similar to: [PATCH v3 1/7] virtio-gpu: add virtio_gpu_queue_ctrl_buffer_locked

Add virtio_gpu_queue_ctrl_buffer_locked function, which does the same as virtio_gpu_queue_ctrl_buffer but does not take the virtqueue lock. The caller must hold the lock instead. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git

Add virtio_gpu_queue_ctrl_buffer_locked function, which does the same as virtio_gpu_queue_ctrl_buffer but does not take the virtqueue lock. The caller must hold the lock instead. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git

Add virtio_gpu_queue_ctrl_buffer_nolock function, which does the same as virtio_gpu_queue_ctrl_buffer but does not take the virtqueue lock. The caller must hold the lock instead. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git

Add virtio_gpu_queue_ctrl_buffer_nolock function, which does the same as virtio_gpu_queue_ctrl_buffer but does not take the virtqueue lock. The caller must hold the lock instead. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git

Userspace requested command buffer allocations could be too large to make as a contiguous allocation. Use vmalloc if necessary to satisfy those allocations. Signed-off-by: David Riley <davidriley at chromium.org> --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 4 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 114 ++++++++++++++++++++----- 2 files changed, 96 insertions(+), 22 deletions(-)

Userspace requested command buffer allocations could be too large to make as a contiguous allocation. Use vmalloc if necessary to satisfy those allocations. Signed-off-by: David Riley <davidriley at chromium.org> --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 4 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 114 ++++++++++++++++++++----- 2 files changed, 96 insertions(+), 22 deletions(-)

Split virtqueue_kick() call into virtqueue_kick_prepare(), which requires serialization, and virtqueue_notify(), which does not. Move the virtqueue_notify() call out of the critical section protected by the queue lock. This avoids triggering a vmexit while holding the lock and thereby fixes a rather bad spinlock contention. Suggested-by: Chia-I Wu <olvaffe at gmail.com> Signed-off-by:

Userspace requested command buffer allocations could be too large to make as a contiguous allocation. Use vmalloc if necessary to satisfy those allocations. Signed-off-by: David Riley <davidriley at chromium.org> --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 4 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 78 +++++++++++++++++++++++--- 2 files changed, 72 insertions(+), 10 deletions(-)

Make the queue functions return void, none of the call sites checks the return value. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 41 ++++++++++------------------- 1 file changed, 14 insertions(+), 27 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 7ac20490e1b4..ca91e83ffaef 100644

Add helper function to handle the submission of fenced control requests. Make sure we initialize the fence while holding the virtqueue lock, so requests can't be reordered. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_fence.c | 2 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 40 +++++++++++++++++++++++++++++----- 2 files changed, 35

Add helper function to handle the submission of fenced control requests. Make sure we initialize the fence while holding the virtqueue lock, so requests can't be reordered. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_fence.c | 2 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 40 +++++++++++++++++++++++++++++----- 2 files changed, 35

Add helper function to handle the submission of fenced control requests. Make sure we initialize the fence while holding the virtqueue lock, so requests can't be reordered. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_fence.c | 2 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 40 +++++++++++++++++++++++++++++----- 2 files changed, 35

Add helper function to handle the submission of fenced control requests. Make sure we initialize the fence while holding the virtqueue lock, so requests can't be reordered. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_fence.c | 2 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 40 +++++++++++++++++++++++++++++----- 2 files changed, 35

Userspace requested command buffer allocations could be too large to make as a contiguous allocation. Use vmalloc if necessary to satisfy those allocations. Signed-off-by: David Riley <davidriley at chromium.org> --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 4 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 79 +++++++++++++++++++++++--- 2 files changed, 73 insertions(+), 10 deletions(-)

Factor function in preparation to generating scatterlist prior to locking. Signed-off-by: David Riley <davidriley at chromium.org> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 981ee16e3ee9..bf5a4a50b002 100644 ---

Factor function in preparation to generating scatterlist prior to locking. Signed-off-by: David Riley <davidriley at chromium.org> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 981ee16e3ee9..bf5a4a50b002 100644 ---

virtio_gpu_queue_ctrl_buffer_locked is called with ctrlq.qlock taken, it releases and acquires this lock. This causes a sparse warning. Add appropriate annotations for sparse context checking. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c

Factor function in preparation to generating scatterlist prior to locking. Signed-off-by: David Riley <davidriley at chromium.org> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 7fd2851f7b97..5a64c776138d 100644 ---

In case queuing virtio commands fails (can happen when the device got unplugged) pass up the error. Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_vq.c | 36 +++++++++++++++-------------- 1 file changed, 19 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index

Replace virtqueue_kick by virtqueue_kick_prepare, which requires serialization, and virtqueue_notify, which does not. Repurpose the return values to indicate whether the vq should be notified. This fixes a lock contention with qemu host. When the guest calls vibad rtqueue_notify, the qemu vcpu thread exits the guest and waits for the qemu iothread to perform the MMIO. If the qemu iothread is