From dfe44d177afc0cc56507c80b34f6f1e4e106441f Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 13 Nov 2025 17:42:05 -0500 Subject: [PATCH] vhost: switch to arrays of feature bits The current interface where caller has to know in which 64 bit chunk each bit is, is inelegant and fragile. Let's simply use arrays of bits. By using unroll macros text size grows only slightly. Message-ID: <637e182e139980e5930d50b928ba5ac072d628a9.1764225384.git.mst@redhat.com> Signed-off-by: Michael S. Tsirkin --- drivers/vhost/net.c | 19 ++++++++++--------- drivers/vhost/scsi.c | 9 ++++++--- drivers/vhost/test.c | 6 +++++- drivers/vhost/vhost.h | 42 ++++++++++++++++++++++++++++++++++-------- drivers/vhost/vsock.c | 10 ++++++---- 5 files changed, 61 insertions(+), 25 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index d057ea55f5add..f8ed39337f567 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -69,15 +69,15 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" #define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN) -static const u64 vhost_net_features[VIRTIO_FEATURES_U64S] = { - VHOST_FEATURES | - (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | - (1ULL << VIRTIO_NET_F_MRG_RXBUF) | - (1ULL << VIRTIO_F_ACCESS_PLATFORM) | - (1ULL << VIRTIO_F_RING_RESET) | - (1ULL << VIRTIO_F_IN_ORDER), - VIRTIO_BIT(VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO) | - VIRTIO_BIT(VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO), +static const int vhost_net_bits[] = { + VHOST_FEATURES, + VHOST_NET_F_VIRTIO_NET_HDR, + VIRTIO_NET_F_MRG_RXBUF, + VIRTIO_F_ACCESS_PLATFORM, + VIRTIO_F_RING_RESET, + VIRTIO_F_IN_ORDER, + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO }; enum { @@ -1720,6 +1720,7 @@ out: static long vhost_net_ioctl(struct file *f, unsigned int ioctl, unsigned long arg) { + const DEFINE_VHOST_FEATURES_ARRAY(vhost_net_features, vhost_net_bits); u64 all_features[VIRTIO_FEATURES_U64S]; struct vhost_net *n = f->private_data; void __user *argp = (void __user *)arg; diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 98e4f68f4e3cb..f43c1fe9fad9a 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -197,11 +197,14 @@ enum { }; /* Note: can't set VIRTIO_F_VERSION_1 yet, since that implies ANY_LAYOUT. */ -enum { - VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG) | - (1ULL << VIRTIO_SCSI_F_T10_PI) +static const int vhost_scsi_bits[] = { + VHOST_FEATURES, + VIRTIO_SCSI_F_HOTPLUG, + VIRTIO_SCSI_F_T10_PI }; +#define VHOST_SCSI_FEATURES VHOST_FEATURES_U64(vhost_scsi_bits, 0) + #define VHOST_SCSI_MAX_TARGET 256 #define VHOST_SCSI_MAX_IO_VQ 1024 #define VHOST_SCSI_MAX_EVENT 128 diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c index 94cd09f36f59c..1e4e36edbcd26 100644 --- a/drivers/vhost/test.c +++ b/drivers/vhost/test.c @@ -28,7 +28,11 @@ */ #define VHOST_TEST_PKT_WEIGHT 256 -#define VHOST_TEST_FEATURES VHOST_FEATURES +static const int vhost_test_bits[] = { + VHOST_FEATURES +}; + +#define VHOST_TEST_FEATURES VHOST_FEATURES_U64(vhost_test_bits, 0) enum { VHOST_TEST_VQ = 0, diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 621a6d9a8791f..c7b92730668e0 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -14,6 +14,7 @@ #include #include #include +#include struct vhost_work; struct vhost_task; @@ -279,14 +280,39 @@ void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, eventfd_signal((vq)->error_ctx);\ } while (0) -enum { - VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | - (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | - (1ULL << VIRTIO_RING_F_EVENT_IDX) | - (1ULL << VHOST_F_LOG_ALL) | - (1ULL << VIRTIO_F_ANY_LAYOUT) | - (1ULL << VIRTIO_F_VERSION_1) -}; +#define VHOST_FEATURES \ + VIRTIO_F_NOTIFY_ON_EMPTY, \ + VIRTIO_RING_F_INDIRECT_DESC, \ + VIRTIO_RING_F_EVENT_IDX, \ + VHOST_F_LOG_ALL, \ + VIRTIO_F_ANY_LAYOUT, \ + VIRTIO_F_VERSION_1 + +static inline u64 vhost_features_u64(const int *features, int size, int idx) +{ + u64 res = 0; + + unrolled_count(VIRTIO_FEATURES_BITS) + for (int i = 0; i < size; ++i) { + int bit = features[i]; + + if (virtio_features_chk_bit(bit) && VIRTIO_U64(bit) == idx) + res |= VIRTIO_BIT(bit); + } + return res; +} + +#define VHOST_FEATURES_U64(features, idx) \ + vhost_features_u64(features, ARRAY_SIZE(features), idx) + +#define DEFINE_VHOST_FEATURES_ARRAY_ENTRY(idx, features) \ + [idx] = VHOST_FEATURES_U64(features, idx), + +#define DEFINE_VHOST_FEATURES_ARRAY(array, features) \ + u64 array[VIRTIO_FEATURES_U64S] = { \ + UNROLL(VIRTIO_FEATURES_U64S, \ + DEFINE_VHOST_FEATURES_ARRAY_ENTRY, features) \ + } /** * vhost_vq_set_backend - Set backend. diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index ae01457ea2cdb..0298ddc348242 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -29,12 +29,14 @@ */ #define VHOST_VSOCK_PKT_WEIGHT 256 -enum { - VHOST_VSOCK_FEATURES = VHOST_FEATURES | - (1ULL << VIRTIO_F_ACCESS_PLATFORM) | - (1ULL << VIRTIO_VSOCK_F_SEQPACKET) +static const int vhost_vsock_bits[] = { + VHOST_FEATURES, + VIRTIO_F_ACCESS_PLATFORM, + VIRTIO_VSOCK_F_SEQPACKET }; +#define VHOST_VSOCK_FEATURES VHOST_FEATURES_U64(vhost_vsock_bits, 0) + enum { VHOST_VSOCK_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) }; -- 2.47.3