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[212.43.115.213]) by smtp.gmail.com with ESMTPSA id p12-20020a37420c000000b007426ec97253sm8383058qka.111.2023.03.02.03.35.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Mar 2023 03:35:16 -0800 (PST) From: Stefano Garzarella To: virtualization@lists.linux-foundation.org Cc: Andrey Zhadchenko , eperezma@redhat.com, netdev@vger.kernel.org, stefanha@redhat.com, linux-kernel@vger.kernel.org, Jason Wang , "Michael S. Tsirkin" , kvm@vger.kernel.org, Stefano Garzarella Subject: [PATCH v2 7/8] vdpa_sim: replace the spinlock with a mutex to protect the state Date: Thu, 2 Mar 2023 12:34:20 +0100 Message-Id: <20230302113421.174582-8-sgarzare@redhat.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230302113421.174582-1-sgarzare@redhat.com> References: <20230302113421.174582-1-sgarzare@redhat.com> MIME-Version: 1.0 Content-type: text/plain Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The spinlock we use to protect the state of the simulator is sometimes held for a long time (for example, when devices handle requests). This also prevents us from calling functions that might sleep (such as kthread_flush_work() in the next patch), and thus having to release and retake the lock. For these reasons, let's replace the spinlock with a mutex that gives us more flexibility. Suggested-by: Jason Wang Signed-off-by: Stefano Garzarella Acked-by: Jason Wang --- drivers/vdpa/vdpa_sim/vdpa_sim.h | 4 ++-- drivers/vdpa/vdpa_sim/vdpa_sim.c | 34 ++++++++++++++-------------- drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 4 ++-- drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 4 ++-- 4 files changed, 23 insertions(+), 23 deletions(-) diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h index ce83f9130a5d..4774292fba8c 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.h +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h @@ -60,8 +60,8 @@ struct vdpasim { struct kthread_worker *worker; struct kthread_work work; struct vdpasim_dev_attr dev_attr; - /* spinlock to synchronize virtqueue state */ - spinlock_t lock; + /* mutex to synchronize virtqueue state */ + struct mutex mutex; /* virtio config according to device type */ void *config; struct vhost_iotlb *iommu; diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c index 6feb29726c2a..a28103a67ae7 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -166,7 +166,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr, if (IS_ERR(vdpasim->worker)) goto err_iommu; - spin_lock_init(&vdpasim->lock); + mutex_init(&vdpasim->mutex); spin_lock_init(&vdpasim->iommu_lock); dev = &vdpasim->vdpa.dev; @@ -275,13 +275,13 @@ static void vdpasim_set_vq_ready(struct vdpa_device *vdpa, u16 idx, bool ready) struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; bool old_ready; - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); old_ready = vq->ready; vq->ready = ready; if (vq->ready && !old_ready) { vdpasim_queue_ready(vdpasim, idx); } - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); } static bool vdpasim_get_vq_ready(struct vdpa_device *vdpa, u16 idx) @@ -299,9 +299,9 @@ static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx, struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; struct vringh *vrh = &vq->vring; - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); vrh->last_avail_idx = state->split.avail_index; - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); return 0; } @@ -398,9 +398,9 @@ static u8 vdpasim_get_status(struct vdpa_device *vdpa) struct vdpasim *vdpasim = vdpa_to_sim(vdpa); u8 status; - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); status = vdpasim->status; - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); return status; } @@ -409,19 +409,19 @@ static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status) { struct vdpasim *vdpasim = vdpa_to_sim(vdpa); - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); vdpasim->status = status; - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); } static int vdpasim_reset(struct vdpa_device *vdpa) { struct vdpasim *vdpasim = vdpa_to_sim(vdpa); - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); vdpasim->status = 0; vdpasim_do_reset(vdpasim); - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); return 0; } @@ -430,9 +430,9 @@ static int vdpasim_suspend(struct vdpa_device *vdpa) { struct vdpasim *vdpasim = vdpa_to_sim(vdpa); - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); vdpasim->running = false; - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); return 0; } @@ -442,7 +442,7 @@ static int vdpasim_resume(struct vdpa_device *vdpa) struct vdpasim *vdpasim = vdpa_to_sim(vdpa); int i; - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); vdpasim->running = true; if (vdpasim->pending_kick) { @@ -453,7 +453,7 @@ static int vdpasim_resume(struct vdpa_device *vdpa) vdpasim->pending_kick = false; } - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); return 0; } @@ -525,14 +525,14 @@ static int vdpasim_set_group_asid(struct vdpa_device *vdpa, unsigned int group, iommu = &vdpasim->iommu[asid]; - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); for (i = 0; i < vdpasim->dev_attr.nvqs; i++) if (vdpasim_get_vq_group(vdpa, i) == group) vringh_set_iotlb(&vdpasim->vqs[i].vring, iommu, &vdpasim->iommu_lock); - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); return 0; } diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c index eb4897c8541e..568119e1553f 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c @@ -290,7 +290,7 @@ static void vdpasim_blk_work(struct vdpasim *vdpasim) bool reschedule = false; int i; - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK)) goto out; @@ -321,7 +321,7 @@ static void vdpasim_blk_work(struct vdpasim *vdpasim) } } out: - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); if (reschedule) vdpasim_schedule_work(vdpasim); diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c index e61a9ecbfafe..7ab434592bfe 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c @@ -201,7 +201,7 @@ static void vdpasim_net_work(struct vdpasim *vdpasim) u64 rx_drops = 0, rx_overruns = 0, rx_errors = 0, tx_errors = 0; int err; - spin_lock(&vdpasim->lock); + mutex_lock(&vdpasim->mutex); if (!vdpasim->running) goto out; @@ -264,7 +264,7 @@ static void vdpasim_net_work(struct vdpasim *vdpasim) } out: - spin_unlock(&vdpasim->lock); + mutex_unlock(&vdpasim->mutex); u64_stats_update_begin(&net->tx_stats.syncp); net->tx_stats.pkts += tx_pkts;