On 26/04/2019 20:32, Halil Pasic wrote:
Before virtio-ccw could get away with not using DMA API for the pieces of
memory it does ccw I/O with. With protected virtualization this has to
change, since the hypervisor needs to read and sometimes also write these
pieces of memory.
The hypervisor is supposed to poke the classic notifiers, if these are
used, out of band with regards to ccw I/O. So these need to be allocated
as DMA memory (which is shared memory for protected virtualization
guests).
Let us factor out everything from struct virtio_ccw_device that needs to
be DMA memory in a satellite that is allocated as such.
Note: The control blocks of I/O instructions do not need to be shared.
These are marshalled by the ultravisor.
Signed-off-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
---
drivers/s390/virtio/virtio_ccw.c | 177 +++++++++++++++++++++------------------
1 file changed, 96 insertions(+), 81 deletions(-)
diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 1f3e7d56924f..613b18001a0c 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -46,9 +46,15 @@ struct vq_config_block {
#define VIRTIO_CCW_CONFIG_SIZE 0x100
/* same as PCI config space size, should be enough for all drivers */
+struct vcdev_dma_area {
+ unsigned long indicators;
+ unsigned long indicators2;
+ struct vq_config_block config_block;
+ __u8 status;
+};
+
struct virtio_ccw_device {
struct virtio_device vdev;
- __u8 *status;
__u8 config[VIRTIO_CCW_CONFIG_SIZE];
struct ccw_device *cdev;
__u32 curr_io;
@@ -58,24 +64,22 @@ struct virtio_ccw_device {
spinlock_t lock;
struct mutex io_lock; /* Serializes I/O requests */
struct list_head virtqueues;
- unsigned long indicators;
- unsigned long indicators2;
- struct vq_config_block *config_block;
bool is_thinint;
bool going_away;
bool device_lost;
unsigned int config_ready;
void *airq_info;
+ struct vcdev_dma_area *dma_area;
};
static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
{
- return &vcdev->indicators;
+ return &vcdev->dma_area->indicators;
}
static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
{
- return &vcdev->indicators2;
+ return &vcdev->dma_area->indicators2;
}
struct vq_info_block_legacy {
@@ -176,6 +180,22 @@ static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
return container_of(vdev, struct virtio_ccw_device, vdev);
}
+static inline void *__vc_dma_alloc(struct virtio_device *vdev, size_t size)
+{
+ return ccw_device_dma_zalloc(to_vc_device(vdev)->cdev, size);
+}
+
+static inline void __vc_dma_free(struct virtio_device *vdev, size_t size,
+ void *cpu_addr)
+{
+ return ccw_device_dma_free(to_vc_device(vdev)->cdev, cpu_addr, size);
+}
+
+#define vc_dma_alloc_struct(vdev, ptr) \
+ ({ptr = __vc_dma_alloc(vdev, sizeof(*(ptr))); })
+#define vc_dma_free_struct(vdev, ptr) \
+ __vc_dma_free(vdev, sizeof(*(ptr)), (ptr))
+
static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
{
unsigned long i, flags;
@@ -335,8 +355,7 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
struct airq_info *airq_info = vcdev->airq_info;
if (vcdev->is_thinint) {
- thinint_area = kzalloc(sizeof(*thinint_area),
- GFP_DMA | GFP_KERNEL);
+ vc_dma_alloc_struct(&vcdev->vdev, thinint_area);
if (!thinint_area)
return;
thinint_area->summary_indicator =
@@ -347,8 +366,8 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
ccw->cda = (__u32)(unsigned long) thinint_area;
} else {
/* payload is the address of the indicators */
- indicatorp = kmalloc(sizeof(indicators(vcdev)),
- GFP_DMA | GFP_KERNEL);
+ indicatorp = __vc_dma_alloc(&vcdev->vdev,
+ sizeof(indicators(vcdev)));
should be sizeof(long) ?
This is a recurrent error, but it is not an issue because the size of
the indicators is unsigned long as the size of the pointer.
Regards,
Pierre
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
