From 328e566479449194979d64685ae6d74c989599bb Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Thu, 24 Mar 2016 11:21:04 +0100 Subject: KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/put We don't have to save/restore the VMCR on every entry to/from the guest, since on GICv2 we can access the control interface from EL1 and on VHE systems with GICv3 we can access the control interface from KVM running in EL2. GICv3 systems without VHE becomes the rare case, which has to save/restore the register on each round trip. Note that userspace accesses may see out-of-date values if the VCPU is running while accessing the VGIC state via the KVM device API, but this is already the case and it is up to userspace to quiesce the CPUs before reading the CPU registers from the GIC for an up-to-date view. Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Christoffer Dall --- virt/kvm/arm/vgic/vgic.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'virt/kvm/arm/vgic/vgic.h') diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index db28f7cadab2..9afb4557c7e8 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -130,6 +130,9 @@ int vgic_v2_map_resources(struct kvm *kvm); int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address, enum vgic_type); +void vgic_v2_load(struct kvm_vcpu *vcpu); +void vgic_v2_put(struct kvm_vcpu *vcpu); + static inline void vgic_get_irq_kref(struct vgic_irq *irq) { if (irq->intid < VGIC_MIN_LPI) @@ -150,6 +153,9 @@ int vgic_v3_probe(const struct gic_kvm_info *info); int vgic_v3_map_resources(struct kvm *kvm); int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address); +void vgic_v3_load(struct kvm_vcpu *vcpu); +void vgic_v3_put(struct kvm_vcpu *vcpu); + int vgic_register_its_iodevs(struct kvm *kvm); bool vgic_has_its(struct kvm *kvm); int kvm_vgic_register_its_device(void); -- cgit v1.2.3 From af0614991ab64a55f86cda257cedff1be4e435fa Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Thu, 29 Dec 2016 15:44:27 +0100 Subject: KVM: arm/arm64: vgic: Get rid of unnecessary process_maintenance operation Since we always read back the LRs that we wrote to the guest and the MISR and EISR registers simply provide a summary of the configuration of the bits in the LRs, there is really no need to read back those status registers and process them. We might as well just signal the notifyfd when folding the LR state and save some cycles in the process. We now clear the underflow bit in the fold_lr_state functions as we only need to clear this bit if we had used all the LRs, so this is as good a place as any to do that work. Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall --- virt/kvm/arm/vgic/vgic.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'virt/kvm/arm/vgic/vgic.h') diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index 9afb4557c7e8..44445dac0835 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -112,7 +112,6 @@ void vgic_kick_vcpus(struct kvm *kvm); int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr, phys_addr_t addr, phys_addr_t alignment); -void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu); void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu); void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr); void vgic_v2_clear_lr(struct kvm_vcpu *vcpu, int lr); @@ -141,7 +140,6 @@ static inline void vgic_get_irq_kref(struct vgic_irq *irq) kref_get(&irq->refcount); } -void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu); void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu); void vgic_v3_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr); void vgic_v3_clear_lr(struct kvm_vcpu *vcpu, int lr); -- cgit v1.2.3