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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm64/kvm/hyp/nvhe/switch.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/switch.c')
-rw-r--r--arch/arm64/kvm/hyp/nvhe/switch.c283
1 files changed, 283 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
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+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
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+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <hyp/switch.h>
+#include <hyp/sysreg-sr.h>
+
+#include <linux/arm-smccc.h>
+#include <linux/kvm_host.h>
+#include <linux/types.h>
+#include <linux/jump_label.h>
+#include <uapi/linux/psci.h>
+
+#include <kvm/arm_psci.h>
+
+#include <asm/barrier.h>
+#include <asm/cpufeature.h>
+#include <asm/kprobes.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+#include <asm/fpsimd.h>
+#include <asm/debug-monitors.h>
+#include <asm/processor.h>
+#include <asm/thread_info.h>
+
+/* Non-VHE specific context */
+DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
+DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
+DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);
+
+static void __activate_traps(struct kvm_vcpu *vcpu)
+{
+ u64 val;
+
+ ___activate_traps(vcpu);
+ __activate_traps_common(vcpu);
+
+ val = CPTR_EL2_DEFAULT;
+ val |= CPTR_EL2_TTA | CPTR_EL2_TZ | CPTR_EL2_TAM;
+ if (!update_fp_enabled(vcpu)) {
+ val |= CPTR_EL2_TFP;
+ __activate_traps_fpsimd32(vcpu);
+ }
+
+ write_sysreg(val, cptr_el2);
+ write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el2);
+
+ if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
+ struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
+
+ isb();
+ /*
+ * At this stage, and thanks to the above isb(), S2 is
+ * configured and enabled. We can now restore the guest's S1
+ * configuration: SCTLR, and only then TCR.
+ */
+ write_sysreg_el1(ctxt_sys_reg(ctxt, SCTLR_EL1), SYS_SCTLR);
+ isb();
+ write_sysreg_el1(ctxt_sys_reg(ctxt, TCR_EL1), SYS_TCR);
+ }
+}
+
+static void __deactivate_traps(struct kvm_vcpu *vcpu)
+{
+ extern char __kvm_hyp_host_vector[];
+ u64 mdcr_el2;
+
+ ___deactivate_traps(vcpu);
+
+ mdcr_el2 = read_sysreg(mdcr_el2);
+
+ if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
+ u64 val;
+
+ /*
+ * Set the TCR and SCTLR registers in the exact opposite
+ * sequence as __activate_traps (first prevent walks,
+ * then force the MMU on). A generous sprinkling of isb()
+ * ensure that things happen in this exact order.
+ */
+ val = read_sysreg_el1(SYS_TCR);
+ write_sysreg_el1(val | TCR_EPD1_MASK | TCR_EPD0_MASK, SYS_TCR);
+ isb();
+ val = read_sysreg_el1(SYS_SCTLR);
+ write_sysreg_el1(val | SCTLR_ELx_M, SYS_SCTLR);
+ isb();
+ }
+
+ __deactivate_traps_common();
+
+ mdcr_el2 &= MDCR_EL2_HPMN_MASK;
+ mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
+
+ write_sysreg(mdcr_el2, mdcr_el2);
+ write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
+ write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
+ write_sysreg(__kvm_hyp_host_vector, vbar_el2);
+}
+
+static void __load_host_stage2(void)
+{
+ write_sysreg(0, vttbr_el2);
+}
+
+/* Save VGICv3 state on non-VHE systems */
+static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
+{
+ if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
+ __vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
+ __vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
+ }
+}
+
+/* Restore VGICv3 state on non_VEH systems */
+static void __hyp_vgic_restore_state(struct kvm_vcpu *vcpu)
+{
+ if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
+ __vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
+ __vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
+ }
+}
+
+/**
+ * Disable host events, enable guest events
+ */
+static bool __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt)
+{
+ struct kvm_host_data *host;
+ struct kvm_pmu_events *pmu;
+
+ host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
+ pmu = &host->pmu_events;
+
+ if (pmu->events_host)
+ write_sysreg(pmu->events_host, pmcntenclr_el0);
+
+ if (pmu->events_guest)
+ write_sysreg(pmu->events_guest, pmcntenset_el0);
+
+ return (pmu->events_host || pmu->events_guest);
+}
+
+/**
+ * Disable guest events, enable host events
+ */
+static void __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt)
+{
+ struct kvm_host_data *host;
+ struct kvm_pmu_events *pmu;
+
+ host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
+ pmu = &host->pmu_events;
+
+ if (pmu->events_guest)
+ write_sysreg(pmu->events_guest, pmcntenclr_el0);
+
+ if (pmu->events_host)
+ write_sysreg(pmu->events_host, pmcntenset_el0);
+}
+
+/* Switch to the guest for legacy non-VHE systems */
+int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *host_ctxt;
+ struct kvm_cpu_context *guest_ctxt;
+ bool pmu_switch_needed;
+ u64 exit_code;
+
+ /*
+ * Having IRQs masked via PMR when entering the guest means the GIC
+ * will not signal the CPU of interrupts of lower priority, and the
+ * only way to get out will be via guest exceptions.
+ * Naturally, we want to avoid this.
+ */
+ if (system_uses_irq_prio_masking()) {
+ gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
+ pmr_sync();
+ }
+
+ host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+ host_ctxt->__hyp_running_vcpu = vcpu;
+ guest_ctxt = &vcpu->arch.ctxt;
+
+ pmu_switch_needed = __pmu_switch_to_guest(host_ctxt);
+
+ __sysreg_save_state_nvhe(host_ctxt);
+ /*
+ * We must flush and disable the SPE buffer for nVHE, as
+ * the translation regime(EL1&0) is going to be loaded with
+ * that of the guest. And we must do this before we change the
+ * translation regime to EL2 (via MDCR_EL2_E2PB == 0) and
+ * before we load guest Stage1.
+ */
+ __debug_save_host_buffers_nvhe(vcpu);
+
+ /*
+ * We must restore the 32-bit state before the sysregs, thanks
+ * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
+ *
+ * Also, and in order to be able to deal with erratum #1319537 (A57)
+ * and #1319367 (A72), we must ensure that all VM-related sysreg are
+ * restored before we enable S2 translation.
+ */
+ __sysreg32_restore_state(vcpu);
+ __sysreg_restore_state_nvhe(guest_ctxt);
+
+ __load_guest_stage2(kern_hyp_va(vcpu->arch.hw_mmu));
+ __activate_traps(vcpu);
+
+ __hyp_vgic_restore_state(vcpu);
+ __timer_enable_traps(vcpu);
+
+ __debug_switch_to_guest(vcpu);
+
+ do {
+ /* Jump in the fire! */
+ exit_code = __guest_enter(vcpu);
+
+ /* And we're baaack! */
+ } while (fixup_guest_exit(vcpu, &exit_code));
+
+ __sysreg_save_state_nvhe(guest_ctxt);
+ __sysreg32_save_state(vcpu);
+ __timer_disable_traps(vcpu);
+ __hyp_vgic_save_state(vcpu);
+
+ __deactivate_traps(vcpu);
+ __load_host_stage2();
+
+ __sysreg_restore_state_nvhe(host_ctxt);
+
+ if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED)
+ __fpsimd_save_fpexc32(vcpu);
+
+ __debug_switch_to_host(vcpu);
+ /*
+ * This must come after restoring the host sysregs, since a non-VHE
+ * system may enable SPE here and make use of the TTBRs.
+ */
+ __debug_restore_host_buffers_nvhe(vcpu);
+
+ if (pmu_switch_needed)
+ __pmu_switch_to_host(host_ctxt);
+
+ /* Returning to host will clear PSR.I, remask PMR if needed */
+ if (system_uses_irq_prio_masking())
+ gic_write_pmr(GIC_PRIO_IRQOFF);
+
+ host_ctxt->__hyp_running_vcpu = NULL;
+
+ return exit_code;
+}
+
+void __noreturn hyp_panic(void)
+{
+ u64 spsr = read_sysreg_el2(SYS_SPSR);
+ u64 elr = read_sysreg_el2(SYS_ELR);
+ u64 par = read_sysreg_par();
+ struct kvm_cpu_context *host_ctxt;
+ struct kvm_vcpu *vcpu;
+
+ host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+ vcpu = host_ctxt->__hyp_running_vcpu;
+
+ if (vcpu) {
+ __timer_disable_traps(vcpu);
+ __deactivate_traps(vcpu);
+ __load_host_stage2();
+ __sysreg_restore_state_nvhe(host_ctxt);
+ }
+
+ __hyp_do_panic(host_ctxt, spsr, elr, par);
+ unreachable();
+}
+
+asmlinkage void kvm_unexpected_el2_exception(void)
+{
+ __kvm_unexpected_el2_exception();
+}