The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From ce5977b181c1613072eafbc7546bcb6c463ea68c Mon Sep 17 00:00:00 2001 From: Li RongQing lirongqing@baidu.com Date: Thu, 4 Nov 2021 19:56:13 +0800 Subject: [PATCH] KVM: x86: don't print when fail to read/write pv eoi memory
If guest gives MSR_KVM_PV_EOI_EN a wrong value, this printk() will be trigged, and kernel log is spammed with the useless message
Fixes: 0d88800d5472 ("kvm: x86: ioapic and apic debug macros cleanup") Reported-by: Vitaly Kuznetsov vkuznets@redhat.com Reviewed-by: Vitaly Kuznetsov vkuznets@redhat.com Signed-off-by: Li RongQing lirongqing@baidu.com Cc: stable@kernel.org Message-Id: 1636026974-50555-1-git-send-email-lirongqing@baidu.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index bbac8477b3ec..8f4d872f3ffa 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -676,31 +676,25 @@ static inline bool pv_eoi_enabled(struct kvm_vcpu *vcpu) static bool pv_eoi_get_pending(struct kvm_vcpu *vcpu) { u8 val; - if (pv_eoi_get_user(vcpu, &val) < 0) { - printk(KERN_WARNING "Can't read EOI MSR value: 0x%llx\n", - (unsigned long long)vcpu->arch.pv_eoi.msr_val); + if (pv_eoi_get_user(vcpu, &val) < 0) return false; - } + return val & KVM_PV_EOI_ENABLED; }
static void pv_eoi_set_pending(struct kvm_vcpu *vcpu) { - if (pv_eoi_put_user(vcpu, KVM_PV_EOI_ENABLED) < 0) { - printk(KERN_WARNING "Can't set EOI MSR value: 0x%llx\n", - (unsigned long long)vcpu->arch.pv_eoi.msr_val); + if (pv_eoi_put_user(vcpu, KVM_PV_EOI_ENABLED) < 0) return; - } + __set_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention); }
static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu) { - if (pv_eoi_put_user(vcpu, KVM_PV_EOI_DISABLED) < 0) { - printk(KERN_WARNING "Can't clear EOI MSR value: 0x%llx\n", - (unsigned long long)vcpu->arch.pv_eoi.msr_val); + if (pv_eoi_put_user(vcpu, KVM_PV_EOI_DISABLED) < 0) return; - } + __clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention); }