From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH] Introduce bitmask for apic attention reasons. Date: Thu, 19 Apr 2012 13:05:57 +0300 Message-ID: <20120419100557.GA25901@redhat.com> References: <1334828002-12709-1-git-send-email-gleb@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, avi@redhat.com, mtosatti@redhat.com To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:30654 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753471Ab2DSKFr (ORCPT ); Thu, 19 Apr 2012 06:05:47 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q3JA5kIH004100 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 19 Apr 2012 06:05:47 -0400 Content-Disposition: inline In-Reply-To: <1334828002-12709-1-git-send-email-gleb@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Apr 19, 2012 at 12:33:22PM +0300, Gleb Natapov wrote: > The patch introduces a bitmap that will hold reasons apic should be > checked during vmexit. This is in a preparation for vp eoi patch > that will add one more check on vmexit. With the bitmap we can do > if(apic_attention) to check everything simultaneously which will > add zero overhead on the fast path. > > Signed-off-by: Gleb Natapov Looks very clean, thanks! I'll integrate this in the eoi patchset. > --- > arch/x86/include/asm/kvm_host.h | 3 +++ > arch/x86/kvm/lapic.c | 12 +++++++----- > 2 files changed, 10 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index f624ca7..fe4e85b 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -172,6 +172,8 @@ enum { > #define DR7_FIXED_1 0x00000400 > #define DR7_VOLATILE 0xffff23ff > > +#define KVM_APIC_CHECK_VAPIC 0 > + > /* > * We don't want allocation failures within the mmu code, so we preallocate > * enough memory for a single page fault in a cache. > @@ -337,6 +339,7 @@ struct kvm_vcpu_arch { > u64 efer; > u64 apic_base; > struct kvm_lapic *apic; /* kernel irqchip context */ > + unsigned long apic_attention; > int32_t apic_arb_prio; > int mp_state; > int sipi_vector; > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index 992b4ea..93c1574 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -1088,6 +1088,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu) > apic_update_ppr(apic); > > vcpu->arch.apic_arb_prio = 0; > + vcpu->arch.apic_attention = 0; > > apic_debug(KERN_INFO "%s: vcpu=%p, id=%d, base_msr=" > "0x%016" PRIx64 ", base_address=0x%0lx.\n", __func__, > @@ -1287,7 +1288,7 @@ void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu) > u32 data; > void *vapic; > > - if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr) > + if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention)) > return; > > vapic = kmap_atomic(vcpu->arch.apic->vapic_page); > @@ -1304,7 +1305,7 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu) > struct kvm_lapic *apic; > void *vapic; > > - if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr) > + if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention)) > return; > > apic = vcpu->arch.apic; > @@ -1324,10 +1325,11 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu) > > void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr) > { > - if (!irqchip_in_kernel(vcpu->kvm)) > - return; > - > vcpu->arch.apic->vapic_addr = vapic_addr; > + if (vapic_addr) > + __set_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention); > + else > + __clear_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention); > } > > int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data) > -- > 1.7.7.3