From: Christian Borntraeger <borntraeger@de.ibm.com> mainline inclusion from mainline-5.2 commit cdd6ad3ac63d2fa320baefcf92a02a918375c30f category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=34 CVE: NA There are cases where halt polling is unwanted. For example when running KVM on an over committed LPAR we rather want to give back the CPU to neighbour LPARs instead of polling. Let us provide a callback that allows architectures to disable polling. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Yubo Miao <miaoyubo@huawei.com> Signed-off-by: Xiangyou Xie <xiexiangyou@huawei.com> Reviewed-by: Hailiang Zhang <zhang.zhanghailiang@huawei.com> Reviewed-by: Hanjun Guo <guohanjun@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Jiajun Chen <chenjiajun8@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- include/linux/kvm_host.h | 10 ++++++++++ virt/kvm/Kconfig | 3 +++ virt/kvm/kvm_main.c | 2 +- 3 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b9443fedf24eb..27e31d972dfb5 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1320,6 +1320,16 @@ static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu) } #endif /* CONFIG_HAVE_KVM_INVALID_WAKEUPS */ +#ifdef CONFIG_HAVE_KVM_NO_POLL +/* Callback that tells if we must not poll */ +bool kvm_arch_no_poll(struct kvm_vcpu *vcpu); +#else +static inline bool kvm_arch_no_poll(struct kvm_vcpu *vcpu) +{ + return false; +} +#endif /* CONFIG_HAVE_KVM_NO_POLL */ + #ifdef CONFIG_HAVE_KVM_VCPU_ASYNC_IOCTL long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg); diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index ea434ddc84992..aad9284c043a0 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -57,3 +57,6 @@ config HAVE_KVM_VCPU_ASYNC_IOCTL config HAVE_KVM_VCPU_RUN_PID_CHANGE bool + +config HAVE_KVM_NO_POLL + bool diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ff1d6ba8e95f2..20c53b5cf4837 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2219,7 +2219,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) kvm_arch_vcpu_blocking(vcpu); start = cur = ktime_get(); - if (vcpu->halt_poll_ns) { + if (vcpu->halt_poll_ns && !kvm_arch_no_poll(vcpu)) { ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); ++vcpu->stat.halt_attempted_poll; -- 2.25.1