[Qemu-devel] [RFC PATCH v6 0/4] reload images from host rootfs on reset to save footprint

[Qemu-devel] [RFC PATCH v6 0/4] reload images from host rootfs on reset to save footprint

[Olivia Yin]

The current model of loader copy "rom blobs" and kept in memory until a reset
occurs and waste host memory.

This serial of patches uses private reset handlers to load uimage/initrd/vmlinux
from hard disk on reset, which could make loader framework more dynamic and 
reduce the memory consumption of QEMU process.

Olivia Yin (4):
  use image_file_reset to reload initrd
  use uimage_reset to reload uimage
  use elf_reset to reload elf image
  free rom->data when rom_reset

 elf.h        |   10 +++++
 hw/elf_ops.h |   44 ++++++++++++++++++++---
 hw/loader.c  |  114 +++++++++++++++++++++++++++++++++++++++++++++++++---------
 hw/loader.h  |   12 ++++++
 4 files changed, 158 insertions(+), 22 deletions(-)

v6:
patch 3/4: load symbol only when startup

v5: 
patch 2/4: remove global variables is_linux and kernel_loaded.
patch 3/4: register reset handlers in loader.c for elf images.
           extract the duplicated source code into function elf_phy_loader().
patch 4/4: fix the issue of memory increasing (about 1.4MB) once reload elf image.

v4: fix elf reload and register reset handler in hw/elf_ops.h

v3: reload elf

v2: Rename target_phys_addr_t to hwaddr

v1: support uimage/initrd reload

[Qemu-devel] [RFC PATCH v6 1/4] use image_file_reset to reload initrd

[Olivia Yin]

Signed-off-by: Olivia Yin <hong-hua.yin@freescale.com>
---
 hw/loader.c |   39 +++++++++++++++++++++++++++++++++++++++
 hw/loader.h |    6 ++++++
 2 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/hw/loader.c b/hw/loader.c
index ba01ca6..e45f56a 100644
--- a/hw/loader.c
+++ b/hw/loader.c
@@ -86,6 +86,39 @@ int load_image(const char *filename, uint8_t *addr)
     return size;
 }
 
+static void image_file_reset(void *opaque)
+{
+    ImageFile *image = opaque;
+    GError *err = NULL;
+    gboolean res;
+    gchar *content;
+    gsize size;
+
+    if(image->dir) {
+        const char *basename;
+        char fw_file_name[56];
+
+        basename = strrchr(image->name, '/');
+        if (basename) {
+            basename++;
+        } else {
+            basename = image->name;
+        }
+        snprintf(fw_file_name, sizeof(fw_file_name), "%s/%s", image->dir,
+                 basename);
+        image->name = g_strdup(fw_file_name);
+    }
+
+    res = g_file_get_contents(image->name, &content, &size, &err);
+    if (res == FALSE) {
+       error_report("failed to read image file: %s\n", image->name);
+       g_error_free(err);
+    } else {
+       cpu_physical_memory_write(image->addr, (uint8_t *)content, size);
+       g_free(content);
+    }
+}
+
 /* read()-like version */
 ssize_t read_targphys(const char *name,
                       int fd, hwaddr dst_addr, size_t nbytes)
@@ -113,6 +146,12 @@ int load_image_targphys(const char *filename,
     }
     if (size > 0) {
         rom_add_file_fixed(filename, addr, -1);
+
+        ImageFile *image;
+        image = g_malloc0(sizeof(*image));
+        image->name = g_strdup(filename);
+        image->addr = addr;
+        qemu_register_reset(image_file_reset, image);
     }
     return size;
 }
diff --git a/hw/loader.h b/hw/loader.h
index 26480ad..9e76ebd 100644
--- a/hw/loader.h
+++ b/hw/loader.h
@@ -1,6 +1,12 @@
 #ifndef LOADER_H
 #define LOADER_H
 
+typedef struct ImageFile ImageFile;
+struct ImageFile {
+    char *name;
+    hwaddr addr;
+};
+
 /* loader.c */
 int get_image_size(const char *filename);
 int load_image(const char *filename, uint8_t *addr); /* deprecated */
-- 
1.7.1

[Qemu-devel] [RFC PATCH v6 2/4] use uimage_reset to reload uimage

[Olivia Yin]

Signed-off-by: Olivia Yin <hong-hua.yin@freescale.com>
---
 hw/loader.c |   57 +++++++++++++++++++++++++++++++++++++++++++++------------
 hw/loader.h |    6 ++++++
 2 files changed, 51 insertions(+), 12 deletions(-)

diff --git a/hw/loader.c b/hw/loader.c
index e45f56a..0d93c3b 100644
--- a/hw/loader.c
+++ b/hw/loader.c
@@ -472,15 +472,15 @@ static ssize_t gunzip(void *dst, size_t dstlen, uint8_t *src,
     return dstbytes;
 }
 
-/* Load a U-Boot image.  */
-int load_uimage(const char *filename, hwaddr *ep,
-                hwaddr *loadaddr, int *is_linux)
+/* write uimage into memory */
+static int uimage_physical_loader(const char *filename, hwaddr *ep, 
+                                  uint8_t **data, hwaddr *loadaddr,
+                                  int *is_linux, int reset)
 {
     int fd;
     int size;
     uboot_image_header_t h;
     uboot_image_header_t *hdr = &h;
-    uint8_t *data = NULL;
     int ret = -1;
 
     fd = open(filename, O_RDONLY | O_BINARY);
@@ -522,9 +522,9 @@ int load_uimage(const char *filename, hwaddr *ep,
     }
 
     *ep = hdr->ih_ep;
-    data = g_malloc(hdr->ih_size);
+    *data = g_malloc(hdr->ih_size);
 
-    if (read(fd, data, hdr->ih_size) != hdr->ih_size) {
+    if (read(fd, *data, hdr->ih_size) != hdr->ih_size) {
         fprintf(stderr, "Error reading file\n");
         goto out;
     }
@@ -534,11 +534,11 @@ int load_uimage(const char *filename, hwaddr *ep,
         size_t max_bytes;
         ssize_t bytes;
 
-        compressed_data = data;
+        compressed_data = *data;
         max_bytes = UBOOT_MAX_GUNZIP_BYTES;
-        data = g_malloc(max_bytes);
+        *data = g_malloc(max_bytes);
 
-        bytes = gunzip(data, max_bytes, compressed_data, hdr->ih_size);
+        bytes = gunzip(*data, max_bytes, compressed_data, hdr->ih_size);
         g_free(compressed_data);
         if (bytes < 0) {
             fprintf(stderr, "Unable to decompress gzipped image!\n");
@@ -547,7 +547,11 @@ int load_uimage(const char *filename, hwaddr *ep,
         hdr->ih_size = bytes;
     }
 
-    rom_add_blob_fixed(filename, data, hdr->ih_size, hdr->ih_load);
+    if (!reset) {
+        rom_add_blob_fixed(filename, *data, hdr->ih_size, hdr->ih_load);
+    } else {
+        cpu_physical_memory_write(hdr->ih_load, *data, hdr->ih_size);
+    }
 
     if (loadaddr)
         *loadaddr = hdr->ih_load;
@@ -555,12 +559,41 @@ int load_uimage(const char *filename, hwaddr *ep,
     ret = hdr->ih_size;
 
 out:
-    if (data)
-        g_free(data);
     close(fd);
     return ret;
 }
 
+static void uimage_reset(void *opaque)
+{
+    ImageFile *image = opaque;
+    uint8_t *data = NULL;
+
+    uimage_physical_loader(image->name, image->ep, &data, &image->addr, 
+                           image->is_linux, 1);
+    g_free(data);
+}
+
+/* Load a U-Boot image.  */
+int load_uimage(const char *filename, hwaddr *ep,
+                hwaddr *loadaddr, int *is_linux)
+{
+    int size;
+    ImageFile *image;
+    uint8_t *data = NULL;
+
+    size = uimage_physical_loader(filename, ep, &data, loadaddr, is_linux, 0);
+    if (size > 0) {
+        g_free(data);
+        image = g_malloc0(sizeof(*image));
+        image->name = g_strdup(filename);
+        image->addr = *loadaddr;
+        image->ep = ep;
+        image->is_linux = is_linux;
+        qemu_register_reset(uimage_reset, image);
+    }
+    return size;
+}
+
 /*
  * Functions for reboot-persistent memory regions.
  *  - used for vga bios and option roms.
diff --git a/hw/loader.h b/hw/loader.h
index 9e76ebd..17654fa 100644
--- a/hw/loader.h
+++ b/hw/loader.h
@@ -5,6 +5,12 @@ typedef struct ImageFile ImageFile;
 struct ImageFile {
     char *name;
     hwaddr addr;
+    int reset;
+    /* rom file */
+    char *dir;
+    /* uimage */
+    hwaddr *ep;
+    int *is_linux; 
 };
 
 /* loader.c */
-- 
1.7.1

[Qemu-devel] [RFC PATCH v6 3/4] use elf_reset to reload elf image

[Olivia Yin]

Signed-off-by: Olivia Yin <hong-hua.yin@freescale.com>
---
 elf.h        |   10 ++++++++++
 hw/elf_ops.h |   44 +++++++++++++++++++++++++++++++++++++++-----
 hw/loader.c  |   11 +++++++++++
 3 files changed, 60 insertions(+), 5 deletions(-)

diff --git a/elf.h b/elf.h
index a21ea53..335f1af 100644
--- a/elf.h
+++ b/elf.h
@@ -1078,6 +1078,16 @@ typedef struct elf64_hdr {
   Elf64_Half e_shstrndx;
 } Elf64_Ehdr;
 
+typedef struct ImageElf ImageElf;
+struct ImageElf {
+    char *name;
+    uint64_t (*fn)(void *, uint64_t);
+    void *opaque;
+    int swab;
+    int machine;
+    int lsb;
+};
+
 /* These constants define the permissions on sections in the program
    header, p_flags. */
 #define PF_R		0x4
diff --git a/hw/elf_ops.h b/hw/elf_ops.h
index 531a425..3ff8ffd 100644
--- a/hw/elf_ops.h
+++ b/hw/elf_ops.h
@@ -187,12 +187,12 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
     return -1;
 }
 
-static int glue(load_elf, SZ)(const char *name, int fd,
+static int glue(elf_phy_loader, SZ)(const char *name, int fd,
                               uint64_t (*translate_fn)(void *, uint64_t),
                               void *translate_opaque,
                               int must_swab, uint64_t *pentry,
                               uint64_t *lowaddr, uint64_t *highaddr,
-                              int elf_machine, int clear_lsb)
+                              int elf_machine, int clear_lsb, int reset)
 {
     struct elfhdr ehdr;
     struct elf_phdr *phdr = NULL, *ph;
@@ -202,6 +202,9 @@ static int glue(load_elf, SZ)(const char *name, int fd,
     uint8_t *data = NULL;
     char label[128];
 
+    if (reset) {
+        fd = open(name, O_RDONLY | O_BINARY);
+    }
     if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
         goto fail;
     if (must_swab) {
@@ -232,7 +235,9 @@ static int glue(load_elf, SZ)(const char *name, int fd,
     if (pentry)
    	*pentry = (uint64_t)(elf_sword)ehdr.e_entry;
 
-    glue(load_symbols, SZ)(&ehdr, fd, must_swab, clear_lsb);
+    if (!reset) {
+        glue(load_symbols, SZ)(&ehdr, fd, must_swab, clear_lsb);
+    }
 
     size = ehdr.e_phnum * sizeof(phdr[0]);
     lseek(fd, ehdr.e_phoff, SEEK_SET);
@@ -280,8 +285,12 @@ static int glue(load_elf, SZ)(const char *name, int fd,
                 *pentry = ehdr.e_entry - ph->p_vaddr + ph->p_paddr;
             }
 
-            snprintf(label, sizeof(label), "phdr #%d: %s", i, name);
-            rom_add_blob_fixed(label, data, mem_size, addr);
+            if (!reset) {
+                snprintf(label, sizeof(label), "phdr #%d: %s", i, name);
+                rom_add_blob_fixed(label, data, mem_size, addr);
+            } else {
+                cpu_physical_memory_write(addr, data, mem_size);
+            }
 
             total_size += mem_size;
             if (addr < low)
@@ -304,3 +313,28 @@ static int glue(load_elf, SZ)(const char *name, int fd,
     g_free(phdr);
     return -1;
 }
+
+static void glue(elf_reset, SZ)(void *opaque)
+{
+    ImageElf *elf = opaque;
+    int fd;
+    
+    fd = open(elf->name, O_RDONLY | O_BINARY);
+    glue(elf_phy_loader, SZ)(elf->name, fd, elf->fn, elf->opaque, elf->swab, 
+                             NULL, NULL, NULL, elf->machine, elf->lsb, 1);
+}
+
+static int glue(load_elf, SZ)(const char *name, int fd,
+                              uint64_t (*translate_fn)(void *, uint64_t),
+                              void *translate_opaque,
+                              int must_swab, uint64_t *pentry,
+                              uint64_t *lowaddr, uint64_t *highaddr,
+                              int elf_machine, int clear_lsb)
+{
+    int ret;
+
+    ret = glue(elf_phy_loader, SZ)(name, fd, (*translate_fn), translate_opaque,
+                                   must_swab, pentry, lowaddr, highaddr,
+                                   elf_machine, clear_lsb, 0);
+    return ret;
+}
diff --git a/hw/loader.c b/hw/loader.c
index 0d93c3b..d075ed3 100644
--- a/hw/loader.c
+++ b/hw/loader.c
@@ -357,13 +357,24 @@ int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
         goto fail;
     }
 
+    ImageElf *elf;
+    elf = g_malloc0(sizeof(*elf));
+    elf->name = g_strdup(filename);
+    elf->fn = translate_fn;
+    elf->opaque = translate_opaque;
+    elf->swab = must_swab;
+    elf->machine = elf_machine;
+    elf->lsb = clear_lsb;
+
     lseek(fd, 0, SEEK_SET);
     if (e_ident[EI_CLASS] == ELFCLASS64) {
         ret = load_elf64(filename, fd, translate_fn, translate_opaque, must_swab,
                          pentry, lowaddr, highaddr, elf_machine, clear_lsb);
+        qemu_register_reset(elf_reset64, elf);
     } else {
         ret = load_elf32(filename, fd, translate_fn, translate_opaque, must_swab,
                          pentry, lowaddr, highaddr, elf_machine, clear_lsb);
+        qemu_register_reset(elf_reset32, elf);
     }
 
     close(fd);
-- 
1.7.1

[Qemu-devel] [RFC PATCH v6 4/4] free rom->data when rom_reset

[Olivia Yin]

Signed-off-by: Olivia Yin <hong-hua.yin@freescale.com>
---
 hw/loader.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/hw/loader.c b/hw/loader.c
index d075ed3..2dde6ba 100644
--- a/hw/loader.c
+++ b/hw/loader.c
@@ -752,11 +752,8 @@ static void rom_reset(void *unused)
             continue;
         }
         cpu_physical_memory_write_rom(rom->addr, rom->data, rom->romsize);
-        if (rom->isrom) {
-            /* rom needs to be written only once */
-            g_free(rom->data);
-            rom->data = NULL;
-        }
+        g_free(rom->data);
+        rom->data = NULL;
     }
 }
 
-- 
1.7.1