Handle the exit of a VM, decoding the exit reason from HYP mode and calling the corresponding handler. Reviewed-by: Christopher Covington <cov@xxxxxxxxxxxxxx> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- arch/arm64/kvm/handle_exit.c | 119 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 arch/arm64/kvm/handle_exit.c diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c new file mode 100644 index 0000000..c65d115 --- /dev/null +++ b/arch/arm64/kvm/handle_exit.c @@ -0,0 +1,119 @@ +/* + * Copyright (C) 2012,2013 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@xxxxxxx> + * + * Derived from arch/arm/kvm/handle_exit.c: + * Copyright (C) 2012 - Virtual Open Systems and Columbia University + * Author: Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx> + * + * 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/kvm.h> +#include <linux/kvm_host.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_coproc.h> +#include <asm/kvm_mmu.h> + +typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *); + +static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + /* + * Guest called HVC instruction: + * Let it know we don't want that by injecting an undefined exception. + */ + kvm_debug("hvc: %x (at %08lx)", kvm_vcpu_get_hsr(vcpu) & ((1 << 16) - 1), + *vcpu_pc(vcpu)); + kvm_debug(" HSR: %8x", kvm_vcpu_get_hsr(vcpu)); + kvm_inject_undefined(vcpu); + return 1; +} + +static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + /* We don't support SMC; don't do that. */ + kvm_debug("smc: at %08lx", *vcpu_pc(vcpu)); + kvm_inject_undefined(vcpu); + return 1; +} + +/** + * kvm_handle_wfi - handle a wait-for-interrupts instruction executed by a guest + * @vcpu: the vcpu pointer + * + * 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_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + kvm_vcpu_block(vcpu); + return 1; +} + +static exit_handle_fn arm_exit_handlers[] = { + [ESR_EL2_EC_WFI] = kvm_handle_wfi, + [ESR_EL2_EC_HVC64] = handle_hvc, + [ESR_EL2_EC_SMC64] = handle_smc, + [ESR_EL2_EC_SYS64] = kvm_handle_sys_reg, + [ESR_EL2_EC_IABT] = kvm_handle_guest_abort, + [ESR_EL2_EC_DABT] = kvm_handle_guest_abort, +}; + +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("Unkown 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_TRAP: + /* + * 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; + } +} -- 1.8.2.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
