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authorChristoffer Dall <christoffer.dall@linaro.org>2017-10-05 17:19:19 +0200
committerMarc Zyngier <marc.zyngier@arm.com>2018-03-19 10:53:21 +0000
commit2d0e63e030babe19c94b4453ef4b272c0aacd75a (patch)
treec73409c2a22592b03f50bbe5d7e825fe028ab16a /arch/arm64/kvm
parent923a2e30e5745a8f94f953f7aacaafd3d551e12d (diff)
downloadlinux-2d0e63e030babe19c94b4453ef4b272c0aacd75a.tar.bz2
KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQs
We can finally get completely rid of any calls to the VGICv3 save/restore functions when the AP lists are empty on VHE systems. This requires carefully factoring out trap configuration from saving and restoring state, and carefully choosing what to do on the VHE and non-VHE path. One of the challenges is that we cannot save/restore the VMCR lazily because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end up being delivered as FIQ. To solve this problem, and still provide fast performance in the fast path of exiting a VM when no interrupts are pending (which also optimized the latency for actually delivering virtual interrupts coming from physical interrupts), we orchestrate a dance of only doing the activate/deactivate traps in vgic load/put for VHE systems (which can have ICC_SRE_EL1.SRE cleared when running in the host), and doing the configuration on every round-trip on non-VHE systems. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/kvm')
-rw-r--r--arch/arm64/kvm/hyp/switch.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 86abbee40d3f..07b572173265 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -195,15 +195,19 @@ static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu)
/* Save VGICv3 state on non-VHE systems */
static void __hyp_text __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
{
- if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
__vgic_v3_save_state(vcpu);
+ __vgic_v3_deactivate_traps(vcpu);
+ }
}
/* Restore VGICv3 state on non_VEH systems */
static void __hyp_text __hyp_vgic_restore_state(struct kvm_vcpu *vcpu)
{
- if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
+ __vgic_v3_activate_traps(vcpu);
__vgic_v3_restore_state(vcpu);
+ }
}
static bool __hyp_text __true_value(void)