From: Nicolas Saenz Julienne <nsaenz@amazon.com> stable inclusion from stable-v6.6.3 commit e0c63803d729cd2d81394d6d29b8601f09c262a2 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8LBQP Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- arch/x86/kvm/hyperv.c | 10 ++++++---- 1 file 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); -- 2.25.1