From 1cc1455511ff6ada7f4b3c4e23d8ff82f820f1ff Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>

Date: Wed, 13 Dec 2017 13:38:38 +0100

Subject: [PATCH 07/41] fw-cfg: support writeable blobs

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RH-Author: Marc-André Lureau <marcandre.lureau@redhat.com>

Message-id: <20171213133912.26176-8-marcandre.lureau@redhat.com>

Patchwork-id: 78356

O-Subject: [RHEL-7.5 qemu-kvm PATCH v3 07/41] fw-cfg: support writeable blobs

Bugzilla: 1411490

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: "Michael S. Tsirkin" <mst@redhat.com>

Useful to send guest data back to QEMU.

Changes from Laszlo Ersek <lersek@redhat.com>:

- rebase the patch from Michael Tsirkin's original postings at [1] and [2]

  to the following patches:

  - loader: Allow a custom AddressSpace when loading ROMs

  - loader: Add AddressSpace loading support to uImages

  - loader: fix handling of custom address spaces when adding ROM blobs

- reject such writes immediately that would exceed the end of the array,

  rather than performing a partial write before setting the error bit: see

  the (len != dma.length) condition

- document the write interface

[1] http://lists.nongnu.org/archive/html/qemu-devel/2016-02/msg04968.html

[2] http://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg02735.html

Cc: "Gabriel L. Somlo" <somlo@cmu.edu>

Cc: "Michael S. Tsirkin" <mst@redhat.com>

Cc: Gerd Hoffmann <kraxel@redhat.com>

Cc: Igor Mammedov <imammedo@redhat.com>

Cc: Michael Walle <michael@walle.cc>

Cc: Paolo Bonzini <pbonzini@redhat.com>

Cc: Peter Maydell <peter.maydell@linaro.org>

Cc: Shannon Zhao <zhaoshenglong@huawei.com>

Cc: qemu-arm@nongnu.org

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>

Acked-by: Gabriel Somlo <somlo@cmu.edu>

Tested-by: Gabriel Somlo <somlo@cmu.edu>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

(cherry picked from commit baf2d5bfbac015b27f4db74feab235e167df0c84)

RHEL: major conflict due to internal API changes, but functional

      changes minor.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 hw/core/loader.c          | 19 ++++++++++++-------

 hw/i386/acpi-build.c      |  2 +-

 hw/lm32/lm32_hwsetup.h    |  3 ++-

 hw/nvram/fw_cfg.c         | 35 +++++++++++++++++++++++++++++------

 include/hw/loader.h       |  5 +++--

 include/hw/nvram/fw_cfg.h |  2 +-

 6 files changed, 48 insertions(+), 18 deletions(-)

diff --git a/hw/core/loader.c b/hw/core/loader.c

index 9309b8c..c824bc2 100644

--- a/hw/core/loader.c

+++ b/hw/core/loader.c

@@ -575,13 +575,13 @@ static void rom_insert(Rom *rom)

     QTAILQ_INSERT_TAIL(&roms, rom, next);

 }

-static void *rom_set_mr(Rom *rom, const char *name)

+static void *rom_set_mr(Rom *rom, const char *name, bool ro)

 {

     void *data;

     rom->mr = g_malloc(sizeof(*rom->mr));

     memory_region_init_ram(rom->mr, name, rom->datasize);

-    memory_region_set_readonly(rom->mr, true);

+    memory_region_set_readonly(rom->mr, ro);

     vmstate_register_ram_global(rom->mr);

     data = memory_region_get_ram_ptr(rom->mr);

@@ -645,7 +645,7 @@ int rom_add_file(const char *file, const char *fw_dir,

         snprintf(devpath, sizeof(devpath), "/rom@%s", fw_file_name);

         if ((!option_rom || option_rom_has_mr) && rom_file_has_mr) {

-            data = rom_set_mr(rom, devpath);

+            data = rom_set_mr(rom, devpath, true);

         } else {

             data = rom->data;

         }

@@ -670,7 +670,8 @@ err:

 void *rom_add_blob(const char *name, const void *blob, size_t len,

                    hwaddr addr, const char *fw_file_name,

-                   FWCfgReadCallback fw_callback, void *callback_opaque)

+                   FWCfgReadCallback fw_callback, void *callback_opaque,

+                   bool read_only)

 {

     Rom *rom;

     void *data = NULL;

@@ -686,17 +687,21 @@ void *rom_add_blob(const char *name, const void *blob, size_t len,

     if (fw_file_name && fw_cfg) {

         char devpath[100];

-        snprintf(devpath, sizeof(devpath), "/rom@%s", fw_file_name);

+        if (read_only) {

+            snprintf(devpath, sizeof(devpath), "/rom@%s", fw_file_name);

+        } else {

+            snprintf(devpath, sizeof(devpath), "/ram@%s", fw_file_name);

+        }

         if (rom_file_has_mr) {

-            data = rom_set_mr(rom, devpath);

+            data = rom_set_mr(rom, devpath, read_only);

         } else {

             data = rom->data;

         }

         fw_cfg_add_file_callback(fw_cfg, fw_file_name,

                                  fw_callback, callback_opaque,

-                                 data, rom->romsize);

+                                 data, rom->romsize, read_only);

     }

     return data;

 }

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c

index 85291f5..52dd500 100644

--- a/hw/i386/acpi-build.c

+++ b/hw/i386/acpi-build.c

@@ -1182,7 +1182,7 @@ static void *acpi_add_rom_blob(AcpiBuildState *build_state, GArray *blob,

                                const char *name)

 {

     return rom_add_blob(name, blob->data, acpi_data_len(blob), -1, name,

-                        acpi_build_update, build_state);

+                        acpi_build_update, build_state, true);

 }

 static const VMStateDescription vmstate_acpi_build = {

diff --git a/hw/lm32/lm32_hwsetup.h b/hw/lm32/lm32_hwsetup.h

index 9fd5e69..92f952f 100644

--- a/hw/lm32/lm32_hwsetup.h

+++ b/hw/lm32/lm32_hwsetup.h

@@ -73,7 +73,8 @@ static inline void hwsetup_free(HWSetup *hw)

 static inline void hwsetup_create_rom(HWSetup *hw,

         hwaddr base)

 {

-    rom_add_blob("hwsetup", hw->data, TARGET_PAGE_SIZE, base, NULL, NULL, NULL);

+    rom_add_blob("hwsetup", hw->data, TARGET_PAGE_SIZE,

+                 base, NULL, NULL, NULL, true);

 }

 static inline void hwsetup_add_u8(HWSetup *hw, uint8_t u)

diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c

index 1317df7..1789487 100644

--- a/hw/nvram/fw_cfg.c

+++ b/hw/nvram/fw_cfg.c

@@ -46,9 +46,11 @@

 #define FW_CFG_DMA_CTL_READ    0x02

 #define FW_CFG_DMA_CTL_SKIP    0x04

 #define FW_CFG_DMA_CTL_SELECT  0x08

+#define FW_CFG_DMA_CTL_WRITE   0x10

 typedef struct FWCfgEntry {

     uint32_t len;

+    bool allow_write;

     uint8_t *data;

     void *callback_opaque;

     FWCfgReadCallback read_callback;

@@ -279,7 +281,7 @@ static void fw_cfg_dma_transfer(FWCfgState *s)

     FWCfgDmaAccess dma;

     int arch;

     FWCfgEntry *e;

-    int read;

+    int read = 0, write = 0;

     dma_addr_t dma_addr;

     /* Reset the address before the next access */

@@ -306,8 +308,13 @@ static void fw_cfg_dma_transfer(FWCfgState *s)

     if (dma.control & FW_CFG_DMA_CTL_READ) {

         read = 1;

+        write = 0;

+    } else if (dma.control & FW_CFG_DMA_CTL_WRITE) {

+        read = 0;

+        write = 1;

     } else if (dma.control & FW_CFG_DMA_CTL_SKIP) {

         read = 0;

+        write = 0;

     } else {

         dma.length = 0;

     }

@@ -328,6 +335,9 @@ static void fw_cfg_dma_transfer(FWCfgState *s)

                 }

             }

+            if (write) {

+                dma.control |= FW_CFG_DMA_CTL_ERROR;

+            }

         } else {

             if (dma.length <= (e->len - s->cur_offset)) {

                 len = dma.length;

@@ -349,6 +359,16 @@ static void fw_cfg_dma_transfer(FWCfgState *s)

                 }

             }

+            if (write) {

+                if (!e->allow_write ||

+                    len != dma.length ||

+                    dma_memory_read(s->dma, dma.address,

+                                    &e->data[s->cur_offset], len)) {

+                    dma.control |= FW_CFG_DMA_CTL_ERROR;

+                }

+            }

+

+

             s->cur_offset += len;

         }

@@ -539,7 +559,8 @@ static const VMStateDescription vmstate_fw_cfg = {

 static void fw_cfg_add_bytes_read_callback(FWCfgState *s, uint16_t key,

                                            FWCfgReadCallback callback,

                                            void *callback_opaque,

-                                           void *data, size_t len)

+                                           void *data, size_t len,

+                                           bool read_only)

 {

     int arch = !!(key & FW_CFG_ARCH_LOCAL);

@@ -552,11 +573,12 @@ static void fw_cfg_add_bytes_read_callback(FWCfgState *s, uint16_t key,

     s->entries[arch][key].len = (uint32_t)len;

     s->entries[arch][key].read_callback = callback;

     s->entries[arch][key].callback_opaque = callback_opaque;

+    s->entries[arch][key].allow_write = !read_only;

 }

 void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len)

 {

-    fw_cfg_add_bytes_read_callback(s, key, NULL, NULL, data, len);

+    fw_cfg_add_bytes_read_callback(s, key, NULL, NULL, data, len, true);

 }

 void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value)

@@ -595,7 +617,7 @@ void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value)

 void fw_cfg_add_file_callback(FWCfgState *s,  const char *filename,

                               FWCfgReadCallback callback, void *callback_opaque,

-                              void *data, size_t len)

+                              void *data, size_t len, bool read_only)

 {

     int i, index;

     size_t dsize;

@@ -620,7 +642,8 @@ void fw_cfg_add_file_callback(FWCfgState *s,  const char *filename,

     }

     fw_cfg_add_bytes_read_callback(s, FW_CFG_FILE_FIRST + index,

-                                   callback, callback_opaque, data, len);

+                                   callback, callback_opaque, data, len,

+                                   read_only);

     s->files->f[index].size   = cpu_to_be32(len);

     s->files->f[index].select = cpu_to_be16(FW_CFG_FILE_FIRST + index);

@@ -632,7 +655,7 @@ void fw_cfg_add_file_callback(FWCfgState *s,  const char *filename,

 void fw_cfg_add_file(FWCfgState *s,  const char *filename,

                      void *data, size_t len)

 {

-    fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len);

+    fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len, true);

 }

 static void fw_cfg_machine_ready(struct Notifier *n, void *data)

diff --git a/include/hw/loader.h b/include/hw/loader.h

index a5e02ce..f04a834 100644

--- a/include/hw/loader.h

+++ b/include/hw/loader.h

@@ -31,7 +31,8 @@ int rom_add_file(const char *file, const char *fw_dir,

                  bool option_rom);

 void *rom_add_blob(const char *name, const void *blob, size_t len,

                    hwaddr addr, const char *fw_file_name,

-                   FWCfgReadCallback fw_callback, void *callback_opaque);

+                   FWCfgReadCallback fw_callback, void *callback_opaque,

+                   bool read_only);

 int rom_add_elf_program(const char *name, void *data, size_t datasize,

                         size_t romsize, hwaddr addr);

 int rom_load_all(void);

@@ -44,7 +45,7 @@ void do_info_roms(Monitor *mon, const QDict *qdict);

 #define rom_add_file_fixed(_f, _a, _i)          \

     rom_add_file(_f, NULL, _a, _i, false)

 #define rom_add_blob_fixed(_f, _b, _l, _a)      \

-    (rom_add_blob(_f, _b, _l, _a, NULL, NULL, NULL) ? 0 : -1)

+    (rom_add_blob(_f, _b, _l, _a, NULL, NULL, NULL, true) ? 0 : -1)

 #define PC_ROM_MIN_VGA     0xc0000

 #define PC_ROM_MIN_OPTION  0xc8000

diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h

index b193e38..76fc787 100644

--- a/include/hw/nvram/fw_cfg.h

+++ b/include/hw/nvram/fw_cfg.h

@@ -83,7 +83,7 @@ void fw_cfg_add_file(FWCfgState *s, const char *filename, void *data,

                      size_t len);

 void fw_cfg_add_file_callback(FWCfgState *s, const char *filename,

                               FWCfgReadCallback callback, void *callback_opaque,

-                              void *data, size_t len);

+                              void *data, size_t len, bool read_only);

 FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,

                         hwaddr crl_addr, hwaddr data_addr);

 FWCfgState *fw_cfg_init_io_dma(uint32_t iobase, uint32_t dma_iobase,

-- 

1.8.3.1