linux/arch/arm64/kvm/handle_exit.c
Wei Huang 0d97f88481 arm/arm64: KVM: add tracing support for arm64 exit handler
arm64 uses its own copy of exit handler (arm64/kvm/handle_exit.c).
Currently this file doesn't hook up with any trace points. As a result
users might not see certain events (e.g. HVC & WFI) while using ftrace
with arm64 KVM. This patch fixes this issue by adding a new trace file
and defining two trace events (one of which is shared by wfi and wfe)
for arm64. The new trace points are then linked with related functions
in handle_exit.c.

Signed-off-by: Wei Huang <wei@redhat.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-15 12:43:30 +01:00

145 lines
3.9 KiB
C

/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Derived from arch/arm/kvm/handle_exit.c:
* 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, 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>
#include <asm/kvm_psci.h>
#define CREATE_TRACE_POINTS
#include "trace.h"
typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
int ret;
trace_kvm_hvc_arm64(*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;
}
/**
* kvm_handle_wfx - handle a wait-for-interrupts or wait-for-event
* instruction executed by a guest
*
* @vcpu: the vcpu 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) & ESR_EL2_EC_WFI_ISS_WFE) {
trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true);
kvm_vcpu_on_spin(vcpu);
} else {
trace_kvm_wfx_arm64(*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[] = {
[ESR_EL2_EC_WFI] = kvm_handle_wfx,
[ESR_EL2_EC_CP15_32] = kvm_handle_cp15_32,
[ESR_EL2_EC_CP15_64] = kvm_handle_cp15_64,
[ESR_EL2_EC_CP14_MR] = kvm_handle_cp14_32,
[ESR_EL2_EC_CP14_LS] = kvm_handle_cp14_load_store,
[ESR_EL2_EC_CP14_64] = kvm_handle_cp14_64,
[ESR_EL2_EC_HVC32] = handle_hvc,
[ESR_EL2_EC_SMC32] = handle_smc,
[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("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_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;
}
}