diff options
| author | Nicolas Saenz Julienne | 2023-10-17 15:51:02 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-11-28 17:07:08 +0000 |
| commit | 7e218114a2193e9d320396b0409f5515e8e8a7a5 (patch) | |
| tree | 73e1f02e3c9130ea702a148510fce734770743f5 /arch/x86 | |
| parent | 41689ef19b7e4c0b62c141f941649c2eb3ab8fe6 (diff) | |
KVM: x86: hyper-v: Don't auto-enable stimer on write from user-space
commit d6800af51c76b6dae20e6023bbdc9b3da3ab5121 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
| -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 0adf4a437e85..04cca46fed1e 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -705,10 +705,12 @@ 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); |