From: Oliver Upton commit e9b152cb957c ("arm/arm64: kvm: Set vcpu->cpu to -1 on vcpu_put") reset vcpu->cpu in order for the VGIC to determine if there was any vCPU running at the time of access. The VGIC has gone through an entire rewrite since then, and with commit 7d450e282171 ("KVM: arm/arm64: vgic-new: Add userland access to VGIC dist registers") the user accessors just grab all vCPU mutexes instead. Drop this remaining vestige such that kvm_arch_vcpu_load() can properly detect a CPU migration. While at it, rework kvm_reset_vcpu() to do a much more pedantic check that the provided vCPU is actually what's running on the present CPU. Signed-off-by: Oliver Upton Signed-off-by: Akihiko Odaki Reviewed-by: Fuad Tabba --- arch/arm64/kvm/arm.c | 1 - arch/arm64/kvm/reset.c | 16 +++++++++++----- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 8eff03c32418..dce6ba0f51e6 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -754,7 +754,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) kvm_arm_vmid_clear_active(); vcpu_clear_on_unsupported_cpu(vcpu); - vcpu->cpu = -1; } static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 10eb7249aa9e..cdcdea850909 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -178,17 +178,24 @@ static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu) void kvm_reset_vcpu(struct kvm_vcpu *vcpu) { struct vcpu_reset_state reset_state; - bool loaded; + struct kvm_vcpu *running; + bool loaded = false; spin_lock(&vcpu->arch.mp_state_lock); reset_state = vcpu->arch.reset_state; vcpu->arch.reset_state.reset = false; spin_unlock(&vcpu->arch.mp_state_lock); - preempt_disable(); - loaded = (vcpu->cpu != -1); - if (loaded) + guard(preempt)(); + + running = kvm_get_running_vcpu(); + if (running) { + if (KVM_BUG_ON(running != vcpu, vcpu->kvm)) + return; + + loaded = true; kvm_arch_vcpu_put(vcpu); + } if (!kvm_arm_vcpu_sve_finalized(vcpu)) { if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) @@ -215,7 +222,6 @@ void kvm_reset_vcpu(struct kvm_vcpu *vcpu) if (loaded) kvm_arch_vcpu_load(vcpu, smp_processor_id()); - preempt_enable(); } u32 kvm_get_pa_bits(struct kvm *kvm) -- 2.55.0