x86/paravirt: remove lazy mode in interrupts
Impact: simplification, robustness
Make paravirt_lazy_mode() always return PARAVIRT_LAZY_NONE
when in an interrupt. This prevents interrupt code from
accidentally inheriting an outer lazy state, and instead
does everything synchronously. Outer batched operations
are left deferred.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index a03b727..cfbb4a7 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -225,12 +225,10 @@
if (!pmd_present(*pmd_k))
return NULL;
- if (!pmd_present(*pmd)) {
+ if (!pmd_present(*pmd))
set_pmd(pmd, *pmd_k);
- arch_flush_lazy_mmu_mode();
- } else {
+ else
BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k));
- }
return pmd_k;
}