[PATCH v2 0/3] Fix and cleanup for 32-bit PV sysexit

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

The first patch fixes Xen PV regression introduced by 32-bit rewrite. Unlike the
earlier version it uses ALTERNATIVE instruction and avoids using xen_sysexit
(and sysret32 in compat mode) pv ops, as suggested by Andy.

As result of this patch irq_enable_sysexit and usergs_sysret32 pv ops are not
used anymore by anyone and so can be removed.


v2:
  * patch both TEST and JZ intructions with a single JMP
  * Add magic prefix to X86_FEATURE_XENPV comment to avoid having it printed in
    /proc/cpuinfo
  * Clarify in commit messages why irq_enable_sysexit and usergs_sysret32 are
    removed


Boris Ostrovsky (3):
  x86/xen: Avoid fast syscall path for Xen PV guests
  x86: irq_enable_sysexit pv op is no longer needed
  x86: usergs_sysret32 pv op is no longer needed

 arch/x86/entry/entry_32.S             | 13 +++++--------
 arch/x86/entry/entry_64_compat.S      | 20 ++++++++------------
 arch/x86/include/asm/cpufeature.h     |  1 +
 arch/x86/include/asm/paravirt.h       | 12 ------------
 arch/x86/include/asm/paravirt_types.h | 17 -----------------
 arch/x86/kernel/asm-offsets.c         |  3 ---
 arch/x86/kernel/asm-offsets_64.c      |  1 -
 arch/x86/kernel/paravirt.c            | 12 ------------
 arch/x86/kernel/paravirt_patch_32.c   |  2 --
 arch/x86/kernel/paravirt_patch_64.c   |  3 ---
 arch/x86/xen/enlighten.c              |  7 +++----
 arch/x86/xen/xen-asm_32.S             | 14 --------------
 arch/x86/xen/xen-asm_64.S             | 19 -------------------
 arch/x86/xen/xen-ops.h                |  3 ---
 14 files changed, 17 insertions(+), 110 deletions(-)

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1.8.1.4