From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v4 31/40] KVM: arm64: Move common VHE/non-VHE trap config in separate functions Date: Wed, 21 Feb 2018 17:59:37 +0000 Message-ID: <86zi42jkae.wl-marc.zyngier@arm.com> References: <20180215210332.8648-1-christoffer.dall@linaro.org> <20180215210332.8648-32-christoffer.dall@linaro.org> Mime-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Andrew Jones , kvm@vger.kernel.org, Tomasz Nowicki , kvmarm@lists.cs.columbia.edu, Julien Grall , Yury Norov , linux-arm-kernel@lists.infradead.org, Dave Martin , Shih-Wei Li To: Christoffer Dall Return-path: In-Reply-To: <20180215210332.8648-32-christoffer.dall@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: kvm.vger.kernel.org On Thu, 15 Feb 2018 21:03:23 +0000, Christoffer Dall wrote: > > As we are about to be more lazy with some of the trap configuration > register read/writes for VHE systems, move the logic that is currently > shared between VHE and non-VHE into a separate function which can be > called from either the world-switch path or from vcpu_load/vcpu_put. > > Signed-off-by: Christoffer Dall > --- > > Notes: > Changes since v3: > - Separate fpsimd32 trap configuration into a separate function > which is still called from __activate_traps, because we no longer > defer saving/restoring of VFP registers to load/put. > > arch/arm64/kvm/hyp/switch.c | 76 +++++++++++++++++++++++++++------------------ > 1 file changed, 45 insertions(+), 31 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > index 909aa3fe9196..17e3c6f26a34 100644 > --- a/arch/arm64/kvm/hyp/switch.c > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -56,7 +56,45 @@ static inline void __hyp_text __fpsimd_save_fpexc32(struct kvm_vcpu *vcpu) > vcpu->arch.ctxt.sys_regs[FPEXC32_EL2] = read_sysreg(fpexc32_el2); > } > > -static void __hyp_text __activate_traps_vhe(void) > +static void __hyp_text __activate_traps_fpsimd32(struct kvm_vcpu *vcpu) > +{ > + /* > + * We are about to set CPTR_EL2.TFP to trap all floating point > + * register accesses to EL2, however, the ARM ARM clearly states that > + * traps are only taken to EL2 if the operation would not otherwise > + * trap to EL1. Therefore, always make sure that for 32-bit guests, > + * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit. > + * If FP/ASIMD is not implemented, FPEXC is UNDEFINED and any access to > + * it will cause an exception. > + */ > + if (vcpu_el1_is_32bit(vcpu) && system_supports_fpsimd()) { > + write_sysreg(1 << 30, fpexc32_el2); > + isb(); > + } > +} > + > +static void __hyp_text __activate_traps_common(struct kvm_vcpu *vcpu) > +{ > + /* Trap on AArch32 cp15 c15 (impdef sysregs) accesses (EL1 or EL0) */ > + write_sysreg(1 << 15, hstr_el2); > + /* > + * Make sure we trap PMU access from EL0 to EL2. Also sanitize > + * PMSELR_EL0 to make sure it never contains the cycle > + * counter, which could make a PMXEVCNTR_EL0 access UNDEF at > + * EL1 instead of being trapped to EL2. > + */ > + write_sysreg(0, pmselr_el0); > + write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); > + write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); > +} > + > +static void __hyp_text __deactivate_traps_common(void) > +{ > + write_sysreg(0, hstr_el2); > + write_sysreg(0, pmuserenr_el0); > +} > + > +static void __hyp_text __activate_traps_vhe(struct kvm_vcpu *vcpu) > { > u64 val; > > @@ -68,7 +106,7 @@ static void __hyp_text __activate_traps_vhe(void) > write_sysreg(kvm_get_hyp_vector(), vbar_el1); > } > > -static void __hyp_text __activate_traps_nvhe(void) > +static void __hyp_text __activate_traps_nvhe(struct kvm_vcpu *vcpu) I have the ugly feeling that this hunk should not be in this patch. Have you tried bisecting the compilation of this series? > { > u64 val; > > @@ -85,37 +123,14 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu) > { > u64 hcr = vcpu->arch.hcr_el2; > > - /* > - * We are about to set CPTR_EL2.TFP to trap all floating point > - * register accesses to EL2, however, the ARM ARM clearly states that > - * traps are only taken to EL2 if the operation would not otherwise > - * trap to EL1. Therefore, always make sure that for 32-bit guests, > - * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit. > - * If FP/ASIMD is not implemented, FPEXC is UNDEFINED and any access to > - * it will cause an exception. > - */ > - if (vcpu_el1_is_32bit(vcpu) && system_supports_fpsimd()) { > - write_sysreg(1 << 30, fpexc32_el2); > - isb(); > - } > + write_sysreg(hcr, hcr_el2); > > if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE)) > write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2); > > - write_sysreg(hcr, hcr_el2); > - > - /* Trap on AArch32 cp15 c15 accesses (EL1 or EL0) */ > - write_sysreg(1 << 15, hstr_el2); > - /* > - * Make sure we trap PMU access from EL0 to EL2. Also sanitize > - * PMSELR_EL0 to make sure it never contains the cycle > - * counter, which could make a PMXEVCNTR_EL0 access UNDEF at > - * EL1 instead of being trapped to EL2. > - */ > - write_sysreg(0, pmselr_el0); > - write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); > - write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); > - __activate_traps_arch()(); > + __activate_traps_fpsimd32(vcpu); > + __activate_traps_common(vcpu); > + __activate_traps_arch()(vcpu); > } > > static void __hyp_text __deactivate_traps_vhe(void) > @@ -160,9 +175,8 @@ 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()(); > - write_sysreg(0, hstr_el2); > - write_sysreg(0, pmuserenr_el0); > } > > static void __hyp_text __activate_vm(struct kvm *kvm) > -- > 2.14.2 > Otherwise: Reviewed-by: Marc Zyngier M. -- Jazz is not dead, it just smell funny. From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Wed, 21 Feb 2018 17:59:37 +0000 Subject: [PATCH v4 31/40] KVM: arm64: Move common VHE/non-VHE trap config in separate functions In-Reply-To: <20180215210332.8648-32-christoffer.dall@linaro.org> References: <20180215210332.8648-1-christoffer.dall@linaro.org> <20180215210332.8648-32-christoffer.dall@linaro.org> Message-ID: <86zi42jkae.wl-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 15 Feb 2018 21:03:23 +0000, Christoffer Dall wrote: > > As we are about to be more lazy with some of the trap configuration > register read/writes for VHE systems, move the logic that is currently > shared between VHE and non-VHE into a separate function which can be > called from either the world-switch path or from vcpu_load/vcpu_put. > > Signed-off-by: Christoffer Dall > --- > > Notes: > Changes since v3: > - Separate fpsimd32 trap configuration into a separate function > which is still called from __activate_traps, because we no longer > defer saving/restoring of VFP registers to load/put. > > arch/arm64/kvm/hyp/switch.c | 76 +++++++++++++++++++++++++++------------------ > 1 file changed, 45 insertions(+), 31 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > index 909aa3fe9196..17e3c6f26a34 100644 > --- a/arch/arm64/kvm/hyp/switch.c > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -56,7 +56,45 @@ static inline void __hyp_text __fpsimd_save_fpexc32(struct kvm_vcpu *vcpu) > vcpu->arch.ctxt.sys_regs[FPEXC32_EL2] = read_sysreg(fpexc32_el2); > } > > -static void __hyp_text __activate_traps_vhe(void) > +static void __hyp_text __activate_traps_fpsimd32(struct kvm_vcpu *vcpu) > +{ > + /* > + * We are about to set CPTR_EL2.TFP to trap all floating point > + * register accesses to EL2, however, the ARM ARM clearly states that > + * traps are only taken to EL2 if the operation would not otherwise > + * trap to EL1. Therefore, always make sure that for 32-bit guests, > + * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit. > + * If FP/ASIMD is not implemented, FPEXC is UNDEFINED and any access to > + * it will cause an exception. > + */ > + if (vcpu_el1_is_32bit(vcpu) && system_supports_fpsimd()) { > + write_sysreg(1 << 30, fpexc32_el2); > + isb(); > + } > +} > + > +static void __hyp_text __activate_traps_common(struct kvm_vcpu *vcpu) > +{ > + /* Trap on AArch32 cp15 c15 (impdef sysregs) accesses (EL1 or EL0) */ > + write_sysreg(1 << 15, hstr_el2); > + /* > + * Make sure we trap PMU access from EL0 to EL2. Also sanitize > + * PMSELR_EL0 to make sure it never contains the cycle > + * counter, which could make a PMXEVCNTR_EL0 access UNDEF at > + * EL1 instead of being trapped to EL2. > + */ > + write_sysreg(0, pmselr_el0); > + write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); > + write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); > +} > + > +static void __hyp_text __deactivate_traps_common(void) > +{ > + write_sysreg(0, hstr_el2); > + write_sysreg(0, pmuserenr_el0); > +} > + > +static void __hyp_text __activate_traps_vhe(struct kvm_vcpu *vcpu) > { > u64 val; > > @@ -68,7 +106,7 @@ static void __hyp_text __activate_traps_vhe(void) > write_sysreg(kvm_get_hyp_vector(), vbar_el1); > } > > -static void __hyp_text __activate_traps_nvhe(void) > +static void __hyp_text __activate_traps_nvhe(struct kvm_vcpu *vcpu) I have the ugly feeling that this hunk should not be in this patch. Have you tried bisecting the compilation of this series? > { > u64 val; > > @@ -85,37 +123,14 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu) > { > u64 hcr = vcpu->arch.hcr_el2; > > - /* > - * We are about to set CPTR_EL2.TFP to trap all floating point > - * register accesses to EL2, however, the ARM ARM clearly states that > - * traps are only taken to EL2 if the operation would not otherwise > - * trap to EL1. Therefore, always make sure that for 32-bit guests, > - * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit. > - * If FP/ASIMD is not implemented, FPEXC is UNDEFINED and any access to > - * it will cause an exception. > - */ > - if (vcpu_el1_is_32bit(vcpu) && system_supports_fpsimd()) { > - write_sysreg(1 << 30, fpexc32_el2); > - isb(); > - } > + write_sysreg(hcr, hcr_el2); > > if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE)) > write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2); > > - write_sysreg(hcr, hcr_el2); > - > - /* Trap on AArch32 cp15 c15 accesses (EL1 or EL0) */ > - write_sysreg(1 << 15, hstr_el2); > - /* > - * Make sure we trap PMU access from EL0 to EL2. Also sanitize > - * PMSELR_EL0 to make sure it never contains the cycle > - * counter, which could make a PMXEVCNTR_EL0 access UNDEF at > - * EL1 instead of being trapped to EL2. > - */ > - write_sysreg(0, pmselr_el0); > - write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); > - write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); > - __activate_traps_arch()(); > + __activate_traps_fpsimd32(vcpu); > + __activate_traps_common(vcpu); > + __activate_traps_arch()(vcpu); > } > > static void __hyp_text __deactivate_traps_vhe(void) > @@ -160,9 +175,8 @@ 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()(); > - write_sysreg(0, hstr_el2); > - write_sysreg(0, pmuserenr_el0); > } > > static void __hyp_text __activate_vm(struct kvm *kvm) > -- > 2.14.2 > Otherwise: Reviewed-by: Marc Zyngier M. -- Jazz is not dead, it just smell funny.