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From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Vitaly Kuznetsov" <vkuznets@redhat.com>
Subject: [PATCH v5 6/6] KVM: X86: Expose PV_SEND_IPI CPUID feature bit to guest
Date: Mon, 23 Jul 2018 14:39:56 +0800	[thread overview]
Message-ID: <1532327996-17619-7-git-send-email-wanpengli@tencent.com> (raw)
In-Reply-To: <1532327996-17619-1-git-send-email-wanpengli@tencent.com>

From: Wanpeng Li <wanpengli@tencent.com>

Expose PV_SEND_IPI feature bit to guest, the guest can check this feature
bit before using paravirtualized send IPIs.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
 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


      parent reply	other threads:[~2018-07-23  6:40 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-23  6:39 [PATCH v5 0/6] KVM: X86: Implement Exit-less IPIs support Wanpeng Li
2018-07-23  6:39 ` [PATCH v5 1/6] KVM: X86: Add kvm hypervisor init time platform setup callback Wanpeng Li
2018-07-23  6:39 ` [PATCH v5 2/6] KVM: X86: Implement PV IPIs in linux guest Wanpeng Li
2018-07-23  6:39 ` [PATCH v5 3/6] KVM: X86: Fallback to original apic hooks when bad happens Wanpeng Li
2018-08-02 13:01   ` Paolo Bonzini
2018-07-23  6:39 ` [PATCH v5 4/6] KVM: X86: Implement PV IPIs send hypercall Wanpeng Li
2018-08-02 13:04   ` Paolo Bonzini
2018-08-03  4:09     ` Wanpeng Li
2018-07-23  6:39 ` [PATCH v5 5/6] KVM: X86: Add NMI support to PV IPIs Wanpeng Li
2018-07-23  6:39 ` Wanpeng Li [this message]

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