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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On Mon, Jun 21, 2021 at 12:18 PM Steven Price wrote: > > It's now safe for the VMM to enable MTE in a guest, so expose the > capability to user space. > > Reviewed-by: Catalin Marinas > Signed-off-by: Steven Price > --- > arch/arm64/kvm/arm.c | 9 +++++++++ > arch/arm64/kvm/reset.c | 4 ++++ > arch/arm64/kvm/sys_regs.c | 3 +++ > 3 files changed, 16 insertions(+) > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index e720148232a0..28ce26a68f09 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -93,6 +93,12 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, > r = 0; > kvm->arch.return_nisv_io_abort_to_user = true; > break; > + case KVM_CAP_ARM_MTE: > + if (!system_supports_mte() || kvm->created_vcpus) > + return -EINVAL; > + r = 0; > + kvm->arch.mte_enabled = true; > + break; > default: > r = -EINVAL; > break; > @@ -237,6 +243,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > */ > r = 1; > break; > + case KVM_CAP_ARM_MTE: > + r = system_supports_mte(); > + break; > case KVM_CAP_STEAL_TIME: > r = kvm_arm_pvtime_supported(); > break; > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > index d37ebee085cf..9e6922b9503a 100644 > --- a/arch/arm64/kvm/reset.c > +++ b/arch/arm64/kvm/reset.c > @@ -244,6 +244,10 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) > switch (vcpu->arch.target) { > default: > if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) { > + if (vcpu->kvm->arch.mte_enabled) { > + ret = -EINVAL; > + goto out; > + } > pstate = VCPU_RESET_PSTATE_SVC; > } else { > pstate = VCPU_RESET_PSTATE_EL1; nit: I was wondering whether this check would be better suited in kvm_vcpu_set_target, rather than here (kvm_reset_vcpu). kvm_reset_vcpu is called by kvm_vcpu_set_target, but kvm_vcpu_set_target is where checking for supported features happens. It might be better to group all such checks together. I don't think that there is any risk of this feature being toggled by the other call path to kvm_reset_vcpu (via check_vcpu_requests). Cheers, /fuad > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index 5c75b24eae21..f6f126eb6ac1 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -1312,6 +1312,9 @@ static bool access_ccsidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, > static unsigned int mte_visibility(const struct kvm_vcpu *vcpu, > const struct sys_reg_desc *rd) > { > + if (kvm_has_mte(vcpu->kvm)) > + return 0; > + > return REG_HIDDEN; > } > > -- > 2.20.1 > > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel