Message ID | 1577456594-22884-9-git-send-email-sughosh.ganu@linaro.org |
---|---|
State | Superseded, archived |
Delegated to: | Heinrich Schuchardt |
Headers | show |
Series | Add a random number generator uclass | expand |
On 12/27/19 3:23 PM, Sughosh Ganu wrote: > Add a driver for the virtio-rng device on the qemu platform. The > device uses pci as a transport medium. The driver can be enabled with > the following configs > > CONFIG_VIRTIO > CONFIG_DM_RNG > CONFIG_VIRTIO_PCI > CONFIG_VIRTIO_RNG > > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org> > --- > * Handle review comments from Heinrich Schuchardt to read all the > bytes requested in the individual drivers. > > drivers/virtio/Kconfig | 6 +++ > drivers/virtio/Makefile | 1 + > drivers/virtio/virtio-uclass.c | 1 + > drivers/virtio/virtio_rng.c | 87 ++++++++++++++++++++++++++++++++++++++++++ > include/virtio.h | 4 +- > 5 files changed, 98 insertions(+), 1 deletion(-) > create mode 100644 drivers/virtio/virtio_rng.c > > diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig > index a9d5fd0..2e3dd3b 100644 > --- a/drivers/virtio/Kconfig > +++ b/drivers/virtio/Kconfig > @@ -59,4 +59,10 @@ config VIRTIO_BLK > This is the virtual block driver for virtio. It can be used with > QEMU based targets. > > +config VIRTIO_RNG > + bool "virtio rng driver" > + depends on VIRTIO > + help > + This is the virtual random number generator driver. It can be used > + with Qemu based targets. > endmenu > diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile > index 4579044..dc88809 100644 > --- a/drivers/virtio/Makefile > +++ b/drivers/virtio/Makefile > @@ -9,3 +9,4 @@ obj-$(CONFIG_VIRTIO_PCI) += virtio_pci_legacy.o virtio_pci_modern.o > obj-$(CONFIG_VIRTIO_SANDBOX) += virtio_sandbox.o > obj-$(CONFIG_VIRTIO_NET) += virtio_net.o > obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o > +obj-$(CONFIG_VIRTIO_RNG) += virtio_rng.o > diff --git a/drivers/virtio/virtio-uclass.c b/drivers/virtio/virtio-uclass.c > index 34397d7..436faa4 100644 > --- a/drivers/virtio/virtio-uclass.c > +++ b/drivers/virtio/virtio-uclass.c > @@ -24,6 +24,7 @@ > static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = { > [VIRTIO_ID_NET] = VIRTIO_NET_DRV_NAME, > [VIRTIO_ID_BLOCK] = VIRTIO_BLK_DRV_NAME, > + [VIRTIO_ID_RNG] = VIRTIO_RNG_DRV_NAME, > }; > > int virtio_get_config(struct udevice *vdev, unsigned int offset, > diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c > new file mode 100644 > index 0000000..f8c10bf > --- /dev/null > +++ b/drivers/virtio/virtio_rng.c > @@ -0,0 +1,87 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Copyright (c) 2019, Linaro Limited > + */ > + > +#include <common.h> > +#include <dm.h> > +#include <rng.h> > +#include <virtio_types.h> > +#include <virtio.h> > +#include <virtio_ring.h> > + > +struct virtio_rng_priv { > + struct virtqueue *rng_vq; > +}; > + > +static int virtio_rng_read(struct udevice *dev, void *data, size_t len) > +{ > + int ret; > + unsigned int rsize = 0; > + size_t nbytes = len; > + unsigned char *buf = data; > + struct virtio_sg sg; > + struct virtio_sg *sgs[1]; > + struct virtio_rng_priv *priv = dev_get_priv(dev); > + > + if (!len) > + return 0; > + > + do { > + sg.addr = buf; As described in the response to an earlier version of the patch the address passed as sg.addr has to be 4 byte aligned because virtqueue_get_buf() internally copies u32. With qemu-system-aarch64 -M virt \ -device virtio-rng-pci,disable-legacy=on,max-bytes=15,period=1000 sg.addr will not even be 4 byte aligned if data is 4 byte aligned. So if QEMU some day will correctly emulate alignment traps this function may lead to a crash. So I would prefer to use a local variable as buffer and then copy the random bytes from the buffer to data. See suggestion below. Best regards Heinrich #define BUFFER_SIZE 16UL static int virtio_rng_read(struct udevice *dev, void *data, size_t len) { int ret; unsigned int rsize = 0; unsigned char buf[BUFFER_SIZE]; unsigned char *ptr = data; struct virtio_sg sg; struct virtio_sg *sgs = sg; struct virtio_rng_priv *priv = dev_get_priv(dev); while (len) { sg.addr = buf; sg.length = min(BUFFER_SIZE, len); ret = virtqueue_add(priv->rng_vq, &sgs, 0, 1); if (ret) return ret; virtqueue_kick(priv->rng_vq); while (!virtqueue_get_buf(priv->rng_vq, &rsize)) ; memcpy(ptr, buf, rsize); len -= rsize; ptr += rsize; } return 0; } > + sg.length = nbytes; > + sgs[0] = &sg; > + > + ret = virtqueue_add(priv->rng_vq, sgs, 0, 1); > + if (ret) > + return ret; > + > + virtqueue_kick(priv->rng_vq); > + > + while (!virtqueue_get_buf(priv->rng_vq, &rsize)) > + ; > + nbytes -= rsize; > + buf += rsize; > + } while (nbytes != 0); > + > + return 0; > +} > + > +static int virtio_rng_bind(struct udevice *dev) > +{ > + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent); > + > + /* Indicate what driver features we support */ > + virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0); > + > + return 0; > +} > + > +static int virtio_rng_probe(struct udevice *dev) > +{ > + struct virtio_rng_priv *priv = dev_get_priv(dev); > + int ret; > + > + ret = virtio_find_vqs(dev, 1, &priv->rng_vq); > + if (ret < 0) { > + debug("%s: virtio_find_vqs failed\n", __func__); > + return ret; > + } > + > + return 0; > +} > + > +static const struct dm_rng_ops virtio_rng_ops = { > + .read = virtio_rng_read, > +}; > + > +U_BOOT_DRIVER(virtio_rng) = { > + .name = VIRTIO_RNG_DRV_NAME, > + .id = UCLASS_RNG, > + .bind = virtio_rng_bind, > + .probe = virtio_rng_probe, > + .remove = virtio_reset, > + .ops = &virtio_rng_ops, > + .priv_auto_alloc_size = sizeof(struct virtio_rng_priv), > + .flags = DM_FLAG_ACTIVE_DMA, > +}; > diff --git a/include/virtio.h b/include/virtio.h > index 654fdf1..561dcc3 100644 > --- a/include/virtio.h > +++ b/include/virtio.h > @@ -22,10 +22,12 @@ > > #define VIRTIO_ID_NET 1 /* virtio net */ > #define VIRTIO_ID_BLOCK 2 /* virtio block */ > -#define VIRTIO_ID_MAX_NUM 3 > +#define VIRTIO_ID_RNG 4 /* virtio rng */ > +#define VIRTIO_ID_MAX_NUM 5 > > #define VIRTIO_NET_DRV_NAME "virtio-net" > #define VIRTIO_BLK_DRV_NAME "virtio-blk" > +#define VIRTIO_RNG_DRV_NAME "virtio-rng" > > /* Status byte for guest to report progress, and synchronize features */ > >
On 12/28/19 7:09 AM, Heinrich Schuchardt wrote: > #define BUFFER_SIZE 16UL > > static int virtio_rng_read(struct udevice *dev, void *data, size_t len) > { > int ret; > unsigned int rsize = 0; > unsigned char buf[BUFFER_SIZE]; This should be unsigned char buf[BUFFER_SIZE] __aligned(4); > unsigned char *ptr = data; > struct virtio_sg sg; > struct virtio_sg *sgs = sg; > struct virtio_rng_priv *priv = dev_get_priv(dev); > > while (len) { > sg.addr = buf; > sg.length = min(BUFFER_SIZE, len); > > ret = virtqueue_add(priv->rng_vq, &sgs, 0, 1); > if (ret) > return ret; > > virtqueue_kick(priv->rng_vq); > > while (!virtqueue_get_buf(priv->rng_vq, &rsize)) > ; > memcpy(ptr, buf, rsize); > len -= rsize; > ptr += rsize; > } > > return 0; > }
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index a9d5fd0..2e3dd3b 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -59,4 +59,10 @@ config VIRTIO_BLK This is the virtual block driver for virtio. It can be used with QEMU based targets. +config VIRTIO_RNG + bool "virtio rng driver" + depends on VIRTIO + help + This is the virtual random number generator driver. It can be used + with Qemu based targets. endmenu diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 4579044..dc88809 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_VIRTIO_PCI) += virtio_pci_legacy.o virtio_pci_modern.o obj-$(CONFIG_VIRTIO_SANDBOX) += virtio_sandbox.o obj-$(CONFIG_VIRTIO_NET) += virtio_net.o obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o +obj-$(CONFIG_VIRTIO_RNG) += virtio_rng.o diff --git a/drivers/virtio/virtio-uclass.c b/drivers/virtio/virtio-uclass.c index 34397d7..436faa4 100644 --- a/drivers/virtio/virtio-uclass.c +++ b/drivers/virtio/virtio-uclass.c @@ -24,6 +24,7 @@ static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = { [VIRTIO_ID_NET] = VIRTIO_NET_DRV_NAME, [VIRTIO_ID_BLOCK] = VIRTIO_BLK_DRV_NAME, + [VIRTIO_ID_RNG] = VIRTIO_RNG_DRV_NAME, }; int virtio_get_config(struct udevice *vdev, unsigned int offset, diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c new file mode 100644 index 0000000..f8c10bf --- /dev/null +++ b/drivers/virtio/virtio_rng.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <rng.h> +#include <virtio_types.h> +#include <virtio.h> +#include <virtio_ring.h> + +struct virtio_rng_priv { + struct virtqueue *rng_vq; +}; + +static int virtio_rng_read(struct udevice *dev, void *data, size_t len) +{ + int ret; + unsigned int rsize = 0; + size_t nbytes = len; + unsigned char *buf = data; + struct virtio_sg sg; + struct virtio_sg *sgs[1]; + struct virtio_rng_priv *priv = dev_get_priv(dev); + + if (!len) + return 0; + + do { + sg.addr = buf; + sg.length = nbytes; + sgs[0] = &sg; + + ret = virtqueue_add(priv->rng_vq, sgs, 0, 1); + if (ret) + return ret; + + virtqueue_kick(priv->rng_vq); + + while (!virtqueue_get_buf(priv->rng_vq, &rsize)) + ; + nbytes -= rsize; + buf += rsize; + } while (nbytes != 0); + + return 0; +} + +static int virtio_rng_bind(struct udevice *dev) +{ + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent); + + /* Indicate what driver features we support */ + virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0); + + return 0; +} + +static int virtio_rng_probe(struct udevice *dev) +{ + struct virtio_rng_priv *priv = dev_get_priv(dev); + int ret; + + ret = virtio_find_vqs(dev, 1, &priv->rng_vq); + if (ret < 0) { + debug("%s: virtio_find_vqs failed\n", __func__); + return ret; + } + + return 0; +} + +static const struct dm_rng_ops virtio_rng_ops = { + .read = virtio_rng_read, +}; + +U_BOOT_DRIVER(virtio_rng) = { + .name = VIRTIO_RNG_DRV_NAME, + .id = UCLASS_RNG, + .bind = virtio_rng_bind, + .probe = virtio_rng_probe, + .remove = virtio_reset, + .ops = &virtio_rng_ops, + .priv_auto_alloc_size = sizeof(struct virtio_rng_priv), + .flags = DM_FLAG_ACTIVE_DMA, +}; diff --git a/include/virtio.h b/include/virtio.h index 654fdf1..561dcc3 100644 --- a/include/virtio.h +++ b/include/virtio.h @@ -22,10 +22,12 @@ #define VIRTIO_ID_NET 1 /* virtio net */ #define VIRTIO_ID_BLOCK 2 /* virtio block */ -#define VIRTIO_ID_MAX_NUM 3 +#define VIRTIO_ID_RNG 4 /* virtio rng */ +#define VIRTIO_ID_MAX_NUM 5 #define VIRTIO_NET_DRV_NAME "virtio-net" #define VIRTIO_BLK_DRV_NAME "virtio-blk" +#define VIRTIO_RNG_DRV_NAME "virtio-rng" /* Status byte for guest to report progress, and synchronize features */
Add a driver for the virtio-rng device on the qemu platform. The device uses pci as a transport medium. The driver can be enabled with the following configs CONFIG_VIRTIO CONFIG_DM_RNG CONFIG_VIRTIO_PCI CONFIG_VIRTIO_RNG Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org> --- * Handle review comments from Heinrich Schuchardt to read all the bytes requested in the individual drivers. drivers/virtio/Kconfig | 6 +++ drivers/virtio/Makefile | 1 + drivers/virtio/virtio-uclass.c | 1 + drivers/virtio/virtio_rng.c | 87 ++++++++++++++++++++++++++++++++++++++++++ include/virtio.h | 4 +- 5 files changed, 98 insertions(+), 1 deletion(-) create mode 100644 drivers/virtio/virtio_rng.c