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| author | Juergen Gross <jgross@suse.com> | 2017-08-31 19:42:49 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-08-31 21:35:10 +0200 |
| commit | 5878d5d6fdef6447d73b0acc121ba445bef37f53 (patch) | |
| tree | b4d36a16451274496a02a43adef75a68b84fdf6f /arch/x86/entry/entry_64.S | |
| parent | ef1d4deab953ecb1dfcf9f167043bda8b3f14a11 (diff) | |
| download | lwn-5878d5d6fdef6447d73b0acc121ba445bef37f53.tar.gz lwn-5878d5d6fdef6447d73b0acc121ba445bef37f53.zip | |
x86/xen: Get rid of paravirt op adjust_exception_frame
When running as Xen pv-guest the exception frame on the stack contains
%r11 and %rcx additional to the other data pushed by the processor.
Instead of having a paravirt op being called for each exception type
prepend the Xen specific code to each exception entry. When running as
Xen pv-guest just use the exception entry with prepended instructions,
otherwise use the entry without the Xen specific code.
[ tglx: Merged through tip to avoid ugly merge conflict ]
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Cc: luto@amacapital.net
Link: http://lkml.kernel.org/r/20170831174249.26853-1-jg@pfupf.net
Diffstat (limited to 'arch/x86/entry/entry_64.S')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 23 |
1 files changed, 4 insertions, 19 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 7a1d383c2192..bdd024a9afc9 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -821,7 +821,6 @@ ENTRY(\sym) .endif ASM_CLAC - PARAVIRT_ADJUST_EXCEPTION_FRAME .ifeq \has_error_code pushq $-1 /* ORIG_RAX: no syscall to restart */ @@ -967,7 +966,7 @@ ENTRY(do_softirq_own_stack) ENDPROC(do_softirq_own_stack) #ifdef CONFIG_XEN -idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0 +idtentry hypervisor_callback xen_do_hypervisor_callback has_error_code=0 /* * A note on the "critical region" in our callback handler. @@ -1034,8 +1033,6 @@ ENTRY(xen_failsafe_callback) movq 8(%rsp), %r11 addq $0x30, %rsp pushq $0 /* RIP */ - pushq %r11 - pushq %rcx UNWIND_HINT_IRET_REGS offset=8 jmp general_protection 1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */ @@ -1066,9 +1063,8 @@ idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK idtentry stack_segment do_stack_segment has_error_code=1 #ifdef CONFIG_XEN -idtentry xen_debug do_debug has_error_code=0 -idtentry xen_int3 do_int3 has_error_code=0 -idtentry xen_stack_segment do_stack_segment has_error_code=1 +idtentry xendebug do_debug has_error_code=0 +idtentry xenint3 do_int3 has_error_code=0 #endif idtentry general_protection do_general_protection has_error_code=1 @@ -1232,21 +1228,10 @@ ENTRY(error_exit) END(error_exit) /* Runs on exception stack */ +/* XXX: broken on Xen PV */ ENTRY(nmi) UNWIND_HINT_IRET_REGS /* - * Fix up the exception frame if we're on Xen. - * PARAVIRT_ADJUST_EXCEPTION_FRAME is guaranteed to push at most - * one value to the stack on native, so it may clobber the rdx - * scratch slot, but it won't clobber any of the important - * slots past it. - * - * Xen is a different story, because the Xen frame itself overlaps - * the "NMI executing" variable. - */ - PARAVIRT_ADJUST_EXCEPTION_FRAME - - /* * We allow breakpoints in NMIs. If a breakpoint occurs, then * the iretq it performs will take us out of NMI context. * This means that we can have nested NMIs where the next |