From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH] KVM: Optimize kvm_arch_vcpu_ioctl_run function References: <20200413034523.110548-1-tianjia.zhang@linux.alibaba.com> <875ze2ywhy.fsf@vitty.brq.redhat.com> From: Tianjia Zhang Message-ID: Date: Wed, 15 Apr 2020 10:19:04 +0800 MIME-Version: 1.0 In-Reply-To: <875ze2ywhy.fsf@vitty.brq.redhat.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: To: Vitaly Kuznetsov Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, pbonzini@redhat.com, sean.j.christopherson@intel.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, maz@kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com On 2020/4/14 22:26, Vitaly Kuznetsov wrote: > Tianjia Zhang writes: > >> kvm_arch_vcpu_ioctl_run() is only called in the file kvm_main.c, >> where vcpu->run is the kvm_run parameter, so it has been replaced. >> >> Signed-off-by: Tianjia Zhang >> --- >> arch/x86/kvm/x86.c | 8 ++++---- >> virt/kvm/arm/arm.c | 2 +- >> 2 files changed, 5 insertions(+), 5 deletions(-) >> >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index 3bf2ecafd027..70e3f4abbd4d 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -8726,18 +8726,18 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) >> r = -EAGAIN; >> if (signal_pending(current)) { >> r = -EINTR; >> - vcpu->run->exit_reason = KVM_EXIT_INTR; >> + kvm_run->exit_reason = KVM_EXIT_INTR; > > I have a more generic question: why do we need to pass 'kvm_run' to > kvm_arch_vcpu_ioctl_run() if it can be extracted from 'struct kvm_vcpu'? > The only call site looks like > > virt/kvm/kvm_main.c: r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run); > In the earlier version, kvm_run is used to pass parameters with user mode and is not included in the vcpu structure, so it has been retained until now. Thanks, Tianjia >> ++vcpu->stat.signal_exits; >> } >> goto out; >> } >> >> - if (vcpu->run->kvm_valid_regs & ~KVM_SYNC_X86_VALID_FIELDS) { >> + if (kvm_run->kvm_valid_regs & ~KVM_SYNC_X86_VALID_FIELDS) { >> r = -EINVAL; >> goto out; >> } >> >> - if (vcpu->run->kvm_dirty_regs) { >> + if (kvm_run->kvm_dirty_regs) { >> r = sync_regs(vcpu); >> if (r != 0) >> goto out; >> @@ -8767,7 +8767,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) >> >> out: >> kvm_put_guest_fpu(vcpu); >> - if (vcpu->run->kvm_valid_regs) >> + if (kvm_run->kvm_valid_regs) >> store_regs(vcpu); >> post_kvm_run_save(vcpu); >> kvm_sigset_deactivate(vcpu); >> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c >> index 48d0ec44ad77..ab9d7966a4c8 100644 >> --- a/virt/kvm/arm/arm.c >> +++ b/virt/kvm/arm/arm.c >> @@ -659,7 +659,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) >> return ret; >> >> if (run->exit_reason == KVM_EXIT_MMIO) { >> - ret = kvm_handle_mmio_return(vcpu, vcpu->run); >> + ret = kvm_handle_mmio_return(vcpu, run); >> if (ret) >> return ret; >> } >