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-rw-r--r--arch/arm/kvm/handle_exit.c173
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c
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+++ b/arch/arm/kvm/handle_exit.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.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, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_coproc.h>
+#include <asm/kvm_mmu.h>
+#include <asm/kvm_psci.h>
+#include <trace/events/kvm.h>
+
+#include "trace.h"
+
+typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
+
+static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ /* SVC called from Hyp mode should never get here */
+ kvm_debug("SVC called from Hyp mode shouldn't go here\n");
+ BUG();
+ return -EINVAL; /* Squash warning */
+}
+
+static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ int ret;
+
+ trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
+ kvm_vcpu_hvc_get_imm(vcpu));
+
+ ret = kvm_psci_call(vcpu);
+ if (ret < 0) {
+ kvm_inject_undefined(vcpu);
+ return 1;
+ }
+
+ return ret;
+}
+
+static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ kvm_inject_undefined(vcpu);
+ return 1;
+}
+
+static int handle_pabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ /* The hypervisor should never cause aborts */
+ kvm_err("Prefetch Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
+ kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
+ return -EFAULT;
+}
+
+static int handle_dabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ /* This is either an error in the ws. code or an external abort */
+ kvm_err("Data Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
+ kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
+ return -EFAULT;
+}
+
+/**
+ * kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests
+ * @vcpu: the vcpu pointer
+ * @run: the kvm_run structure pointer
+ *
+ * WFE: Yield the CPU and come back to this vcpu when the scheduler
+ * decides to.
+ * WFI: Simply call kvm_vcpu_block(), which will halt execution of
+ * world-switches and schedule other host processes until there is an
+ * incoming IRQ or FIQ to the VM.
+ */
+static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE) {
+ trace_kvm_wfx(*vcpu_pc(vcpu), true);
+ kvm_vcpu_on_spin(vcpu);
+ } else {
+ trace_kvm_wfx(*vcpu_pc(vcpu), false);
+ kvm_vcpu_block(vcpu);
+ }
+
+ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+
+ return 1;
+}
+
+static exit_handle_fn arm_exit_handlers[] = {
+ [HSR_EC_WFI] = kvm_handle_wfx,
+ [HSR_EC_CP15_32] = kvm_handle_cp15_32,
+ [HSR_EC_CP15_64] = kvm_handle_cp15_64,
+ [HSR_EC_CP14_MR] = kvm_handle_cp14_access,
+ [HSR_EC_CP14_LS] = kvm_handle_cp14_load_store,
+ [HSR_EC_CP14_64] = kvm_handle_cp14_access,
+ [HSR_EC_CP_0_13] = kvm_handle_cp_0_13_access,
+ [HSR_EC_CP10_ID] = kvm_handle_cp10_id,
+ [HSR_EC_SVC_HYP] = handle_svc_hyp,
+ [HSR_EC_HVC] = handle_hvc,
+ [HSR_EC_SMC] = handle_smc,
+ [HSR_EC_IABT] = kvm_handle_guest_abort,
+ [HSR_EC_IABT_HYP] = handle_pabt_hyp,
+ [HSR_EC_DABT] = kvm_handle_guest_abort,
+ [HSR_EC_DABT_HYP] = handle_dabt_hyp,
+};
+
+static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
+{
+ u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
+
+ if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
+ !arm_exit_handlers[hsr_ec]) {
+ kvm_err("Unknown exception class: hsr: %#08x\n",
+ (unsigned int)kvm_vcpu_get_hsr(vcpu));
+ BUG();
+ }
+
+ return arm_exit_handlers[hsr_ec];
+}
+
+/*
+ * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
+ * proper exit to userspace.
+ */
+int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
+ int exception_index)
+{
+ exit_handle_fn exit_handler;
+
+ switch (exception_index) {
+ case ARM_EXCEPTION_IRQ:
+ return 1;
+ case ARM_EXCEPTION_UNDEFINED:
+ kvm_err("Undefined exception in Hyp mode at: %#08lx\n",
+ kvm_vcpu_get_hyp_pc(vcpu));
+ BUG();
+ panic("KVM: Hypervisor undefined exception!\n");
+ case ARM_EXCEPTION_DATA_ABORT:
+ case ARM_EXCEPTION_PREF_ABORT:
+ case ARM_EXCEPTION_HVC:
+ /*
+ * See ARM ARM B1.14.1: "Hyp traps on instructions
+ * that fail their condition code check"
+ */
+ if (!kvm_condition_valid(vcpu)) {
+ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+ return 1;
+ }
+
+ exit_handler = kvm_get_exit_handler(vcpu);
+
+ return exit_handler(vcpu, run);
+ default:
+ kvm_pr_unimpl("Unsupported exception type: %d",
+ exception_index);
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ return 0;
+ }
+}