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| author | Juergen Gross <jgross@suse.com> | 2022-11-25 07:32:47 +0100 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2023-02-13 06:53:19 +0100 |
| commit | 336f560a8917fd60bcdb71b97263257611411453 (patch) | |
| tree | ba662f8f2eee6e9dc22f99f1dde34ab7e32dfe7e /arch/x86/xen/xen-head.S | |
| parent | drivers/xen/hypervisor: Expose Xen SIF flags to userspace (diff) | |
| download | linux-336f560a8917fd60bcdb71b97263257611411453.tar.xz linux-336f560a8917fd60bcdb71b97263257611411453.zip | |
x86/xen: don't let xen_pv_play_dead() return
A function called via the paravirt play_dead() hook should not return
to the caller.
xen_pv_play_dead() has a problem in this regard, as it currently will
return in case an offlined cpu is brought to life again. This can be
changed only by doing basically a longjmp() to cpu_bringup_and_idle(),
as the hypercall for bringing down the cpu will just return when the
cpu is coming up again. Just re-initializing the cpu isn't possible,
as the Xen hypervisor will deny that operation.
So introduce xen_cpu_bringup_again() resetting the stack and calling
cpu_bringup_and_idle(), which can be called after HYPERVISOR_vcpu_op()
in xen_pv_play_dead().
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221125063248.30256-2-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86/xen/xen-head.S')
| -rw-r--r-- | arch/x86/xen/xen-head.S | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index ffaa62167f6e..e36ea4268bd2 100644 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -76,6 +76,13 @@ SYM_CODE_START(asm_cpu_bringup_and_idle) call cpu_bringup_and_idle SYM_CODE_END(asm_cpu_bringup_and_idle) + +SYM_CODE_START(xen_cpu_bringup_again) + UNWIND_HINT_FUNC + mov %rdi, %rsp + UNWIND_HINT_REGS + call cpu_bringup_and_idle +SYM_CODE_END(xen_cpu_bringup_again) .popsection #endif #endif |