> When vfio module is not loaded when kernel support vfio feature, the
> routine still try to open the container to get file description.
>
> This action is not safe, and of cause got error messages:
>
> EAL: Detected 40 lcore(s)
> EAL: unsupported IOMMU type!
> EAL: VFIO support could not be initialized
> EAL: Setting up memory...
>
> This may make user confuse, this patch make it reasonable and much more
> soomth to user.
>
> Signed-off-by: Michael Qiu <michael.qiu at intel.com>
> ---
> v4 --> v3:
> 1. Remove RTE_LOG for params check
> 2. Remove "vfio" module check as "vfio_iommu_type1"
> loaded indecated "vfio" loaded
>
> v3 --> v2:
> 1. Add error log in rte_eal_check_module()
> 2. Some code clean up.
>
> v2 --> v1:
> 1. Move check_module() from rte_common.h to eal_private.h
> and rename to rte_eal_check_module().
> To make it linuxapp only.
> 2. Some code clean up.
>
> lib/librte_eal/common/eal_private.h | 42
> ++++++++++++++++++++++++++++++
> lib/librte_eal/linuxapp/eal/eal_pci_vfio.c | 29 ++++++++++++++++++---
> 2 files changed, 68 insertions(+), 3 deletions(-)
>
> diff --git a/lib/librte_eal/common/eal_private.h
> b/lib/librte_eal/common/eal_private.h
> index 232fcec..e877a25 100644
> --- a/lib/librte_eal/common/eal_private.h
> +++ b/lib/librte_eal/common/eal_private.h
> @@ -35,6 +35,9 @@
> #define _EAL_PRIVATE_H_
>
> #include <stdio.h>
> +#include <string.h>
> +#include <rte_log.h>
> +#include <errno.h>
>
> /**
> * Initialize the memzone subsystem (private to eal).
> @@ -203,4 +206,43 @@ int rte_eal_alarm_init(void);
> */
> int rte_eal_dev_init(void);
>
> +/**
> + * Function is to check if the kernel module(like, vfio,
> +vfio_iommu_type1,
> + * etc.) loaded.
> + *
> + * @param module_name
> + * The module's name which need to be checked
> + *
> + * @return
> + * -1 means some error happens(NULL pointer or open failure)
> + * 0 means the module not loaded
> + * 1 means the module loaded
> + */
> +static inline int
> +rte_eal_check_module(const char *module_name) {
> + char mod_name[30]; /* Any module names can be longer than 30
> bytes? */
> + int ret = 0;
> +
> + if (NULL == module_name)
> + return -1;
> +
> + FILE * fd = fopen("/proc/modules", "r");
> + if (NULL == fd) {
> + RTE_LOG(ERR, EAL, "Open /proc/modules failed!"
> + " error %i (%s)\n", errno, strerror(errno));
> + return -1;
> + }
> + while(!feof(fd)) {
> + fscanf(fd, "%s %*[^\n]", mod_name);
> + if(!strcmp(mod_name, module_name)) {
> + ret = 1;
> + break;
> + }
> + }
> + fclose(fd);
> +
> + return ret;
> +}
> +
Apologies for not bringing this up before, but do we really want the
rte_eal_check_module inline in the header? I think it would be better to
declare it in eal_private but move the definition into eal.c.
> #endif /* _EAL_PRIVATE_H_ */
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
> b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
> index c1246e8..8c54d2a 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
> @@ -44,6 +44,7 @@
> #include <rte_tailq.h>
> #include <rte_eal_memconfig.h>
> #include <rte_malloc.h>
> +#include <eal_private.h>
>
> #include "eal_filesystem.h"
> #include "eal_pci_init.h"
> @@ -339,10 +340,15 @@ pci_vfio_get_container_fd(void)
> ret = ioctl(vfio_container_fd, VFIO_CHECK_EXTENSION,
> VFIO_TYPE1_IOMMU);
> if (ret != 1) {
> if (ret < 0)
> - RTE_LOG(ERR, EAL, " could not get IOMMU
> type, "
> - "error %i (%s)\n", errno,
> strerror(errno));
> + RTE_LOG(ERR, EAL, " could not get IOMMU
> type,"
> + " error %i (%s)\n", errno,
> + strerror(errno));
> else
> - RTE_LOG(ERR, EAL, " unsupported IOMMU
> type!\n");
> + /* Better to show the IOMMU type return
> from
> + * kernel for easy debug
> + */
> + RTE_LOG(ERR, EAL, " unsupported IOMMU
> type"
> + " detected: %d in VFIO\n", ret);
I'm not sure this message is meaningful. That ioctl call can either -1, 0 or 1.
We already handle 1 separately; -1 means an error; 0 means IOMMU type 1 is not
supported. The return value will *not* indicate which IOMMU types *are*
currently supported - it will only indicate that the IOMMU type you requested
is not supported. So there's really no point in indicating the return value in
case of ret 0 - it is best to just mention that requested IOMMU type support is
not enabled in VFIO.
> close(vfio_container_fd);
> return -1;
> }
> @@ -783,11 +789,28 @@ pci_vfio_enable(void) {
> /* initialize group list */
> int i;
> + int module_vfio_type1;
>
> for (i = 0; i < VFIO_MAX_GROUPS; i++) {
> vfio_cfg.vfio_groups[i].fd = -1;
> vfio_cfg.vfio_groups[i].group_no = -1;
> }
> +
> + module_vfio_type1 = rte_eal_check_module("vfio_iommu_type1");
> +
> + /* return error directly */
> + if (module_vfio_type1 == -1) {
> + RTE_LOG(INFO, EAL, "Could not get loaded module
> details!\n");
> + return -1;
> + }
> +
> + /* return 0 if VFIO modules not loaded */
> + if (module_vfio_type1 == 0) {
> + RTE_LOG(INFO, EAL, "VFIO modules not all loaded,"
> + " skip VFIO support ...\n");
> + return 0;
> + }
> +
> vfio_cfg.vfio_container_fd = pci_vfio_get_container_fd();
>
> /* check if we have VFIO driver enabled */
> --
> 1.9.3
