Re: [PATCH v3 2/2] drivers/vfio: Support EEH error injection

David Gibson
2015-03-24T01:30:13Z

[-- Attachment #1: Type: text/plain, Size: 13107 bytes --]

On Tue, Mar 24, 2015 at 09:47:54AM +1100, Gavin Shan wrote:
> On Mon, Mar 23, 2015 at 10:14:59AM -0600, Alex Williamson wrote:
> >On Mon, 2015-03-23 at 16:20 +1100, Gavin Shan wrote:
> >> On Mon, Mar 23, 2015 at 04:10:20PM +1100, David Gibson wrote:
> >> >On Mon, Mar 23, 2015 at 04:03:59PM +1100, Gavin Shan wrote:
> >> >> On Mon, Mar 23, 2015 at 02:43:03PM +1100, David Gibson wrote:
> >> >> >On Mon, Mar 23, 2015 at 12:56:36PM +1100, Gavin Shan wrote:
> >> >> >> On Mon, Mar 23, 2015 at 12:39:45PM +1100, David Gibson wrote:
> >> >> >> >On Sat, Mar 21, 2015 at 06:58:45AM +1100, Gavin Shan wrote:
> >> >> >> >> The patch adds one more EEH sub-command (VFIO_EEH_PE_INJECT_ERR)
> >> >> >> >> to inject the specified EEH error, which is represented by
> >> >> >> >> (struct vfio_eeh_pe_err), to the indicated PE for testing purpose.
> >> >> >> >>
> >> >> >> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> >> >> >> >
> >> >> >> >Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> >> >> >> >
> >> >> >> >> ---
> >> >> >> >> Documentation/vfio.txt | 12 ++++++++++++
> >> >> >> >> drivers/vfio/vfio_spapr_eeh.c | 10 ++++++++++
> >> >> >> >> include/uapi/linux/vfio.h | 36 +++++++++++++++++++++++++++++++++++-
> >> >> >> >> 3 files changed, 57 insertions(+), 1 deletion(-)
> >> >> >> >>
> >> >> >> >> diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
> >> >> >> >> index 96978ec..c6e11a3 100644
> >> >> >> >> --- a/Documentation/vfio.txt
> >> >> >> >> +++ b/Documentation/vfio.txt
> >> >> >> >> @@ -385,6 +385,18 @@ The code flow from the example above should be slightly changed:
> >> >> >> >>
> >> >> >> >> ....
> >> >> >> >>
> >> >> >> >> + /* Inject EEH error, which is expected to be caused by 32-bits
> >> >> >> >> + * config load.
> >> >> >> >> + */
> >> >> >> >> + pe_op.op = VFIO_EEH_PE_INJECT_ERR;
> >> >> >> >> + pe_op.err.type = VFIO_EEH_ERR_TYPE_32;
> >> >> >> >> + pe_op.err.func = VFIO_EEH_ERR_FUNC_LD_CFG_ADDR;
> >> >> >> >> + pe_op.err.addr = 0ul;
> >> >> >> >> + pe_op.err.mask = 0ul;
> >> >> >> >> + ioctl(container, VFIO_EEH_PE_OP, &pe_op);
> >> >> >> >> +
> >> >> >> >> + ....
> >> >> >> >> +
> >> >> >> >> /* When 0xFF's returned from reading PCI config space or IO BARs
> >> >> >> >> * of the PCI device. Check the PE's state to see if that has been
> >> >> >> >> * frozen.
> >> >> >> >> diff --git a/drivers/vfio/vfio_spapr_eeh.c b/drivers/vfio/vfio_spapr_eeh.c
> >> >> >> >> index 5fa42db..38edeb4 100644
> >> >> >> >> --- a/drivers/vfio/vfio_spapr_eeh.c
> >> >> >> >> +++ b/drivers/vfio/vfio_spapr_eeh.c
> >> >> >> >> @@ -85,6 +85,16 @@ long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
> >> >> >> >> case VFIO_EEH_PE_CONFIGURE:
> >> >> >> >> ret = eeh_pe_configure(pe);
> >> >> >> >> break;
> >> >> >> >> + case VFIO_EEH_PE_INJECT_ERR:
> >> >> >> >> + minsz = offsetofend(struct vfio_eeh_pe_op, err.mask);
> >> >> >> >> + if (op.argsz < minsz)
> >> >> >> >> + return -EINVAL;
> >> >> >> >> + if (copy_from_user(&op, (void __user *)arg, minsz))
> >> >> >> >> + return -EFAULT;
> >> >> >> >> +
> >> >> >> >> + ret = eeh_pe_inject_err(pe, op.err.type, op.err.func,
> >> >> >> >> + op.err.addr, op.err.mask);
> >> >> >> >> + break;
> >> >> >> >> default:
> >> >> >> >> ret = -EINVAL;
> >> >> >> >> }
> >> >> >> >> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> >> >> >> >> index 82889c3..f68e962 100644
> >> >> >> >> --- a/include/uapi/linux/vfio.h
> >> >> >> >> +++ b/include/uapi/linux/vfio.h
> >> >> >> >> @@ -468,12 +468,23 @@ struct vfio_iommu_spapr_tce_info {
> >> >> >> >> * - unfreeze IO/DMA for frozen PE;
> >> >> >> >> * - read PE state;
> >> >> >> >> * - reset PE;
> >> >> >> >> - * - configure PE.
> >> >> >> >> + * - configure PE;
> >> >> >> >> + * - inject EEH error.
> >> >> >> >> */
> >> >> >> >> +struct vfio_eeh_pe_err {
> >> >> >> >> + __u32 type;
> >> >> >> >> + __u32 func;
> >> >> >> >> + __u64 addr;
> >> >> >> >> + __u64 mask;
> >> >> >> >> +};
> >> >> >> >> +
> >> >> >> >> struct vfio_eeh_pe_op {
> >> >> >> >> __u32 argsz;
> >> >> >> >> __u32 flags;
> >> >> >> >> __u32 op;
> >> >> >> >> + union {
> >> >> >> >> + struct vfio_eeh_pe_err err;
> >> >> >> >> + };
> >> >> >> >> };
> >> >> >> >>
> >> >> >> >> #define VFIO_EEH_PE_DISABLE 0 /* Disable EEH functionality */
> >> >> >> >> @@ -490,6 +501,29 @@ struct vfio_eeh_pe_op {
> >> >> >> >> #define VFIO_EEH_PE_RESET_HOT 6 /* Assert hot reset */
> >> >> >> >> #define VFIO_EEH_PE_RESET_FUNDAMENTAL 7 /* Assert fundamental reset */
> >> >> >> >> #define VFIO_EEH_PE_CONFIGURE 8 /* PE configuration */
> >> >> >> >> +#define VFIO_EEH_PE_INJECT_ERR 9 /* Inject EEH error */
> >> >> >> >> +#define VFIO_EEH_ERR_TYPE_32 0 /* 32-bits EEH error type */
> >> >> >> >> +#define VFIO_EEH_ERR_TYPE_64 1 /* 64-bits EEH error type */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_LD_MEM_ADDR 0 /* Memory load */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_LD_MEM_DATA 1
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_LD_IO_ADDR 2 /* IO load */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_LD_IO_DATA 3
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_LD_CFG_ADDR 4 /* Config load */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_LD_CFG_DATA 5
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_ST_MEM_ADDR 6 /* Memory store */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_ST_MEM_DATA 7
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_ST_IO_ADDR 8 /* IO store */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_ST_IO_DATA 9
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_ST_CFG_ADDR 10 /* Config store */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_ST_CFG_DATA 11
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_DMA_RD_ADDR 12 /* DMA read */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_DMA_RD_DATA 13
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_DMA_RD_MASTER 14
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_DMA_RD_TARGET 15
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_DMA_WR_ADDR 16 /* DMA write */
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_DMA_WR_DATA 17
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_DMA_WR_MASTER 18
> >> >> >> >> +#define VFIO_EEH_ERR_FUNC_DMA_WR_TARGET 19
> >> >> >> >
> >> >> >> >These all seem to duplicate (under slightly different names) the
> >> >> >> >defines you just added in arch/powerpc/include/asm/eeh.h. It would
> >> >> >> >make more sense to only have the uapi copy, surely.
> >> >> >> >
> >> >> >>
> >> >> >> David, Thanks for your time. The defines in eeh.h is used not only
> >> >> >> for mapping those constants defined in vfio.h, but also for validating
> >> >> >> arguments from debugfs entry "err_injct". So it'd better to keep
> >> >> >> them separate: one set is used by userspace, another set is used
> >> >> >> by host kernel.
> >> >> >
> >> >> >I don't understand why this is an argument for duplicating them. They
> >> >> >have the same meanings and values, why can't you use the uapi versions
> >> >> >everywhere?
> >> >> >
> >> >>
> >> >> We can drop the constants defined in eeh.h and just use those defines
> >> >> in vfio.h. But I prefer separate constants for some ovbious reasons
> >> >> except the one I mentioned above :)
> >> >>
> >> >> - We already had separate sets of constants for EEH and VFIO. For example,
> >> >> VFIO_EEH_PE_STATE_* in include/uapi/vfio.h always have counter part in
> >> >> arch/powerpc/asm/include/eeh.h
> >> >
> >> >Oh.. I see your point.
> >> >
> >> >Yes, the EEH internal code shouldn't need to use the VFIO defined
> >> >constants.
> >> >
> >> >But it's still silly to duplicate, I think the correct think would be
> >> >to expose the EEH constants in uapi, and use those for VFIO as well.
> >> >
> >>
> >> I'm not sure. If Alex.W agree on this, I can have one patch to address
> >> it in future :-)
> >
> >I agree with David, there should be a uapi eeh header and the vfio
> >documentation should define that as the valid set of functions.
> >
> >> >> - The UAPI interface is expected to be stable, or back-compatible when
> >> >> introducing changes to it. The defines (at least their names) in eeh.h
> >> >> doesn't have to be stable.
> >> >
> >> >But is there any reason not to make them stable. The VFIO case shows
> >> >that we need to lock down an interface somewhere. I don't see that
> >> >there's an advantage to having a not locked down interface in addition
> >> >to a locked down one.
> >> >
> >>
> >> I was saying that the UAPI interace should be stable. I don't see
> >> there're any reasons the UAPI interface will be changed in near
> >> future :)
> >
> >When I asked previously whether a translation layer was needed between
> >the vfio uapi and kernel internal eeh api I was told that the values
> >were defined by the spapr spec and therefore not changeable. If that's
> >true, we shouldn't need to worry about exporting them via uapi. Thanks,
> >
>
> Well. It sounds a good idea. I'll add one separate patch, which would be
> PATCH[3/3] in next revision to address it. Currently, there are not
> too much constants, which can be put into arch/powerpc/include/uapi/asm/eeh.h.
> The following list are the candidates from include/api/vfio.h, which can be
> moved to uapi/asm/eeh.h. The names of those constants will be changed from
> "VFIO_EEH_*" to "EEH_*" and then user space will have some code as folows
> to use them. That looks a bit weird. Do we really want moving those constants
> to uapi/asm/eeh.h and rename them accordingly?

I think so, yes. I think the patch series will be cleaner if you do
the exporting of the EEH constants in 1/3 then build your other
patches on top of that.

> #include <stdio.h>
> #include <sys/ioctl.h>
> #include <eeh.h>
> #include <vfio.h>
>
> struct vfio_eeh_pe_op pe_op = { .argsz = sizeof(pe_op), .flags = 0 };
>
> pe_op.op = VFIO_EEH_PE_INJECT_ERR; /* Its prefix is "VFIO_EEH_* */
> pe_op.err.type = EEH_ERR_TYPE_32; /* It starts with "EEH_*" */

I think that's fine.

> pe_op.err.func = EEH_ERR_FUNC_LD_CFG_ADDR;
> pe_op.err.addr = 0ul;
> pe_op.err.mask = 0ul;
> ioctl(container, VFIO_EEH_PE_OP, &pe_op);
>
> ---
>
> #define VFIO_EEH_PE_STATE_NORMAL 0 /* PE in functional state */
> #define VFIO_EEH_PE_STATE_RESET 1 /* PE reset in progress */
> #define VFIO_EEH_PE_STATE_STOPPED 2 /* Stopped DMA and IO */
> #define VFIO_EEH_PE_STATE_STOPPED_DMA 4 /* Stopped DMA only */
> #define VFIO_EEH_PE_STATE_UNAVAIL 5 /* State unavailable */
>
> #define VFIO_EEH_ERR_TYPE_32 0 /* 32-bits EEH error type */
> #define VFIO_EEH_ERR_TYPE_64 1 /* 64-bits EEH error type */
> #define VFIO_EEH_ERR_FUNC_LD_MEM_ADDR 0 /* Memory load */
> #define VFIO_EEH_ERR_FUNC_LD_MEM_DATA 1
> #define VFIO_EEH_ERR_FUNC_LD_IO_ADDR 2 /* IO load */
> #define VFIO_EEH_ERR_FUNC_LD_IO_DATA 3
> #define VFIO_EEH_ERR_FUNC_LD_CFG_ADDR 4 /* Config load */
> #define VFIO_EEH_ERR_FUNC_LD_CFG_DATA 5
> #define VFIO_EEH_ERR_FUNC_ST_MEM_ADDR 6 /* Memory store */
> #define VFIO_EEH_ERR_FUNC_ST_MEM_DATA 7
> #define VFIO_EEH_ERR_FUNC_ST_IO_ADDR 8 /* IO store */
> #define VFIO_EEH_ERR_FUNC_ST_IO_DATA 9
> #define VFIO_EEH_ERR_FUNC_ST_CFG_ADDR 10 /* Config store */
> #define VFIO_EEH_ERR_FUNC_ST_CFG_DATA 11
> #define VFIO_EEH_ERR_FUNC_DMA_RD_ADDR 12 /* DMA read */
> #define VFIO_EEH_ERR_FUNC_DMA_RD_DATA 13
> #define VFIO_EEH_ERR_FUNC_DMA_RD_MASTER 14
> #define VFIO_EEH_ERR_FUNC_DMA_RD_TARGET 15
> #define VFIO_EEH_ERR_FUNC_DMA_WR_ADDR 16 /* DMA write */
> #define VFIO_EEH_ERR_FUNC_DMA_WR_DATA 17
> #define VFIO_EEH_ERR_FUNC_DMA_WR_MASTER 18
> #define VFIO_EEH_ERR_FUNC_DMA_WR_TARGET 19
>
> Thanks,
> Gavin
>
> >Alex
> >
> >> >> - I would like keep the code between EEH/VFIO independent to each other
> >> >> enough.
> >> >>
> >> >> Thanks,
> >> >> Gavin
> >> >>
> >> >> >> By the way, Alex Williamson, could you please ACK this if you don't
> >> >> >> find obvious errors in the patch. I really want this to be merged
> >> >> >> to 4.1.
> >> >> >>
> >> >> >> Thanks,
> >> >> >> Gavin
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >
> >> >>
> >> >>
> >> >
> >>
> >>
> >
> >
> >
> >_______________________________________________
> >Linuxppc-dev mailing list
> >Linuxppc-dev@lists.ozlabs.org
> >https://lists.ozlabs.org/listinfo/linuxppc-dev
>

--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]