From 479c2a6a296d4fafc713746bf96127c1b20c381e 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() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 (cherry picked from commit 1cae88b9f4121c9af0bf677435c6129e643280fd) Signed-off-by: Bruce Rogers Signed-off-by: Andreas Färber --- kvm-all.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/kvm-all.c b/kvm-all.c index cbc2532..26621d0 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) -- 1.7.11.2