linux-kernel - RE: [PATCH 05/19] KVM: SVM: Compute dest based on sender's x2APIC status for AVIC kick

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Date:   Thu, 1 Sep 2022 02:56:42 +0000
From:   "Li,Rongqing" <lirongqing@...du.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
CC:     "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Suravee Suthikulpanit" <suravee.suthikulpanit@....com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: RE: [PATCH 05/19] KVM: SVM: Compute dest based on sender's x2APIC
 status for AVIC kick

> -----Original Message-----
> From: Sean Christopherson <seanjc@...gle.com>
> Sent: Wednesday, August 31, 2022 8:35 AM
> To: Sean Christopherson <seanjc@...gle.com>; Paolo Bonzini
> <pbonzini@...hat.com>
> Cc: kvm@...r.kernel.org; linux-kernel@...r.kernel.org; Suravee Suthikulpanit
> <suravee.suthikulpanit@....com>; Maxim Levitsky <mlevitsk@...hat.com>;
> Li,Rongqing <lirongqing@...du.com>
> Subject: [PATCH 05/19] KVM: SVM: Compute dest based on sender's x2APIC
> status for AVIC kick
> 
> Compute the destination from ICRH using the sender's x2APIC status, not each
> (potential) target's x2APIC status.
> 
> Fixes: c514d3a348ac ("KVM: SVM: Update avic_kick_target_vcpus to support
> 32-bit APIC ID")
> Cc: Li RongQing <lirongqing@...du.com>
> Signed-off-by: Sean Christopherson <seanjc@...gle.com>
> ---
>  arch/x86/kvm/svm/avic.c | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index
> b59f8ee2671f..3ace0f2f52f0 100644
> --- a/arch/x86/kvm/svm/avic.c
> +++ b/arch/x86/kvm/svm/avic.c
> @@ -441,6 +441,7 @@ static int avic_kick_target_vcpus_fast(struct kvm *kvm,
> struct kvm_lapic *source  static void avic_kick_target_vcpus(struct kvm *kvm,
> struct kvm_lapic *source,
>  				   u32 icrl, u32 icrh, u32 index)
>  {
> +	u32 dest = apic_x2apic_mode(source) ? icrh :
> +GET_XAPIC_DEST_FIELD(icrh);
>  	unsigned long i;
>  	struct kvm_vcpu *vcpu;
> 
> @@ -456,13 +457,6 @@ static void avic_kick_target_vcpus(struct kvm *kvm,
> struct kvm_lapic *source,
>  	 * since entered the guest will have processed pending IRQs at VMRUN.
>  	 */
>  	kvm_for_each_vcpu(i, vcpu, kvm) {
> -		u32 dest;
> -
> -		if (apic_x2apic_mode(vcpu->arch.apic))
> -			dest = icrh;
> -		else
> -			dest = GET_XAPIC_DEST_FIELD(icrh);
> -
>  		if (kvm_apic_match_dest(vcpu, source, icrl & APIC_SHORT_MASK,
>  					dest, icrl & APIC_DEST_MASK)) {
>  			vcpu->arch.apic->irr_pending = true;
> --
> 2.37.2.672.g94769d06f0-goog

Reviewed-by: Li RongQing <lirongqing@...du.com>

Thanks.

-Li