From: Jason Wang <jasowang@redhat.com> To: Eli Cohen <elic@nvidia.com> Cc: mst@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, netdev@vger.kernel.org, eli@mellanox.com Subject: Re: [PATCH V2 3/4] vp_vdpa: allow set vq state to initial state after reset Date: Wed, 2 Jun 2021 15:05:35 +0800 [thread overview] Message-ID: <091dc6d0-8754-7b2a-64ec-985ef9db6329@redhat.com> (raw) In-Reply-To: <20210602061324.GA8662@mtl-vdi-166.wap.labs.mlnx> 在 2021/6/2 下午2:13, Eli Cohen 写道: > On Wed, Jun 02, 2021 at 10:10:42AM +0800, Jason Wang wrote: >> We used to fail the set_vq_state() since it was not supported yet by >> the virtio spec. But if the bus tries to set the state which is equal >> to the device initial state after reset, we can let it go. >> >> This is a must for virtio_vdpa() to set vq state during probe which is >> required for some vDPA parents. >> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> drivers/vdpa/virtio_pci/vp_vdpa.c | 42 ++++++++++++++++++++++++++++--- >> 1 file changed, 39 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c >> index c76ebb531212..18bf4a422772 100644 >> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c >> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c >> @@ -210,13 +210,49 @@ static int vp_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 qid, >> return -EOPNOTSUPP; >> } >> >> +static int vp_vdpa_set_vq_state_split(struct vdpa_device *vdpa, >> + const struct vdpa_vq_state *state) >> +{ >> + const struct vdpa_vq_state_split *split = &state->split; >> + >> + if (split->avail_index == 0) >> + return 0; >> + >> + return -EOPNOTSUPP; >> +} >> + >> +static int vp_vdpa_set_vq_state_packed(struct vdpa_device *vdpa, >> + const struct vdpa_vq_state *state) >> +{ >> + const struct vdpa_vq_state_packed *packed = &state->packed; >> + >> + if (packed->last_avail_counter == 1 && > Can you elaborate on the requirement on last_avail_counter and > last_used_counter? This is required by the virtio spec: " 2.7.1 Driver and Device Ring Wrap Counters Each of the driver and the device are expected to maintain, internally, a single-bit ring wrap counter initialized to 1. " For virtio-pci device, since there's no way to assign the value of those counters, the counters will be reset to 1 after reset, otherwise the driver can't work. Thanks > >> + packed->last_avail_idx == 0 && >> + packed->last_used_counter == 1 && >> + packed->last_used_idx == 0) >> + return 0; >> + >> + return -EOPNOTSUPP; >> +} >> + >> static int vp_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid, >> const struct vdpa_vq_state *state) >> { >> - /* Note that this is not supported by virtio specification, so >> - * we return -ENOPOTSUPP here. This means we can't support live >> - * migration, vhost device start/stop. >> + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); >> + >> + /* Note that this is not supported by virtio specification. >> + * But if the state is by chance equal to the device initial >> + * state, we can let it go. >> */ >> + if ((vp_modern_get_status(mdev) & VIRTIO_CONFIG_S_FEATURES_OK) && >> + !vp_modern_get_queue_enable(mdev, qid)) { >> + if (vp_modern_get_driver_features(mdev) & >> + BIT_ULL(VIRTIO_F_RING_PACKED)) >> + return vp_vdpa_set_vq_state_packed(vdpa, state); >> + else >> + return vp_vdpa_set_vq_state_split(vdpa, state); >> + } >> + >> return -EOPNOTSUPP; >> } >> >> -- >> 2.25.1 >>
WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com> To: Eli Cohen <elic@nvidia.com> Cc: kvm@vger.kernel.org, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, eli@mellanox.com Subject: Re: [PATCH V2 3/4] vp_vdpa: allow set vq state to initial state after reset Date: Wed, 2 Jun 2021 15:05:35 +0800 [thread overview] Message-ID: <091dc6d0-8754-7b2a-64ec-985ef9db6329@redhat.com> (raw) In-Reply-To: <20210602061324.GA8662@mtl-vdi-166.wap.labs.mlnx> 在 2021/6/2 下午2:13, Eli Cohen 写道: > On Wed, Jun 02, 2021 at 10:10:42AM +0800, Jason Wang wrote: >> We used to fail the set_vq_state() since it was not supported yet by >> the virtio spec. But if the bus tries to set the state which is equal >> to the device initial state after reset, we can let it go. >> >> This is a must for virtio_vdpa() to set vq state during probe which is >> required for some vDPA parents. >> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> drivers/vdpa/virtio_pci/vp_vdpa.c | 42 ++++++++++++++++++++++++++++--- >> 1 file changed, 39 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c >> index c76ebb531212..18bf4a422772 100644 >> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c >> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c >> @@ -210,13 +210,49 @@ static int vp_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 qid, >> return -EOPNOTSUPP; >> } >> >> +static int vp_vdpa_set_vq_state_split(struct vdpa_device *vdpa, >> + const struct vdpa_vq_state *state) >> +{ >> + const struct vdpa_vq_state_split *split = &state->split; >> + >> + if (split->avail_index == 0) >> + return 0; >> + >> + return -EOPNOTSUPP; >> +} >> + >> +static int vp_vdpa_set_vq_state_packed(struct vdpa_device *vdpa, >> + const struct vdpa_vq_state *state) >> +{ >> + const struct vdpa_vq_state_packed *packed = &state->packed; >> + >> + if (packed->last_avail_counter == 1 && > Can you elaborate on the requirement on last_avail_counter and > last_used_counter? This is required by the virtio spec: " 2.7.1 Driver and Device Ring Wrap Counters Each of the driver and the device are expected to maintain, internally, a single-bit ring wrap counter initialized to 1. " For virtio-pci device, since there's no way to assign the value of those counters, the counters will be reset to 1 after reset, otherwise the driver can't work. Thanks > >> + packed->last_avail_idx == 0 && >> + packed->last_used_counter == 1 && >> + packed->last_used_idx == 0) >> + return 0; >> + >> + return -EOPNOTSUPP; >> +} >> + >> static int vp_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid, >> const struct vdpa_vq_state *state) >> { >> - /* Note that this is not supported by virtio specification, so >> - * we return -ENOPOTSUPP here. This means we can't support live >> - * migration, vhost device start/stop. >> + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); >> + >> + /* Note that this is not supported by virtio specification. >> + * But if the state is by chance equal to the device initial >> + * state, we can let it go. >> */ >> + if ((vp_modern_get_status(mdev) & VIRTIO_CONFIG_S_FEATURES_OK) && >> + !vp_modern_get_queue_enable(mdev, qid)) { >> + if (vp_modern_get_driver_features(mdev) & >> + BIT_ULL(VIRTIO_F_RING_PACKED)) >> + return vp_vdpa_set_vq_state_packed(vdpa, state); >> + else >> + return vp_vdpa_set_vq_state_split(vdpa, state); >> + } >> + >> return -EOPNOTSUPP; >> } >> >> -- >> 2.25.1 >> _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2021-06-02 7:05 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-02 2:10 [PATCH V2 0/4] Jason Wang 2021-06-02 2:10 ` Jason Wang 2021-06-02 2:10 ` [PATCH V2 1/4] vdpa: support packed virtqueue for set/get_vq_state() Jason Wang 2021-06-02 2:10 ` Jason Wang 2021-06-02 2:10 ` [PATCH V2 2/4] virtio-pci library: introduce vp_modern_get_driver_features() Jason Wang 2021-06-02 2:10 ` Jason Wang 2021-06-02 2:10 ` [PATCH V2 3/4] vp_vdpa: allow set vq state to initial state after reset Jason Wang 2021-06-02 2:10 ` Jason Wang 2021-06-02 6:13 ` Eli Cohen 2021-06-02 7:05 ` Jason Wang [this message] 2021-06-02 7:05 ` Jason Wang 2021-06-02 7:42 ` Eli Cohen 2021-06-02 2:10 ` [PATCH V2 4/4] virtio/vdpa: clear the virtqueue state during probe Jason Wang 2021-06-02 2:10 ` Jason Wang 2021-06-02 6:17 ` Eli Cohen 2021-06-02 7:07 ` Jason Wang 2021-06-02 7:07 ` Jason Wang 2021-06-02 7:43 ` Eli Cohen 2021-06-02 2:15 ` [PATCH V2 0/4] Jason Wang 2021-06-02 2:15 ` Jason Wang
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