Although the nVHE behaviour requires HCRX_EL2 to be switched on each switch between host and guest, there is nothing in this register that would affect a VHE host. It is thus possible to save/restore this register on load/put on VHE systems, avoiding unnecessary sysreg access on the hot path. Additionally, it avoids unnecessary traps when running with NV. To achieve this, simply move the read/writes to the *_common() helpers, which are called on load/put on VHE, and more eagerly on nVHE. Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> --- arch/arm64/kvm/hyp/include/hyp/switch.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 5fa1ae26f075..f07523d7d4ec 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -196,6 +196,9 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) vcpu->arch.mdcr_el2_host = read_sysreg(mdcr_el2); write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); + if (cpus_have_final_cap(ARM64_HAS_HCX)) + write_sysreg_s(HCRX_GUEST_FLAGS, SYS_HCRX_EL2); + __activate_traps_hfgxtr(vcpu); } @@ -212,6 +215,9 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) vcpu_clear_flag(vcpu, PMUSERENR_ON_CPU); } + if (cpus_have_final_cap(ARM64_HAS_HCX)) + write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2); + __deactivate_traps_hfgxtr(vcpu); } @@ -226,9 +232,6 @@ static inline void ___activate_traps(struct kvm_vcpu *vcpu) if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE)) write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2); - - if (cpus_have_final_cap(ARM64_HAS_HCX)) - write_sysreg_s(HCRX_GUEST_FLAGS, SYS_HCRX_EL2); } static inline void ___deactivate_traps(struct kvm_vcpu *vcpu) @@ -243,9 +246,6 @@ static inline void ___deactivate_traps(struct kvm_vcpu *vcpu) vcpu->arch.hcr_el2 &= ~HCR_VSE; vcpu->arch.hcr_el2 |= read_sysreg(hcr_el2) & HCR_VSE; } - - if (cpus_have_final_cap(ARM64_HAS_HCX)) - write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2); } static inline bool __populate_fault_info(struct kvm_vcpu *vcpu) -- 2.34.1
