| Message ID | 20181206173126.139877-7-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Workaround for Cortex-A76 erratum 1165522 | expand |
On Thu, Dec 06, 2018 at 05:31:24PM +0000, Marc Zyngier wrote: > In order to ensure that slipping HCR_EL2.TGE is done at the right > time when switching translation regime, let insert the required ISBs > that will be patched in when erratum 1165522 is detected. > > Take this opportunity to add the missing include of asm/alternative.h > which was getting there by pure luck. > > Reviewed-by: James Morse <james.morse@arm.com> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/arm64/include/asm/kvm_hyp.h | 8 ++++++++ > arch/arm64/kvm/hyp/switch.c | 19 +++++++++++++++++++ > 2 files changed, 27 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h > index 23aca66767f9..a80a7ef57325 100644 > --- a/arch/arm64/include/asm/kvm_hyp.h > +++ b/arch/arm64/include/asm/kvm_hyp.h > @@ -20,6 +20,7 @@ > > #include <linux/compiler.h> > #include <linux/kvm_host.h> > +#include <asm/alternative.h> > #include <asm/sysreg.h> > > #define __hyp_text __section(.hyp.text) notrace > @@ -163,6 +164,13 @@ static __always_inline void __hyp_text __load_guest_stage2(struct kvm *kvm) > { > write_sysreg(kvm->arch.vtcr, vtcr_el2); > write_sysreg(kvm->arch.vttbr, vttbr_el2); > + > + /* > + * ARM erratum 1165522 requires the actual execution of the above > + * before we can switch to the EL1/EL0 translation regime used by > + * the guest. > + */ > + asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522)); > } > > #endif /* __ARM64_KVM_HYP_H__ */ > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > index a8fa61c68c32..31ee0bfc432f 100644 > --- a/arch/arm64/kvm/hyp/switch.c > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -143,6 +143,14 @@ static void deactivate_traps_vhe(void) > { > extern char vectors[]; /* kernel exception vectors */ > write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2); > + > + /* > + * ARM erratum 1165522 requires the actual execution of the above > + * before we can switch to the EL2/EL0 translation regime used by > + * the host. > + */ > + asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522)); > + > write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1); > write_sysreg(vectors, vbar_el1); > } > @@ -499,6 +507,17 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) > > sysreg_save_host_state_vhe(host_ctxt); > > + /* > + * ARM erratum 1165522 requires us to configure both stage 1 and > + * stage 2 translation for the guest context before we clear > + * HCR_EL2.TGE. > + * > + * We have already configured the guest's stage 1 translation in > + * kvm_vcpu_load_sysregs above. We must now call __activate_vm > + * before __activate_traps, because __activate_vm configures > + * stage 2 translation, and __activate_traps clear HCR_EL2.TGE > + * (among other things). > + */ > __activate_vm(vcpu->kvm); > __activate_traps(vcpu); > > -- > 2.19.2 > Acked-by: Christoffer Dall <christoffer.dall@arm.com>
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index 23aca66767f9..a80a7ef57325 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -20,6 +20,7 @@ #include <linux/compiler.h> #include <linux/kvm_host.h> +#include <asm/alternative.h> #include <asm/sysreg.h> #define __hyp_text __section(.hyp.text) notrace @@ -163,6 +164,13 @@ static __always_inline void __hyp_text __load_guest_stage2(struct kvm *kvm) { write_sysreg(kvm->arch.vtcr, vtcr_el2); write_sysreg(kvm->arch.vttbr, vttbr_el2); + + /* + * ARM erratum 1165522 requires the actual execution of the above + * before we can switch to the EL1/EL0 translation regime used by + * the guest. + */ + asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522)); } #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index a8fa61c68c32..31ee0bfc432f 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -143,6 +143,14 @@ static void deactivate_traps_vhe(void) { extern char vectors[]; /* kernel exception vectors */ write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2); + + /* + * ARM erratum 1165522 requires the actual execution of the above + * before we can switch to the EL2/EL0 translation regime used by + * the host. + */ + asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522)); + write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1); write_sysreg(vectors, vbar_el1); } @@ -499,6 +507,17 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) sysreg_save_host_state_vhe(host_ctxt); + /* + * ARM erratum 1165522 requires us to configure both stage 1 and + * stage 2 translation for the guest context before we clear + * HCR_EL2.TGE. + * + * We have already configured the guest's stage 1 translation in + * kvm_vcpu_load_sysregs above. We must now call __activate_vm + * before __activate_traps, because __activate_vm configures + * stage 2 translation, and __activate_traps clear HCR_EL2.TGE + * (among other things). + */ __activate_vm(vcpu->kvm); __activate_traps(vcpu);