[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PULL 01/14] x86: return modified setup_data only if read as memory, not
From: |
Paolo Bonzini |
Subject: |
[PULL 01/14] x86: return modified setup_data only if read as memory, not as file |
Date: |
Thu, 29 Sep 2022 18:30:01 +0200 |
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
If setup_data is being read into a specific memory location, then
generally the setup_data address parameter is read first, so that the
caller knows where to read it into. In that case, we should return
setup_data containing the absolute addresses that are hard coded and
determined a priori. This is the case when kernels are loaded by BIOS,
for example. In contrast, when setup_data is read as a file, then we
shouldn't modify setup_data, since the absolute address will be wrong by
definition. This is the case when OVMF loads the image.
This allows setup_data to be used like normal, without crashing when EFI
tries to use it.
(As a small development note, strangely, fw_cfg_add_file_callback() was
exported but fw_cfg_add_bytes_callback() wasn't, so this makes that
consistent.)
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Laurent Vivier <laurent@vivier.eu>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20220921093134.2936487-1-Jason@zx2c4.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
hw/i386/x86.c | 46 ++++++++++++++++++++++++++++++---------
hw/nvram/fw_cfg.c | 12 +++++-----
include/hw/nvram/fw_cfg.h | 22 +++++++++++++++++++
3 files changed, 64 insertions(+), 16 deletions(-)
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 050eedc0c8..96d205927e 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -37,6 +37,7 @@
#include "sysemu/whpx.h"
#include "sysemu/numa.h"
#include "sysemu/replay.h"
+#include "sysemu/reset.h"
#include "sysemu/sysemu.h"
#include "sysemu/cpu-timers.h"
#include "sysemu/xen.h"
@@ -764,6 +765,24 @@ static bool load_elfboot(const char *kernel_filename,
return true;
}
+typedef struct SetupDataFixup {
+ void *pos;
+ hwaddr orig_val, new_val;
+ uint32_t addr;
+} SetupDataFixup;
+
+static void fixup_setup_data(void *opaque)
+{
+ SetupDataFixup *fixup = opaque;
+ stq_p(fixup->pos, fixup->new_val);
+}
+
+static void reset_setup_data(void *opaque)
+{
+ SetupDataFixup *fixup = opaque;
+ stq_p(fixup->pos, fixup->orig_val);
+}
+
void x86_load_linux(X86MachineState *x86ms,
FWCfgState *fw_cfg,
int acpi_data_size,
@@ -1088,8 +1107,11 @@ void x86_load_linux(X86MachineState *x86ms,
qemu_guest_getrandom_nofail(setup_data->data, RNG_SEED_LENGTH);
}
- /* Offset 0x250 is a pointer to the first setup_data link. */
- stq_p(header + 0x250, first_setup_data);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, kernel_size);
+ fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size);
+ sev_load_ctx.kernel_data = (char *)kernel;
+ sev_load_ctx.kernel_size = kernel_size;
/*
* If we're starting an encrypted VM, it will be OVMF based, which uses the
@@ -1099,16 +1121,20 @@ void x86_load_linux(X86MachineState *x86ms,
* file the user passed in.
*/
if (!sev_enabled()) {
+ SetupDataFixup *fixup = g_malloc(sizeof(*fixup));
+
memcpy(setup, header, MIN(sizeof(header), setup_size));
+ /* Offset 0x250 is a pointer to the first setup_data link. */
+ fixup->pos = setup + 0x250;
+ fixup->orig_val = ldq_p(fixup->pos);
+ fixup->new_val = first_setup_data;
+ fixup->addr = cpu_to_le32(real_addr);
+ fw_cfg_add_bytes_callback(fw_cfg, FW_CFG_SETUP_ADDR, fixup_setup_data,
NULL,
+ fixup, &fixup->addr, sizeof(fixup->addr),
true);
+ qemu_register_reset(reset_setup_data, fixup);
+ } else {
+ fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_ADDR, real_addr);
}
-
- fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr);
- fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, kernel_size);
- fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size);
- sev_load_ctx.kernel_data = (char *)kernel;
- sev_load_ctx.kernel_size = kernel_size;
-
- fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_ADDR, real_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, setup_size);
fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA, setup, setup_size);
sev_load_ctx.setup_data = (char *)setup;
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index d605f3f45a..564bda3395 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -692,12 +692,12 @@ static const VMStateDescription vmstate_fw_cfg = {
}
};
-static void fw_cfg_add_bytes_callback(FWCfgState *s, uint16_t key,
- FWCfgCallback select_cb,
- FWCfgWriteCallback write_cb,
- void *callback_opaque,
- void *data, size_t len,
- bool read_only)
+void fw_cfg_add_bytes_callback(FWCfgState *s, uint16_t key,
+ FWCfgCallback select_cb,
+ FWCfgWriteCallback write_cb,
+ void *callback_opaque,
+ void *data, size_t len,
+ bool read_only)
{
int arch = !!(key & FW_CFG_ARCH_LOCAL);
diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
index 0e7a8bc7af..e4fef393be 100644
--- a/include/hw/nvram/fw_cfg.h
+++ b/include/hw/nvram/fw_cfg.h
@@ -117,6 +117,28 @@ struct FWCfgMemState {
*/
void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len);
+/**
+ * fw_cfg_add_bytes_callback:
+ * @s: fw_cfg device being modified
+ * @key: selector key value for new fw_cfg item
+ * @select_cb: callback function when selecting
+ * @write_cb: callback function after a write
+ * @callback_opaque: argument to be passed into callback function
+ * @data: pointer to start of item data
+ * @len: size of item data
+ * @read_only: is file read only
+ *
+ * Add a new fw_cfg item, available by selecting the given key, as a raw
+ * "blob" of the given size. The data referenced by the starting pointer
+ * is only linked, NOT copied, into the data structure of the fw_cfg device.
+ */
+void fw_cfg_add_bytes_callback(FWCfgState *s, uint16_t key,
+ FWCfgCallback select_cb,
+ FWCfgWriteCallback write_cb,
+ void *callback_opaque,
+ void *data, size_t len,
+ bool read_only);
+
/**
* fw_cfg_add_string:
* @s: fw_cfg device being modified
--
2.37.3
- [PULL 00/14] x86 + misc changes for 2022-09-29, Paolo Bonzini, 2022/09/29
- [PULL 01/14] x86: return modified setup_data only if read as memory, not as file,
Paolo Bonzini <=
- [PULL 06/14] configure: do not invoke as/ld directly for pc-bios/optionrom, Paolo Bonzini, 2022/09/29
- [PULL 07/14] watchdog: remove -watchdog option, Paolo Bonzini, 2022/09/29
- [PULL 05/14] qboot: rebuild based on latest commit, Paolo Bonzini, 2022/09/29
- [PULL 02/14] x86: use typedef for SetupData struct, Paolo Bonzini, 2022/09/29
- [PULL 03/14] x86: reinitialize RNG seed on system reboot, Paolo Bonzini, 2022/09/29
- [PULL 08/14] ui: fix path to dbus-display1.h, Paolo Bonzini, 2022/09/29
- [PULL 04/14] x86: re-enable rng seeding via SetupData, Paolo Bonzini, 2022/09/29
- [PULL 09/14] meson: require 0.61.3, Paolo Bonzini, 2022/09/29
- [PULL 10/14] meson: multiple names can be passed to dependency(), Paolo Bonzini, 2022/09/29
- [PULL 11/14] configure, meson: move C++ compiler detection to meson.build, Paolo Bonzini, 2022/09/29