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Fri, 15 Sep 2023 17:31:28 -0700 (PDT) Date: Fri, 15 Sep 2023 17:30:56 -0700 In-Reply-To: <20230916003118.2540661-1-seanjc@google.com> Mime-Version: 1.0 References: <20230916003118.2540661-1-seanjc@google.com> X-Mailer: git-send-email 2.42.0.459.ge4e396fd5e-goog Message-ID: <20230916003118.2540661-5-seanjc@google.com> Subject: [PATCH 04/26] vfio: Add struct to hold KVM assets and dedup group vs. iommufd code From: Sean Christopherson To: Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Peter Zijlstra , Arnaldo Carvalho de Melo , Sean Christopherson , Paolo Bonzini , Tony Krowiak , Halil Pasic , Jason Herne , Harald Freudenberger , Alex Williamson , Andy Lutomirski Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Anish Ghulati , Venkatesh Srinivas , Andrew Thornton X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230916_013137_878875_901B74F4 X-CRM114-Status: GOOD ( 23.37 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Sean Christopherson Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add a struct to hold the KVM assets need to manage and pass along KVM references to VFIO devices. Providing a common struct deduplicates the group vs. iommufd code, and will make it easier to rework the attachment logic so that VFIO doesn't have to do a symbol lookup to retrieve the get/put helpers from KVM. Signed-off-by: Sean Christopherson Reviewed-by: Alex Williamson --- drivers/vfio/device_cdev.c | 9 +------- drivers/vfio/group.c | 18 ++-------------- drivers/vfio/vfio.h | 22 +++++++++---------- drivers/vfio/vfio_main.c | 43 +++++++++++++++++++++++++++----------- 4 files changed, 45 insertions(+), 47 deletions(-) diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c index e75da0a70d1f..e484d6d6400a 100644 --- a/drivers/vfio/device_cdev.c +++ b/drivers/vfio/device_cdev.c @@ -46,13 +46,6 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep) return ret; } -static void vfio_df_get_kvm_safe(struct vfio_device_file *df) -{ - spin_lock(&df->kvm_ref_lock); - vfio_device_get_kvm_safe(df->device, df->kvm); - spin_unlock(&df->kvm_ref_lock); -} - long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df, struct vfio_device_bind_iommufd __user *arg) { @@ -99,7 +92,7 @@ long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df, * a reference. This reference is held until device closed. * Save the pointer in the device for use by drivers. */ - vfio_df_get_kvm_safe(df); + vfio_device_get_kvm_safe(df->device, &df->kvm_ref); ret = vfio_df_open(df); if (ret) diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c index 610a429c6191..756e47ff4cf0 100644 --- a/drivers/vfio/group.c +++ b/drivers/vfio/group.c @@ -157,13 +157,6 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group, return ret; } -static void vfio_device_group_get_kvm_safe(struct vfio_device *device) -{ - spin_lock(&device->group->kvm_ref_lock); - vfio_device_get_kvm_safe(device, device->group->kvm); - spin_unlock(&device->group->kvm_ref_lock); -} - static int vfio_df_group_open(struct vfio_device_file *df) { struct vfio_device *device = df->device; @@ -184,7 +177,7 @@ static int vfio_df_group_open(struct vfio_device_file *df) * the pointer in the device for use by drivers. */ if (device->open_count == 0) - vfio_device_group_get_kvm_safe(device); + vfio_device_get_kvm_safe(device, &device->group->kvm_ref); df->iommufd = device->group->iommufd; if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count == 0) { @@ -560,7 +553,7 @@ static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, refcount_set(&group->drivers, 1); mutex_init(&group->group_lock); - spin_lock_init(&group->kvm_ref_lock); + spin_lock_init(&group->kvm_ref.lock); INIT_LIST_HEAD(&group->device_list); mutex_init(&group->device_lock); group->iommu_group = iommu_group; @@ -884,13 +877,6 @@ bool vfio_group_enforced_coherent(struct vfio_group *group) return ret; } -void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm) -{ - spin_lock(&group->kvm_ref_lock); - group->kvm = kvm; - spin_unlock(&group->kvm_ref_lock); -} - /** * vfio_file_has_dev - True if the VFIO file is a handle for device * @file: VFIO file to check diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index c26d1ad68105..a1f741365075 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -12,18 +12,23 @@ #include #include +struct kvm; struct iommufd_ctx; struct iommu_group; struct vfio_container; +struct vfio_kvm_reference { + struct kvm *kvm; + spinlock_t lock; +}; + struct vfio_device_file { struct vfio_device *device; struct vfio_group *group; u8 access_granted; u32 devid; /* only valid when iommufd is valid */ - spinlock_t kvm_ref_lock; /* protect kvm field */ - struct kvm *kvm; + struct vfio_kvm_reference kvm_ref; struct iommufd_ctx *iommufd; /* protected by struct vfio_device_set::lock */ }; @@ -88,11 +93,10 @@ struct vfio_group { #endif enum vfio_group_type type; struct mutex group_lock; - struct kvm *kvm; + struct vfio_kvm_reference kvm_ref; struct file *opened_file; struct blocking_notifier_head notifier; struct iommufd_ctx *iommufd; - spinlock_t kvm_ref_lock; unsigned int cdev_device_open_cnt; }; @@ -108,7 +112,6 @@ void vfio_device_group_unuse_iommu(struct vfio_device *device); void vfio_df_group_close(struct vfio_device_file *df); struct vfio_group *vfio_group_from_file(struct file *file); bool vfio_group_enforced_coherent(struct vfio_group *group); -void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm); bool vfio_device_has_container(struct vfio_device *device); int __init vfio_group_init(void); void vfio_group_cleanup(void); @@ -171,10 +174,6 @@ static inline bool vfio_group_enforced_coherent(struct vfio_group *group) return true; } -static inline void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm) -{ -} - static inline bool vfio_device_has_container(struct vfio_device *device) { return false; @@ -435,11 +434,12 @@ static inline void vfio_virqfd_exit(void) #endif #if IS_ENABLED(CONFIG_KVM) -void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm); +void vfio_device_get_kvm_safe(struct vfio_device *device, + struct vfio_kvm_reference *ref); void vfio_device_put_kvm(struct vfio_device *device); #else static inline void vfio_device_get_kvm_safe(struct vfio_device *device, - struct kvm *kvm) + struct vfio_kvm_reference *ref) { } diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 124cc88966a7..e77e8c6aae2f 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -397,7 +397,7 @@ vfio_allocate_device_file(struct vfio_device *device) return ERR_PTR(-ENOMEM); df->device = device; - spin_lock_init(&df->kvm_ref_lock); + spin_lock_init(&df->kvm_ref.lock); return df; } @@ -1303,7 +1303,8 @@ bool vfio_file_enforced_coherent(struct file *file) EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent); #if IS_ENABLED(CONFIG_KVM) -void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm) +void vfio_device_get_kvm_safe(struct vfio_device *device, + struct vfio_kvm_reference *ref) { void (*pfn)(struct kvm *kvm); bool (*fn)(struct kvm *kvm); @@ -1311,28 +1312,33 @@ void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm) lockdep_assert_held(&device->dev_set->lock); - if (!kvm) - return; + spin_lock(&ref->lock); + + if (!ref->kvm) + goto out; pfn = symbol_get(kvm_put_kvm); if (WARN_ON(!pfn)) - return; + goto out; fn = symbol_get(kvm_get_kvm_safe); if (WARN_ON(!fn)) { symbol_put(kvm_put_kvm); - return; + goto out; } - ret = fn(kvm); + ret = fn(ref->kvm); symbol_put(kvm_get_kvm_safe); if (!ret) { symbol_put(kvm_put_kvm); - return; + goto out; } device->put_kvm = pfn; - device->kvm = kvm; + device->kvm = ref->kvm; + +out: + spin_unlock(&ref->lock); } void vfio_device_put_kvm(struct vfio_device *device) @@ -1353,6 +1359,21 @@ void vfio_device_put_kvm(struct vfio_device *device) device->kvm = NULL; } +static void vfio_device_set_kvm(struct vfio_kvm_reference *ref, + struct kvm *kvm) +{ + spin_lock(&ref->lock); + ref->kvm = kvm; + spin_unlock(&ref->lock); +} + +static void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm) +{ +#if IS_ENABLED(CONFIG_VFIO_GROUP) + vfio_device_set_kvm(&group->kvm_ref, kvm); +#endif +} + static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm) { struct vfio_device_file *df = file->private_data; @@ -1362,9 +1383,7 @@ static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm) * be propagated to vfio_device::kvm when the file is bound to * iommufd successfully in the vfio device cdev path. */ - spin_lock(&df->kvm_ref_lock); - df->kvm = kvm; - spin_unlock(&df->kvm_ref_lock); + vfio_device_set_kvm(&df->kvm_ref, kvm); } /**