These scripts are most useful when populating VDs. VDs can't be populated
directly, since they don't correspond to real devices. Using:
- xc_dom_control.py vbd_add vd:your_vd_id /dev/whatever 0 w
+ xc_dom_control.py vbd_add 0 vd:your_vd_id /dev/whatever w
You can make a virtual disk available to DOM0. Sensible devices to map VDs to
in DOM0 are the /dev/xvd* nodes, since that makes it obvious that they are Xen
You can then format, mount and populate the VD through the nominated device
node. When you've finished, use:
- xc_dom_control.py vbd_remove /dev/whatever 0
+ xc_dom_control.py vbd_remove 0 /dev/whatever
To revoke DOM0's access to it. It's then ready for use in a guest domain.
as "phy:device", where device is the name of the device as seen from domain 0,
or from normal Linux without Xen. For instance:
-> xc_dom_control.py vbd_add phy:hdc /dev/whatever 2 r
+> xc_dom_control.py vbd_add 2 phy:hdc /dev/whatever r
Will grant domain 2 read-only access to the device /dev/hdc (as seen from Dom0
/ normal Linux running on the same machine - i.e. the master drive on the
in order to do this. To give DOM0 r/w access to the VD, use the following
command line, substituting the ID you got earlier.
-> xc_dom_control.py vbd_add vd:<id> /dev/xvda 0 w
+> xc_dom_control.py vbd_add 0 vd:<id> /dev/xvda w
This attaches the VD to the device /dev/xvda in domain zero, with read / write
privileges - you can use other devices nodes if you choose too.
changing it in DOM0, whilst the guest domain is using it (which could cause
filesystem corruption, and confuse Linux).
-> xc_dom_control.py vbd_remove /dev/xvda 0
+> xc_dom_control.py vbd_remove 0 /dev/xvda
It should now be possible to boot a guest domain from the VD. To do this, you
should specify the the VD's details in some way so that xc_dom_create.py will
unsigned char tmp[MYSEEK_BUFSIZE];
int c;
- if (offset < 0) {
+ if ( offset < 0 )
+ {
ERROR("seek back not supported");
return -1;
}
- while (offset) {
+ while ( offset != 0 )
+ {
c = offset;
- if (c > MYSEEK_BUFSIZE)
+ if ( c > MYSEEK_BUFSIZE )
c = MYSEEK_BUFSIZE;
- if (gzread(gfd, tmp, c) != c) {
+ if ( gzread(gfd, tmp, c) != c )
+ {
PERROR("Error seeking in image.");
return -1;
}
p = NULL;
maxva = 0;
- if (gzread(kernel_gfd, &ehdr, sizeof(Elf_Ehdr)) != sizeof(Elf_Ehdr)) {
+ if ( gzread(kernel_gfd, &ehdr, sizeof(Elf_Ehdr)) != sizeof(Elf_Ehdr) )
+ {
PERROR("Error reading kernel image ELF header.");
goto out;
}
curpos = sizeof(Elf_Ehdr);
- if (!IS_ELF(ehdr)) {
+ if ( !IS_ELF(ehdr) )
+ {
PERROR("Image does not have an ELF header.");
goto out;
}
*virt_load_addr = ehdr.e_entry;
- if ((*virt_load_addr & (PAGE_SIZE-1)) != 0) {
+ if ( (*virt_load_addr & (PAGE_SIZE-1)) != 0 )
+ {
ERROR("We can only deal with page-aligned load addresses");
goto out;
}
- if ((*virt_load_addr + (tot_pages << PAGE_SHIFT)) >
- HYPERVISOR_VIRT_START) {
+ if ( (*virt_load_addr + (tot_pages << PAGE_SHIFT)) >
+ HYPERVISOR_VIRT_START )
+ {
ERROR("Cannot map all domain memory without hitting Xen space");
goto out;
}
phdr = malloc(ehdr.e_phnum * sizeof(Elf_Phdr));
- if (phdr == NULL) {
+ if ( phdr == NULL )
+ {
ERROR("Cannot allocate memory for Elf_Phdrs");
goto out;
}
- if (myseek(kernel_gfd, ehdr.e_phoff - curpos, SEEK_SET) == -1) {
+ if ( myseek(kernel_gfd, ehdr.e_phoff - curpos, SEEK_SET) == -1 )
+ {
ERROR("Seek to program header failed");
goto out;
}
curpos = ehdr.e_phoff;
- if (gzread(kernel_gfd, phdr, ehdr.e_phnum * sizeof(Elf_Phdr)) !=
- ehdr.e_phnum * sizeof(Elf_Phdr)) {
+ if ( gzread(kernel_gfd, phdr, ehdr.e_phnum * sizeof(Elf_Phdr)) !=
+ ehdr.e_phnum * sizeof(Elf_Phdr) )
+ {
PERROR("Error reading kernel image ELF program header.");
goto out;
}
curpos += ehdr.e_phnum * sizeof(Elf_Phdr);
- /* Copy kernel .text .data .bss segments into physical memory */
- for (h = 0; h < ehdr.e_phnum; h++) {
- if (phdr[h].p_type != PT_LOAD ||
- (phdr[h].p_flags & (PF_W|PF_X)) == 0)
+ /* Copy run-time 'load' segments that are writeable and/or executable. */
+ for ( h = 0; h < ehdr.e_phnum; h++ )
+ {
+ if ( (phdr[h].p_type != PT_LOAD) ||
+ ((phdr[h].p_flags & (PF_W|PF_X)) == 0) )
continue;
- if (IS_TEXT(phdr[h]) || IS_DATA(phdr[h])) {
- if (myseek(kernel_gfd, phdr[h].p_offset - curpos, SEEK_SET) ==
- -1) {
+ if ( IS_TEXT(phdr[h]) || IS_DATA(phdr[h]) )
+ {
+ if ( myseek(kernel_gfd, phdr[h].p_offset - curpos,
+ SEEK_SET) == -1 )
+ {
ERROR("Seek to section failed");
goto out;
}
curpos = phdr[h].p_offset;
- for (iva = phdr[h].p_vaddr;
- iva < phdr[h].p_vaddr + phdr[h].p_filesz; iva += c) {
+ for ( iva = phdr[h].p_vaddr;
+ iva < phdr[h].p_vaddr + phdr[h].p_filesz;
+ iva += c)
+ {
c = PAGE_SIZE - (iva & (PAGE_SIZE - 1));
if (iva + c > phdr[h].p_vaddr + phdr[h].p_filesz)
c = phdr[h].p_vaddr + phdr[h].p_filesz - iva;
- if (gzread(kernel_gfd, page, c) != c) {
+ if ( gzread(kernel_gfd, page, c) != c )
+ {
PERROR("Error reading kernel image page.");
goto out;
}
curpos += c;
vaddr = map_pfn(pm_handle, page_array[(iva - *virt_load_addr)
>> PAGE_SHIFT]);
- if (vaddr == NULL) {
+ if ( vaddr == NULL )
+ {
ERROR("Couldn't map guest memory");
goto out;
}
unmap_pfn(pm_handle, vaddr);
}
- if (phdr[h].p_vaddr + phdr[h].p_filesz > maxva)
+ if ( phdr[h].p_vaddr + phdr[h].p_filesz > maxva )
maxva = phdr[h].p_vaddr + phdr[h].p_filesz;
}
- if (IS_BSS(phdr[h])) {
+ if ( IS_BSS(phdr[h]) )
+ {
/* XXX maybe clear phdr[h].p_memsz bytes from
phdr[h].p_vaddr + phdr[h].p_filesz ??? */
if (phdr[h].p_vaddr + phdr[h].p_memsz > maxva)
p = malloc(sizeof(int) + sizeof(Elf_Ehdr) +
ehdr.e_shnum * sizeof(Elf_Shdr));
- if (p == NULL) {
+ if ( p == NULL )
+ {
ERROR("Cannot allocate memory for Elf_Shdrs");
goto out;
}
shdr = (Elf_Shdr *)(p + sizeof(int) + sizeof(Elf_Ehdr));
- if (myseek(kernel_gfd, ehdr.e_shoff - curpos, SEEK_SET) == -1) {
+ if ( myseek(kernel_gfd, ehdr.e_shoff - curpos, SEEK_SET) == -1 )
+ {
ERROR("Seek to symbol header failed");
goto out;
}
curpos = ehdr.e_shoff;
- if (gzread(kernel_gfd, shdr, ehdr.e_shnum * sizeof(Elf_Shdr)) !=
- ehdr.e_shnum * sizeof(Elf_Shdr)) {
+ if ( gzread(kernel_gfd, shdr, ehdr.e_shnum * sizeof(Elf_Shdr)) !=
+ ehdr.e_shnum * sizeof(Elf_Shdr) )
+ {
PERROR("Error reading kernel image ELF symbol header.");
goto out;
}
maxva = (maxva + ELFROUND - 1) & ~(ELFROUND - 1);
/* Copy kernel string / symbol tables into physical memory */
- for (h = 0; h < ehdr.e_shnum; h++) {
- if (shdr[h].sh_type == SHT_STRTAB) {
- for (i = 0; i < ehdr.e_shnum; i++)
- if (shdr[i].sh_type == SHT_SYMTAB &&
- shdr[i].sh_link == h)
+ for ( h = 0; h < ehdr.e_shnum; h++ )
+ {
+ if ( shdr[h].sh_type == SHT_STRTAB )
+ {
+ /* Look for a strtab @i linked to symtab @h. */
+ for ( i = 0; i < ehdr.e_shnum; i++ )
+ if ( (shdr[i].sh_type == SHT_SYMTAB) &&
+ (shdr[i].sh_link == h) )
break;
- if (i == ehdr.e_shnum) {
+ /* Skip symtab @h if we found no corresponding strtab @i. */
+ if ( i == ehdr.e_shnum )
+ {
shdr[h].sh_offset = 0;
- continue; /* Skip string tables which are not for symbol tables */
+ continue;
}
}
- if (shdr[h].sh_type == SHT_STRTAB ||
- shdr[h].sh_type == SHT_SYMTAB) {
- if (myseek(kernel_gfd, shdr[h].sh_offset - curpos, SEEK_SET) ==
- -1) {
+ if ( (shdr[h].sh_type == SHT_STRTAB) ||
+ (shdr[h].sh_type == SHT_SYMTAB) )
+ {
+ if ( myseek(kernel_gfd, shdr[h].sh_offset - curpos,
+ SEEK_SET) == -1 )
+ {
ERROR("Seek to symbol section failed");
goto out;
}
curpos = shdr[h].sh_offset;
- shdr[h].sh_offset = maxva - *symtab_addr; /* Mangled to be based on ELF header location */
+ /* Mangled to be based on ELF header location. */
+ shdr[h].sh_offset = maxva - *symtab_addr;
DPRINTF(("copy section %d, size 0x%x\n", h, shdr[h].sh_size));
- for (i = 0; i < shdr[h].sh_size; i += c, maxva += c) {
+ for ( i = 0; i < shdr[h].sh_size; i += c, maxva += c )
+ {
c = PAGE_SIZE - (maxva & (PAGE_SIZE - 1));
- if (c > (shdr[h].sh_size - i))
+ if ( c > (shdr[h].sh_size - i) )
c = shdr[h].sh_size - i;
- if (gzread(kernel_gfd, page, c) != c) {
+ if ( gzread(kernel_gfd, page, c) != c )
+ {
PERROR("Error reading kernel image page.");
goto out;
}
vaddr = map_pfn(pm_handle, page_array[(maxva - *virt_load_addr)
>> PAGE_SHIFT]);
- if (vaddr == NULL) {
+ if ( vaddr == NULL )
+ {
ERROR("Couldn't map guest memory");
goto out;
}
maxva = (maxva + ELFROUND - 1) & ~(ELFROUND - 1);
}
- shdr[h].sh_name = 0; /* Name is NULL */
+ shdr[h].sh_name = 0; /* Name is NULL. */
}
- if (*symtab_len == 0) {
+ if ( *symtab_len == 0 )
+ {
DPRINTF(("no symbol table\n"));
*symtab_addr = 0;
ret = 0;
/* Copy total length, crafted ELF header and section header table */
s = sizeof(int) + sizeof(Elf_Ehdr) + ehdr.e_shnum * sizeof(Elf_Shdr);
- for (i = 0; i < s; i += c, symva += c) {
+ for ( i = 0; i < s; i += c, symva += c )
+ {
c = PAGE_SIZE - (symva & (PAGE_SIZE - 1));
- if (c > s - i)
+ if ( c > s - i )
c = s - i;
vaddr = map_pfn(pm_handle, page_array[(symva - *virt_load_addr)
>> PAGE_SHIFT]);
- if (vaddr == NULL) {
+ if ( vaddr == NULL )
+ {
ERROR("Couldn't map guest memory");
goto out;
}
ret = 0;
out:
- if (ret == 0) {
+ if ( ret == 0 )
+ {
maxva = (maxva + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
*ksize = (maxva - *virt_load_addr) >> PAGE_SHIFT;
(void *)*symtab_len));
}
- if (phdr)
+ if ( phdr != NULL )
free(phdr);
- if (p)
+ if ( p != NULL )
free(p);
return ret;
}
projects / xen.git / commitdiff