Commit b8bcfe997e4 made paravirt pte updates synchronous in interrupt context. Unfortunately the KVM pv mmu code caches the lazy/nonlazy mode internally, so a pte update from interrupt context during a lazy mmu operation can be batched while it should be performed synchronously. https://bugzilla.redhat.com/show_bug.cgi?id=518022 Drop the internal mode variable and use paravirt_get_lazy_mode(), which returns the correct state. Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index c664d51..63b0ec8 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -34,7 +34,6 @@ struct kvm_para_state { u8 mmu_queue[MMU_QUEUE_SIZE]; int mmu_queue_len; - enum paravirt_lazy_mode mode; }; static DEFINE_PER_CPU(struct kvm_para_state, para_state); @@ -77,7 +76,7 @@ static void kvm_deferred_mmu_op(void *buffer, int len) { struct kvm_para_state *state = kvm_para_state(); - if (state->mode != PARAVIRT_LAZY_MMU) { + if (paravirt_get_lazy_mode() != PARAVIRT_LAZY_MMU) { kvm_mmu_op(buffer, len); return; } @@ -185,10 +184,7 @@ static void kvm_release_pt(unsigned long pfn) static void kvm_enter_lazy_mmu(void) { - struct kvm_para_state *state = kvm_para_state(); - paravirt_enter_lazy_mmu(); - state->mode = paravirt_get_lazy_mode(); } static void kvm_leave_lazy_mmu(void) @@ -197,7 +193,6 @@ static void kvm_leave_lazy_mmu(void) mmu_queue_flush(state); paravirt_leave_lazy_mmu(); - state->mode = paravirt_get_lazy_mode(); } static void __init paravirt_ops_setup(void) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
