From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wanpeng Li Subject: [PATCH v3 6/6] KVM: X86: Expose PV_SEND_IPI CPUID feature bit to guest Date: Tue, 3 Jul 2018 14:21:31 +0800 Message-ID: <1530598891-21370-7-git-send-email-wanpengli@tencent.com> References: <1530598891-21370-1-git-send-email-wanpengli@tencent.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Vitaly Kuznetsov To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Return-path: In-Reply-To: <1530598891-21370-1-git-send-email-wanpengli@tencent.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org From: Wanpeng Li Expose PV_SEND_IPI feature bit to guest, the guest can check this feature bit before using paravirtualized send IPIs. Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Vitaly Kuznetsov Signed-off-by: Wanpeng Li --- Documentation/virtual/kvm/cpuid.txt | 4 ++++ arch/x86/kvm/cpuid.c | 3 ++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt index ab022dc..97ca194 100644 --- a/Documentation/virtual/kvm/cpuid.txt +++ b/Documentation/virtual/kvm/cpuid.txt @@ -62,6 +62,10 @@ KVM_FEATURE_ASYNC_PF_VMEXIT || 10 || paravirtualized async PF VM exit || || can be enabled by setting bit 2 || || when writing to msr 0x4b564d02 ------------------------------------------------------------------------------ +KVM_FEATURE_PV_SEND_IPI || 11 || guest checks this feature bit + || || before using paravirtualized + || || send IPIs. +------------------------------------------------------------------------------ KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no guest-side || || per-cpu warps are expected in || || kvmclock. diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 7e042e3..7bcfa61 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -621,7 +621,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | (1 << KVM_FEATURE_PV_UNHALT) | (1 << KVM_FEATURE_PV_TLB_FLUSH) | - (1 << KVM_FEATURE_ASYNC_PF_VMEXIT); + (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) | + (1 << KVM_FEATURE_PV_SEND_IPI); if (sched_info_on()) entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); -- 2.7.4