linux-kernel - Re: [PATCH 1/2] KVM: LAPIC: Fix updating DFR missing apic map recalculation

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Date:   Sat, 12 Sep 2020 08:21:43 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Wanpeng Li <kernellwp@...il.com>,
        LKML <linux-kernel@...r.kernel.org>, kvm <kvm@...r.kernel.org>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>
Subject: Re: [PATCH 1/2] KVM: LAPIC: Fix updating DFR missing apic map
 recalculation

On 09/09/20 10:41, Wanpeng Li wrote:
> Any Reviewed-by for these two patches? :)
> On Wed, 19 Aug 2020 at 16:55, Wanpeng Li <kernellwp@...il.com> wrote:
>>
>> From: Wanpeng Li <wanpengli@...cent.com>
>>
>> There is missing apic map recalculation after updating DFR, if it is
>> INIT RESET, in x2apic mode, local apic is software enabled before.
>> This patch fix it by introducing the function kvm_apic_set_dfr() to
>> be called in INIT RESET handling path.
>>
>> Signed-off-by: Wanpeng Li <wanpengli@...cent.com>
>> ---
>>  arch/x86/kvm/lapic.c | 15 ++++++++++-----
>>  1 file changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
>> index 5ccbee7..248095a 100644
>> --- a/arch/x86/kvm/lapic.c
>> +++ b/arch/x86/kvm/lapic.c
>> @@ -310,6 +310,12 @@ static inline void kvm_apic_set_ldr(struct kvm_lapic *apic, u32 id)
>>         atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
>>  }
>>
>> +static inline void kvm_apic_set_dfr(struct kvm_lapic *apic, u32 val)
>> +{
>> +       kvm_lapic_set_reg(apic, APIC_DFR, val);
>> +       atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
>> +}
>> +
>>  static inline u32 kvm_apic_calc_x2apic_ldr(u32 id)
>>  {
>>         return ((id >> 4) << 16) | (1 << (id & 0xf));
>> @@ -1984,10 +1990,9 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
>>                 break;
>>
>>         case APIC_DFR:
>> -               if (!apic_x2apic_mode(apic)) {
>> -                       kvm_lapic_set_reg(apic, APIC_DFR, val | 0x0FFFFFFF);
>> -                       atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
>> -               } else
>> +               if (!apic_x2apic_mode(apic))
>> +                       kvm_apic_set_dfr(apic, val | 0x0FFFFFFF);
>> +               else
>>                         ret = 1;
>>                 break;
>>
>> @@ -2303,7 +2308,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
>>                              SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT));
>>         apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0));
>>
>> -       kvm_lapic_set_reg(apic, APIC_DFR, 0xffffffffU);
>> +       kvm_apic_set_dfr(apic, 0xffffffffU);
>>         apic_set_spiv(apic, 0xff);
>>         kvm_lapic_set_reg(apic, APIC_TASKPRI, 0);
>>         if (!apic_x2apic_mode(apic))
>> --
>> 2.7.4
>>
> 

Queued, thanks.

Paolo