diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/tlb.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/tlb.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/tlb.c b/arch/arm64/kvm/hyp/nvhe/tlb.c new file mode 100644 index 000000000..d296d617f --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/tlb.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/tlbflush.h> + +#include <nvhe/mem_protect.h> + +struct tlb_inv_context { + u64 tcr; +}; + +static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu, + struct tlb_inv_context *cxt) +{ + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + u64 val; + + /* + * For CPUs that are affected by ARM 1319367, we need to + * avoid a host Stage-1 walk while we have the guest's + * VMID set in the VTTBR in order to invalidate TLBs. + * We're guaranteed that the S1 MMU is enabled, so we can + * simply set the EPD bits to avoid any further TLB fill. + */ + val = cxt->tcr = read_sysreg_el1(SYS_TCR); + val |= TCR_EPD1_MASK | TCR_EPD0_MASK; + write_sysreg_el1(val, SYS_TCR); + isb(); + } + + /* + * __load_stage2() includes an ISB only when the AT + * workaround is applied. Take care of the opposite condition, + * ensuring that we always have an ISB, but not two ISBs back + * to back. + */ + __load_stage2(mmu, kern_hyp_va(mmu->arch)); + asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT)); +} + +static void __tlb_switch_to_host(struct tlb_inv_context *cxt) +{ + __load_host_stage2(); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + /* Ensure write of the host VMID */ + isb(); + /* Restore the host's TCR_EL1 */ + write_sysreg_el1(cxt->tcr, SYS_TCR); + } +} + +void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, + phys_addr_t ipa, int level) +{ + struct tlb_inv_context cxt; + + dsb(ishst); + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + /* + * 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_level(ipas2e1is, ipa, level); + + /* + * 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 (icache_is_vpipt()) + icache_inval_all_pou(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu) +{ + struct tlb_inv_context cxt; + + dsb(ishst); + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + __tlbi(vmalls12e1is); + dsb(ish); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu) +{ + struct tlb_inv_context cxt; + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + __tlbi(vmalle1); + asm volatile("ic iallu"); + dsb(nsh); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_flush_vm_context(void) +{ + dsb(ishst); + __tlbi(alle1is); + + /* + * VIPT and PIPT caches are not affected by VMID, so no maintenance + * is necessary across a VMID rollover. + * + * VPIPT caches constrain lookup and maintenance to the active VMID, + * so we need to invalidate lines with a stale VMID to avoid an ABA + * race after multiple rollovers. + * + */ + if (icache_is_vpipt()) + asm volatile("ic ialluis"); + + dsb(ish); +} |