linux-kernel - Re: [PATCH 4/5] KVM: x86: remove unnecessary sync_pir_to

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20161026202837.GF4212@potion>
Date:   Wed, 26 Oct 2016 22:28:38 +0200
From:   Radim Krčmář <rkrcmar@...hat.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        yang.zhang.wz@...il.com, feng.wu@...el.com, mst@...hat.com
Subject: Re: [PATCH 4/5] KVM: x86: remove unnecessary sync_pir_to_irr

2016-10-14 20:21+0200, Paolo Bonzini:
> Synchronizing PIR to IRR is not needed in most callers of
> apic_find_highest_irr.  Move it to the one place that matters,
> interrupt acknowledgement.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
> ---

Reviewed-by: Radim Krčmář <rkrcmar@...hat.com>

> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> @@ -1973,6 +1971,9 @@ int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu)
>  		return -1;
>  
>  	apic_update_ppr(apic);
> +
> +	if (apic->vcpu->arch.apicv_active)
> +		kvm_x86_ops->sync_pir_to_irr(apic->vcpu);

Btw. do all callers of kvm_apic_has_interrupt() need it?

Thanks.

>  	highest_irr = apic_find_highest_irr(apic);
>  	if ((highest_irr == -1) ||
>  	    ((highest_irr & 0xF0) <= kvm_lapic_get_reg(apic, APIC_PROCPRI)))