Re: [Xen-devel] [PATCH 1/5] xen: drop support for Xen 4.1 and older.

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Tue, 9 Feb 2016, Ian Campbell wrote:
> Xen 4.2 become unsupported upstream in 09/2105 (see
> http://wiki.xen.org/wiki/Xen_Release_Features). However as far as the
> interfaces provided by the toolstack libraries go 4.2 and 4.3 are
> indistinguishable.
> 
> Therefore drop support for Xen 4.1 and earlier which removes a whole
> pile of compatibility code which makes future work (to use stable
> library interfaces provided by upstream) more difficult. In particular
> all supported versions now use a pointer as a libxc handle (4.1 and
> earlier used an integer, resulting in various shim layers).
> 
> Also Xen 4.2 was the first version of Xen to formally support upstream
> QEMU (as a preview) so that makes sense as a cut-off now.
> 
> This change drops all the configure-y and resulting ifdefs in a mostly
> mechanical way. A follow up will refactor wrappers which are now
> unused.
> 
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> ---
>  configure                   | 100 +-----------------------------
>  hw/i386/xen/xen_apic.c      |   4 --
>  include/hw/xen/xen.h        |   4 --
>  include/hw/xen/xen_common.h | 146 
> ++------------------------------------------
>  xen-hvm.c                   |  19 ------
>  5 files changed, 6 insertions(+), 267 deletions(-)
> 
> diff --git a/configure b/configure
> index d4411a1..6a6fda6 100755
> --- a/configure
> +++ b/configure
> @@ -2111,100 +2111,9 @@ EOF
>      xen_ctrl_version=420
>      xen=yes
>  
> -  elif
> -      cat > $TMPC <<EOF &&
> -#include <xenctrl.h>
> -#include <xs.h>
> -#include <stdint.h>
> -#include <xen/hvm/hvm_info_table.h>
> -#if !defined(HVM_MAX_VCPUS)
> -# error HVM_MAX_VCPUS not defined
> -#endif
> -int main(void) {
> -  xs_daemon_open();
> -  xc_interface_open(0, 0, 0);
> -  xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
> -  xc_gnttab_open(NULL, 0);
> -  xc_domain_add_to_physmap(0, 0, XENMAPSPACE_gmfn, 0, 0);
> -  return 0;
> -}
> -EOF
> -      compile_prog "" "$xen_libs"
> -    then
> -    xen_ctrl_version=410
> -    xen=yes
> -
> -  # Xen 4.0.0
> -  elif
> -      cat > $TMPC <<EOF &&
> -#include <xenctrl.h>
> -#include <xs.h>
> -#include <stdint.h>
> -#include <xen/hvm/hvm_info_table.h>
> -#if !defined(HVM_MAX_VCPUS)
> -# error HVM_MAX_VCPUS not defined
> -#endif
> -int main(void) {
> -  struct xen_add_to_physmap xatp = {
> -    .domid = 0, .space = XENMAPSPACE_gmfn, .idx = 0, .gpfn = 0,
> -  };
> -  xs_daemon_open();
> -  xc_interface_open();
> -  xc_gnttab_open();
> -  xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
> -  xc_memory_op(0, XENMEM_add_to_physmap, &xatp);
> -  return 0;
> -}
> -EOF
> -      compile_prog "" "$xen_libs"
> -    then
> -    xen_ctrl_version=400
> -    xen=yes
> -
> -  # Xen 3.4.0
> -  elif
> -      cat > $TMPC <<EOF &&
> -#include <xenctrl.h>
> -#include <xs.h>
> -int main(void) {
> -  struct xen_add_to_physmap xatp = {
> -    .domid = 0, .space = XENMAPSPACE_gmfn, .idx = 0, .gpfn = 0,
> -  };
> -  xs_daemon_open();
> -  xc_interface_open();
> -  xc_gnttab_open();
> -  xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
> -  xc_memory_op(0, XENMEM_add_to_physmap, &xatp);
> -  return 0;
> -}
> -EOF
> -      compile_prog "" "$xen_libs"
> -    then
> -    xen_ctrl_version=340
> -    xen=yes
> -
> -  # Xen 3.3.0
> -  elif
> -      cat > $TMPC <<EOF &&
> -#include <xenctrl.h>
> -#include <xs.h>
> -int main(void) {
> -  xs_daemon_open();
> -  xc_interface_open();
> -  xc_gnttab_open();
> -  xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
> -  return 0;
> -}
> -EOF
> -      compile_prog "" "$xen_libs"
> -    then
> -    xen_ctrl_version=330
> -    xen=yes
> -
> -  # Xen version unsupported
>    else
>      if test "$xen" = "yes" ; then
> -      feature_not_found "xen (unsupported version)" "Install supported xen 
> (e.g. 4.0, 3.4, 3.3)"
> +      feature_not_found "xen (unsupported version)" "Install supported xen 
> (e.g. 4.2 onwards)"

We can rephrase the message now, maybe something like

"xen (unsupported version)" "Install a supported xen version (xen 4.2 or newer)"


>      fi
>      xen=no
>    fi
> @@ -2218,15 +2127,10 @@ EOF
>  fi
>  
>  if test "$xen_pci_passthrough" != "no"; then
> -  if test "$xen" = "yes" && test "$linux" = "yes" &&
> -    test "$xen_ctrl_version" -ge 340; then
> +  if test "$xen" = "yes" && test "$linux" = "yes"; then
>      xen_pci_passthrough=yes
>    else
>      if test "$xen_pci_passthrough" = "yes"; then

Given that the code has been greatly simplified, I think that we can get
rid of the test above.


> -      if test "$xen_ctrl_version" -lt 340; then
> -        error_exit "User requested feature Xen PCI Passthrough" \
> -            "This feature does not work with Xen 3.3"
> -      fi
>        error_exit "User requested feature Xen PCI Passthrough" \
>            " but this feature requires /sys from Linux"
>      fi

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel