From: Christoffer Dall <christoffer.dall@xxxxxxxxxx> As we are about to move a bunch of save/restore logic for VHE kernels to the load and put functions, we need some infrastructure to do this. Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx> Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- arch/arm/include/asm/kvm_host.h | 3 +++ arch/arm64/include/asm/kvm_host.h | 3 +++ arch/arm64/kvm/hyp/sysreg-sr.c | 30 ++++++++++++++++++++++++++++++ virt/kvm/arm/arm.c | 2 ++ 4 files changed, 38 insertions(+) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 6137195ab815..c6a749568dd6 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -312,4 +312,7 @@ static inline bool kvm_arm_harden_branch_predictor(void) return false; } +static inline void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) {} +static inline void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) {} + #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index b027a7f025d4..c30fc96992df 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -435,4 +435,7 @@ static inline bool kvm_arm_harden_branch_predictor(void) return cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR); } +void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu); +void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu); + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 43b7dd65e3e6..434f0fc9cfb3 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -190,6 +190,36 @@ void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu) write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2); } +/** + * kvm_vcpu_load_sysregs - Load guest system registers to the physical CPU + * + * @vcpu: The VCPU pointer + * + * Load system registers that do not affect the host's execution, for + * example EL1 system registers on a VHE system where the host kernel + * runs at EL2. This function is called from KVM's vcpu_load() function + * and loading system register state early avoids having to load them on + * every entry to the VM. + */ +void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) +{ +} + +/** + * kvm_vcpu_put_sysregs - Restore host system registers to the physical CPU + * + * @vcpu: The VCPU pointer + * + * Save guest system registers that do not affect the host's execution, for + * example EL1 system registers on a VHE system where the host kernel + * runs at EL2. This function is called from KVM's vcpu_put() function + * and deferring saving system register state until we're no longer running the + * VCPU avoids having to save them on every exit from the VM. + */ +void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) +{ +} + void __hyp_text __kvm_set_tpidr_el2(u64 tpidr_el2) { asm("msr tpidr_el2, %0": : "r" (tpidr_el2)); diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 49d13510e9c2..2062d9357971 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -362,10 +362,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_arm_set_running_vcpu(vcpu); kvm_vgic_load(vcpu); kvm_timer_vcpu_load(vcpu); + kvm_vcpu_load_sysregs(vcpu); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + kvm_vcpu_put_sysregs(vcpu); kvm_timer_vcpu_put(vcpu); kvm_vgic_put(vcpu); -- 2.14.2 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm