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-rw-r--r--arch/arm64/kvm/hyp/vhe/tlb.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/vhe/tlb.c b/arch/arm64/kvm/hyp/vhe/tlb.c
new file mode 100644
index 000000000..24cef9b87
--- /dev/null
+++ b/arch/arm64/kvm/hyp/vhe/tlb.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/irqflags.h>
+
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+#include <asm/tlbflush.h>
+
+struct tlb_inv_context {
+ unsigned long flags;
+ u64 tcr;
+ u64 sctlr;
+};
+
+static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu,
+ struct tlb_inv_context *cxt)
+{
+ u64 val;
+
+ local_irq_save(cxt->flags);
+
+ if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
+ /*
+ * For CPUs that are affected by ARM errata 1165522 or 1530923,
+ * we cannot trust stage-1 to be in a correct state at that
+ * point. Since we do not want to force a full load of the
+ * vcpu state, we prevent the EL1 page-table walker to
+ * allocate new TLBs. This is done by setting the EPD bits
+ * in the TCR_EL1 register. We also need to prevent it to
+ * allocate IPA->PA walks, so we enable the S1 MMU...
+ */
+ val = cxt->tcr = read_sysreg_el1(SYS_TCR);
+ val |= TCR_EPD1_MASK | TCR_EPD0_MASK;
+ write_sysreg_el1(val, SYS_TCR);
+ val = cxt->sctlr = read_sysreg_el1(SYS_SCTLR);
+ val |= SCTLR_ELx_M;
+ write_sysreg_el1(val, SYS_SCTLR);
+ }
+
+ /*
+ * 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.
+ *
+ * ARM erratum 1165522 requires some special handling (again),
+ * as we need to make sure both stages of translation are in
+ * place before clearing TGE. __load_stage2() already
+ * has an ISB in order to deal with this.
+ */
+ __load_stage2(mmu, mmu->arch);
+ val = read_sysreg(hcr_el2);
+ val &= ~HCR_TGE;
+ write_sysreg(val, hcr_el2);
+ isb();
+}
+
+static void __tlb_switch_to_host(struct tlb_inv_context *cxt)
+{
+ /*
+ * 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();
+
+ if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
+ /* Restore the registers to what they were */
+ write_sysreg_el1(cxt->tcr, SYS_TCR);
+ write_sysreg_el1(cxt->sctlr, SYS_SCTLR);
+ }
+
+ local_irq_restore(cxt->flags);
+}
+
+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();
+
+ __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);
+}