Received-SPF: pass (google.com: domain of linux-kernel+bounces-32726-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Date: Mon, 22 Jan 2024 11:21:48 +0100
From: Stefano Garzarella <sgarzare@redhat.com>
To: Steve Sistare <steven.sistare@oracle.com>
Cc: virtualization@lists.linux-foundation.org, 
	linux-kernel@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>, 
	Jason Wang <jasowang@redhat.com>, Eugenio Perez Martin <eperezma@redhat.com>, 
	Si-Wei Liu <si-wei.liu@oracle.com>
Subject: Re: [PATCH V1] vdpa_sim: reset must not run
Message-ID: <mhnsrwlvqjeftu5aa77iaowdk2wrq366yofjchbn5fwchgcbna@kcjtoj46fawi>
References: <1705519403-255169-1-git-send-email-steven.sistare@oracle.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1; format=flowed
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1705519403-255169-1-git-send-email-steven.sistare@oracle.com>

On Wed, Jan 17, 2024 at 11:23:23AM -0800, Steve Sistare wrote:
>vdpasim_do_reset sets running to true, which is wrong, as it allows
>vdpasim_kick_vq to post work requests before the device has been
>configured.  To fix, do not set running until VIRTIO_CONFIG_S_FEATURES_OK
>is set.
>
>Fixes: 0c89e2a3a9d0 ("vdpa_sim: Implement suspend vdpa op")
>Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
>Reviewed-by: Eugenio P?rez <eperezma@redhat.com>
>---
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>index be2925d0d283..6304cb0b4770 100644
>--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
>+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>@@ -160,7 +160,7 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim, u32 flags)
> 		}
> 	}
>
>-	vdpasim->running = true;
>+	vdpasim->running = false;
> 	spin_unlock(&vdpasim->iommu_lock);
>
> 	vdpasim->features = 0;
>@@ -483,6 +483,7 @@ static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
>
> 	mutex_lock(&vdpasim->mutex);
> 	vdpasim->status = status;
>+	vdpasim->running = (status & VIRTIO_CONFIG_S_FEATURES_OK) != 0;
> 	mutex_unlock(&vdpasim->mutex);

Should we do something similar also in vdpasim_resume() ?

I mean something like this:

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index be2925d0d283..55e4633d5442 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -520,7 +520,7 @@ static int vdpasim_resume(struct vdpa_device *vdpa)
         int i;

         mutex_lock(&vdpasim->mutex);
-       vdpasim->running = true;
+       vdpasim->running = (vdpasim->status & VIRTIO_CONFIG_S_FEATURES_OK) != 0;

         if (vdpasim->pending_kick) {
                 /* Process pending descriptors */

Thanks,
Stefano