qemu/hw/i386/vmport.c
Philippe Mathieu-Daudé c781a2cc42 hw/i386/vmport: Allow QTest use without crashing
Trying libFuzzer on the vmport device, we get:

  AddressSanitizer:DEADLYSIGNAL
  =================================================================
  ==29476==ERROR: AddressSanitizer: SEGV on unknown address 0x000000008840 (pc 0x56448bec4d79 bp 0x7ffeec9741b0 sp 0x7ffeec9740e0 T0)
  ==29476==The signal is caused by a READ memory access.
    #0 0x56448bec4d78 in vmport_ioport_read (qemu-fuzz-i386+0x1260d78)
    #1 0x56448bb5f175 in memory_region_read_accessor (qemu-fuzz-i386+0xefb175)
    #2 0x56448bb30c13 in access_with_adjusted_size (qemu-fuzz-i386+0xeccc13)
    #3 0x56448bb2ea27 in memory_region_dispatch_read1 (qemu-fuzz-i386+0xecaa27)
    #4 0x56448bb2e443 in memory_region_dispatch_read (qemu-fuzz-i386+0xeca443)
    #5 0x56448b961ab1 in flatview_read_continue (qemu-fuzz-i386+0xcfdab1)
    #6 0x56448b96336d in flatview_read (qemu-fuzz-i386+0xcff36d)
    #7 0x56448b962ec4 in address_space_read_full (qemu-fuzz-i386+0xcfeec4)

This is easily reproducible using:

  $ echo inb 0x5658 | qemu-system-i386 -M isapc,accel=qtest -qtest stdio
  [I 1589796572.009763] OPENED
  [R +0.008069] inb 0x5658
  Segmentation fault (core dumped)

  $ coredumpctl gdb -q
  Program terminated with signal SIGSEGV, Segmentation fault.
  #0  0x00005605b54d0f21 in vmport_ioport_read (opaque=0x5605b7531ce0, addr=0, size=4) at hw/i386/vmport.c:77
  77          eax = env->regs[R_EAX];
  (gdb) p cpu
  $1 = (X86CPU *) 0x0
  (gdb) bt
  #0  0x00005605b54d0f21 in vmport_ioport_read (opaque=0x5605b7531ce0, addr=0, size=4) at hw/i386/vmport.c:77
  #1  0x00005605b53db114 in memory_region_read_accessor (mr=0x5605b7531d80, addr=0, value=0x7ffc9d261a30, size=4, shift=0, mask=4294967295, attrs=...) at memory.c:434
  #2  0x00005605b53db5d4 in access_with_adjusted_size (addr=0, value=0x7ffc9d261a30, size=1, access_size_min=4, access_size_max=4, access_fn=
      0x5605b53db0d2 <memory_region_read_accessor>, mr=0x5605b7531d80, attrs=...) at memory.c:544
  #3  0x00005605b53de156 in memory_region_dispatch_read1 (mr=0x5605b7531d80, addr=0, pval=0x7ffc9d261a30, size=1, attrs=...) at memory.c:1396
  #4  0x00005605b53de228 in memory_region_dispatch_read (mr=0x5605b7531d80, addr=0, pval=0x7ffc9d261a30, op=MO_8, attrs=...) at memory.c:1424
  #5  0x00005605b537c80a in flatview_read_continue (fv=0x5605b7650290, addr=22104, attrs=..., ptr=0x7ffc9d261b4b, len=1, addr1=0, l=1, mr=0x5605b7531d80) at exec.c:3200
  #6  0x00005605b537c95d in flatview_read (fv=0x5605b7650290, addr=22104, attrs=..., buf=0x7ffc9d261b4b, len=1) at exec.c:3239
  #7  0x00005605b537c9e6 in address_space_read_full (as=0x5605b5f74ac0 <address_space_io>, addr=22104, attrs=..., buf=0x7ffc9d261b4b, len=1) at exec.c:3252
  #8  0x00005605b53d5a5d in address_space_read (len=1, buf=0x7ffc9d261b4b, attrs=..., addr=22104, as=0x5605b5f74ac0 <address_space_io>) at include/exec/memory.h:2401
  #9  0x00005605b53d5a5d in cpu_inb (addr=22104) at ioport.c:88

X86CPU is NULL because QTest accelerator does not use CPU.
Fix by returning default values when QTest accelerator is used.

Reported-by: Clang AddressSanitizer
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:10:27 -04:00

313 lines
9.5 KiB
C

/*
* QEMU VMPort emulation
*
* Copyright (C) 2007 Hervé Poussineau
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/*
* Guest code that interacts with this virtual device can be found
* in VMware open-vm-tools open-source project:
* https://github.com/vmware/open-vm-tools
*/
#include "qemu/osdep.h"
#include "hw/isa/isa.h"
#include "hw/i386/vmport.h"
#include "hw/qdev-properties.h"
#include "sysemu/sysemu.h"
#include "sysemu/hw_accel.h"
#include "sysemu/qtest.h"
#include "qemu/log.h"
#include "cpu.h"
#include "trace.h"
#define VMPORT_MAGIC 0x564D5868
/* Compatibility flags for migration */
#define VMPORT_COMPAT_READ_SET_EAX_BIT 0
#define VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD_BIT 1
#define VMPORT_COMPAT_REPORT_VMX_TYPE_BIT 2
#define VMPORT_COMPAT_CMDS_V2_BIT 3
#define VMPORT_COMPAT_READ_SET_EAX \
(1 << VMPORT_COMPAT_READ_SET_EAX_BIT)
#define VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD \
(1 << VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD_BIT)
#define VMPORT_COMPAT_REPORT_VMX_TYPE \
(1 << VMPORT_COMPAT_REPORT_VMX_TYPE_BIT)
#define VMPORT_COMPAT_CMDS_V2 \
(1 << VMPORT_COMPAT_CMDS_V2_BIT)
/* vCPU features reported by CMD_GET_VCPU_INFO */
#define VCPU_INFO_SLC64_BIT 0
#define VCPU_INFO_SYNC_VTSCS_BIT 1
#define VCPU_INFO_HV_REPLAY_OK_BIT 2
#define VCPU_INFO_LEGACY_X2APIC_BIT 3
#define VCPU_INFO_RESERVED_BIT 31
#define VMPORT(obj) OBJECT_CHECK(VMPortState, (obj), TYPE_VMPORT)
typedef struct VMPortState {
ISADevice parent_obj;
MemoryRegion io;
VMPortReadFunc *func[VMPORT_ENTRIES];
void *opaque[VMPORT_ENTRIES];
uint32_t vmware_vmx_version;
uint8_t vmware_vmx_type;
uint32_t compat_flags;
} VMPortState;
static VMPortState *port_state;
void vmport_register(VMPortCommand command, VMPortReadFunc *func, void *opaque)
{
assert(command < VMPORT_ENTRIES);
assert(port_state);
trace_vmport_register(command, func, opaque);
port_state->func[command] = func;
port_state->opaque[command] = opaque;
}
static uint64_t vmport_ioport_read(void *opaque, hwaddr addr,
unsigned size)
{
VMPortState *s = opaque;
CPUState *cs = current_cpu;
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env;
unsigned char command;
uint32_t eax;
if (qtest_enabled()) {
return -1;
}
env = &cpu->env;
cpu_synchronize_state(cs);
eax = env->regs[R_EAX];
if (eax != VMPORT_MAGIC) {
goto err;
}
command = env->regs[R_ECX];
trace_vmport_command(command);
if (command >= VMPORT_ENTRIES || !s->func[command]) {
qemu_log_mask(LOG_UNIMP, "vmport: unknown command %x\n", command);
goto err;
}
eax = s->func[command](s->opaque[command], addr);
goto out;
err:
if (s->compat_flags & VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD) {
eax = UINT32_MAX;
}
out:
/*
* The call above to cpu_synchronize_state() gets vCPU registers values
* to QEMU but also cause QEMU to write QEMU vCPU registers values to
* vCPU implementation (e.g. Accelerator such as KVM) just before
* resuming guest.
*
* Therefore, in order to make IOPort return value propagate to
* guest EAX, we need to explicitly update QEMU EAX register value.
*/
if (s->compat_flags & VMPORT_COMPAT_READ_SET_EAX) {
cpu->env.regs[R_EAX] = eax;
}
return eax;
}
static void vmport_ioport_write(void *opaque, hwaddr addr,
uint64_t val, unsigned size)
{
X86CPU *cpu = X86_CPU(current_cpu);
if (qtest_enabled()) {
return;
}
cpu->env.regs[R_EAX] = vmport_ioport_read(opaque, addr, 4);
}
static uint32_t vmport_cmd_get_version(void *opaque, uint32_t addr)
{
X86CPU *cpu = X86_CPU(current_cpu);
if (qtest_enabled()) {
return -1;
}
cpu->env.regs[R_EBX] = VMPORT_MAGIC;
if (port_state->compat_flags & VMPORT_COMPAT_REPORT_VMX_TYPE) {
cpu->env.regs[R_ECX] = port_state->vmware_vmx_type;
}
return port_state->vmware_vmx_version;
}
static uint32_t vmport_cmd_get_bios_uuid(void *opaque, uint32_t addr)
{
X86CPU *cpu = X86_CPU(current_cpu);
uint32_t *uuid_parts = (uint32_t *)(qemu_uuid.data);
cpu->env.regs[R_EAX] = le32_to_cpu(uuid_parts[0]);
cpu->env.regs[R_EBX] = le32_to_cpu(uuid_parts[1]);
cpu->env.regs[R_ECX] = le32_to_cpu(uuid_parts[2]);
cpu->env.regs[R_EDX] = le32_to_cpu(uuid_parts[3]);
return cpu->env.regs[R_EAX];
}
static uint32_t vmport_cmd_ram_size(void *opaque, uint32_t addr)
{
X86CPU *cpu = X86_CPU(current_cpu);
if (qtest_enabled()) {
return -1;
}
cpu->env.regs[R_EBX] = 0x1177;
return ram_size;
}
static uint32_t vmport_cmd_get_hz(void *opaque, uint32_t addr)
{
X86CPU *cpu = X86_CPU(current_cpu);
if (cpu->env.tsc_khz && cpu->env.apic_bus_freq) {
uint64_t tsc_freq = (uint64_t)cpu->env.tsc_khz * 1000;
cpu->env.regs[R_ECX] = cpu->env.apic_bus_freq;
cpu->env.regs[R_EBX] = (uint32_t)(tsc_freq >> 32);
cpu->env.regs[R_EAX] = (uint32_t)tsc_freq;
} else {
/* Signal cmd as not supported */
cpu->env.regs[R_EBX] = UINT32_MAX;
}
return cpu->env.regs[R_EAX];
}
static uint32_t vmport_cmd_get_vcpu_info(void *opaque, uint32_t addr)
{
X86CPU *cpu = X86_CPU(current_cpu);
uint32_t ret = 0;
if (cpu->env.features[FEAT_1_ECX] & CPUID_EXT_X2APIC) {
ret |= 1 << VCPU_INFO_LEGACY_X2APIC_BIT;
}
return ret;
}
static const MemoryRegionOps vmport_ops = {
.read = vmport_ioport_read,
.write = vmport_ioport_write,
.impl = {
.min_access_size = 4,
.max_access_size = 4,
},
.endianness = DEVICE_LITTLE_ENDIAN,
};
static void vmport_realizefn(DeviceState *dev, Error **errp)
{
ISADevice *isadev = ISA_DEVICE(dev);
VMPortState *s = VMPORT(dev);
memory_region_init_io(&s->io, OBJECT(s), &vmport_ops, s, "vmport", 1);
isa_register_ioport(isadev, &s->io, 0x5658);
port_state = s;
/* Register some generic port commands */
vmport_register(VMPORT_CMD_GETVERSION, vmport_cmd_get_version, NULL);
vmport_register(VMPORT_CMD_GETRAMSIZE, vmport_cmd_ram_size, NULL);
if (s->compat_flags & VMPORT_COMPAT_CMDS_V2) {
vmport_register(VMPORT_CMD_GETBIOSUUID, vmport_cmd_get_bios_uuid, NULL);
vmport_register(VMPORT_CMD_GETHZ, vmport_cmd_get_hz, NULL);
vmport_register(VMPORT_CMD_GET_VCPU_INFO, vmport_cmd_get_vcpu_info,
NULL);
}
}
static Property vmport_properties[] = {
/* Used to enforce compatibility for migration */
DEFINE_PROP_BIT("x-read-set-eax", VMPortState, compat_flags,
VMPORT_COMPAT_READ_SET_EAX_BIT, true),
DEFINE_PROP_BIT("x-signal-unsupported-cmd", VMPortState, compat_flags,
VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD_BIT, true),
DEFINE_PROP_BIT("x-report-vmx-type", VMPortState, compat_flags,
VMPORT_COMPAT_REPORT_VMX_TYPE_BIT, true),
DEFINE_PROP_BIT("x-cmds-v2", VMPortState, compat_flags,
VMPORT_COMPAT_CMDS_V2_BIT, true),
/* Default value taken from open-vm-tools code VERSION_MAGIC definition */
DEFINE_PROP_UINT32("vmware-vmx-version", VMPortState,
vmware_vmx_version, 6),
/*
* Value determines which VMware product type host report itself to guest.
*
* Most guests are fine with exposing host as VMware ESX server.
* Some legacy/proprietary guests hard-code a given type.
*
* For a complete list of values, refer to enum VMXType at open-vm-tools
* project (Defined at lib/include/vm_vmx_type.h).
*
* Reasonable options:
* 0 - Unset
* 1 - VMware Express (deprecated)
* 2 - VMware ESX Server
* 3 - VMware Server (Deprecated)
* 4 - VMware Workstation
* 5 - ACE 1.x (Deprecated)
*/
DEFINE_PROP_UINT8("vmware-vmx-type", VMPortState, vmware_vmx_type, 2),
DEFINE_PROP_END_OF_LIST(),
};
static void vmport_class_initfn(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = vmport_realizefn;
/* Reason: realize sets global port_state */
dc->user_creatable = false;
device_class_set_props(dc, vmport_properties);
}
static const TypeInfo vmport_info = {
.name = TYPE_VMPORT,
.parent = TYPE_ISA_DEVICE,
.instance_size = sizeof(VMPortState),
.class_init = vmport_class_initfn,
};
static void vmport_register_types(void)
{
type_register_static(&vmport_info);
}
type_init(vmport_register_types)