On Wed, Jan 14, 2009 at 09:00:38PM -0700, Bruce Rogers wrote:
> The "change" to the format is as follows: Now the file format for a
> cross-bit configuration will be the same as would have been produced by a
> same-bitness configuration, which crash of course already handles. So crash
> should be fine with this change. In fact that was part of how I determined
> that it was working right.
> I consider that the cross-bitness format was simply not valid as there is no
> reason for there to be a different format for the file simply because the
> host was a different bitsize than the guest (and it didn't work with crash &
> gdb-xenserver as it was).
>
Yes, I agree with you. However for FV case, e_ident[EI_DATA] is set
according to the host configuration because XEN_DOMCTL_[sg]et_address_bits
doesn't make sense. And there is no easy way to determine the guest OS mode.
The following patch looks okay?
dump-core: update the documentation
This patch updates the document on dump-core file format.
Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
diff --git a/docs/misc/dump-core-format.txt b/docs/misc/dump-core-format.txt
--- a/docs/misc/dump-core-format.txt
+++ b/docs/misc/dump-core-format.txt
@@ -30,8 +30,13 @@ The elf header members are set as follow
e_ident[EI_OSABI] = ELFOSABI_SYSV = 0
e_type = ET_CORE = 4
ELFCLASS64 is always used independent of architecture.
-e_ident[EI_DATA] and e_flags are set according to the dumping system's
-architecture. Other members are set as usual.
+e_ident[EI_DATA] is set as follows
+ For x86 PV domain case, it is set according to the guest configuration
+ (i.e. if guest is 32bit it is set to EM_386 even when the dom0 is 64 bit.)
+ For other domain case (x86 HVM domain case and ia64 domain case),
+ it is set according to the dumping system's architecture.
+e_flags is set according to the dumping system's architecture.
+Other members are set as usual.
Sections
--------
@@ -241,3 +246,7 @@ Currently only (major, minor) = (0, 1) i
The format version isn't bumped because analysis tools can distinguish it.
- .xen_ia64_mapped_regs section was made only for ia64 PV domain.
In case of IA64 HVM domain, this section doesn't exist.
+- elf header e_ident[EI_DATA]
+ On x86 PV domain case, it is set according to the guest configuration.
+ I.e. 32-on-64 case, the file will be set EM_386 instead of EM_X86_64.
+ This is the same as 32-on-32 case, so there is no impact on analysis tools.
> - Bruce
>
> >>> Isaku Yamahata <yamahata@xxxxxxxxxxxxx> 01/14/09 8:17 PM >>>
> [CCed to Anderson, Oda and crash-utility ml]
> Hi Bruce. Nice patch.
>
> Could you please update the documentation about its format too?
> docs/misc/dump-core-format.txt
> - Elf header section, and
> - revision history at the end of the file.
>
> And what is the impact on the crash utility?
>
> thanks,
>
> On Wed, Jan 14, 2009 at 04:47:41PM -0700, Bruce Rogers wrote:
> > This patch allows core-dumping to work on a cross-bit host/guest
> > configuration, whereas previously that was not supported. It supports both
> > PV and FV guests. The core file format generated by the host, needs to
> > match that of the guest, so an alignment issue is addressed, along with the
> > p2m frame list handling being done according to the guest size.
> >
> > Signed-off-by: Bruce Rogers <brogers@xxxxxxxxxx>
> >
>
> > diff -r 77476eeb8c42 tools/libxc/xc_core.c
> > --- a/tools/libxc/xc_core.c Wed Jan 14 11:39:01 2009 +0000
> > +++ b/tools/libxc/xc_core.c Wed Jan 14 16:40:17 2009 -0700
> > @@ -57,9 +57,6 @@
> >
> > /* number of pages to write at a time */
> > #define DUMP_INCREMENT (4 * 1024)
> > -
> > -/* Don't yet support cross-address-size core dump */
> > -#define guest_width (sizeof (unsigned long))
> >
> > /* string table */
> > struct xc_core_strtab {
> > @@ -240,7 +237,7 @@ xc_core_ehdr_init(Elf64_Ehdr *ehdr)
> > ehdr->e_ident[EI_ABIVERSION] = EV_CURRENT;
> >
> > ehdr->e_type = ET_CORE;
> > - ehdr->e_machine = ELF_ARCH_MACHINE;
> > + /* e_machine will be filled in later */
> > ehdr->e_version = EV_CURRENT;
> > ehdr->e_entry = 0;
> > ehdr->e_phoff = 0;
> > @@ -359,7 +356,8 @@ elfnote_dump_core_header(
> > }
> >
> > static int
> > -elfnote_dump_xen_version(void *args, dumpcore_rtn_t dump_rtn, int
> > xc_handle)
> > +elfnote_dump_xen_version(void *args, dumpcore_rtn_t dump_rtn, int
> > xc_handle,
> > + unsigned int guest_width)
> > {
> > int sts;
> > struct elfnote elfnote;
> > @@ -371,6 +369,12 @@ elfnote_dump_xen_version(void *args, dum
> > elfnote.descsz = sizeof(xen_version);
> > elfnote.type = XEN_ELFNOTE_DUMPCORE_XEN_VERSION;
> > elfnote_fill_xen_version(xc_handle, &xen_version);
> > + if (guest_width < sizeof(unsigned long))
> > + {
> > + // 32 bit elf file format differs in pagesize's alignment
> > + char *p = (char *)&xen_version.pagesize;
> > + memmove(p - 4, p, sizeof(xen_version.pagesize));
> > + }
> > sts = dump_rtn(args, (char*)&elfnote, sizeof(elfnote));
> > if ( sts != 0 )
> > return sts;
> > @@ -396,6 +400,24 @@ elfnote_dump_format_version(void *args,
> > return dump_rtn(args, (char*)&format_version, sizeof(format_version));
> > }
> >
> > +static int
> > +get_guest_width(int xc_handle,
> > + uint32_t domid,
> > + unsigned int *guest_width)
> > +{
> > + DECLARE_DOMCTL;
> > +
> > + memset(&domctl, 0, sizeof(domctl));
> > + domctl.domain = domid;
> > + domctl.cmd = XEN_DOMCTL_get_address_size;
> > +
> > + if ( do_domctl(xc_handle, &domctl) != 0 )
> > + return 1;
> > +
> > + *guest_width = domctl.u.address_size.size / 8;
> > + return 0;
> > +}
> > +
> > int
> > xc_domain_dumpcore_via_callback(int xc_handle,
> > uint32_t domid,
> > @@ -403,7 +425,8 @@ xc_domain_dumpcore_via_callback(int xc_h
> > dumpcore_rtn_t dump_rtn)
> > {
> > xc_dominfo_t info;
> > - shared_info_t *live_shinfo = NULL;
> > + shared_info_any_t *live_shinfo = NULL;
> > + unsigned int guest_width;
> >
> > int nr_vcpus = 0;
> > char *dump_mem, *dump_mem_start = NULL;
> > @@ -437,6 +460,12 @@ xc_domain_dumpcore_via_callback(int xc_h
> > uint16_t strtab_idx;
> > struct xc_core_section_headers *sheaders = NULL;
> > Elf64_Shdr *shdr;
> > +
> > + if ( get_guest_width(xc_handle, domid, &guest_width) != 0 )
> > + {
> > + PERROR("Could not get address size for domain");
> > + return sts;
> > + }
> >
> > xc_core_arch_context_init(&arch_ctxt);
> > if ( (dump_mem_start = malloc(DUMP_INCREMENT*PAGE_SIZE)) == NULL )
> > @@ -500,7 +529,7 @@ xc_domain_dumpcore_via_callback(int xc_h
> > goto out;
> > }
> >
> > - sts = xc_core_arch_map_p2m(xc_handle, &info, live_shinfo,
> > + sts = xc_core_arch_map_p2m(xc_handle, guest_width, &info,
> > live_shinfo,
> > &p2m, &p2m_size);
> > if ( sts != 0 )
> > goto out;
> > @@ -676,6 +705,7 @@ xc_domain_dumpcore_via_callback(int xc_h
> > /* write out elf header */
> > ehdr.e_shnum = sheaders->num;
> > ehdr.e_shstrndx = strtab_idx;
> > + ehdr.e_machine = ELF_ARCH_MACHINE;
> > sts = dump_rtn(args, (char*)&ehdr, sizeof(ehdr));
> > if ( sts != 0 )
> > goto out;
> > @@ -697,7 +727,7 @@ xc_domain_dumpcore_via_callback(int xc_h
> > goto out;
> >
> > /* elf note section: xen version */
> > - sts = elfnote_dump_xen_version(args, dump_rtn, xc_handle);
> > + sts = elfnote_dump_xen_version(args, dump_rtn, xc_handle, guest_width);
> > if ( sts != 0 )
> > goto out;
> >
> > @@ -757,9 +787,21 @@ xc_domain_dumpcore_via_callback(int xc_h
> >
> > if ( !auto_translated_physmap )
> > {
> > - gmfn = p2m[i];
> > - if ( gmfn == INVALID_P2M_ENTRY )
> > - continue;
> > + if ( guest_width >= sizeof(unsigned long) )
> > + {
> > + if ( guest_width == sizeof(unsigned long) )
> > + gmfn = p2m[i];
> > + else
> > + gmfn = ((uint64_t *)p2m)[i];
> > + if ( gmfn == INVALID_P2M_ENTRY )
> > + continue;
> > + }
> > + else
> > + {
> > + gmfn = ((uint32_t *)p2m)[i];
> > + if ( gmfn == (uint32_t)INVALID_P2M_ENTRY )
> > + continue;
> > + }
> >
> > p2m_array[j].pfn = i;
> > p2m_array[j].gmfn = gmfn;
> > @@ -802,7 +844,7 @@ copy_done:
> > /* When live dump-mode (-L option) is specified,
> > * guest domain may reduce memory. pad with zero pages.
> > */
> > - IPRINTF("j (%ld) != nr_pages (%ld)", j , nr_pages);
> > + IPRINTF("j (%ld) != nr_pages (%ld)", j, nr_pages);
> > memset(dump_mem_start, 0, PAGE_SIZE);
> > for (; j < nr_pages; j++) {
> > sts = dump_rtn(args, dump_mem_start, PAGE_SIZE);
> > @@ -891,7 +933,7 @@ xc_domain_dumpcore(int xc_handle,
> > struct dump_args da;
> > int sts;
> >
> > - if ( (da.fd = open(corename, O_CREAT|O_RDWR, S_IWUSR|S_IRUSR)) < 0 )
> > + if ( (da.fd = open(corename, O_CREAT|O_RDWR|O_TRUNC, S_IWUSR|S_IRUSR))
> > < 0 )
> > {
> > PERROR("Could not open corefile %s", corename);
> > return -errno;
> > diff -r 77476eeb8c42 tools/libxc/xc_core.h
> > --- a/tools/libxc/xc_core.h Wed Jan 14 11:39:01 2009 +0000
> > +++ b/tools/libxc/xc_core.h Wed Jan 14 16:40:17 2009 -0700
> > @@ -136,12 +136,12 @@ struct xc_core_arch_context;
> > struct xc_core_arch_context;
> > int xc_core_arch_memory_map_get(int xc_handle,
> > struct xc_core_arch_context *arch_ctxt,
> > - xc_dominfo_t *info, shared_info_t
> > *live_shinfo,
> > + xc_dominfo_t *info, shared_info_any_t
> > *live_shinfo,
> > xc_core_memory_map_t **mapp,
> > unsigned int *nr_entries);
> > -int xc_core_arch_map_p2m(int xc_handle, xc_dominfo_t *info,
> > - shared_info_t *live_shinfo, xen_pfn_t **live_p2m,
> > - unsigned long *pfnp);
> > +int xc_core_arch_map_p2m(int xc_handle, unsigned int guest_width,
> > + xc_dominfo_t *info, shared_info_any_t
> > *live_shinfo,
> > + xen_pfn_t **live_p2m, unsigned long *pfnp);
> >
> >
> > #if defined (__i386__) || defined (__x86_64__)
> > diff -r 77476eeb8c42 tools/libxc/xc_core_ia64.c
> > --- a/tools/libxc/xc_core_ia64.c Wed Jan 14 11:39:01 2009 +0000
> > +++ b/tools/libxc/xc_core_ia64.c Wed Jan 14 16:40:17 2009 -0700
> > @@ -235,7 +235,7 @@ old:
> > }
> >
> > int
> > -xc_core_arch_map_p2m(int xc_handle, xc_dominfo_t *info,
> > +xc_core_arch_map_p2m(int xc_handle, unsigned int guest_width, xc_dominfo_t
> > *info,
> > shared_info_t *live_shinfo, xen_pfn_t **live_p2m,
> > unsigned long *pfnp)
> > {
> > diff -r 77476eeb8c42 tools/libxc/xc_core_x86.c
> > --- a/tools/libxc/xc_core_x86.c Wed Jan 14 11:39:01 2009 +0000
> > +++ b/tools/libxc/xc_core_x86.c Wed Jan 14 16:40:17 2009 -0700
> > @@ -20,9 +20,25 @@
> >
> > #include "xg_private.h"
> > #include "xc_core.h"
> > +#include "xc_e820.h"
> >
> > -/* Don't yet support cross-address-size core dump */
> > -#define guest_width (sizeof (unsigned long))
> > +#define GET_FIELD(_p, _f) ((guest_width==8) ? ((_p)->x64._f) :
> > ((_p)->x32._f))
> > +
> > +#ifndef MAX
> > +#define MAX(_a, _b) ((_a) >= (_b) ? (_a) : (_b))
> > +#endif
> > +
> > +int
> > +xc_core_arch_gpfn_may_present(struct xc_core_arch_context *arch_ctxt,
> > + unsigned long pfn)
> > +{
> > + if ((pfn >= 0xa0 && pfn < 0xc0) /* VGA hole */
> > + || (pfn >= (HVM_BELOW_4G_MMIO_START >> PAGE_SHIFT)
> > + && pfn < (1ULL<<32) >> PAGE_SHIFT)) /* MMIO */
> > + return 0;
> > + return 1;
> > +}
> > +
> >
> > static int nr_gpfns(int xc_handle, domid_t domid)
> > {
> > @@ -37,7 +53,7 @@ xc_core_arch_auto_translated_physmap(con
> >
> > int
> > xc_core_arch_memory_map_get(int xc_handle, struct xc_core_arch_context
> > *unused,
> > - xc_dominfo_t *info, shared_info_t *live_shinfo,
> > + xc_dominfo_t *info, shared_info_any_t
> > *live_shinfo,
> > xc_core_memory_map_t **mapp,
> > unsigned int *nr_entries)
> > {
> > @@ -60,17 +76,22 @@ xc_core_arch_memory_map_get(int xc_handl
> > }
> >
> > int
> > -xc_core_arch_map_p2m(int xc_handle, xc_dominfo_t *info,
> > - shared_info_t *live_shinfo, xen_pfn_t **live_p2m,
> > +xc_core_arch_map_p2m(int xc_handle, unsigned int guest_width, xc_dominfo_t
> > *info,
> > + shared_info_any_t *live_shinfo, xen_pfn_t **live_p2m,
> > unsigned long *pfnp)
> > {
> > /* Double and single indirect references to the live P2M table */
> > xen_pfn_t *live_p2m_frame_list_list = NULL;
> > xen_pfn_t *live_p2m_frame_list = NULL;
> > + /* Copies of the above. */
> > + xen_pfn_t *p2m_frame_list_list = NULL;
> > + xen_pfn_t *p2m_frame_list = NULL;
> > +
> > uint32_t dom = info->domid;
> > unsigned long p2m_size = nr_gpfns(xc_handle, info->domid);
> > int ret = -1;
> > int err;
> > + int i;
> >
> > if ( p2m_size < info->nr_pages )
> > {
> > @@ -80,7 +101,7 @@ xc_core_arch_map_p2m(int xc_handle, xc_d
> >
> > live_p2m_frame_list_list =
> > xc_map_foreign_range(xc_handle, dom, PAGE_SIZE, PROT_READ,
> > - live_shinfo->arch.pfn_to_mfn_frame_list_list);
> > + GET_FIELD(live_shinfo,
> > arch.pfn_to_mfn_frame_list_list));
> >
> > if ( !live_p2m_frame_list_list )
> > {
> > @@ -88,9 +109,28 @@ xc_core_arch_map_p2m(int xc_handle, xc_d
> > goto out;
> > }
> >
> > + /* Get a local copy of the live_P2M_frame_list_list */
> > + if ( !(p2m_frame_list_list = malloc(PAGE_SIZE)) )
> > + {
> > + ERROR("Couldn't allocate p2m_frame_list_list array");
> > + goto out;
> > + }
> > + memcpy(p2m_frame_list_list, live_p2m_frame_list_list, PAGE_SIZE);
> > +
> > + /* Canonicalize guest's unsigned long vs ours */
> > + if ( guest_width > sizeof(unsigned long) )
> > + for ( i = 0; i < PAGE_SIZE/sizeof(unsigned long); i++ )
> > + if ( i < PAGE_SIZE/guest_width )
> > + p2m_frame_list_list[i] = ((uint64_t
> > *)p2m_frame_list_list)[i];
> > + else
> > + p2m_frame_list_list[i] = 0;
> > + else if ( guest_width < sizeof(unsigned long) )
> > + for ( i = PAGE_SIZE/sizeof(unsigned long) - 1; i >= 0; i-- )
> > + p2m_frame_list_list[i] = ((uint32_t *)p2m_frame_list_list)[i];
> > +
> > live_p2m_frame_list =
> > xc_map_foreign_pages(xc_handle, dom, PROT_READ,
> > - live_p2m_frame_list_list,
> > + p2m_frame_list_list,
> > P2M_FLL_ENTRIES);
> >
> > if ( !live_p2m_frame_list )
> > @@ -99,8 +139,25 @@ xc_core_arch_map_p2m(int xc_handle, xc_d
> > goto out;
> > }
> >
> > + /* Get a local copy of the live_P2M_frame_list */
> > + if ( !(p2m_frame_list = malloc(P2M_TOOLS_FL_SIZE)) )
> > + {
> > + ERROR("Couldn't allocate p2m_frame_list array");
> > + goto out;
> > + }
> > + memset(p2m_frame_list, 0, P2M_TOOLS_FL_SIZE);
> > + memcpy(p2m_frame_list, live_p2m_frame_list, P2M_GUEST_FL_SIZE);
> > +
> > + /* Canonicalize guest's unsigned long vs ours */
> > + if ( guest_width > sizeof(unsigned long) )
> > + for ( i = 0; i < P2M_FL_ENTRIES; i++ )
> > + p2m_frame_list[i] = ((uint64_t *)p2m_frame_list)[i];
> > + else if ( guest_width < sizeof(unsigned long) )
> > + for ( i = P2M_FL_ENTRIES - 1; i >= 0; i-- )
> > + p2m_frame_list[i] = ((uint32_t *)p2m_frame_list)[i];
> > +
> > *live_p2m = xc_map_foreign_pages(xc_handle, dom, PROT_READ,
> > - live_p2m_frame_list,
> > + p2m_frame_list,
> > P2M_FL_ENTRIES);
> >
> > if ( !*live_p2m )
> > @@ -122,6 +179,12 @@ out:
> > if ( live_p2m_frame_list )
> > munmap(live_p2m_frame_list, P2M_FLL_ENTRIES * PAGE_SIZE);
> >
> > + if ( p2m_frame_list_list )
> > + free(p2m_frame_list_list);
> > +
> > + if ( p2m_frame_list )
> > + free(p2m_frame_list);
> > +
> > errno = err;
> > return ret;
> > }
> > diff -r 77476eeb8c42 tools/libxc/xc_core_x86.h
> > --- a/tools/libxc/xc_core_x86.h Wed Jan 14 11:39:01 2009 +0000
> > +++ b/tools/libxc/xc_core_x86.h Wed Jan 14 16:40:17 2009 -0700
> > @@ -21,15 +21,8 @@
> > #ifndef XC_CORE_X86_H
> > #define XC_CORE_X86_H
> >
> > -#if defined(__i386__) || defined(__x86_64__)
> > #define ELF_ARCH_DATA ELFDATA2LSB
> > -#if defined (__i386__)
> > -# define ELF_ARCH_MACHINE EM_386
> > -#else
> > -# define ELF_ARCH_MACHINE EM_X86_64
> > -#endif
> > -#endif /* __i386__ or __x86_64__ */
> > -
> > +#define ELF_ARCH_MACHINE (guest_width == 8 ? EM_X86_64 : EM_386)
> >
> > struct xc_core_arch_context {
> > /* nothing */
> > @@ -40,8 +33,10 @@ struct xc_core_arch_context {
> > #define xc_core_arch_context_get(arch_ctxt, ctxt, xc_handle, domid) \
> > (0)
> > #define xc_core_arch_context_dump(arch_ctxt, args, dump_rtn) (0)
> > -#define xc_core_arch_gpfn_may_present(arch_ctxt, i) (1)
> >
> > +int
> > +xc_core_arch_gpfn_may_present(struct xc_core_arch_context *arch_ctxt,
> > + unsigned long pfn);
> > static inline int
> > xc_core_arch_context_get_shdr(struct xc_core_arch_context *arch_ctxt,
> > struct xc_core_section_headers *sheaders,
>
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
>
>
--
yamahata
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home