From 1cae88b9f4121c9af0bf677435c6129e643280fd Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 18 Oct 2011 19:43:12 +0200 Subject: [PATCH] kvm: avoid reentring kvm_flush_coalesced_mmio_buffer() mmio callbacks invoked by kvm_flush_coalesced_mmio_buffer() may themselves indirectly call kvm_flush_coalesced_mmio_buffer(). Prevent reentering the function by checking a flag that indicates we're processing coalesced mmio requests. Signed-off-by: Avi Kivity --- kvm-all.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/kvm-all.c b/kvm-all.c index e7faf5cba9..c09ddf7ac5 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -64,6 +64,7 @@ struct KVMState int vmfd; int coalesced_mmio; struct kvm_coalesced_mmio_ring *coalesced_mmio_ring; + bool coalesced_flush_in_progress; int broken_set_mem_region; int migration_log; int vcpu_events; @@ -876,6 +877,13 @@ static int kvm_handle_internal_error(CPUState *env, struct kvm_run *run) void kvm_flush_coalesced_mmio_buffer(void) { KVMState *s = kvm_state; + + if (s->coalesced_flush_in_progress) { + return; + } + + s->coalesced_flush_in_progress = true; + if (s->coalesced_mmio_ring) { struct kvm_coalesced_mmio_ring *ring = s->coalesced_mmio_ring; while (ring->first != ring->last) { @@ -888,6 +896,8 @@ void kvm_flush_coalesced_mmio_buffer(void) ring->first = (ring->first + 1) % KVM_COALESCED_MMIO_MAX; } } + + s->coalesced_flush_in_progress = false; } static void do_kvm_cpu_synchronize_state(void *_env)