diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/tlb.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/tlb.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/tlb.c b/arch/arm64/kvm/hyp/tlb.c new file mode 100644 index 000000000..c041eab3d --- /dev/null +++ b/arch/arm64/kvm/hyp/tlb.c @@ -0,0 +1,173 @@ +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/irqflags.h> + +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/tlbflush.h> + +static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm, + unsigned long *flags) +{ + u64 val; + + local_irq_save(*flags); + + /* + * 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, + unsigned long *flags) +{ + 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, + unsigned long flags) +{ + /* + * 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); + isb(); + local_irq_restore(flags); +} + +static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm, + unsigned long flags) +{ + 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) +{ + unsigned long flags; + + dsb(ishst); + + /* Switch to requested VMID */ + kvm = kern_hyp_va(kvm); + __tlb_switch_to_guest()(kvm, &flags); + + /* + * We could do so much better if we had the VA as well. + * Instead, we invalidate Stage-2 for this IPA, and the + * whole of Stage-1. Weep... + */ + ipa >>= 12; + __tlbi(ipas2e1is, ipa); + + /* + * We have to ensure completion of the invalidation at Stage-2, + * since a table walk on another CPU could refill a TLB with a + * complete (S1 + S2) walk based on the old Stage-2 mapping if + * the Stage-1 invalidation happened first. + */ + dsb(ish); + __tlbi(vmalle1is); + dsb(ish); + isb(); + + /* + * If the host is running at EL1 and we have a VPIPT I-cache, + * then we must perform I-cache maintenance at EL2 in order for + * it to have an effect on the guest. Since the guest cannot hit + * I-cache lines allocated with a different VMID, we don't need + * to worry about junk out of guest reset (we nuke the I-cache on + * VMID rollover), but we do need to be careful when remapping + * executable pages for the same guest. This can happen when KSM + * takes a CoW fault on an executable page, copies the page into + * a page that was previously mapped in the guest and then needs + * to invalidate the guest view of the I-cache for that page + * from EL1. To solve this, we invalidate the entire I-cache when + * unmapping a page from a guest if we have a VPIPT I-cache but + * the host is running at EL1. As above, we could do better if + * we had the VA. + * + * The moral of this story is: if you have a VPIPT I-cache, then + * you should be running with VHE enabled. + */ + if (!has_vhe() && icache_is_vpipt()) + __flush_icache_all(); + + __tlb_switch_to_host()(kvm, flags); +} + +void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm) +{ + unsigned long flags; + + dsb(ishst); + + /* Switch to requested VMID */ + kvm = kern_hyp_va(kvm); + __tlb_switch_to_guest()(kvm, &flags); + + __tlbi(vmalls12e1is); + dsb(ish); + isb(); + + __tlb_switch_to_host()(kvm, flags); +} + +void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm); + unsigned long flags; + + /* Switch to requested VMID */ + __tlb_switch_to_guest()(kvm, &flags); + + __tlbi(vmalle1); + dsb(nsh); + isb(); + + __tlb_switch_to_host()(kvm, flags); +} + +void __hyp_text __kvm_flush_vm_context(void) +{ + dsb(ishst); + __tlbi(alle1is); + asm volatile("ic ialluis" : : ); + dsb(ish); +} |