diff options
| author | Nicolas Saenz Julienne <nsaenz@amazon.com> | 2023-10-17 15:51:02 +0000 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-10-17 16:41:02 -0700 |
| commit | d6800af51c76b6dae20e6023bbdc9b3da3ab5121 (patch) | |
| tree | 26e55e782fe66c06d04c87dd1d9a5f1d82e15a4d | |
| parent | 5a989bbead4cc9cd67c3911226ad857d293643d8 (diff) | |
KVM: x86: hyper-v: Don't auto-enable stimer on write from user-space
Don't apply the stimer's counter side effects when modifying its
value from user-space, as this may trigger spurious interrupts.
For example:
- The stimer is configured in auto-enable mode.
- The stimer's count is set and the timer enabled.
- The stimer expires, an interrupt is injected.
- The VM is live migrated.
- The stimer config and count are deserialized, auto-enable is ON, the
stimer is re-enabled.
- The stimer expires right away, and injects an unwarranted interrupt.
Cc: stable@vger.kernel.org
Fixes: 1f4b34f825e8 ("kvm/x86: Hyper-V SynIC timers")
Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20231017155101.40677-1-nsaenz@amazon.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 7c2dac6824e2..238afd7335e4 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -727,10 +727,12 @@ static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count, stimer_cleanup(stimer); stimer->count = count; - if (stimer->count == 0) - stimer->config.enable = 0; - else if (stimer->config.auto_enable) - stimer->config.enable = 1; + if (!host) { + if (stimer->count == 0) + stimer->config.enable = 0; + else if (stimer->config.auto_enable) + stimer->config.enable = 1; + } if (stimer->config.enable) stimer_mark_pending(stimer, false); |