From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 3 Nov 2022 16:30:40 -0400 From: "Michael S. Tsirkin" Message-ID: <20221103162957-mutt-send-email-mst@kernel.org> References: <20220802095010.3330793-1-alex.bennee@linaro.org> <20220802095010.3330793-11-alex.bennee@linaro.org> <20221103123856-mutt-send-email-mst@kernel.org> <87o7tnkfqy.fsf@linaro.org> MIME-Version: 1.0 In-Reply-To: <87o7tnkfqy.fsf@linaro.org> Content-Type: text/plain; charset="windows-1252" Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [Virtio-fs] [PATCH v4 10/22] hw/virtio: move vm_running check to virtio_device_started List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex =?iso-8859-1?Q?Benn=E9e?= Cc: qemu-devel@nongnu.org, slp@redhat.com, marcandre.lureau@redhat.com, stefanha@redhat.com, mathieu.poirier@linaro.org, viresh.kumar@linaro.org, "Dr. David Alan Gilbert" , "open list:virtiofs" On Thu, Nov 03, 2022 at 07:18:30PM +0000, Alex Benn=E9e wrote: >=20 > "Michael S. Tsirkin" writes: >=20 > > On Tue, Aug 02, 2022 at 10:49:58AM +0100, Alex Benn=E9e wrote: > >> All the boilerplate virtio code does the same thing (or should at > >> least) of checking to see if the VM is running before attempting to > >> start VirtIO. Push the logic up to the common function to avoid > >> getting a copy and paste wrong. > >>=20 > >> Signed-off-by: Alex Benn=E9e > > > > How bad is it if we drop this? >=20 >=20 > I assume it will break gpio. Why do we want to drop this now? It has > been merged awhile. However there was a follow-up patch which tweaked > the order of checks in virtio_device_started. And that follow up patch trips up UBSAN: https://gitlab.com/mitsirkin/qemu/-/pipelines/684763327 > > > >> --- > >> include/hw/virtio/virtio.h | 5 +++++ > >> hw/virtio/vhost-user-fs.c | 6 +----- > >> hw/virtio/vhost-user-i2c.c | 6 +----- > >> hw/virtio/vhost-user-rng.c | 6 +----- > >> hw/virtio/vhost-user-vsock.c | 6 +----- > >> hw/virtio/vhost-vsock.c | 6 +----- > >> 6 files changed, 10 insertions(+), 25 deletions(-) > >>=20 > >> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > >> index 9bb2485415..74e7ad5a92 100644 > >> --- a/include/hw/virtio/virtio.h > >> +++ b/include/hw/virtio/virtio.h > >> @@ -100,6 +100,7 @@ struct VirtIODevice > >> VirtQueue *vq; > >> MemoryListener listener; > >> uint16_t device_id; > >> + /* @vm_running: current VM running state via virtio_vmstate_chang= e() */ > >> bool vm_running; > >> bool broken; /* device in invalid state, needs reset */ > >> bool use_disabled_flag; /* allow use of 'disable' flag when neede= d */ > >> @@ -376,6 +377,10 @@ static inline bool virtio_device_started(VirtIODe= vice *vdev, uint8_t status) > >> return vdev->started; > >> } > >> =20 > >> + if (!vdev->vm_running) { > >> + return false; > >> + } > >> + > >> return status & VIRTIO_CONFIG_S_DRIVER_OK; > >> } > >> =20 > >> diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c > >> index e513e4fdda..d2bebba785 100644 > >> --- a/hw/virtio/vhost-user-fs.c > >> +++ b/hw/virtio/vhost-user-fs.c > >> @@ -122,11 +122,7 @@ static void vuf_stop(VirtIODevice *vdev) > >> static void vuf_set_status(VirtIODevice *vdev, uint8_t status) > >> { > >> VHostUserFS *fs =3D VHOST_USER_FS(vdev); > >> - bool should_start =3D status & VIRTIO_CONFIG_S_DRIVER_OK; > >> - > >> - if (!vdev->vm_running) { > >> - should_start =3D false; > >> - } > >> + bool should_start =3D virtio_device_started(vdev, status); > >> =20 > >> if (fs->vhost_dev.started =3D=3D should_start) { > >> return; > >> diff --git a/hw/virtio/vhost-user-i2c.c b/hw/virtio/vhost-user-i2c.c > >> index 6020eee093..b930cf6d5e 100644 > >> --- a/hw/virtio/vhost-user-i2c.c > >> +++ b/hw/virtio/vhost-user-i2c.c > >> @@ -93,11 +93,7 @@ static void vu_i2c_stop(VirtIODevice *vdev) > >> static void vu_i2c_set_status(VirtIODevice *vdev, uint8_t status) > >> { > >> VHostUserI2C *i2c =3D VHOST_USER_I2C(vdev); > >> - bool should_start =3D status & VIRTIO_CONFIG_S_DRIVER_OK; > >> - > >> - if (!vdev->vm_running) { > >> - should_start =3D false; > >> - } > >> + bool should_start =3D virtio_device_started(vdev, status); > >> =20 > >> if (i2c->vhost_dev.started =3D=3D should_start) { > >> return; > >> diff --git a/hw/virtio/vhost-user-rng.c b/hw/virtio/vhost-user-rng.c > >> index 3a7bf8e32d..a9c1c4bc79 100644 > >> --- a/hw/virtio/vhost-user-rng.c > >> +++ b/hw/virtio/vhost-user-rng.c > >> @@ -90,11 +90,7 @@ static void vu_rng_stop(VirtIODevice *vdev) > >> static void vu_rng_set_status(VirtIODevice *vdev, uint8_t status) > >> { > >> VHostUserRNG *rng =3D VHOST_USER_RNG(vdev); > >> - bool should_start =3D status & VIRTIO_CONFIG_S_DRIVER_OK; > >> - > >> - if (!vdev->vm_running) { > >> - should_start =3D false; > >> - } > >> + bool should_start =3D virtio_device_started(vdev, status); > >> =20 > >> if (rng->vhost_dev.started =3D=3D should_start) { > >> return; > >> diff --git a/hw/virtio/vhost-user-vsock.c b/hw/virtio/vhost-user-vsock= .c > >> index 0f8ff99f85..22c1616ebd 100644 > >> --- a/hw/virtio/vhost-user-vsock.c > >> +++ b/hw/virtio/vhost-user-vsock.c > >> @@ -55,11 +55,7 @@ const VhostDevConfigOps vsock_ops =3D { > >> static void vuv_set_status(VirtIODevice *vdev, uint8_t status) > >> { > >> VHostVSockCommon *vvc =3D VHOST_VSOCK_COMMON(vdev); > >> - bool should_start =3D status & VIRTIO_CONFIG_S_DRIVER_OK; > >> - > >> - if (!vdev->vm_running) { > >> - should_start =3D false; > >> - } > >> + bool should_start =3D virtio_device_started(vdev, status); > >> =20 > >> if (vvc->vhost_dev.started =3D=3D should_start) { > >> return; > >> diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c > >> index 0338de892f..8031c164a5 100644 > >> --- a/hw/virtio/vhost-vsock.c > >> +++ b/hw/virtio/vhost-vsock.c > >> @@ -70,13 +70,9 @@ static int vhost_vsock_set_running(VirtIODevice *vd= ev, int start) > >> static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status) > >> { > >> VHostVSockCommon *vvc =3D VHOST_VSOCK_COMMON(vdev); > >> - bool should_start =3D status & VIRTIO_CONFIG_S_DRIVER_OK; > >> + bool should_start =3D virtio_device_started(vdev, status); > >> int ret; > >> =20 > >> - if (!vdev->vm_running) { > >> - should_start =3D false; > >> - } > >> - > >> if (vvc->vhost_dev.started =3D=3D should_start) { > >> return; > >> } > >> --=20 > >> 2.30.2 >=20 >=20 > --=20 > Alex Benn=E9e