x86/xen: remove 32-bit Xen PV guest support
Xen is requiring 64-bit machines today and since Xen 4.14 it can be
built without 32-bit PV guest support. There is no need to carry the
burden of 32-bit PV guest support in the kernel any longer, as new
guests can be either HVM or PVH, or they can use a 64 bit kernel.
Remove the 32-bit Xen PV support from the kernel.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 2d0bd5d..494d3224 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -449,8 +449,6 @@
.macro SWITCH_TO_KERNEL_STACK
- ALTERNATIVE "", "jmp .Lend_\@", X86_FEATURE_XENPV
-
BUG_IF_WRONG_CR3
SWITCH_TO_KERNEL_CR3 scratch_reg=%eax
@@ -599,8 +597,6 @@
*/
.macro SWITCH_TO_ENTRY_STACK
- ALTERNATIVE "", "jmp .Lend_\@", X86_FEATURE_XENPV
-
/* Bytes to copy */
movl $PTREGS_SIZE, %ecx
@@ -872,17 +868,6 @@
* will ignore all of the single-step traps generated in this range.
*/
-#ifdef CONFIG_XEN_PV
-/*
- * Xen doesn't set %esp to be precisely what the normal SYSENTER
- * entry point expects, so fix it up before using the normal path.
- */
-SYM_CODE_START(xen_sysenter_target)
- addl $5*4, %esp /* remove xen-provided frame */
- jmp .Lsysenter_past_esp
-SYM_CODE_END(xen_sysenter_target)
-#endif
-
/*
* 32-bit SYSENTER entry.
*
@@ -965,9 +950,8 @@
movl %esp, %eax
call do_SYSENTER_32
- /* XEN PV guests always use IRET path */
- ALTERNATIVE "testl %eax, %eax; jz .Lsyscall_32_done", \
- "jmp .Lsyscall_32_done", X86_FEATURE_XENPV
+ testl %eax, %eax
+ jz .Lsyscall_32_done
STACKLEAK_ERASE
@@ -1165,95 +1149,6 @@
#endif
.endm
-#ifdef CONFIG_PARAVIRT
-SYM_CODE_START(native_iret)
- iret
- _ASM_EXTABLE(native_iret, asm_iret_error)
-SYM_CODE_END(native_iret)
-#endif
-
-#ifdef CONFIG_XEN_PV
-/*
- * See comment in entry_64.S for further explanation
- *
- * Note: This is not an actual IDT entry point. It's a XEN specific entry
- * point and therefore named to match the 64-bit trampoline counterpart.
- */
-SYM_FUNC_START(xen_asm_exc_xen_hypervisor_callback)
- /*
- * Check to see if we got the event in the critical
- * region in xen_iret_direct, after we've reenabled
- * events and checked for pending events. This simulates
- * iret instruction's behaviour where it delivers a
- * pending interrupt when enabling interrupts:
- */
- cmpl $xen_iret_start_crit, (%esp)
- jb 1f
- cmpl $xen_iret_end_crit, (%esp)
- jae 1f
- call xen_iret_crit_fixup
-1:
- pushl $-1 /* orig_ax = -1 => not a system call */
- SAVE_ALL
- ENCODE_FRAME_POINTER
-
- mov %esp, %eax
- call xen_pv_evtchn_do_upcall
- jmp handle_exception_return
-SYM_FUNC_END(xen_asm_exc_xen_hypervisor_callback)
-
-/*
- * Hypervisor uses this for application faults while it executes.
- * We get here for two reasons:
- * 1. Fault while reloading DS, ES, FS or GS
- * 2. Fault while executing IRET
- * Category 1 we fix up by reattempting the load, and zeroing the segment
- * register if the load fails.
- * Category 2 we fix up by jumping to do_iret_error. We cannot use the
- * normal Linux return path in this case because if we use the IRET hypercall
- * to pop the stack frame we end up in an infinite loop of failsafe callbacks.
- * We distinguish between categories by maintaining a status value in EAX.
- */
-SYM_FUNC_START(xen_failsafe_callback)
- pushl %eax
- movl $1, %eax
-1: mov 4(%esp), %ds
-2: mov 8(%esp), %es
-3: mov 12(%esp), %fs
-4: mov 16(%esp), %gs
- /* EAX == 0 => Category 1 (Bad segment)
- EAX != 0 => Category 2 (Bad IRET) */
- testl %eax, %eax
- popl %eax
- lea 16(%esp), %esp
- jz 5f
- jmp asm_iret_error
-5: pushl $-1 /* orig_ax = -1 => not a system call */
- SAVE_ALL
- ENCODE_FRAME_POINTER
- jmp handle_exception_return
-
-.section .fixup, "ax"
-6: xorl %eax, %eax
- movl %eax, 4(%esp)
- jmp 1b
-7: xorl %eax, %eax
- movl %eax, 8(%esp)
- jmp 2b
-8: xorl %eax, %eax
- movl %eax, 12(%esp)
- jmp 3b
-9: xorl %eax, %eax
- movl %eax, 16(%esp)
- jmp 4b
-.previous
- _ASM_EXTABLE(1b, 6b)
- _ASM_EXTABLE(2b, 7b)
- _ASM_EXTABLE(3b, 8b)
- _ASM_EXTABLE(4b, 9b)
-SYM_FUNC_END(xen_failsafe_callback)
-#endif /* CONFIG_XEN_PV */
-
SYM_CODE_START_LOCAL_NOALIGN(handle_exception)
/* the function address is in %gs's slot on the stack */
SAVE_ALL switch_stacks=1 skip_gs=1 unwind_espfix=1