From 68925176296a8b995e503349200e256674bfe5ac Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 17 Feb 2017 14:32:18 +0000 Subject: [PATCH] arm64: KVM: VHE: Clear HCR_TGE when invalidating guest TLBs When invalidating guest TLBs, special care must be taken to actually shoot the guest TLBs and not the host ones if we're running on a VHE system. This is controlled by the HCR_EL2.TGE bit, which we forget to clear before invalidating TLBs. Address the issue by introducing two wrappers (__tlb_switch_to_guest and __tlb_switch_to_host) that take care of both the VTTBR_EL2 and HCR_EL2.TGE switching. Reported-by: Tomasz Nowicki Tested-by: Tomasz Nowicki Reviewed-by: Christoffer Dall Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/tlb.c | 64 ++++++++++++++++++++++++++++++++++------ 1 file changed, 55 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kvm/hyp/tlb.c b/arch/arm64/kvm/hyp/tlb.c index e8e7ba2bc11f..9e1d2b75eecd 100644 --- a/arch/arm64/kvm/hyp/tlb.c +++ b/arch/arm64/kvm/hyp/tlb.c @@ -18,14 +18,62 @@ #include #include +static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm) +{ + u64 val; + + /* + * With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and + * most TLB operations target EL2/EL0. In order to affect the + * guest TLBs (EL1/EL0), we need to change one of these two + * bits. Changing E2H is impossible (goodbye TTBR1_EL2), so + * let's flip TGE before executing the TLB operation. + */ + write_sysreg(kvm->arch.vttbr, vttbr_el2); + val = read_sysreg(hcr_el2); + val &= ~HCR_TGE; + write_sysreg(val, hcr_el2); + isb(); +} + +static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm) +{ + write_sysreg(kvm->arch.vttbr, vttbr_el2); + isb(); +} + +static hyp_alternate_select(__tlb_switch_to_guest, + __tlb_switch_to_guest_nvhe, + __tlb_switch_to_guest_vhe, + ARM64_HAS_VIRT_HOST_EXTN); + +static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm) +{ + /* + * We're done with the TLB operation, let's restore the host's + * view of HCR_EL2. + */ + write_sysreg(0, vttbr_el2); + write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2); +} + +static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm) +{ + write_sysreg(0, vttbr_el2); +} + +static hyp_alternate_select(__tlb_switch_to_host, + __tlb_switch_to_host_nvhe, + __tlb_switch_to_host_vhe, + ARM64_HAS_VIRT_HOST_EXTN); + void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) { dsb(ishst); /* Switch to requested VMID */ kvm = kern_hyp_va(kvm); - write_sysreg(kvm->arch.vttbr, vttbr_el2); - isb(); + __tlb_switch_to_guest()(kvm); /* * We could do so much better if we had the VA as well. @@ -46,7 +94,7 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) dsb(ish); isb(); - write_sysreg(0, vttbr_el2); + __tlb_switch_to_host()(kvm); } void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm) @@ -55,14 +103,13 @@ void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm) /* Switch to requested VMID */ kvm = kern_hyp_va(kvm); - write_sysreg(kvm->arch.vttbr, vttbr_el2); - isb(); + __tlb_switch_to_guest()(kvm); __tlbi(vmalls12e1is); dsb(ish); isb(); - write_sysreg(0, vttbr_el2); + __tlb_switch_to_host()(kvm); } void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu) @@ -70,14 +117,13 @@ void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu) struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm); /* Switch to requested VMID */ - write_sysreg(kvm->arch.vttbr, vttbr_el2); - isb(); + __tlb_switch_to_guest()(kvm); __tlbi(vmalle1); dsb(nsh); isb(); - write_sysreg(0, vttbr_el2); + __tlb_switch_to_host()(kvm); } void __hyp_text __kvm_flush_vm_context(void) -- 2.20.1