A guest could hang the host kernel if it could hit the WARN_ON, because
of sheer number of those reports. Internal callers have to be sensible
anyway, so we now only check for it in an API function.
Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
---
v2: new
arch/x86/kvm/i8254.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index cbb911728ac8..328b21f3ab7c 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -76,8 +76,6 @@ static void pit_set_gate(struct kvm *kvm, int channel, u32 val)
struct kvm_kpit_channel_state *c =
&kvm->arch.vpit->pit_state.channels[channel];
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
switch (c->mode) {
default:
case 0:
@@ -99,8 +97,6 @@ static void pit_set_gate(struct kvm *kvm, int channel, u32 val)
static int pit_get_gate(struct kvm *kvm, int channel)
{
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
return kvm->arch.vpit->pit_state.channels[channel].gate;
}
@@ -144,8 +140,6 @@ static int pit_get_count(struct kvm *kvm, int channel)
s64 d, t;
int counter;
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
t = kpit_elapsed(kvm, c, channel);
d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
@@ -174,8 +168,6 @@ static int pit_get_out(struct kvm *kvm, int channel)
s64 d, t;
int out;
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
t = kpit_elapsed(kvm, c, channel);
d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
@@ -207,8 +199,6 @@ static void pit_latch_count(struct kvm *kvm, int channel)
struct kvm_kpit_channel_state *c =
&kvm->arch.vpit->pit_state.channels[channel];
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
if (!c->count_latched) {
c->latched_count = pit_get_count(kvm, channel);
c->count_latched = c->rw_mode;
@@ -220,8 +210,6 @@ static void pit_latch_status(struct kvm *kvm, int channel)
struct kvm_kpit_channel_state *c =
&kvm->arch.vpit->pit_state.channels[channel];
- WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
-
if (!c->status_latched) {
/* TODO: Return NULL COUNT (bit 6). */
c->status = ((pit_get_out(kvm, channel) << 7) |
@@ -367,8 +355,6 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val)
{
struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
- WARN_ON(!mutex_is_locked(&ps->lock));
-
pr_debug("load_count val is %d, channel is %d\n", val, channel);
/*
@@ -406,6 +392,9 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val)
void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start)
{
u8 saved_mode;
+
+ WARN_ON_ONCE(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
+
if (hpet_legacy_start) {
/* save existing mode for later reenablement */
WARN_ON(channel != 0);
--
2.7.1
--
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