kernel_optimize_test/arch/arm/kvm/reset.c
Marc Zyngier 358b28f09f arm/arm64: KVM: Allow a VCPU to fully reset itself
The current kvm_psci_vcpu_on implementation will directly try to
manipulate the state of the VCPU to reset it.  However, since this is
not done on the thread that runs the VCPU, we can end up in a strangely
corrupted state when the source and target VCPUs are running at the same
time.

Fix this by factoring out all reset logic from the PSCI implementation
and forwarding the required information along with a request to the
target VCPU.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-02-07 11:44:13 +00:00

99 lines
2.7 KiB
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, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <asm/unified.h>
#include <asm/ptrace.h>
#include <asm/cputype.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_coproc.h>
#include <asm/kvm_emulate.h>
#include <kvm/arm_arch_timer.h>
/******************************************************************************
* Cortex-A15 and Cortex-A7 Reset Values
*/
static struct kvm_regs cortexa_regs_reset = {
.usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
};
/*******************************************************************************
* Exported reset function
*/
/**
* kvm_reset_vcpu - sets core registers and cp15 registers to reset value
* @vcpu: The VCPU pointer
*
* This function finds the right table above and sets the registers on the
* virtual CPU struct to their architecturally defined reset values.
*/
int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
{
struct kvm_regs *reset_regs;
switch (vcpu->arch.target) {
case KVM_ARM_TARGET_CORTEX_A7:
case KVM_ARM_TARGET_CORTEX_A15:
reset_regs = &cortexa_regs_reset;
vcpu->arch.midr = read_cpuid_id();
break;
default:
return -ENODEV;
}
/* Reset core registers */
memcpy(&vcpu->arch.ctxt.gp_regs, reset_regs, sizeof(vcpu->arch.ctxt.gp_regs));
/* Reset CP15 registers */
kvm_reset_coprocs(vcpu);
/*
* Additional reset state handling that PSCI may have imposed on us.
* Must be done after all the sys_reg reset.
*/
if (READ_ONCE(vcpu->arch.reset_state.reset)) {
unsigned long target_pc = vcpu->arch.reset_state.pc;
/* Gracefully handle Thumb2 entry point */
if (target_pc & 1) {
target_pc &= ~1UL;
vcpu_set_thumb(vcpu);
}
/* Propagate caller endianness */
if (vcpu->arch.reset_state.be)
kvm_vcpu_set_be(vcpu);
*vcpu_pc(vcpu) = target_pc;
vcpu_set_reg(vcpu, 0, vcpu->arch.reset_state.r0);
vcpu->arch.reset_state.reset = false;
}
/* Reset arch_timer context */
return kvm_timer_vcpu_reset(vcpu);
}