cfg.arch.enable_ptrauth && !supported) > + die("--enable-ptrauth not supported on this host"); > + > /* > * Always enable Pointer Authentication if system supports > * this extension unless disable-ptrauth option is present. > */ > - if (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) && > - kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC) && > - !kvm->cfg.arch.disable_ptrauth) { > + if (supported && !kvm->cfg.arch.disable_ptrauth) { > init->features[0] |= 1UL << KVM_ARM_VCPU_PTRAUTH_ADDRESS; > init->features[0] |= 1UL << KVM_ARM_VCPU_PTRAUTH_GENERIC; > } > diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c > index 764fb05..1652f6f 100644 > --- a/arm/kvm-cpu.c > +++ b/arm/kvm-cpu.c > @@ -108,12 +108,8 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, > unsigned long cpu_id) > die("Unable to find matching target"); > } > > - if (err || target->init(vcpu)) { > - if (kvm->cfg.arch.enable_ptrauth) > - die("Unable to initialise vcpu with pointer > authentication feature"); > - else > - die("Unable to initialise vcpu"); > - } > + if (err || target->init(vcpu)) > + die("Unable to initialise vcpu"); > > coalesced_offset = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION, > KVM_CAP_COALESCED_MMIO); _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm