On Thu, 15 Feb 2018 21:03:25 +0000, Christoffer Dall wrote: > > We do not have to change the c15 trap setting on each switch to/from the > guest on VHE systems, because this setting only affects EL0.
Did you mean EL1 instead? > > The PMU and debug trap configuration can also be done on vcpu load/put > instead, because they don't affect how the host kernel can access the > debug registers while executing KVM kernel code. > > Signed-off-by: Christoffer Dall <[email protected]> > --- > arch/arm64/include/asm/kvm_hyp.h | 3 +++ > arch/arm64/kvm/hyp/switch.c | 31 ++++++++++++++++++++++--------- > arch/arm64/kvm/hyp/sysreg-sr.c | 4 ++++ > 3 files changed, 29 insertions(+), 9 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_hyp.h > b/arch/arm64/include/asm/kvm_hyp.h > index 2b1fda90dde4..949f2e77ae58 100644 > --- a/arch/arm64/include/asm/kvm_hyp.h > +++ b/arch/arm64/include/asm/kvm_hyp.h > @@ -147,6 +147,9 @@ void __fpsimd_save_state(struct user_fpsimd_state > *fp_regs); > void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs); > bool __fpsimd_enabled(void); > > +void activate_traps_vhe_load(struct kvm_vcpu *vcpu); > +void deactivate_traps_vhe_put(void); > + > u64 __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host_ctxt); > void __noreturn __hyp_do_panic(unsigned long, ...); > > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > index 9c40e203bd09..5e94955b89ea 100644 > --- a/arch/arm64/kvm/hyp/switch.c > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -101,6 +101,8 @@ static void __hyp_text __activate_traps_nvhe(struct > kvm_vcpu *vcpu) > { > u64 val; > > + __activate_traps_common(vcpu); > + > val = CPTR_EL2_DEFAULT; > val |= CPTR_EL2_TTA | CPTR_EL2_TFP | CPTR_EL2_TZ; > write_sysreg(val, cptr_el2); > @@ -120,20 +122,12 @@ static void __hyp_text __activate_traps(struct kvm_vcpu > *vcpu) > write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2); > > __activate_traps_fpsimd32(vcpu); > - __activate_traps_common(vcpu); > __activate_traps_arch()(vcpu); > } > > static void __hyp_text __deactivate_traps_vhe(void) > { > extern char vectors[]; /* kernel exception vectors */ > - u64 mdcr_el2 = read_sysreg(mdcr_el2); > - > - mdcr_el2 &= MDCR_EL2_HPMN_MASK | > - MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT | > - MDCR_EL2_TPMS; > - > - write_sysreg(mdcr_el2, mdcr_el2); > write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2); > write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1); > write_sysreg(vectors, vbar_el1); > @@ -143,6 +137,8 @@ static void __hyp_text __deactivate_traps_nvhe(void) > { > u64 mdcr_el2 = read_sysreg(mdcr_el2); > > + __deactivate_traps_common(); > + > mdcr_el2 &= MDCR_EL2_HPMN_MASK; > mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; > > @@ -166,10 +162,27 @@ static void __hyp_text __deactivate_traps(struct > kvm_vcpu *vcpu) > if (vcpu->arch.hcr_el2 & HCR_VSE) > vcpu->arch.hcr_el2 = read_sysreg(hcr_el2); > > - __deactivate_traps_common(); > __deactivate_traps_arch()(); > } > > +void activate_traps_vhe_load(struct kvm_vcpu *vcpu) > +{ > + __activate_traps_common(vcpu); > +} > + > +void deactivate_traps_vhe_put(void) > +{ > + u64 mdcr_el2 = read_sysreg(mdcr_el2); > + > + mdcr_el2 &= MDCR_EL2_HPMN_MASK | > + MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT | > + MDCR_EL2_TPMS; > + > + write_sysreg(mdcr_el2, mdcr_el2); > + > + __deactivate_traps_common(); > +} > + > static void __hyp_text __activate_vm(struct kvm *kvm) > { > write_sysreg(kvm->arch.vttbr, vttbr_el2); > diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c > index aacba4636871..b3894df6bf1a 100644 > --- a/arch/arm64/kvm/hyp/sysreg-sr.c > +++ b/arch/arm64/kvm/hyp/sysreg-sr.c > @@ -254,6 +254,8 @@ void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) > __sysreg_restore_el1_state(guest_ctxt); > > vcpu->arch.sysregs_loaded_on_cpu = true; > + > + activate_traps_vhe_load(vcpu); > } > > /** > @@ -275,6 +277,8 @@ void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) > if (!has_vhe()) > return; > > + deactivate_traps_vhe_put(); > + > __sysreg_save_el1_state(guest_ctxt); > __sysreg_save_user_state(guest_ctxt); > __sysreg32_save_state(vcpu); > -- > 2.14.2 > I must admit that I find these two layers of trap configuration mildly confusing. I can see why it is done like this (there is hardly any other way), but still... Reviewed-by: Marc Zyngier <[email protected]> M. -- Jazz is not dead, it just smell funny. _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
