* Re: [PATCH v2 4/4] virtio_test: enable indirection feature [not found] ` <20220707024409.1869-5-qtxuning1999@sjtu.edu.cn> @ 2022-07-07 4:59 ` Michael S. Tsirkin [not found] ` <2ff418ad-0ab8-1474-4308-2d163c1e6652@sjtu.edu.cn> 0 siblings, 1 reply; 5+ messages in thread From: Michael S. Tsirkin @ 2022-07-07 4:59 UTC (permalink / raw) To: Guo Zhi; +Cc: eperezma, linux-kernel, virtualization On Thu, Jul 07, 2022 at 10:44:09AM +0800, Guo Zhi wrote: > Prior implementation don't use indirection feature because there is only > one descriptor for every io event, actually prior implementation don't > support indirection because vhost can't translate and find the indirect > descriptors. This commit enable virtio_test malloc indirect descriptors > in a indirect buffer and map this buffer to vhost, thus resolve this > problem. > > Signed-off-by: Guo Zhi <qtxuning1999@sjtu.edu.cn> > --- > tools/virtio/virtio_test.c | 50 ++++++++++++++++++++++++++++++++------ > 1 file changed, 42 insertions(+), 8 deletions(-) > > diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c > index 363695b33..dca408a5c 100644 > --- a/tools/virtio/virtio_test.c > +++ b/tools/virtio/virtio_test.c > @@ -25,7 +25,7 @@ > #define RINGSIZE 256 > #define TEST_BUF_NUM 0x100000 > #define BUF_SIZE 1024 > -/* Unused */ > +#define INDIRECTS_SIZE (RINGSIZE * sizeof(struct vring_desc) * 8) > void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end; > > struct vq_info { > @@ -47,6 +47,8 @@ struct vdev_info { > int nvqs; > void *buf; > size_t buf_size; > + void *indirects; > + size_t indirects_size; What are these exactly? > struct vhost_memory *mem; > }; > > @@ -131,6 +133,8 @@ static void vq_info_add(struct vdev_info *dev, int num) > static void vdev_info_init(struct vdev_info* dev, unsigned long long features) > { > int r; > + int nregions = 2; > + > memset(dev, 0, sizeof *dev); > dev->vdev.features = features; > INIT_LIST_HEAD(&dev->vdev.vqs); > @@ -138,19 +142,25 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features) > dev->buf_size = BUF_SIZE; > dev->buf = malloc(dev->buf_size); > assert(dev->buf); > - dev->control = open("/dev/vhost-test", O_RDWR); > + dev->indirects_size = INDIRECTS_SIZE; > + dev->indirects = malloc(dev->indirects_size); > + assert(dev->indirects); > + dev->control = open("/dev/vhost-test", O_RDWR); > assert(dev->control >= 0); > r = ioctl(dev->control, VHOST_SET_OWNER, NULL); > assert(r >= 0); > dev->mem = malloc(offsetof(struct vhost_memory, regions) + > - sizeof dev->mem->regions[0]); > + (sizeof(dev->mem->regions[0])) * nregions); > assert(dev->mem); > memset(dev->mem, 0, offsetof(struct vhost_memory, regions) + > - sizeof dev->mem->regions[0]); > - dev->mem->nregions = 1; > + (sizeof(dev->mem->regions[0])) * nregions); > + dev->mem->nregions = nregions; > dev->mem->regions[0].guest_phys_addr = (long)dev->buf; > dev->mem->regions[0].userspace_addr = (long)dev->buf; > dev->mem->regions[0].memory_size = dev->buf_size; > + dev->mem->regions[1].guest_phys_addr = (long)dev->indirects; > + dev->mem->regions[1].userspace_addr = (long)dev->indirects; > + dev->mem->regions[1].memory_size = dev->indirects_size; > r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem); > assert(r >= 0); > } > @@ -170,6 +180,19 @@ static void wait_for_interrupt(struct vdev_info *dev) > } > } > > +static int test_virtqueue_add_outbuf(struct virtqueue *vq, > + struct scatterlist *sg, unsigned int num, > + void *data, void *indirects) > +{ > + int r; > + > + __kmalloc_fake = indirects; > + r = virtqueue_add_outbuf(vq, sg, num, data, > + GFP_ATOMIC); > + __kmalloc_fake = NULL; > + return r; > +} > + Quite a hack. Please add comments with documentation. Also - no way to avoid hacks? > static void run_test(struct vdev_info *dev, struct vq_info *vq, > bool delayed, int batch, int reset_n, int bufs) > { > @@ -181,6 +204,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > unsigned len; > long long spurious = 0; > const bool random_batch = batch == RANDOM_BATCH; > + void *indirects; > > r = ioctl(dev->control, VHOST_TEST_RUN, &test); > assert(r >= 0); > @@ -188,10 +212,15 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > next_reset = INT_MAX; > } > > + /* Don't kfree indirects. */ > + __kfree_ignore_start = dev->indirects; > + __kfree_ignore_end = dev->indirects + dev->indirects_size; > + > for (;;) { > virtqueue_disable_cb(vq->vq); > completed_before = completed; > started_before = started; > + indirects = dev->indirects; > do { > const bool reset = completed > next_reset; > if (random_batch) > @@ -203,9 +232,13 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > sg_init_table(sg, sg_size); > for (int i = 0; i < sg_size; ++i) > sg_set_buf(&sg[i], dev->buf + i, 0x1); > - r = virtqueue_add_outbuf(vq->vq, sg, sg_size, > - dev->buf + started, > - GFP_ATOMIC); > + > + // use indirects buffer repeatedly C style comments please. > + if (indirects + sg_size * sizeof(struct vring_desc) > > + dev->indirects + dev->indirects_size) > + indirects = dev->indirects; > + r = test_virtqueue_add_outbuf(vq->vq, sg, sg_size, > + dev->buf + started, indirects); > if (unlikely(r != 0)) { > if (r == -ENOSPC && > started > started_before) > @@ -216,6 +249,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > } > > ++started; > + indirects += sg_size * sizeof(struct vring_desc); > } > if (unlikely(!virtqueue_kick(vq->vq))) { > r = -1; > -- > 2.17.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <2ff418ad-0ab8-1474-4308-2d163c1e6652@sjtu.edu.cn>]
* Re: [PATCH v2 4/4] virtio_test: enable indirection feature [not found] ` <2ff418ad-0ab8-1474-4308-2d163c1e6652@sjtu.edu.cn> @ 2022-07-07 5:59 ` Michael S. Tsirkin 0 siblings, 0 replies; 5+ messages in thread From: Michael S. Tsirkin @ 2022-07-07 5:59 UTC (permalink / raw) To: Guo Zhi; +Cc: eperezma, linux-kernel, virtualization On Thu, Jul 07, 2022 at 01:56:37PM +0800, Guo Zhi wrote: > On 2022/7/7 12:59, Michael S. Tsirkin wrote: > > On Thu, Jul 07, 2022 at 10:44:09AM +0800, Guo Zhi wrote: > > > Prior implementation don't use indirection feature because there is only > > > one descriptor for every io event, actually prior implementation don't > > > support indirection because vhost can't translate and find the indirect > > > descriptors. This commit enable virtio_test malloc indirect descriptors > > > in a indirect buffer and map this buffer to vhost, thus resolve this > > > problem. > > > > > > Signed-off-by: Guo Zhi <qtxuning1999@sjtu.edu.cn> > > > --- > > > tools/virtio/virtio_test.c | 50 ++++++++++++++++++++++++++++++++------ > > > 1 file changed, 42 insertions(+), 8 deletions(-) > > > > > > diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c > > > index 363695b33..dca408a5c 100644 > > > --- a/tools/virtio/virtio_test.c > > > +++ b/tools/virtio/virtio_test.c > > > @@ -25,7 +25,7 @@ > > > #define RINGSIZE 256 > > > #define TEST_BUF_NUM 0x100000 > > > #define BUF_SIZE 1024 > > > -/* Unused */ > > > +#define INDIRECTS_SIZE (RINGSIZE * sizeof(struct vring_desc) * 8) > > > void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end; > > > struct vq_info { > > > @@ -47,6 +47,8 @@ struct vdev_info { > > > int nvqs; > > > void *buf; > > > size_t buf_size; > > > + void *indirects; > > > + size_t indirects_size; > > What are these exactly? > The buffer is used to put indirect descriptors, and the buffer will be added > in the vhost iotlb through VHOST_SET_MEM_TABLE, so that vhost can translate > the descriptors in user mode correctly. Pls come up with a better name. indirect_buf and indirect_buf_size? And add a comment. > > > > > struct vhost_memory *mem; > > > }; > > > @@ -131,6 +133,8 @@ static void vq_info_add(struct vdev_info *dev, int num) > > > static void vdev_info_init(struct vdev_info* dev, unsigned long long features) > > > { > > > int r; > > > + int nregions = 2; > > > + > > > memset(dev, 0, sizeof *dev); > > > dev->vdev.features = features; > > > INIT_LIST_HEAD(&dev->vdev.vqs); > > > @@ -138,19 +142,25 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features) > > > dev->buf_size = BUF_SIZE; > > > dev->buf = malloc(dev->buf_size); > > > assert(dev->buf); > > > - dev->control = open("/dev/vhost-test", O_RDWR); > > > + dev->indirects_size = INDIRECTS_SIZE; > > > + dev->indirects = malloc(dev->indirects_size); > > > + assert(dev->indirects); > > > + dev->control = open("/dev/vhost-test", O_RDWR); > > > assert(dev->control >= 0); > > > r = ioctl(dev->control, VHOST_SET_OWNER, NULL); > > > assert(r >= 0); > > > dev->mem = malloc(offsetof(struct vhost_memory, regions) + > > > - sizeof dev->mem->regions[0]); > > > + (sizeof(dev->mem->regions[0])) * nregions); > > > assert(dev->mem); > > > memset(dev->mem, 0, offsetof(struct vhost_memory, regions) + > > > - sizeof dev->mem->regions[0]); > > > - dev->mem->nregions = 1; > > > + (sizeof(dev->mem->regions[0])) * nregions); > > > + dev->mem->nregions = nregions; > > > dev->mem->regions[0].guest_phys_addr = (long)dev->buf; > > > dev->mem->regions[0].userspace_addr = (long)dev->buf; > > > dev->mem->regions[0].memory_size = dev->buf_size; > > > + dev->mem->regions[1].guest_phys_addr = (long)dev->indirects; > > > + dev->mem->regions[1].userspace_addr = (long)dev->indirects; > > > + dev->mem->regions[1].memory_size = dev->indirects_size; > > > r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem); > > > assert(r >= 0); > > > } > > > @@ -170,6 +180,19 @@ static void wait_for_interrupt(struct vdev_info *dev) > > > } > > > } > > > +static int test_virtqueue_add_outbuf(struct virtqueue *vq, > > > + struct scatterlist *sg, unsigned int num, > > > + void *data, void *indirects) > > > +{ > > > + int r; > > > + > > > + __kmalloc_fake = indirects; > > > + r = virtqueue_add_outbuf(vq, sg, num, data, > > > + GFP_ATOMIC); > > > + __kmalloc_fake = NULL; > > > + return r; > > > +} > > > + > > Quite a hack. Please add comments with documentation. Also - no way to > > avoid hacks? > > The __kmalloc_fake is refered from vringh_test. > > If not using __kmalloc_fake here, the vhost doesn't know how to translate > the indirects descriptors(user address). > > We may could register a single region as large as the whole virtual space in > the vhost iotlb using 1:1 mapping. > > But since they are tests, IMHO, better here to use VHOST_SET_MEM_TABLE with > more regions. But why do we need to do this on each buffer add? > > > > > static void run_test(struct vdev_info *dev, struct vq_info *vq, > > > bool delayed, int batch, int reset_n, int bufs) > > > { > > > @@ -181,6 +204,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > > > unsigned len; > > > long long spurious = 0; > > > const bool random_batch = batch == RANDOM_BATCH; > > > + void *indirects; > > > r = ioctl(dev->control, VHOST_TEST_RUN, &test); > > > assert(r >= 0); > > > @@ -188,10 +212,15 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > > > next_reset = INT_MAX; > > > } > > > + /* Don't kfree indirects. */ > > > + __kfree_ignore_start = dev->indirects; > > > + __kfree_ignore_end = dev->indirects + dev->indirects_size; > > > + > > > for (;;) { > > > virtqueue_disable_cb(vq->vq); > > > completed_before = completed; > > > started_before = started; > > > + indirects = dev->indirects; > > > do { > > > const bool reset = completed > next_reset; > > > if (random_batch) > > > @@ -203,9 +232,13 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > > > sg_init_table(sg, sg_size); > > > for (int i = 0; i < sg_size; ++i) > > > sg_set_buf(&sg[i], dev->buf + i, 0x1); > > > - r = virtqueue_add_outbuf(vq->vq, sg, sg_size, > > > - dev->buf + started, > > > - GFP_ATOMIC); > > > + > > > + // use indirects buffer repeatedly > > > > C style comments please. > It will be modified. > > > > > + if (indirects + sg_size * sizeof(struct vring_desc) > > > > + dev->indirects + dev->indirects_size) > > > + indirects = dev->indirects; > > > + r = test_virtqueue_add_outbuf(vq->vq, sg, sg_size, > > > + dev->buf + started, indirects); > > > if (unlikely(r != 0)) { > > > if (r == -ENOSPC && > > > started > started_before) > > > @@ -216,6 +249,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > > > } > > > ++started; > > > + indirects += sg_size * sizeof(struct vring_desc); > > > } > > > if (unlikely(!virtqueue_kick(vq->vq))) { > > > r = -1; > > > -- > > > 2.17.1 > _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <20220707024409.1869-3-qtxuning1999@sjtu.edu.cn>]
* Re: [PATCH v2 2/4] virtio_test: move magic number in code as defined constant [not found] ` <20220707024409.1869-3-qtxuning1999@sjtu.edu.cn> @ 2022-07-07 5:09 ` Michael S. Tsirkin [not found] ` <8c15f97f-df6d-9ec5-b9d3-c42350cde887@sjtu.edu.cn> 0 siblings, 1 reply; 5+ messages in thread From: Michael S. Tsirkin @ 2022-07-07 5:09 UTC (permalink / raw) To: Guo Zhi; +Cc: eperezma, linux-kernel, virtualization On Thu, Jul 07, 2022 at 10:44:07AM +0800, Guo Zhi wrote: > We should avoid using magic numbers directly. Not necessarily. For repeated values - I guess. But this kind of thing: #define BUF_SIZE 1024 int buf_size = BUF_SIZE; brings no benefit IMHO. And this has cost - values are now removed from code. > Signed-off-by: Guo Zhi <qtxuning1999@sjtu.edu.cn> > --- > tools/virtio/virtio_test.c | 18 +++++++++++------- > 1 file changed, 11 insertions(+), 7 deletions(-) > > diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c > index 95f78b311..1ecd64271 100644 > --- a/tools/virtio/virtio_test.c > +++ b/tools/virtio/virtio_test.c > @@ -20,7 +20,10 @@ > #include "../../drivers/vhost/test.h" > > #define RANDOM_BATCH -1 > - > +#define ALIGN 4096 > +#define RINGSIZE 256 > +#define TEST_BUF_NUM 0x100000 > +#define BUF_SIZE 1024 > /* Unused */ > void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end; > > @@ -100,8 +103,8 @@ static void vq_reset(struct vq_info *info, int num, struct virtio_device *vdev) > if (info->vq) > vring_del_virtqueue(info->vq); > > - memset(info->ring, 0, vring_size(num, 4096)); > - vring_init(&info->vring, num, info->ring, 4096); > + memset(info->ring, 0, vring_size(num, ALIGN)); > + vring_init(&info->vring, num, info->ring, ALIGN); > info->vq = __vring_new_virtqueue(info->idx, info->vring, vdev, true, > false, vq_notify, vq_callback, "test"); > assert(info->vq); > @@ -115,7 +118,7 @@ static void vq_info_add(struct vdev_info *dev, int num) > info->idx = dev->nvqs; > info->kick = eventfd(0, EFD_NONBLOCK); > info->call = eventfd(0, EFD_NONBLOCK); > - r = posix_memalign(&info->ring, 4096, vring_size(num, 4096)); > + r = posix_memalign(&info->ring, PAGE_SIZE, vring_size(num, ALIGN)); > assert(r >= 0); > vq_reset(info, num, &dev->vdev); > vhost_vq_setup(dev, info); This is actually doing more than what commit log says. > @@ -131,7 +134,7 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features) > dev->vdev.features = features; > INIT_LIST_HEAD(&dev->vdev.vqs); > spin_lock_init(&dev->vdev.vqs_list_lock); > - dev->buf_size = 1024; > + dev->buf_size = BUF_SIZE; This seems to have zero added value. > dev->buf = malloc(dev->buf_size); > assert(dev->buf); > dev->control = open("/dev/vhost-test", O_RDWR); > @@ -396,7 +399,8 @@ int main(int argc, char **argv) > > done: > vdev_info_init(&dev, features); > - vq_info_add(&dev, 256); > - run_test(&dev, &dev.vqs[0], delayed, batch, reset, 0x100000); > + vq_info_add(&dev, RINGSIZE); > + > + run_test(&dev, &dev.vqs[0], delayed, batch, reset, TEST_BUF_NUM); > return 0; This replacement does not buy us anything either. > } > -- > 2.17.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <8c15f97f-df6d-9ec5-b9d3-c42350cde887@sjtu.edu.cn>]
* Re: [PATCH v2 2/4] virtio_test: move magic number in code as defined constant [not found] ` <8c15f97f-df6d-9ec5-b9d3-c42350cde887@sjtu.edu.cn> @ 2022-07-07 7:36 ` Michael S. Tsirkin 0 siblings, 0 replies; 5+ messages in thread From: Michael S. Tsirkin @ 2022-07-07 7:36 UTC (permalink / raw) To: Guo Zhi; +Cc: eperezma, linux-kernel, virtualization On Thu, Jul 07, 2022 at 02:17:19PM +0800, Guo Zhi wrote: > On 2022/7/7 13:09, Michael S. Tsirkin wrote: > > On Thu, Jul 07, 2022 at 10:44:07AM +0800, Guo Zhi wrote: > > > We should avoid using magic numbers directly. > > Not necessarily. For repeated values - I guess. > > But this kind of thing: > > > > #define BUF_SIZE 1024 > > int buf_size = BUF_SIZE; > > > > brings no benefit IMHO. > > > > And this has cost - values are now removed from code. > > Firstly, as a test, user will have to change the config to test virtio and > vhost frequently. If these magic number are put together like these, change > will be more easier. If tweaking these is useful for users we should add a command line flags as opposed to asking users to tweak code. > Secondly, many configs will be repeated, such as MAX_SG_FRAGS, even if some > varibale only appear once, subsequent upgrade of virtio_test will use these > variable in other place. For example, in this series of patch, patch 4/4 > will use RINGSIZE to set INDIRECTS_BUF_SIZE. > > > > Signed-off-by: Guo Zhi <qtxuning1999@sjtu.edu.cn> Isn't there some way to use the size we get as 1st parameter of kmalloc? > > > --- > > > tools/virtio/virtio_test.c | 18 +++++++++++------- > > > 1 file changed, 11 insertions(+), 7 deletions(-) > > > > > > diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c > > > index 95f78b311..1ecd64271 100644 > > > --- a/tools/virtio/virtio_test.c > > > +++ b/tools/virtio/virtio_test.c > > > @@ -20,7 +20,10 @@ > > > #include "../../drivers/vhost/test.h" > > > #define RANDOM_BATCH -1 > > > - > > > +#define ALIGN 4096 > > > +#define RINGSIZE 256 > > > +#define TEST_BUF_NUM 0x100000 > > > +#define BUF_SIZE 1024 > > > /* Unused */ > > > void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end; > > > @@ -100,8 +103,8 @@ static void vq_reset(struct vq_info *info, int num, struct virtio_device *vdev) > > > if (info->vq) > > > vring_del_virtqueue(info->vq); > > > - memset(info->ring, 0, vring_size(num, 4096)); > > > - vring_init(&info->vring, num, info->ring, 4096); > > > + memset(info->ring, 0, vring_size(num, ALIGN)); > > > + vring_init(&info->vring, num, info->ring, ALIGN); > > > info->vq = __vring_new_virtqueue(info->idx, info->vring, vdev, true, > > > false, vq_notify, vq_callback, "test"); > > > assert(info->vq); > > > @@ -115,7 +118,7 @@ static void vq_info_add(struct vdev_info *dev, int num) > > > info->idx = dev->nvqs; > > > info->kick = eventfd(0, EFD_NONBLOCK); > > > info->call = eventfd(0, EFD_NONBLOCK); > > > - r = posix_memalign(&info->ring, 4096, vring_size(num, 4096)); > > > + r = posix_memalign(&info->ring, PAGE_SIZE, vring_size(num, ALIGN)); > > > assert(r >= 0); > > > vq_reset(info, num, &dev->vdev); > > > vhost_vq_setup(dev, info); > > This is actually doing more than what commit log says. > > > > > @@ -131,7 +134,7 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features) > > > dev->vdev.features = features; > > > INIT_LIST_HEAD(&dev->vdev.vqs); > > > spin_lock_init(&dev->vdev.vqs_list_lock); > > > - dev->buf_size = 1024; > > > + dev->buf_size = BUF_SIZE; > > > > > > > > > This seems to have zero added value. > > > > Since the reason above and other magic number have been set as a defined > constant, change here for simplicity and consistency. > > > dev->buf = malloc(dev->buf_size); > > > assert(dev->buf); > > > dev->control = open("/dev/vhost-test", O_RDWR); > > > @@ -396,7 +399,8 @@ int main(int argc, char **argv) > > > done: > > > vdev_info_init(&dev, features); > > > - vq_info_add(&dev, 256); > > > - run_test(&dev, &dev.vqs[0], delayed, batch, reset, 0x100000); > > > + vq_info_add(&dev, RINGSIZE); > > > + > > > + run_test(&dev, &dev.vqs[0], delayed, batch, reset, TEST_BUF_NUM); > > > return 0; > > > > This replacement does not buy us anything either. > RINGSIZE will be used in other place in subsequent modification. > > > > > } > > > -- > > > 2.17.1 > _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <20220707024409.1869-4-qtxuning1999@sjtu.edu.cn>]
* Re: [PATCH v2 3/4] virtio_test: use random length scatterlists to test descriptor chain [not found] ` <20220707024409.1869-4-qtxuning1999@sjtu.edu.cn> @ 2022-07-07 5:16 ` Michael S. Tsirkin 0 siblings, 0 replies; 5+ messages in thread From: Michael S. Tsirkin @ 2022-07-07 5:16 UTC (permalink / raw) To: Guo Zhi; +Cc: eperezma, linux-kernel, virtualization On Thu, Jul 07, 2022 at 10:44:08AM +0800, Guo Zhi wrote: > Prior implementation only use one descriptor for each io event, which > does't test code of descriptor chain. More importantly, one descriptor > will not use indirect feature even indirect feature is specified. Use > random length scatterlists here to test descriptor chain. > > Signed-off-by: Guo Zhi <qtxuning1999@sjtu.edu.cn> > --- > tools/virtio/virtio_test.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c > index 1ecd64271..363695b33 100644 > --- a/tools/virtio/virtio_test.c > +++ b/tools/virtio/virtio_test.c > @@ -20,6 +20,7 @@ > #include "../../drivers/vhost/test.h" > > #define RANDOM_BATCH -1 > +#define MAX_SG_FRAGS 8UL > #define ALIGN 4096 > #define RINGSIZE 256 > #define TEST_BUF_NUM 0x100000 > @@ -172,7 +173,8 @@ static void wait_for_interrupt(struct vdev_info *dev) > static void run_test(struct vdev_info *dev, struct vq_info *vq, > bool delayed, int batch, int reset_n, int bufs) > { > - struct scatterlist sl; > + struct scatterlist sg[MAX_SG_FRAGS]; > + int sg_size = 0; > long started = 0, completed = 0, next_reset = reset_n; > long completed_before, started_before; > int r, test = 1; > @@ -197,8 +199,11 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq, > > while (started < bufs && > (started - completed) < batch) { > - sg_init_one(&sl, dev->buf, dev->buf_size); > - r = virtqueue_add_outbuf(vq->vq, &sl, 1, > + sg_size = random() % (MAX_SG_FRAGS - 1) + 1; > + sg_init_table(sg, sg_size); > + for (int i = 0; i < sg_size; ++i) > + sg_set_buf(&sg[i], dev->buf + i, 0x1); > + r = virtqueue_add_outbuf(vq->vq, sg, sg_size, > dev->buf + started, > GFP_ATOMIC); > if (unlikely(r != 0)) { random on data path is pretty expensive. I would suggest get an array size from user (and maybe a seed?) and pregenerate some numbers, then reuse. > -- > 2.17.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 5+ messages in thread
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2022-07-07 4:59 ` [PATCH v2 4/4] virtio_test: enable indirection feature Michael S. Tsirkin
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2022-07-07 5:59 ` Michael S. Tsirkin
[not found] ` <20220707024409.1869-3-qtxuning1999@sjtu.edu.cn>
2022-07-07 5:09 ` [PATCH v2 2/4] virtio_test: move magic number in code as defined constant Michael S. Tsirkin
[not found] ` <8c15f97f-df6d-9ec5-b9d3-c42350cde887@sjtu.edu.cn>
2022-07-07 7:36 ` Michael S. Tsirkin
[not found] ` <20220707024409.1869-4-qtxuning1999@sjtu.edu.cn>
2022-07-07 5:16 ` [PATCH v2 3/4] virtio_test: use random length scatterlists to test descriptor chain Michael S. Tsirkin
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