On Mon, 16 Nov 2020 20:43:17 +0000, David Brazdil <dbrazdil@xxxxxxxxxx> wrote: > > While protected nVHE KVM is installed, start trapping all host SMCs. > By default, these are simply forwarded to EL3, but PSCI SMCs are > validated first. > > Create new constant HCR_HOST_NVHE_PROTECTED_FLAGS with the new set of HCR > flags to use while the nVHE vector is installed when the kernel was > booted with the protected flag enabled. Switch back to the default HCR > flags when switching back to the stub vector. > > Signed-off-by: David Brazdil <dbrazdil@xxxxxxxxxx> > --- > arch/arm64/include/asm/kvm_arm.h | 1 + > arch/arm64/kvm/hyp/nvhe/hyp-init.S | 12 ++++++++++++ > arch/arm64/kvm/hyp/nvhe/switch.c | 5 ++++- > 3 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > index 64ce29378467..4e90c2debf70 100644 > --- a/arch/arm64/include/asm/kvm_arm.h > +++ b/arch/arm64/include/asm/kvm_arm.h > @@ -80,6 +80,7 @@ > HCR_FMO | HCR_IMO | HCR_PTW ) > #define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF) > #define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK | HCR_ATA) > +#define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC) > #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) > > /* TCR_EL2 Registers bits */ > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S > index 6d8202d2bdfb..8f3602f320ac 100644 > --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S > @@ -88,6 +88,12 @@ SYM_CODE_END(__kvm_hyp_init) > * x0: struct kvm_nvhe_init_params PA > */ > SYM_CODE_START(___kvm_hyp_init) > +alternative_if ARM64_PROTECTED_KVM > + mov_q x1, HCR_HOST_NVHE_PROTECTED_FLAGS > + msr hcr_el2, x1 > + isb Why the ISB? For HCR_TSC to have any effect, you'll have to go via an ERET to EL1 first, which will have the required synchronisation effect. > +alternative_else_nop_endif > + > ldr x1, [x0, #NVHE_INIT_TPIDR_EL2] > msr tpidr_el2, x1 > > @@ -224,6 +230,12 @@ reset: > msr sctlr_el2, x5 > isb > > +alternative_if ARM64_PROTECTED_KVM > + mov_q x5, HCR_HOST_NVHE_FLAGS > + msr hcr_el2, x5 > + isb Same thing here, I believe. > +alternative_else_nop_endif > + > /* Install stub vectors */ > adr_l x5, __hyp_stub_vectors > msr vbar_el2, x5 > diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c > index 8ae8160bc93a..e1f8e0797144 100644 > --- a/arch/arm64/kvm/hyp/nvhe/switch.c > +++ b/arch/arm64/kvm/hyp/nvhe/switch.c > @@ -96,7 +96,10 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu) > mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; > > write_sysreg(mdcr_el2, mdcr_el2); > - write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2); > + if (is_protected_kvm_enabled()) > + write_sysreg(HCR_HOST_NVHE_PROTECTED_FLAGS, hcr_el2); > + else > + write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2); > write_sysreg(CPTR_EL2_DEFAULT, cptr_el2); > write_sysreg(__kvm_hyp_host_vector, vbar_el2); > } > -- > 2.29.2.299.gdc1121823c-goog > > Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
