[PATCH v2 02/17] KVM: arm64: Reject the PVTIME vCPU attribute for protected VMs
From: Fuad Tabba <fuad.tabba@linux.dev>
Date: 2026-09-07 07:00:22
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
pKVM currently doesn't support steal time for protected guests: KVM_CAP_STEAL_TIME reports 0 for them. The host still accepts the KVM_ARM_VCPU_PVTIME_CTRL attribute, whose IPA would point kvm_update_stolen_time() at the guest's private memory on every vCPU load. Return -EPERM for the attribute group instead. Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev> --- arch/arm64/kvm/guest.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index b01d6622b8720..ab659795d4b2f 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c@@ -916,6 +916,10 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, ret = kvm_arm_timer_set_attr(vcpu, attr); break; case KVM_ARM_VCPU_PVTIME_CTRL: + /* Steal time is not advertised to protected guests. */ + if (vcpu_is_protected(vcpu)) + return -EPERM; + ret = kvm_arm_pvtime_set_attr(vcpu, attr); break; default:
@@ -939,6 +943,9 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, ret = kvm_arm_timer_get_attr(vcpu, attr); break; case KVM_ARM_VCPU_PVTIME_CTRL: + if (vcpu_is_protected(vcpu)) + return -EPERM; + ret = kvm_arm_pvtime_get_attr(vcpu, attr); break; default:
@@ -962,6 +969,9 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, ret = kvm_arm_timer_has_attr(vcpu, attr); break; case KVM_ARM_VCPU_PVTIME_CTRL: + if (vcpu_is_protected(vcpu)) + return -EPERM; + ret = kvm_arm_pvtime_has_attr(vcpu, attr); break; default:
--
2.39.5