mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-26 03:40:55 +07:00
8734f16fb2
Admitedly, reading a MMIO register to load PC is very weird. Writing PC to a MMIO register is probably even worse. But the architecture doesn't forbid any of these, and injecting a Prefetch Abort is the wrong thing to do anyway. Remove this check altogether, and let the adventurous guest wander into LaLaLand if they feel compelled to do so. Reported-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
141 lines
3.6 KiB
C
141 lines
3.6 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/kvm_host.h>
|
|
#include <asm/kvm_mmio.h>
|
|
#include <asm/kvm_emulate.h>
|
|
#include <trace/events/kvm.h>
|
|
|
|
#include "trace.h"
|
|
|
|
/**
|
|
* kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
|
|
* @vcpu: The VCPU pointer
|
|
* @run: The VCPU run struct containing the mmio data
|
|
*
|
|
* This should only be called after returning from userspace for MMIO load
|
|
* emulation.
|
|
*/
|
|
int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
|
|
{
|
|
unsigned long *dest;
|
|
unsigned int len;
|
|
int mask;
|
|
|
|
if (!run->mmio.is_write) {
|
|
dest = vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt);
|
|
*dest = 0;
|
|
|
|
len = run->mmio.len;
|
|
if (len > sizeof(unsigned long))
|
|
return -EINVAL;
|
|
|
|
memcpy(dest, run->mmio.data, len);
|
|
|
|
trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
|
|
*((u64 *)run->mmio.data));
|
|
|
|
if (vcpu->arch.mmio_decode.sign_extend &&
|
|
len < sizeof(unsigned long)) {
|
|
mask = 1U << ((len * 8) - 1);
|
|
*dest = (*dest ^ mask) - mask;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
|
|
struct kvm_exit_mmio *mmio)
|
|
{
|
|
unsigned long rt, len;
|
|
bool is_write, sign_extend;
|
|
|
|
if (kvm_vcpu_dabt_isextabt(vcpu)) {
|
|
/* cache operation on I/O addr, tell guest unsupported */
|
|
kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
|
|
return 1;
|
|
}
|
|
|
|
if (kvm_vcpu_dabt_iss1tw(vcpu)) {
|
|
/* page table accesses IO mem: tell guest to fix its TTBR */
|
|
kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
|
|
return 1;
|
|
}
|
|
|
|
len = kvm_vcpu_dabt_get_as(vcpu);
|
|
if (unlikely(len < 0))
|
|
return len;
|
|
|
|
is_write = kvm_vcpu_dabt_iswrite(vcpu);
|
|
sign_extend = kvm_vcpu_dabt_issext(vcpu);
|
|
rt = kvm_vcpu_dabt_get_rd(vcpu);
|
|
|
|
mmio->is_write = is_write;
|
|
mmio->phys_addr = fault_ipa;
|
|
mmio->len = len;
|
|
vcpu->arch.mmio_decode.sign_extend = sign_extend;
|
|
vcpu->arch.mmio_decode.rt = rt;
|
|
|
|
/*
|
|
* The MMIO instruction is emulated and should not be re-executed
|
|
* in the guest.
|
|
*/
|
|
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
|
|
return 0;
|
|
}
|
|
|
|
int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
|
|
phys_addr_t fault_ipa)
|
|
{
|
|
struct kvm_exit_mmio mmio;
|
|
unsigned long rt;
|
|
int ret;
|
|
|
|
/*
|
|
* Prepare MMIO operation. First stash it in a private
|
|
* structure that we can use for in-kernel emulation. If the
|
|
* kernel can't handle it, copy it into run->mmio and let user
|
|
* space do its magic.
|
|
*/
|
|
|
|
if (kvm_vcpu_dabt_isvalid(vcpu)) {
|
|
ret = decode_hsr(vcpu, fault_ipa, &mmio);
|
|
if (ret)
|
|
return ret;
|
|
} else {
|
|
kvm_err("load/store instruction decoding not implemented\n");
|
|
return -ENOSYS;
|
|
}
|
|
|
|
rt = vcpu->arch.mmio_decode.rt;
|
|
trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE :
|
|
KVM_TRACE_MMIO_READ_UNSATISFIED,
|
|
mmio.len, fault_ipa,
|
|
(mmio.is_write) ? *vcpu_reg(vcpu, rt) : 0);
|
|
|
|
if (mmio.is_write)
|
|
memcpy(mmio.data, vcpu_reg(vcpu, rt), mmio.len);
|
|
|
|
if (vgic_handle_mmio(vcpu, run, &mmio))
|
|
return 1;
|
|
|
|
kvm_prepare_mmio(run, &mmio);
|
|
return 0;
|
|
}
|