On 12/10/2014 8:17 AM, Xie, Huawei wrote:
> Hi Michael:
>
>> -----Original Message-----
>> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Qiu, Michael
>> Sent: Monday, December 08, 2014 8:28 AM
>> To: Burakov, Anatoly; dev at dpdk.org
>> Subject: Re: [dpdk-dev] [PATCH v4] VFIO: Avoid to enable vfio while the
>> module
>> not loaded
>>
>> On 2014/12/8 20:19, Burakov, Anatoly wrote:
>>>> 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);
> I see it is already discussed in the other mail that we could limit the count
> to avoid overflow.
> I don't understand why you don't apply it here.
Yes, I have reply in this thread with below:
fscanf(fd, "%30s %*[^\n]", mod_name);
> There are already several existing modules that has 20+ length.
Yes, would you think 30 length is enough? Otherwise I need to increase
the length
Thanks,
Michael
>>>> + 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.
>>
>> No need, actually, I'm very appreciate that you can spend your time to
>> review my patch again and again. I really want to say thank you to you.
>>
>> For rte_eal_check_module inline in the header, it really no need stay in
>> header, so ugly. I will make new version of it, and re-post.
>>
>>
>>>> #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.
>>
>> Yes, you are right, I make a mistake.
>>
>>>> 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
>
