From: Jason Wang <jasowang@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>, linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v2 03/24] virtio: allow __virtioXX, __leXX in config space
Date: Wed, 5 Aug 2020 14:28:23 +0800 [thread overview]
Message-ID: <ce85a206-45a6-da3d-45a7-06f068f3bad7@redhat.com> (raw)
In-Reply-To: <20200803205814.540410-4-mst@redhat.com>
On 2020/8/4 上午4:58, Michael S. Tsirkin wrote:
> Currently all config space fields are of the type __uXX.
> This confuses people and some drivers (notably vdpa)
> access them using CPU endian-ness - which only
> works well for legacy or LE platforms.
>
> Update virtio_cread/virtio_cwrite macros to allow __virtioXX
> and __leXX field types. Follow-up patches will convert
> config space to use these types.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> include/linux/virtio_config.h | 50 +++++++++++++++++++++++++++++++++--
> 1 file changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> index 3b4eae5ac5e3..64da491936f7 100644
> --- a/include/linux/virtio_config.h
> +++ b/include/linux/virtio_config.h
> @@ -6,6 +6,7 @@
> #include <linux/bug.h>
> #include <linux/virtio.h>
> #include <linux/virtio_byteorder.h>
> +#include <linux/compiler_types.h>
> #include <uapi/linux/virtio_config.h>
>
> struct irq_affinity;
> @@ -287,12 +288,57 @@ static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
> return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
> }
>
> +/*
> + * Only the checker differentiates between __virtioXX and __uXX types. But we
> + * try to share as much code as we can with the regular GCC build.
> + */
> +#if !defined(CONFIG_CC_IS_GCC) && !defined(__CHECKER__)
> +
> +/* Not a checker - we can keep things simple */
> +#define __virtio_native_typeof(x) typeof(x)
> +
> +#else
> +
> +/*
> + * We build this out of a couple of helper macros in a vain attempt to
> + * help you keep your lunch down while reading it.
> + */
> +#define __virtio_pick_value(x, type, then, otherwise) \
> + __builtin_choose_expr(__same_type(x, type), then, otherwise)
> +
> +#define __virtio_pick_type(x, type, then, otherwise) \
> + __virtio_pick_value(x, type, (then)0, otherwise)
> +
> +#define __virtio_pick_endian(x, x16, x32, x64, otherwise) \
> + __virtio_pick_type(x, x16, __u16, \
> + __virtio_pick_type(x, x32, __u32, \
> + __virtio_pick_type(x, x64, __u64, \
> + otherwise)))
> +
> +#define __virtio_native_typeof(x) typeof( \
> + __virtio_pick_type(x, __u8, __u8, \
> + __virtio_pick_endian(x, __virtio16, __virtio32, __virtio64, \
> + __virtio_pick_endian(x, __le16, __le32, __le64, \
> + __virtio_pick_endian(x, __u16, __u32, __u64, \
> + /* No other type allowed */ \
> + (void)0)))))
> +
> +#endif
> +
> +#define __virtio_native_type(structname, member) \
> + __virtio_native_typeof(((structname*)0)->member)
> +
> +#define __virtio_typecheck(structname, member, val) \
> + /* Must match the member's type, and be integer */ \
> + typecheck(__virtio_native_type(structname, member), (val))
> +
> +
> /* Config space accessors. */
> #define virtio_cread(vdev, structname, member, ptr) \
> do { \
> might_sleep(); \
> /* Must match the member's type, and be integer */ \
> - if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
> + if (!__virtio_typecheck(structname, member, *(ptr))) \
> (*ptr) = 1; \
A silly question, compare to using set()/get() directly, what's the
value of the accessors macro here?
Thanks
> \
> switch (sizeof(*ptr)) { \
> @@ -322,7 +368,7 @@ static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
> do { \
> might_sleep(); \
> /* Must match the member's type, and be integer */ \
> - if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
> + if (!__virtio_typecheck(structname, member, *(ptr))) \
> BUG_ON((*ptr) == 1); \
> \
> switch (sizeof(*ptr)) { \
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next prev parent reply other threads:[~2020-08-05 6:28 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-03 20:58 [PATCH v2 00/24] virtio: config space endian-ness cleanup Michael S. Tsirkin
2020-08-03 20:58 ` [PATCH v2 01/24] virtio_balloon: fix sparse warning Michael S. Tsirkin
2020-08-03 21:25 ` David Hildenbrand
2020-08-04 14:16 ` Cornelia Huck
2020-08-03 20:58 ` [PATCH v2 02/24] virtio_ring: sparse warning fixup Michael S. Tsirkin
2020-08-04 14:18 ` Cornelia Huck
2020-08-03 20:58 ` [PATCH v2 03/24] virtio: allow __virtioXX, __leXX in config space Michael S. Tsirkin
2020-08-04 14:23 ` Cornelia Huck
2020-08-04 14:28 ` Michael S. Tsirkin
2020-08-05 6:28 ` Jason Wang [this message]
2020-08-05 11:45 ` Michael S. Tsirkin
2020-08-06 3:37 ` Jason Wang
2020-08-06 5:58 ` Michael S. Tsirkin
2020-08-07 3:26 ` Jason Wang
2020-08-03 20:58 ` [PATCH v2 04/24] virtio_9p: correct tags for config space fields Michael S. Tsirkin
2020-08-04 14:25 ` Cornelia Huck
2020-08-03 20:58 ` [PATCH v2 05/24] virtio_balloon: " Michael S. Tsirkin
2020-08-03 21:26 ` David Hildenbrand
2020-08-04 14:26 ` Cornelia Huck
2020-08-03 20:58 ` [PATCH v2 06/24] virtio_blk: " Michael S. Tsirkin
2020-08-04 14:29 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 07/24] virtio_console: " Michael S. Tsirkin
2020-08-04 14:31 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 08/24] virtio_crypto: " Michael S. Tsirkin
2020-08-04 14:32 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 09/24] virtio_fs: " Michael S. Tsirkin
2020-08-04 13:36 ` Vivek Goyal
2020-08-04 14:33 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 10/24] virtio_gpu: " Michael S. Tsirkin
2020-08-04 14:34 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 11/24] virtio_input: " Michael S. Tsirkin
2020-08-04 6:01 ` Gerd Hoffmann
2020-08-04 14:35 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 12/24] virtio_iommu: " Michael S. Tsirkin
2020-08-04 8:00 ` Jean-Philippe Brucker
2020-08-04 14:36 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 13/24] virtio_mem: " Michael S. Tsirkin
2020-08-03 21:23 ` David Hildenbrand
2020-08-04 14:37 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 14/24] virtio_net: " Michael S. Tsirkin
2020-08-04 14:44 ` Cornelia Huck
2020-08-05 13:26 ` Michael S. Tsirkin
2020-08-03 20:59 ` [PATCH v2 15/24] virtio_pmem: " Michael S. Tsirkin
2020-08-04 14:46 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 16/24] virtio_scsi: " Michael S. Tsirkin
2020-08-04 14:48 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 17/24] virtio_config: disallow native type fields Michael S. Tsirkin
2020-08-04 14:50 ` Cornelia Huck
2020-08-05 13:29 ` Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 18/24] mlxbf-tmfifo: sparse tags for config access Michael S. Tsirkin
2020-08-04 14:56 ` Cornelia Huck
2020-08-05 13:29 ` Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 19/24] vdpa: make sure set_features in invoked for legacy Michael S. Tsirkin
2020-08-05 6:14 ` Jason Wang
2020-08-05 11:40 ` Michael S. Tsirkin
2020-08-06 3:23 ` Jason Wang
2020-08-06 5:53 ` Michael S. Tsirkin
2020-08-06 7:27 ` Jason Wang
2020-08-06 10:00 ` Michael S. Tsirkin
2020-08-07 3:00 ` Jason Wang
2020-08-03 21:00 ` [PATCH v2 20/24] vhost/vdpa: switch to new helpers Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 21/24] virtio_vdpa: legacy features handling Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 22/24] vdpa_sim: fix endian-ness of config space Michael S. Tsirkin
2020-08-05 6:21 ` Jason Wang
2020-08-05 11:44 ` Michael S. Tsirkin
2020-08-05 12:06 ` Michael S. Tsirkin
2020-08-06 3:23 ` Jason Wang
2020-08-03 21:00 ` [PATCH v2 23/24] virtio_config: cread/write cleanup Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 24/24] virtio_config: rewrite using _Generic Michael S. Tsirkin
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