From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751027AbaKXU5B (ORCPT ); Mon, 24 Nov 2014 15:57:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41274 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750789AbaKXU47 (ORCPT ); Mon, 24 Nov 2014 15:56:59 -0500 Message-ID: <1416862562.11825.81.camel@bling.home> Subject: Re: [PATCH v3 6/8] KVM: kvm-vfio: wrapper to VFIO external API device helpers From: Alex Williamson To: Eric Auger Cc: eric.auger@st.com, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, joel.schopp@amd.com, kim.phillips@freescale.com, paulus@samba.org, gleb@kernel.org, pbonzini@redhat.com, agraf@suse.de, linux-kernel@vger.kernel.org, patches@linaro.org, will.deacon@arm.com, a.motakis@virtualopensystems.com, a.rigo@virtualopensystems.com, john.liuli@huawei.com, ming.lei@canonical.com, feng.wu@intel.com Date: Mon, 24 Nov 2014 13:56:02 -0700 In-Reply-To: <1416767760-14487-7-git-send-email-eric.auger@linaro.org> References: <1416767760-14487-1-git-send-email-eric.auger@linaro.org> <1416767760-14487-7-git-send-email-eric.auger@linaro.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2014-11-23 at 19:35 +0100, Eric Auger wrote: > Provide wrapper functions that allow KVM-VFIO device code to > interact with a vfio device: > - kvm_vfio_device_get_external_user gets a handle to a struct > vfio_device from the vfio device file descriptor and increments > its reference counter, > - kvm_vfio_device_put_external_user decrements the reference counter > to a vfio device, > - kvm_vfio_external_base_device returns a handle to the struct device > of the vfio device. > > The KVM-VFIO device uses the VFIO external API device functions. > > Signed-off-by: Eric Auger > > --- > > v2 -> v3: > reword the commit message and title > > v1 -> v2: > - kvm_vfio_external_get_base_device renamed into > kvm_vfio_external_base_device > - kvm_vfio_external_get_type removed > --- > arch/arm/include/asm/kvm_host.h | 5 +++++ > virt/kvm/vfio.c | 45 +++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 50 insertions(+) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 53036e2..bca5b79 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -169,6 +169,11 @@ void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte); > unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu); > int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices); > > +struct vfio_device; > +struct vfio_device *kvm_vfio_device_get_external_user(struct file *filep); > +void kvm_vfio_device_put_external_user(struct vfio_device *vdev); > +struct device *kvm_vfio_external_base_device(struct vfio_device *vdev); > + This doesn't look right, why doesn't kvm-vfio send the struct dev to the arch callback? Then the below functions can be static. Nothing outside of kvm-vfio device should need to do anything with vfio_device references. > /* We do not have shadow page tables, hence the empty hooks */ > static inline int kvm_age_hva(struct kvm *kvm, unsigned long start, > unsigned long end) > diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c > index 620e37f..6f0cc34 100644 > --- a/virt/kvm/vfio.c > +++ b/virt/kvm/vfio.c > @@ -60,6 +60,51 @@ static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group) > symbol_put(vfio_group_put_external_user); > } > > +struct vfio_device *kvm_vfio_device_get_external_user(struct file *filep) > +{ > + struct vfio_device *vdev; > + struct vfio_device *(*fn)(struct file *); > + > + fn = symbol_get(vfio_device_get_external_user); > + if (!fn) > + return ERR_PTR(-EINVAL); > + > + vdev = fn(filep); > + > + symbol_put(vfio_device_get_external_user); > + > + return vdev; > +} > + > +void kvm_vfio_device_put_external_user(struct vfio_device *vdev) > +{ > + void (*fn)(struct vfio_device *); > + > + fn = symbol_get(vfio_device_put_external_user); > + if (!fn) > + return; > + > + fn(vdev); > + > + symbol_put(vfio_device_put_external_user); > +} > + > +struct device *kvm_vfio_external_base_device(struct vfio_device *vdev) > +{ > + struct device *(*fn)(struct vfio_device *); > + struct device *dev; > + > + fn = symbol_get(vfio_external_base_device); > + if (!fn) > + return NULL; > + > + dev = fn(vdev); > + > + symbol_put(vfio_external_base_device); > + > + return dev; > +} > + > static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group) > { > long (*fn)(struct vfio_group *, unsigned long); From mboxrd@z Thu Jan 1 00:00:00 1970 From: alex.williamson@redhat.com (Alex Williamson) Date: Mon, 24 Nov 2014 13:56:02 -0700 Subject: [PATCH v3 6/8] KVM: kvm-vfio: wrapper to VFIO external API device helpers In-Reply-To: <1416767760-14487-7-git-send-email-eric.auger@linaro.org> References: <1416767760-14487-1-git-send-email-eric.auger@linaro.org> <1416767760-14487-7-git-send-email-eric.auger@linaro.org> Message-ID: <1416862562.11825.81.camel@bling.home> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sun, 2014-11-23 at 19:35 +0100, Eric Auger wrote: > Provide wrapper functions that allow KVM-VFIO device code to > interact with a vfio device: > - kvm_vfio_device_get_external_user gets a handle to a struct > vfio_device from the vfio device file descriptor and increments > its reference counter, > - kvm_vfio_device_put_external_user decrements the reference counter > to a vfio device, > - kvm_vfio_external_base_device returns a handle to the struct device > of the vfio device. > > The KVM-VFIO device uses the VFIO external API device functions. > > Signed-off-by: Eric Auger > > --- > > v2 -> v3: > reword the commit message and title > > v1 -> v2: > - kvm_vfio_external_get_base_device renamed into > kvm_vfio_external_base_device > - kvm_vfio_external_get_type removed > --- > arch/arm/include/asm/kvm_host.h | 5 +++++ > virt/kvm/vfio.c | 45 +++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 50 insertions(+) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 53036e2..bca5b79 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -169,6 +169,11 @@ void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte); > unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu); > int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices); > > +struct vfio_device; > +struct vfio_device *kvm_vfio_device_get_external_user(struct file *filep); > +void kvm_vfio_device_put_external_user(struct vfio_device *vdev); > +struct device *kvm_vfio_external_base_device(struct vfio_device *vdev); > + This doesn't look right, why doesn't kvm-vfio send the struct dev to the arch callback? Then the below functions can be static. Nothing outside of kvm-vfio device should need to do anything with vfio_device references. > /* We do not have shadow page tables, hence the empty hooks */ > static inline int kvm_age_hva(struct kvm *kvm, unsigned long start, > unsigned long end) > diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c > index 620e37f..6f0cc34 100644 > --- a/virt/kvm/vfio.c > +++ b/virt/kvm/vfio.c > @@ -60,6 +60,51 @@ static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group) > symbol_put(vfio_group_put_external_user); > } > > +struct vfio_device *kvm_vfio_device_get_external_user(struct file *filep) > +{ > + struct vfio_device *vdev; > + struct vfio_device *(*fn)(struct file *); > + > + fn = symbol_get(vfio_device_get_external_user); > + if (!fn) > + return ERR_PTR(-EINVAL); > + > + vdev = fn(filep); > + > + symbol_put(vfio_device_get_external_user); > + > + return vdev; > +} > + > +void kvm_vfio_device_put_external_user(struct vfio_device *vdev) > +{ > + void (*fn)(struct vfio_device *); > + > + fn = symbol_get(vfio_device_put_external_user); > + if (!fn) > + return; > + > + fn(vdev); > + > + symbol_put(vfio_device_put_external_user); > +} > + > +struct device *kvm_vfio_external_base_device(struct vfio_device *vdev) > +{ > + struct device *(*fn)(struct vfio_device *); > + struct device *dev; > + > + fn = symbol_get(vfio_external_base_device); > + if (!fn) > + return NULL; > + > + dev = fn(vdev); > + > + symbol_put(vfio_external_base_device); > + > + return dev; > +} > + > static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group) > { > long (*fn)(struct vfio_group *, unsigned long);