[dpdk-dev] [RFC v1 1/1] vfio: set vf token and gain vf device access
Vamsi Krishna Attunuru
vattunuru at marvell.com
Fri Apr 10 09:28:29 CEST 2020
Hi Wang,
> -----Original Message-----
> From: dev <dev-bounces at dpdk.org> On Behalf Of Wang, Haiyue
> Sent: Thursday, April 2, 2020 6:13 PM
> To: Vamsi Krishna Attunuru <vattunuru at marvell.com>; dev at dpdk.org
> Cc: Jerin Jacob Kollanukkaran <jerinj at marvell.com>;
> alex.williamson at redhat.com; thomas at monjalon.net;
> david.marchand at redhat.com
> Subject: Re: [dpdk-dev] [RFC v1 1/1] vfio: set vf token and gain vf device
> access
>
> Hi A Vamsi,
>
> > -----Original Message-----
> > From: dev <dev-bounces at dpdk.org> On Behalf Of vattunuru at marvell.com
> > Sent: Thursday, March 5, 2020 12:33
> > To: dev at dpdk.org
> > Cc: jerinj at marvell.com; alex.williamson at redhat.com;
> > thomas at monjalon.net; david.marchand at redhat.com; Vamsi Attunuru
> > <vattunuru at marvell.com>
> > Subject: [dpdk-dev] [RFC v1 1/1] vfio: set vf token and gain vf device
> > access
> >
> > From: Vamsi Attunuru <vattunuru at marvell.com>
> >
> > vfio-pci driver enables virtual function access from the DPDK
> > applications when those vf device's physical function is also bound to
> > vfio driver.
> >
> > Patch adds the required configuration and checks to enable DPDK
> > applications to access both pf and it's vf devices through vfio-pci
> > driver.
> >
> > See background on vf token scheme in linux vfio driver.
> > https://urldefense.proofpoint.com/v2/url?u=http-3A__patches.dpdk.org_c
> >
> over_65915_&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=2rpxxNF2qeP02g
> VZIWTVrW
> > -6zNZz5-
> uKt9pRqpR_M3U&m=1z1lwkWphoVghrYUNLI304mER44Vei152GYrXBwn4kk&
> s=
> > tvJ4Li8zpLMbp_p3vKQL7QV09DttNcl70YAr6BVHZm8&e=
> >
> > When a physical function is enabled with non-zero virtual functions,
> > patch sets the UUID using VFIO_DEVICE_FEATURE ioctl from physical
> > function's file descriptor. Same UUID is used to gain the access for
> > the virtual functions on those physical function.
> >
> > Following changes required on top of this DPDK patch
> > * Kernel version check for VFIO_DEVICE_FEATURE ioctl
> > * Use uuid gen API to generate UUID.
> >
> > Signed-off-by: Vamsi Attunuru <vattunuru at marvell.com>
> >
> > diff --git a/lib/librte_eal/linux/eal/eal_vfio.c
> > b/lib/librte_eal/linux/eal/eal_vfio.c
> > index 01b5ef3..e2fdd35 100644
> > --- a/lib/librte_eal/linux/eal/eal_vfio.c
> > +++ b/lib/librte_eal/linux/eal/eal_vfio.c
> > @@ -12,6 +12,7 @@
> > #include <rte_log.h>
> > #include <rte_memory.h>
> > #include <rte_eal_memconfig.h>
> > +#include <rte_uuid.h>
> > #include <rte_vfio.h>
> >
> > #include "eal_filesystem.h"
> > @@ -50,6 +51,9 @@ struct vfio_config {
> > struct user_mem_maps mem_maps;
> > };
> >
> > +rte_uuid_t uuid_token = RTE_UUID_INIT(0xf8615163, 0xdf3e, 0x46c5,
> > + 0x913f, 0xf2d2f965ed0eULL);
> > +
> > /* per-process VFIO config */
> > static struct vfio_config vfio_cfgs[VFIO_MAX_CONTAINERS]; static
> > struct vfio_config *default_vfio_cfg = &vfio_cfgs[0]; @@ -657,6
> > +661,102 @@ rte_vfio_clear_group(int vfio_group_fd)
> > return 0;
> > }
> >
> > +static bool
> > +rte_vfio_dev_is_physfn(const char *sysfs_base, const char *dev_addr)
> > +{
> > + char linkname[PATH_MAX];
> > + char filename[PATH_MAX];
> > + int ret;
> > +
> > + memset(linkname, 0, sizeof(linkname));
> > + memset(filename, 0, sizeof(filename));
> > +
> > + /* check if physfn directory exist for this device */
> > + snprintf(linkname, sizeof(linkname),
> > + "%s/%s/physfn", sysfs_base, dev_addr);
> > +
> > + ret = readlink(linkname, filename, sizeof(filename));
> > +
> > + /* For PFs, physfn directory does not exist */
> > + if (ret < 0)
> > + return true;
> > +
> > + return false;
> > +}
> > +
> > +static int
> > +is_vf_token_required(const char *sysfs_base, const char *dev_addr) {
> > + char *tok[16], *physfn, *physfn_drv;
> > + char linkname[PATH_MAX];
> > + char filename[PATH_MAX];
> > + int ret;
> > +
> > + memset(linkname, 0, sizeof(linkname));
> > + memset(filename, 0, sizeof(filename));
> > +
> > + snprintf(linkname, sizeof(linkname),
> > + "%s/%s/physfn", sysfs_base, dev_addr);
> > +
> > + ret = readlink(linkname, filename, sizeof(filename));
> > + if (ret < 0)
> > + return -1;
> > +
> > + ret = rte_strsplit(filename, sizeof(filename),
> > + tok, RTE_DIM(tok), '/');
> > + if (ret <= 0) {
> > + RTE_LOG(ERR, EAL, " %s cannot get it's physfn\n", dev_addr);
> > + return -1;
> > + }
> > +
> > + physfn = tok[ret - 1];
> > +
> > + snprintf(linkname, sizeof(linkname),
> > + "/sys/bus/pci/devices/%s/driver", physfn);
> > + ret = readlink(linkname, filename, sizeof(filename));
> > + if (ret < 0)
> > + return -1;
> > +
> > + ret = rte_strsplit(filename, sizeof(filename),
> > + tok, RTE_DIM(tok), '/');
> > + if (ret <= 0) {
> > + RTE_LOG(ERR, EAL, " %s cannot get it's physfn driver info\n",
> > + dev_addr);
> > + return -1;
> > + }
> > +
> > + physfn_drv = tok[ret - 1];
> > +
> > + if (strncmp(physfn_drv, "vfio-pci", sizeof("vfio-pci")))
> > + return 1;
> > +
> > + /* physfn is bound to vfio-pci */
> > + return 0;
> > +}
> > +
>
> Based on Alex's vfio for qemu patch
> (https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__lore.kernel.org_lkml_20200204161737.34696b91-
> 40w520.home_&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=2rpxxNF2qeP0
> 2gVZIWTVrW-6zNZz5-
> uKt9pRqpR_M3U&m=1z1lwkWphoVghrYUNLI304mER44Vei152GYrXBwn4kk&
> s=0pgRda84NrL2omZa0mn-ufSEzKksSi440O2AYImZLaI&e= ), and understand
> the SR-IOV design by reading your RFC, I scratched a simple design.
Thanks, looks good to me, I guess now it serves the QEMU based use cases as well.
>
> 1. ./usertools/dpdk-devbind.py -b vfio-pci 0000:87:00.0 2. echo 2 >
> /sys/bus/pci/devices/0000:87:00.0/sriov_numvfs
> 3. ./x86_64-native-linux-gcc/app/testpmd -l 22-25 -n 4 -w
> 87:00.0,vf_token=2ab74924-c335-45f4-9b16-8569e5b08258 --file-prefix=pf --
> -i
>
> If no token in VF:
> ./x86_64-native-linux-gcc/app/testpmd -l 26-29 -n 4 -w 87:02.0 --file-
> prefix=vf1 -- -i
> Kernel error: vfio-pci 0000:87:02.0: VF token required to access device
>
> ./x86_64-native-linux-gcc/app/testpmd -l 26-29 -n 4 -w
> 87:02.0,vf_token=2ab74924-c335-45f4-9b16-8569e5b08258 --file-prefix=vf1 -
> - -i
>
>
> static int
> vfio_pci_vf_token_arg_handler(__rte_unused const char *key,
> const char *value, void *opaque) {
> if (rte_uuid_parse(value, opaque)) {
> RTE_LOG(ERR, EAL,
> "The VF token is not a valid uuid : %s\n", value);
> return -1;
> }
>
> return 0;
> }
>
> static int
> vfio_pci_vf_token_arg(struct rte_devargs *devargs, rte_uuid_t uu) {
> const char *key = "vf_token";
> struct rte_kvargs *kvlist;
> int ret = 0;
>
> if (devargs == NULL)
> return 0;
>
> kvlist = rte_kvargs_parse(devargs->args, NULL);
> if (kvlist == NULL)
> return 0;
>
> if (!rte_kvargs_count(kvlist, key))
> goto exit;
>
> if (rte_kvargs_process(kvlist, key,
> vfio_pci_vf_token_arg_handler, uu) < 0)
> goto exit;
>
> ret = 1;
>
> exit:
> rte_kvargs_free(kvlist);
> return ret;
> }
>
>
>
> static int
> pci_vfio_map_resource_primary(struct rte_pci_device *dev) {
> struct vfio_device_info device_info = { .argsz = sizeof(device_info) };
> + rte_uuid_t vf_token = RTE_UUID_INIT(0, 0, 0, 0, 0ULL);
> char pci_addr[PATH_MAX] = {0};
> int vfio_dev_fd;
> struct rte_pci_addr *loc = &dev->addr; @@ -668,8 +712,9 @@
> pci_vfio_map_resource_primary(struct rte_pci_device *dev)
> snprintf(pci_addr, sizeof(pci_addr), PCI_PRI_FMT,
> loc->domain, loc->bus, loc->devid, loc->function);
>
> + vfio_pci_vf_token_arg(dev->device.devargs, vf_token);
> ret = rte_vfio_setup_device(rte_pci_get_sysfs_path(), pci_addr,
> - &vfio_dev_fd, &device_info);
> + &vfio_dev_fd, &device_info,
> vf_token);
> if (ret)
> return ret;
>
>
> int
> rte_vfio_setup_device(const char *sysfs_base, const char *dev_addr,
> - int *vfio_dev_fd, struct vfio_device_info *device_info)
> + int *vfio_dev_fd, struct vfio_device_info *device_info,
> + rte_uuid_t vf_token)
> {
> struct vfio_group_status group_status = {
> .argsz = sizeof(group_status)
> @@ -712,6 +713,7 @@ rte_vfio_setup_device(const char *sysfs_base, const
> char *dev_addr,
> int vfio_container_fd;
> int vfio_group_fd;
> int iommu_group_num;
> + char dev[PATH_MAX];
> int i, ret;
>
> /* get group number */
> @@ -895,8 +897,19 @@ rte_vfio_setup_device(const char *sysfs_base,
> const char *dev_addr,
> t->type_id, t->name);
> }
>
> + if (!rte_uuid_is_null(vf_token)) {
> + char vf_token_str[PATH_MAX];
> +
> + rte_uuid_unparse(vf_token, vf_token_str,
> sizeof(vf_token_str));
> + snprintf(dev, sizeof(dev),
> + "%s vf_token=%s", dev_addr, vf_token_str);
> + } else {
> + snprintf(dev, sizeof(dev),
> + "%s", dev_addr);
> + }
> +
> /* get a file descriptor for the device */
> - *vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD,
> dev_addr);
> + *vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD,
> dev);
>
>
>
> > +static bool
> > +rte_vfio_dev_has_nonzero_numvfs(const char *sysfs_base, const char
> > +*dev_addr) {
> > + char linkname[PATH_MAX];
> > + unsigned long num_vfs;
> > + int ret;
> > +
> > + if (!rte_vfio_dev_is_physfn(sysfs_base, dev_addr))
> > + return false;
> > +
> > + memset(linkname, 0, sizeof(linkname));
> > +
> > + snprintf(linkname, sizeof(linkname),
> > + "%s/%s/sriov_numvfs", sysfs_base, dev_addr);
> > +
> > + ret = eal_parse_sysfs_value(linkname, &num_vfs);
> > +
> > + if ((ret < 0) || (num_vfs == 0))
> > + return false;
> > +
> > + return true;
> > +}
> > +
> > int
> > rte_vfio_setup_device(const char *sysfs_base, const char *dev_addr,
> > int *vfio_dev_fd, struct vfio_device_info *device_info) @@ -
> 669,6
> > +769,7 @@ rte_vfio_setup_device(const char *sysfs_base, const char
> *dev_addr,
> > int vfio_container_fd;
> > int vfio_group_fd;
> > int iommu_group_num;
> > + char dev[PATH_MAX];
> > int i, ret;
> >
> > /* get group number */
> > @@ -683,6 +784,29 @@ rte_vfio_setup_device(const char *sysfs_base,
> const char *dev_addr,
> > if (ret < 0)
> > return -1;
> >
> > + snprintf(dev, sizeof(dev), "%s", dev_addr);
> > +
> > + if (!rte_vfio_dev_is_physfn(sysfs_base, dev_addr)) {
> > + char vf_token[PATH_MAX];
> > + /*
> > + * Check if vf_token is required or not,
> > + * vf_token is required when the VF's physfn is
> > + * binded with vfio-pci driver
> > + */
> > + ret = is_vf_token_required(sysfs_base, dev_addr);
> > + /* if negative, something failed */
> > + if (ret < 0)
> > + return -1;
> > +
> > + if (ret == 0) {
> > + /* vf_token required to open device file descriptor */
> > + rte_uuid_unparse(uuid_token,
> > + vf_token, sizeof(vf_token));
> > + snprintf(dev, sizeof(dev),
> > + "%s vf_token=%s", dev_addr, vf_token);
> > + }
> > + }
> > +
> > /* get the actual group fd */
> > vfio_group_fd = rte_vfio_get_group_fd(iommu_group_num);
> > if (vfio_group_fd < 0)
> > @@ -853,7 +977,7 @@ rte_vfio_setup_device(const char *sysfs_base,
> const char *dev_addr,
> > }
> >
> > /* get a file descriptor for the device */
> > - *vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD,
> dev_addr);
> > + *vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD,
> dev);
> > if (*vfio_dev_fd < 0) {
> > /* if we cannot get a device fd, this implies a problem with
> > * the VFIO group or the container not having IOMMU
> configured.
> > @@ -877,6 +1001,31 @@ rte_vfio_setup_device(const char *sysfs_base,
> const char *dev_addr,
> > rte_vfio_clear_group(vfio_group_fd);
> > return -1;
> > }
> > +
> > + if (rte_vfio_dev_has_nonzero_numvfs(sysfs_base, dev_addr)) {
> #define
> > +VF_TOKEN (sizeof(struct vfio_device_feature) + sizeof(rte_uuid_t))
> > +
> > + struct vfio_device_feature *vf_token;
> > + uint8_t local[VF_TOKEN];
> > +
> > + memset(local, 0, VF_TOKEN);
> > + vf_token = (struct vfio_device_feature *)local;
> > + vf_token->argsz = VF_TOKEN;
> > + vf_token->flags = VFIO_DEVICE_FEATURE_SET |
> > +
> VFIO_DEVICE_FEATURE_PCI_VF_TOKEN;
> > +
> > + memcpy(local + sizeof(struct vfio_device_feature),
> > + &uuid_token, sizeof(uuid_token));
> > +
> > + ret = ioctl(*vfio_dev_fd, VFIO_DEVICE_FEATURE, vf_token);
> > + if (ret) {
> > + RTE_LOG(ERR, EAL, " Failed to set UUID on %s "
> > + "error %i (%s)\n", dev_addr, errno,
> > + strerror(errno));
> > + return -1;
> > + }
> > + }
> > +
> > vfio_group_device_get(vfio_group_fd);
> >
> > return 0;
> > --
> > 2.8.4
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