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f28756a6272f0b6eb04bdce6cb94de196444155b
xen/tools/libxc/xc_hvm_build.c
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/******************************************************************************
* xc_hvm_build.c
*/
#define ELFSIZE 32
#include <stddef.h>
#include <inttypes.h>
#include "xg_private.h"
#include "xc_private.h"
#include "xc_elf.h"
#include <stdlib.h>
#include <unistd.h>
#include <zlib.h>
#include <xen/hvm/hvm_info_table.h>
#include <xen/hvm/params.h>
#include <xen/hvm/e820.h>
#define SCRATCH_PFN 0xFFFFF
#define HVM_LOADER_ENTR_ADDR 0x00100000
static int
parseelfimage(
char *elfbase, unsigned long elfsize, struct domain_setup_info *dsi);
static int
loadelfimage(
char *elfbase, int xch, uint32_t dom, unsigned long *parray,
struct domain_setup_info *dsi);
int xc_set_hvm_param(
int handle, domid_t dom, int param, unsigned long value)
{
DECLARE_HYPERCALL;
xen_hvm_param_t arg;
int rc;
hypercall.op = __HYPERVISOR_hvm_op;
hypercall.arg[0] = HVMOP_set_param;
hypercall.arg[1] = (unsigned long)&arg;
arg.domid = dom;
arg.index = param;
arg.value = value;
if ( lock_pages(&arg, sizeof(arg)) != 0 )
return -1;
rc = do_xen_hypercall(handle, &hypercall);
unlock_pages(&arg, sizeof(arg));
return rc;
}
int xc_get_hvm_param(
int handle, domid_t dom, int param, unsigned long *value)
{
DECLARE_HYPERCALL;
xen_hvm_param_t arg;
int rc;
hypercall.op = __HYPERVISOR_hvm_op;
hypercall.arg[0] = HVMOP_get_param;
hypercall.arg[1] = (unsigned long)&arg;
arg.domid = dom;
arg.index = param;
if ( lock_pages(&arg, sizeof(arg)) != 0 )
return -1;
rc = do_xen_hypercall(handle, &hypercall);
unlock_pages(&arg, sizeof(arg));
*value = arg.value;
return rc;
}
static void build_e820map(void *e820_page, unsigned long long mem_size)
{
struct e820entry *e820entry =
(struct e820entry *)(((unsigned char *)e820_page) + E820_MAP_OFFSET);
unsigned long long extra_mem_size = 0;
unsigned char nr_map = 0;
/*
* Physical address space from HVM_BELOW_4G_RAM_END to 4G is reserved
* for PCI devices MMIO. So if HVM has more than HVM_BELOW_4G_RAM_END
* RAM, memory beyond HVM_BELOW_4G_RAM_END will go to 4G above.
*/
if ( mem_size > HVM_BELOW_4G_RAM_END )
{
extra_mem_size = mem_size - HVM_BELOW_4G_RAM_END;
mem_size = HVM_BELOW_4G_RAM_END;
}
/* 0x0-0x9F000: Ordinary RAM. */
e820entry[nr_map].addr = 0x0;
e820entry[nr_map].size = 0x9F000;
e820entry[nr_map].type = E820_RAM;
nr_map++;
/*
* 0x9F000-0x9F800: SMBIOS tables.
* 0x9FC00-0xA0000: Extended BIOS Data Area (EBDA).
* TODO: SMBIOS tables should be moved higher (>=0xE0000).
* They are unusually low in our memory map: could cause problems?
*/
e820entry[nr_map].addr = 0x9F000;
e820entry[nr_map].size = 0x1000;
e820entry[nr_map].type = E820_RESERVED;
nr_map++;
/*
* Following regions are standard regions of the PC memory map.
* They are not covered by e820 regions. OSes will not use as RAM.
* 0xA0000-0xC0000: VGA memory-mapped I/O. Not covered by E820.
* 0xC0000-0xE0000: 16-bit devices, expansion ROMs (inc. vgabios).
* TODO: hvmloader should free pages which turn out to be unused.
*/
/*
* 0xE0000-0x0F0000: PC-specific area. We place ACPI tables here.
* We *cannot* mark as E820_ACPI, for two reasons:
* 1. ACPI spec. says that E820_ACPI regions below
* 16MB must clip INT15h 0x88 and 0xe801 queries.
* Our rombios doesn't do this.
* 2. The OS is allowed to reclaim ACPI memory after
* parsing the tables. But our FACS is in this
* region and it must not be reclaimed (it contains
* the ACPI global lock!).
* 0xF0000-0x100000: System BIOS.
* TODO: hvmloader should free pages which turn out to be unused.
*/
e820entry[nr_map].addr = 0xE0000;
e820entry[nr_map].size = 0x20000;
e820entry[nr_map].type = E820_RESERVED;
nr_map++;
/* Low RAM goes here. Remove 3 pages for ioreq, bufioreq, and xenstore. */
e820entry[nr_map].addr = 0x100000;
e820entry[nr_map].size = mem_size - 0x100000 - PAGE_SIZE * 3;
e820entry[nr_map].type = E820_RAM;
nr_map++;
if ( extra_mem_size )
{
e820entry[nr_map].addr = (1ULL << 32);
e820entry[nr_map].size = extra_mem_size;
e820entry[nr_map].type = E820_RAM;
nr_map++;
}
*(((unsigned char *)e820_page) + E820_MAP_NR_OFFSET) = nr_map;
}
static int setup_guest(int xc_handle,
uint32_t dom, int memsize,
char *image, unsigned long image_size,
vcpu_guest_context_t *ctxt)
{
xen_pfn_t *page_array = NULL;
unsigned long i, nr_pages = (unsigned long)memsize << (20 - PAGE_SHIFT);
unsigned long shared_page_nr;
struct xen_add_to_physmap xatp;
struct shared_info *shared_info;
void *e820_page;
struct domain_setup_info dsi;
uint64_t v_end;
int rc;
memset(&dsi, 0, sizeof(struct domain_setup_info));
if ( (parseelfimage(image, image_size, &dsi)) != 0 )
goto error_out;
if ( (dsi.v_kernstart & (PAGE_SIZE - 1)) != 0 )
{
PERROR("Guest OS must load to a page boundary.\n");
goto error_out;
}
v_end = (unsigned long long)memsize << 20;
IPRINTF("VIRTUAL MEMORY ARRANGEMENT:\n"
" Loaded HVM loader: %016"PRIx64"->%016"PRIx64"\n"
" TOTAL: %016"PRIx64"->%016"PRIx64"\n",
dsi.v_kernstart, dsi.v_kernend,
dsi.v_start, v_end);
IPRINTF(" ENTRY ADDRESS: %016"PRIx64"\n", dsi.v_kernentry);
if ( (v_end - dsi.v_start) > ((unsigned long long)nr_pages << PAGE_SHIFT) )
{
PERROR("Initial guest OS requires too much space: "
"(%lluMB is greater than %lluMB limit)\n",
(unsigned long long)(v_end - dsi.v_start) >> 20,
((unsigned long long)nr_pages << PAGE_SHIFT) >> 20);
goto error_out;
}
if ( (page_array = malloc(nr_pages * sizeof(xen_pfn_t))) == NULL )
{
PERROR("Could not allocate memory.\n");
goto error_out;
}
for ( i = 0; i < nr_pages; i++ )
page_array[i] = i;
for ( i = HVM_BELOW_4G_RAM_END >> PAGE_SHIFT; i < nr_pages; i++ )
page_array[i] += HVM_BELOW_4G_MMIO_LENGTH >> PAGE_SHIFT;
/* Allocate memory for HVM guest, skipping VGA hole 0xA0000-0xC0000. */
rc = xc_domain_memory_populate_physmap(
xc_handle, dom, (nr_pages > 0xa0) ? 0xa0 : nr_pages,
0, 0, &page_array[0x00]);
if ( (rc == 0) && (nr_pages > 0xc0) )
rc = xc_domain_memory_populate_physmap(
xc_handle, dom, nr_pages - 0xc0, 0, 0, &page_array[0xc0]);
if ( rc != 0 )
{
PERROR("Could not allocate memory for HVM guest.\n");
goto error_out;
}
loadelfimage(image, xc_handle, dom, page_array, &dsi);
if ( (e820_page = xc_map_foreign_range(
xc_handle, dom, PAGE_SIZE, PROT_READ | PROT_WRITE,
E820_MAP_PAGE >> PAGE_SHIFT)) == NULL )
goto error_out;
memset(e820_page, 0, PAGE_SIZE);
build_e820map(e820_page, v_end);
munmap(e820_page, PAGE_SIZE);
/* Map and initialise shared_info page. */
xatp.domid = dom;
xatp.space = XENMAPSPACE_shared_info;
xatp.idx = 0;
xatp.gpfn = SCRATCH_PFN;
if ( (xc_memory_op(xc_handle, XENMEM_add_to_physmap, &xatp) != 0) ||
((shared_info = xc_map_foreign_range(
xc_handle, dom, PAGE_SIZE, PROT_READ | PROT_WRITE,
SCRATCH_PFN)) == NULL) )
goto error_out;
memset(shared_info, 0, PAGE_SIZE);
/* NB. evtchn_upcall_mask is unused: leave as zero. */
memset(&shared_info->evtchn_mask[0], 0xff,
sizeof(shared_info->evtchn_mask));
munmap(shared_info, PAGE_SIZE);
if ( v_end > HVM_BELOW_4G_RAM_END )
shared_page_nr = (HVM_BELOW_4G_RAM_END >> PAGE_SHIFT) - 1;
else
shared_page_nr = (v_end >> PAGE_SHIFT) - 1;
/* Paranoia: clean pages. */
if ( xc_clear_domain_page(xc_handle, dom, shared_page_nr) ||
xc_clear_domain_page(xc_handle, dom, shared_page_nr-1) ||
xc_clear_domain_page(xc_handle, dom, shared_page_nr-2) )
goto error_out;
xc_set_hvm_param(xc_handle, dom, HVM_PARAM_STORE_PFN, shared_page_nr-1);
xc_set_hvm_param(xc_handle, dom, HVM_PARAM_BUFIOREQ_PFN, shared_page_nr-2);
xc_set_hvm_param(xc_handle, dom, HVM_PARAM_IOREQ_PFN, shared_page_nr);
free(page_array);
ctxt->user_regs.eip = dsi.v_kernentry;
return 0;
error_out:
free(page_array);
return -1;
}
static int xc_hvm_build_internal(int xc_handle,
uint32_t domid,
int memsize,
char *image,
unsigned long image_size)
{
struct xen_domctl launch_domctl;
vcpu_guest_context_t ctxt;
int rc;
if ( (image == NULL) || (image_size == 0) )
{
ERROR("Image required");
goto error_out;
}
memset(&ctxt, 0, sizeof(ctxt));
if ( setup_guest(xc_handle, domid, memsize, image, image_size, &ctxt) < 0 )
{
goto error_out;
}
if ( lock_pages(&ctxt, sizeof(ctxt) ) )
{
PERROR("%s: ctxt mlock failed", __func__);
goto error_out;
}
memset(&launch_domctl, 0, sizeof(launch_domctl));
launch_domctl.domain = (domid_t)domid;
launch_domctl.u.vcpucontext.vcpu = 0;
set_xen_guest_handle(launch_domctl.u.vcpucontext.ctxt, &ctxt);
launch_domctl.cmd = XEN_DOMCTL_setvcpucontext;
rc = xc_domctl(xc_handle, &launch_domctl);
unlock_pages(&ctxt, sizeof(ctxt));
return rc;
error_out:
return -1;
}
static inline int is_loadable_phdr(Elf32_Phdr *phdr)
{
return ((phdr->p_type == PT_LOAD) &&
((phdr->p_flags & (PF_W|PF_X)) != 0));
}
static int parseelfimage(char *elfbase,
unsigned long elfsize,
struct domain_setup_info *dsi)
{
Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfbase;
Elf32_Phdr *phdr;
Elf32_Shdr *shdr;
unsigned long kernstart = ~0UL, kernend=0UL;
char *shstrtab;
int h;
if ( !IS_ELF(*ehdr) )
{
xc_set_error(XC_INVALID_KERNEL,
"Kernel image does not have an ELF header.");
return -EINVAL;
}
if ( (ehdr->e_phoff + (ehdr->e_phnum * ehdr->e_phentsize)) > elfsize )
{
xc_set_error(XC_INVALID_KERNEL,
"ELF program headers extend beyond end of image.");
return -EINVAL;
}
if ( (ehdr->e_shoff + (ehdr->e_shnum * ehdr->e_shentsize)) > elfsize )
{
xc_set_error(XC_INVALID_KERNEL,
"ELF section headers extend beyond end of image.");
return -EINVAL;
}
/* Find the section-header strings table. */
if ( ehdr->e_shstrndx == SHN_UNDEF )
{
xc_set_error(XC_INVALID_KERNEL,
"ELF image has no section-header strings table (shstrtab).");
return -EINVAL;
}
shdr = (Elf32_Shdr *)(elfbase + ehdr->e_shoff +
(ehdr->e_shstrndx*ehdr->e_shentsize));
shstrtab = elfbase + shdr->sh_offset;
for ( h = 0; h < ehdr->e_phnum; h++ )
{
phdr = (Elf32_Phdr *)(elfbase + ehdr->e_phoff + (h*ehdr->e_phentsize));
if ( !is_loadable_phdr(phdr) )
continue;
if ( phdr->p_paddr < kernstart )
kernstart = phdr->p_paddr;
if ( (phdr->p_paddr + phdr->p_memsz) > kernend )
kernend = phdr->p_paddr + phdr->p_memsz;
}
if ( (kernstart > kernend) ||
(ehdr->e_entry < kernstart) ||
(ehdr->e_entry > kernend) )
{
xc_set_error(XC_INVALID_KERNEL,
"Malformed ELF image.");
return -EINVAL;
}
dsi->v_start = 0x00000000;
dsi->v_kernstart = kernstart;
dsi->v_kernend = kernend;
dsi->v_kernentry = HVM_LOADER_ENTR_ADDR;
dsi->v_end = dsi->v_kernend;
return 0;
}
static int
loadelfimage(
char *elfbase, int xch, uint32_t dom, unsigned long *parray,
struct domain_setup_info *dsi)
{
Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfbase;
Elf32_Phdr *phdr;
int h;
char *va;
unsigned long pa, done, chunksz;
for ( h = 0; h < ehdr->e_phnum; h++ )
{
phdr = (Elf32_Phdr *)(elfbase + ehdr->e_phoff + (h*ehdr->e_phentsize));
if ( !is_loadable_phdr(phdr) )
continue;
for ( done = 0; done < phdr->p_filesz; done += chunksz )
{
pa = (phdr->p_paddr + done) - dsi->v_start;
if ((va = xc_map_foreign_range(
xch, dom, PAGE_SIZE, PROT_WRITE,
parray[pa >> PAGE_SHIFT])) == 0)
return -1;
chunksz = phdr->p_filesz - done;
if ( chunksz > (PAGE_SIZE - (pa & (PAGE_SIZE-1))) )
chunksz = PAGE_SIZE - (pa & (PAGE_SIZE-1));
memcpy(va + (pa & (PAGE_SIZE-1)),
elfbase + phdr->p_offset + done, chunksz);
munmap(va, PAGE_SIZE);
}
for ( ; done < phdr->p_memsz; done += chunksz )
{
pa = (phdr->p_paddr + done) - dsi->v_start;
if ((va = xc_map_foreign_range(
xch, dom, PAGE_SIZE, PROT_WRITE,
parray[pa >> PAGE_SHIFT])) == 0)
return -1;
chunksz = phdr->p_memsz - done;
if ( chunksz > (PAGE_SIZE - (pa & (PAGE_SIZE-1))) )
chunksz = PAGE_SIZE - (pa & (PAGE_SIZE-1));
memset(va + (pa & (PAGE_SIZE-1)), 0, chunksz);
munmap(va, PAGE_SIZE);
}
}
return 0;
}
/* xc_hvm_build
*
* Create a domain for a virtualized Linux, using files/filenames
*
*/
int xc_hvm_build(int xc_handle,
uint32_t domid,
int memsize,
const char *image_name)
{
char *image;
int sts;
unsigned long image_size;
if ( (image_name == NULL) ||
((image = xc_read_image(image_name, &image_size)) == NULL) )
return -1;
sts = xc_hvm_build_internal(xc_handle, domid, memsize, image, image_size);
free(image);
return sts;
}
/* xc_hvm_build_mem
*
* Create a domain for a virtualized Linux, using buffers
*
*/
int xc_hvm_build_mem(int xc_handle,
uint32_t domid,
int memsize,
const char *image_buffer,
unsigned long image_size)
{
int sts;
unsigned long img_len;
char *img;
/* Validate that there is a kernel buffer */
if ( (image_buffer == NULL) || (image_size == 0) )
{
ERROR("kernel image buffer not present");
return -1;
}
img = xc_inflate_buffer(image_buffer, image_size, &img_len);
if (img == NULL)
{
ERROR("unable to inflate ram disk buffer");
return -1;
}
sts = xc_hvm_build_internal(xc_handle, domid, memsize,
img, img_len);
/* xc_inflate_buffer may return the original buffer pointer (for
for already inflated buffers), so exercise some care in freeing */
if ( (img != NULL) && (img != image_buffer) )
free(img);
return sts;
}
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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