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Revert "x86: don't let decompressed kernel image clobber setup_data"

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This reverts commit eac7a7791b.

Fixes: eac7a7791b ("x86: don't let decompressed kernel image clobber setup_data")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2023-02-08 15:55:36 -05:00
parent 60d09b8dc7
commit b34f2fd17e
5 changed files with 31 additions and 59 deletions
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15
hw/i386/microvm.c
View File

@ -376,8 +376,7 @@ static void microvm_fix_kernel_cmdline(MachineState *machine)
MicrovmMachineState *mms = MICROVM_MACHINE(machine);
BusState *bus;
BusChild *kid;
char *cmdline, *existing_cmdline;
size_t len;
char *cmdline;
/*
* Find MMIO transports with attached devices, and add them to the kernel
@ -386,8 +385,7 @@ static void microvm_fix_kernel_cmdline(MachineState *machine)
* Yes, this is a hack, but one that heavily improves the UX without
* introducing any significant issues.
*/
existing_cmdline = fw_cfg_read_bytes_ptr(x86ms->fw_cfg, FW_CFG_CMDLINE_DATA);
cmdline = g_strdup(existing_cmdline);
cmdline = g_strdup(machine->kernel_cmdline);
bus = sysbus_get_default();
QTAILQ_FOREACH(kid, &bus->children, sibling) {
DeviceState *dev = kid->child;
@ -411,12 +409,9 @@ static void microvm_fix_kernel_cmdline(MachineState *machine)
}
}
len = strlen(cmdline);
if (len > VIRTIO_CMDLINE_TOTAL_MAX_LEN + strlen(existing_cmdline)) {
fprintf(stderr, "qemu: virtio mmio cmdline too large, skipping\n");
} else {
memcpy(existing_cmdline, cmdline, len + 1);
}
fw_cfg_modify_i32(x86ms->fw_cfg, FW_CFG_CMDLINE_SIZE, strlen(cmdline) + 1);
fw_cfg_modify_string(x86ms->fw_cfg, FW_CFG_CMDLINE_DATA, cmdline);
g_free(cmdline);
}

52
hw/i386/x86.c
View File

@ -49,7 +49,6 @@
#include "hw/intc/i8259.h"
#include "hw/rtc/mc146818rtc.h"
#include "target/i386/sev.h"
#include "hw/i386/microvm.h"
#include "hw/acpi/cpu_hotplug.h"
#include "hw/irq.h"
@ -815,18 +814,12 @@ void x86_load_linux(X86MachineState *x86ms,
const char *kernel_filename = machine->kernel_filename;
const char *initrd_filename = machine->initrd_filename;
const char *dtb_filename = machine->dtb;
char *kernel_cmdline;
const char *kernel_cmdline = machine->kernel_cmdline;
SevKernelLoaderContext sev_load_ctx = {};
enum { RNG_SEED_LENGTH = 32 };
/*
* Add the NUL terminator, some padding for the microvm cmdline fiddling
* hack, and then align to 16 bytes as a paranoia measure
*/
cmdline_size = (strlen(machine->kernel_cmdline) + 1 +
VIRTIO_CMDLINE_TOTAL_MAX_LEN + 16) & ~15;
/* Make a copy, since we might append arbitrary bytes to it later. */
kernel_cmdline = g_strndup(machine->kernel_cmdline, cmdline_size);
/* Align to 16 bytes as a paranoia measure */
cmdline_size = (strlen(kernel_cmdline) + 16) & ~15;
/* load the kernel header */
f = fopen(kernel_filename, "rb");
@ -967,6 +960,12 @@ void x86_load_linux(X86MachineState *x86ms,
initrd_max = x86ms->below_4g_mem_size - acpi_data_size - 1;
}
fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_ADDR, cmdline_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE, strlen(kernel_cmdline) + 1);
fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA, kernel_cmdline);
sev_load_ctx.cmdline_data = (char *)kernel_cmdline;
sev_load_ctx.cmdline_size = strlen(kernel_cmdline) + 1;
if (protocol >= 0x202) {
stl_p(header + 0x228, cmdline_addr);
} else {
@ -1093,24 +1092,27 @@ void x86_load_linux(X86MachineState *x86ms,
exit(1);
}
setup_data_offset = cmdline_size;
cmdline_size += sizeof(SetupData) + dtb_size;
kernel_cmdline = g_realloc(kernel_cmdline, cmdline_size);
setup_data = (void *)kernel_cmdline + setup_data_offset;
setup_data_offset = QEMU_ALIGN_UP(kernel_size, 16);
kernel_size = setup_data_offset + sizeof(SetupData) + dtb_size;
kernel = g_realloc(kernel, kernel_size);
setup_data = (SetupData *)(kernel + setup_data_offset);
setup_data->next = cpu_to_le64(first_setup_data);
first_setup_data = cmdline_addr + setup_data_offset;
first_setup_data = prot_addr + setup_data_offset;
setup_data->type = cpu_to_le32(SETUP_DTB);
setup_data->len = cpu_to_le32(dtb_size);
load_image_size(dtb_filename, setup_data->data, dtb_size);
}
if (!legacy_no_rng_seed && protocol >= 0x209) {
setup_data_offset = cmdline_size;
cmdline_size += sizeof(SetupData) + RNG_SEED_LENGTH;
kernel_cmdline = g_realloc(kernel_cmdline, cmdline_size);
setup_data = (void *)kernel_cmdline + setup_data_offset;
if (!legacy_no_rng_seed) {
setup_data_offset = QEMU_ALIGN_UP(kernel_size, 16);
kernel_size = setup_data_offset + sizeof(SetupData) + RNG_SEED_LENGTH;
kernel = g_realloc(kernel, kernel_size);
setup_data = (SetupData *)(kernel + setup_data_offset);
setup_data->next = cpu_to_le64(first_setup_data);
first_setup_data = cmdline_addr + setup_data_offset;
first_setup_data = prot_addr + setup_data_offset;
setup_data->type = cpu_to_le32(SETUP_RNG_SEED);
setup_data->len = cpu_to_le32(RNG_SEED_LENGTH);
qemu_guest_getrandom_nofail(setup_data->data, RNG_SEED_LENGTH);
@ -1121,12 +1123,6 @@ void x86_load_linux(X86MachineState *x86ms,
fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size);
}
fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_ADDR, cmdline_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE, cmdline_size);
fw_cfg_add_bytes(fw_cfg, FW_CFG_CMDLINE_DATA, kernel_cmdline, cmdline_size);
sev_load_ctx.cmdline_data = (char *)kernel_cmdline;
sev_load_ctx.cmdline_size = cmdline_size;
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, kernel_size);
sev_load_ctx.kernel_data = (char *)kernel;
@ -1139,7 +1135,7 @@ void x86_load_linux(X86MachineState *x86ms,
* kernel on the other side of the fw_cfg interface matches the hash of the
* file the user passed in.
*/
if (!sev_enabled() && first_setup_data) {
if (!sev_enabled()) {
SetupDataFixup *fixup = g_malloc(sizeof(*fixup));
memcpy(setup, header, MIN(sizeof(header), setup_size));

9
hw/nvram/fw_cfg.c
View File

@ -741,15 +741,6 @@ void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len)
fw_cfg_add_bytes_callback(s, key, NULL, NULL, NULL, data, len, true);
}
void *fw_cfg_read_bytes_ptr(FWCfgState *s, uint16_t key)
{
int arch = !!(key & FW_CFG_ARCH_LOCAL);
key &= FW_CFG_ENTRY_MASK;
assert(key < fw_cfg_max_entry(s));
return s->entries[arch][key].data;
}
void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value)
{
size_t sz = strlen(value) + 1;

1
include/hw/i386/microvm.h
View File

@ -52,7 +52,6 @@
/* Platform virtio definitions */
#define VIRTIO_MMIO_BASE 0xfeb00000
#define VIRTIO_CMDLINE_MAXLEN 64
#define VIRTIO_CMDLINE_TOTAL_MAX_LEN ((VIRTIO_CMDLINE_MAXLEN + 1) * 16)
#define GED_MMIO_BASE 0xfea00000
#define GED_MMIO_BASE_MEMHP (GED_MMIO_BASE + 0x100)

9
include/hw/nvram/fw_cfg.h
View File

@ -139,15 +139,6 @@ void fw_cfg_add_bytes_callback(FWCfgState *s, uint16_t key,
void *data, size_t len,
bool read_only);
/**
* fw_cfg_read_bytes_ptr:
* @s: fw_cfg device being modified
* @key: selector key value for new fw_cfg item
*
* Reads an existing fw_cfg data pointer.
*/
void *fw_cfg_read_bytes_ptr(FWCfgState *s, uint16_t key);
/**
* fw_cfg_add_string:
* @s: fw_cfg device being modified