linux-kernel - [PATCH 10/12] KVM: SVM: Do not throw warning when calling avic_vcpu

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Message-ID: <20220405230855.15376-11-suravee.suthikulpanit@amd.com>
Date:   Tue, 5 Apr 2022 18:08:53 -0500
From:   Suravee Suthikulpanit <suravee.suthikulpanit@....com>
To:     <linux-kernel@...r.kernel.org>, <kvm@...r.kernel.org>,
        <x86@...nel.org>
CC:     <mlevitsk@...hat.com>, <seanjc@...gle.com>, <pbonzini@...hat.com>,
        <joro@...tes.org>, <tglx@...utronix.de>, <mingo@...hat.com>,
        <bp@...en8.de>, <peterz@...radead.org>, <hpa@...or.com>,
        <jon.grimm@....com>, <wei.huang2@....com>, <terry.bowman@....com>,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Subject: [PATCH 10/12] KVM: SVM: Do not throw warning when calling avic_vcpu_load on a running vcpu

Originalliy, this WARN_ON is designed to detect when calling
avic_vcpu_load() on an already running vcpu in AVIC mode (i.e. the AVIC
is_running bit is set).

However, for x2AVIC, the vCPU can switch from xAPIC to x2APIC mode while in
running state, in which the avic_vcpu_load() will be called from
svm_refresh_apicv_exec_ctrl().

Therefore, remove this warning since it is no longer appropriate.

Reviewed-by: Maxim Levitsky <mlevitsk@...hat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
---
 arch/x86/kvm/svm/avic.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 4f9990526485..a6e161d62837 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -1030,7 +1030,6 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 		return;
 
 	entry = READ_ONCE(*(svm->avic_physical_id_cache));
-	WARN_ON(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK);
 
 	entry &= ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK;
 	entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK);
-- 
2.25.1