linux/arch/arm/include/asm/kvm_emulate.h
Marc Zyngier 57c841f131 arm/arm64: KVM: Handle out-of-RAM cache maintenance as a NOP
So far, our handling of cache maintenance by VA has been pretty
simple: Either the access is in the guest RAM and generates a S2
fault, which results in the page being mapped RW, or we go down
the io_mem_abort() path, and nuke the guest.

The first one is fine, but the second one is extremely weird.
Treating the CM as an I/O is wrong, and nothing in the ARM ARM
indicates that we should generate a fault for something that
cannot end-up in the cache anyway (even if the guest maps it,
it will keep on faulting at stage-2 for emulation).

So let's just skip this instruction, and let the guest get away
with it.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:15 +00:00

259 lines
6.1 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.
*/
#ifndef __ARM_KVM_EMULATE_H__
#define __ARM_KVM_EMULATE_H__
#include <linux/kvm_host.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmio.h>
#include <asm/kvm_arm.h>
#include <asm/cputype.h>
unsigned long *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num);
unsigned long *vcpu_spsr(struct kvm_vcpu *vcpu);
static inline unsigned long vcpu_get_reg(struct kvm_vcpu *vcpu,
u8 reg_num)
{
return *vcpu_reg(vcpu, reg_num);
}
static inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
unsigned long val)
{
*vcpu_reg(vcpu, reg_num) = val;
}
bool kvm_condition_valid(struct kvm_vcpu *vcpu);
void kvm_skip_instr(struct kvm_vcpu *vcpu, bool is_wide_instr);
void kvm_inject_undefined(struct kvm_vcpu *vcpu);
void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);
static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr = HCR_GUEST_MASK;
}
static inline unsigned long vcpu_get_hcr(struct kvm_vcpu *vcpu)
{
return vcpu->arch.hcr;
}
static inline void vcpu_set_hcr(struct kvm_vcpu *vcpu, unsigned long hcr)
{
vcpu->arch.hcr = hcr;
}
static inline bool vcpu_mode_is_32bit(struct kvm_vcpu *vcpu)
{
return 1;
}
static inline unsigned long *vcpu_pc(struct kvm_vcpu *vcpu)
{
return &vcpu->arch.ctxt.gp_regs.usr_regs.ARM_pc;
}
static inline unsigned long *vcpu_cpsr(struct kvm_vcpu *vcpu)
{
return &vcpu->arch.ctxt.gp_regs.usr_regs.ARM_cpsr;
}
static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
{
*vcpu_cpsr(vcpu) |= PSR_T_BIT;
}
static inline bool mode_has_spsr(struct kvm_vcpu *vcpu)
{
unsigned long cpsr_mode = vcpu->arch.ctxt.gp_regs.usr_regs.ARM_cpsr & MODE_MASK;
return (cpsr_mode > USR_MODE && cpsr_mode < SYSTEM_MODE);
}
static inline bool vcpu_mode_priv(struct kvm_vcpu *vcpu)
{
unsigned long cpsr_mode = vcpu->arch.ctxt.gp_regs.usr_regs.ARM_cpsr & MODE_MASK;
return cpsr_mode > USR_MODE;;
}
static inline u32 kvm_vcpu_get_hsr(struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault.hsr;
}
static inline unsigned long kvm_vcpu_get_hfar(struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault.hxfar;
}
static inline phys_addr_t kvm_vcpu_get_fault_ipa(struct kvm_vcpu *vcpu)
{
return ((phys_addr_t)vcpu->arch.fault.hpfar & HPFAR_MASK) << 8;
}
static inline bool kvm_vcpu_dabt_isvalid(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_ISV;
}
static inline bool kvm_vcpu_dabt_iswrite(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_WNR;
}
static inline bool kvm_vcpu_dabt_issext(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_SSE;
}
static inline int kvm_vcpu_dabt_get_rd(struct kvm_vcpu *vcpu)
{
return (kvm_vcpu_get_hsr(vcpu) & HSR_SRT_MASK) >> HSR_SRT_SHIFT;
}
static inline bool kvm_vcpu_dabt_isextabt(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_DABT_EA;
}
static inline bool kvm_vcpu_dabt_iss1tw(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_DABT_S1PTW;
}
static inline bool kvm_vcpu_dabt_is_cm(struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_hsr(vcpu) & HSR_DABT_CM);
}
/* Get Access Size from a data abort */
static inline int kvm_vcpu_dabt_get_as(struct kvm_vcpu *vcpu)
{
switch ((kvm_vcpu_get_hsr(vcpu) >> 22) & 0x3) {
case 0:
return 1;
case 1:
return 2;
case 2:
return 4;
default:
kvm_err("Hardware is weird: SAS 0b11 is reserved\n");
return -EFAULT;
}
}
/* This one is not specific to Data Abort */
static inline bool kvm_vcpu_trap_il_is32bit(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_IL;
}
static inline u8 kvm_vcpu_trap_get_class(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) >> HSR_EC_SHIFT;
}
static inline bool kvm_vcpu_trap_is_iabt(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_trap_get_class(vcpu) == HSR_EC_IABT;
}
static inline u8 kvm_vcpu_trap_get_fault(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_FSC;
}
static inline u8 kvm_vcpu_trap_get_fault_type(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_FSC_TYPE;
}
static inline u32 kvm_vcpu_hvc_get_imm(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_HVC_IMM_MASK;
}
static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
{
return vcpu_cp15(vcpu, c0_MPIDR) & MPIDR_HWID_BITMASK;
}
static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
{
*vcpu_cpsr(vcpu) |= PSR_E_BIT;
}
static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu)
{
return !!(*vcpu_cpsr(vcpu) & PSR_E_BIT);
}
static inline unsigned long vcpu_data_guest_to_host(struct kvm_vcpu *vcpu,
unsigned long data,
unsigned int len)
{
if (kvm_vcpu_is_be(vcpu)) {
switch (len) {
case 1:
return data & 0xff;
case 2:
return be16_to_cpu(data & 0xffff);
default:
return be32_to_cpu(data);
}
} else {
switch (len) {
case 1:
return data & 0xff;
case 2:
return le16_to_cpu(data & 0xffff);
default:
return le32_to_cpu(data);
}
}
}
static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
unsigned long data,
unsigned int len)
{
if (kvm_vcpu_is_be(vcpu)) {
switch (len) {
case 1:
return data & 0xff;
case 2:
return cpu_to_be16(data & 0xffff);
default:
return cpu_to_be32(data);
}
} else {
switch (len) {
case 1:
return data & 0xff;
case 2:
return cpu_to_le16(data & 0xffff);
default:
return cpu_to_le32(data);
}
}
}
#endif /* __ARM_KVM_EMULATE_H__ */