Re: [Xen-devel] [PATCH v2 1/5] xen: drop support for Xen 4.1 and older.

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Wed, 10 Feb 2016, Ian Campbell wrote:
> Xen 4.2 become unsupported upstream in 09/2015 (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>

Reviewed-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


> v2: Don't claim to support 4.1 for another 89 years in the commit
>       message.
>     Tweak message in configure.
> ---
>  configure                   | 101 +-----------------------------
>  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, 7 insertions(+), 267 deletions(-)
> 
> diff --git a/configure b/configure
> index d4411a1..16c7956 100755
> --- a/configure
> +++ b/configure
> @@ -2111,100 +2111,10 @@ 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 "$xen" = "yes" ; then
> -      feature_not_found "xen (unsupported version)" "Install supported xen 
> (e.g. 4.0, 3.4, 3.3)"
> +      feature_not_found "xen (unsupported version)" \
> +                        "Install a supported xen (xen 4.2 or newer)"
>      fi
>      xen=no
>    fi
> @@ -2218,15 +2128,10 @@ EOF
>  fi
>  
>  if test "$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
> -      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
> diff --git a/hw/i386/xen/xen_apic.c b/hw/i386/xen/xen_apic.c
> index 5128146..2b8d709 100644
> --- a/hw/i386/xen/xen_apic.c
> +++ b/hw/i386/xen/xen_apic.c
> @@ -44,11 +44,7 @@ static void xen_apic_realize(DeviceState *dev, Error 
> **errp)
>      s->vapic_control = 0;
>      memory_region_init_io(&s->io_memory, OBJECT(s), &xen_apic_io_ops, s,
>                            "xen-apic-msi", APIC_SPACE_SIZE);
> -
> -#if defined(CONFIG_XEN_CTRL_INTERFACE_VERSION) \
> -    && CONFIG_XEN_CTRL_INTERFACE_VERSION >= 420
>      msi_supported = true;
> -#endif
>  }
>  
>  static void xen_apic_set_base(APICCommonState *s, uint64_t val)
> diff --git a/include/hw/xen/xen.h b/include/hw/xen/xen.h
> index c577354..df33481 100644
> --- a/include/hw/xen/xen.h
> +++ b/include/hw/xen/xen.h
> @@ -48,8 +48,4 @@ void xen_modified_memory(ram_addr_t start, ram_addr_t 
> length);
>  
>  void xen_register_framebuffer(struct MemoryRegion *mr);
>  
> -#if defined(CONFIG_XEN) && CONFIG_XEN_CTRL_INTERFACE_VERSION < 400
> -#  define HVM_MAX_VCPUS 32
> -#endif
> -
>  #endif /* QEMU_HW_XEN_H */
> diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
> index 0d83891..3a5b537 100644
> --- a/include/hw/xen/xen_common.h
> +++ b/include/hw/xen/xen_common.h
> @@ -16,11 +16,7 @@
>  #undef XC_WANT_COMPAT_MAP_FOREIGN_API
>  
>  #include <xenctrl.h>
> -#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 420
> -#  include <xs.h>
> -#else
> -#  include <xenstore.h>
> -#endif
> +#include <xenstore.h>
>  #include <xen/io/xenbus.h>
>  
>  #include "hw/hw.h"
> @@ -30,129 +26,11 @@
>  #include "trace.h"
>  
>  /*
> - * We don't support Xen prior to 3.3.0.
> + * We don't support Xen prior to 4.2.0.
>   */
>  
> -/* Xen before 4.0 */
> -#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 400
> -static inline void *xc_map_foreign_bulk(int xc_handle, uint32_t dom, int 
> prot,
> -                                        xen_pfn_t *arr, int *err,
> -                                        unsigned int num)
> -{
> -    return xc_map_foreign_batch(xc_handle, dom, prot, arr, num);
> -}
> -#endif
> -
> -
> -/* Xen before 4.1 */
> -#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 410
> -
> -typedef int XenXC;
> -typedef int xenevtchn_handle;
> -typedef int xengnttab_handle;
> -typedef int xenforeignmemory_handle;
> -
> -#  define XC_INTERFACE_FMT "%i"
> -#  define XC_HANDLER_INITIAL_VALUE    -1
> -
> -static inline xenevtchn_handle *xenevtchn_open(void *logger,
> -                                               unsigned int open_flags)
> -{
> -    xenevtchn_handle *h = malloc(sizeof(*h));
> -    if (!h) {
> -        return NULL;
> -    }
> -    *h = xc_evtchn_open();
> -    if (*h == -1) {
> -        free(h);
> -        h = NULL;
> -    }
> -    return h;
> -}
> -static inline int xenevtchn_close(xenevtchn_handle *h)
> -{
> -    int rc = xc_evtchn_close(*h);
> -    free(h);
> -    return rc;
> -}
> -#define xenevtchn_fd(h) xc_evtchn_fd(*h)
> -#define xenevtchn_pending(h) xc_evtchn_pending(*h)
> -#define xenevtchn_notify(h, p) xc_evtchn_notify(*h, p)
> -#define xenevtchn_bind_interdomain(h, d, p) xc_evtchn_bind_interdomain(*h, 
> d, p)
> -#define xenevtchn_unmask(h, p) xc_evtchn_unmask(*h, p)
> -#define xenevtchn_unbind(h, p) xc_evtchn_unmask(*h, p)
> -
> -static inline xengnttab_handle *xengnttab_open(void *logger,
> -                                               unsigned int open_flags)
> -{
> -    xengnttab_handle *h = malloc(sizeof(*h));
> -    if (!h) {
> -        return NULL;
> -    }
> -    *h = xc_gnttab_open();
> -    if (*h == -1) {
> -        free(h);
> -        h = NULL;
> -    }
> -    return h;
> -}
> -static inline int xengnttab_close(xengnttab_handle *h)
> -{
> -    int rc = xc_gnttab_close(*h);
> -    free(h);
> -    return rc;
> -}
> -#define xengnttab_set_max_grants(h, n) xc_gnttab_set_max_grants(*h, n)
> -#define xengnttab_map_grant_ref(h, d, r, p) xc_gnttab_map_grant_ref(*h, d, 
> r, p)
> -#define xengnttab_map_grant_refs(h, c, d, r, p) \
> -    xc_gnttab_map_grant_refs(*h, c, d, r, p)
> -#define xengnttab_unmap(h, a, n) xc_gnttab_munmap(*h, a, n)
> -
> -static inline XenXC xen_xc_interface_open(void *logger, void 
> *dombuild_logger,
> -                                          unsigned int open_flags)
> -{
> -    return xc_interface_open();
> -}
> -
> -/* See below for xenforeignmemory_* APIs */
> -
> -static inline int xc_domain_populate_physmap_exact
> -    (XenXC xc_handle, uint32_t domid, unsigned long nr_extents,
> -     unsigned int extent_order, unsigned int mem_flags, xen_pfn_t 
> *extent_start)
> -{
> -    return xc_domain_memory_populate_physmap
> -        (xc_handle, domid, nr_extents, extent_order, mem_flags, 
> extent_start);
> -}
> -
> -static inline int xc_domain_add_to_physmap(int xc_handle, uint32_t domid,
> -                                           unsigned int space, unsigned long 
> idx,
> -                                           xen_pfn_t gpfn)
> -{
> -    struct xen_add_to_physmap xatp = {
> -        .domid = domid,
> -        .space = space,
> -        .idx = idx,
> -        .gpfn = gpfn,
> -    };
> -
> -    return xc_memory_op(xc_handle, XENMEM_add_to_physmap, &xatp);
> -}
> -
> -static inline struct xs_handle *xs_open(unsigned long flags)
> -{
> -    return xs_daemon_open();
> -}
> -
> -static inline void xs_close(struct xs_handle *xsh)
> -{
> -    if (xsh != NULL) {
> -        xs_daemon_close(xsh);
> -    }
> -}
> -
> -
> -/* Xen 4.1 thru 4.6 */
> -#elif CONFIG_XEN_CTRL_INTERFACE_VERSION < 471
> +/* Xen 4.2 thru 4.6 */
> +#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 471
>  
>  typedef xc_interface *XenXC;
>  typedef xc_interface *xenforeignmemory_handle;
> @@ -205,27 +83,11 @@ static inline XenXC xen_xc_interface_open(void *logger, 
> void *dombuild_logger,
>  }
>  #endif
>  
> -/* Xen before 4.2 */
> -#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 420
> -static inline int xen_xc_hvm_inject_msi(XenXC xen_xc, domid_t dom,
> -        uint64_t addr, uint32_t data)
> -{
> -    return -ENOSYS;
> -}
> -/* The followings are only to compile op_discard related code on older
> - * Xen releases. */
> -#define BLKIF_OP_DISCARD 5
> -struct blkif_request_discard {
> -    uint64_t nr_sectors;
> -    uint64_t sector_number;
> -};
> -#else
>  static inline int xen_xc_hvm_inject_msi(XenXC xen_xc, domid_t dom,
>          uint64_t addr, uint32_t data)
>  {
>      return xc_hvm_inject_msi(xen_xc, dom, addr, data);
>  }
> -#endif
>  
>  void destroy_hvm_domain(bool reboot);
>  
> diff --git a/xen-hvm.c b/xen-hvm.c
> index 6861c51..8350ca2 100644
> --- a/xen-hvm.c
> +++ b/xen-hvm.c
> @@ -316,7 +316,6 @@ static hwaddr xen_phys_offset_to_gaddr(hwaddr start_addr,
>      return start_addr;
>  }
>  
> -#if CONFIG_XEN_CTRL_INTERFACE_VERSION >= 340
>  static int xen_add_to_physmap(XenIOState *state,
>                                hwaddr start_addr,
>                                ram_addr_t size,
> @@ -451,24 +450,6 @@ static int xen_remove_from_physmap(XenIOState *state,
>      return 0;
>  }
>  
> -#else
> -static int xen_add_to_physmap(XenIOState *state,
> -                              hwaddr start_addr,
> -                              ram_addr_t size,
> -                              MemoryRegion *mr,
> -                              hwaddr offset_within_region)
> -{
> -    return -ENOSYS;
> -}
> -
> -static int xen_remove_from_physmap(XenIOState *state,
> -                                   hwaddr start_addr,
> -                                   ram_addr_t size)
> -{
> -    return -ENOSYS;
> -}
> -#endif
> -
>  static void xen_set_memory(struct MemoryListener *listener,
>                             MemoryRegionSection *section,
>                             bool add)
> -- 
> 2.1.4
> 

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