On 16.12.14 01:31, Gavin Shan wrote:
> On Tue, Dec 16, 2014 at 01:08:52AM +0100, Alexander Graf wrote:
>>
>>
>> On 16.12.14 00:29, Gavin Shan wrote:
>>> On Tue, Dec 16, 2014 at 12:13:03AM +0100, Alexander Graf wrote:
>>>> On 16.12.14 00:08, Gavin Shan wrote:
>>>>> On Mon, Dec 15, 2014 at 03:52:17PM +0100, Alexander Graf wrote:
>>>>>> On 15.12.14 01:15, Gavin Shan wrote:
>>>>>>> The emulation for EEH RTAS requests from guest isn't covered
>>>>>>> by QEMU yet and the patch implements them.
>>>>>>>
>>>>>>> The patch defines constants used by EEH RTAS calls and adds
>>>>>>> callback sPAPRPHBClass::eeh_handler, which is going to be used
>>>>>>> this way:
>>>>>>>
>>>>>>> * RTAS calls are received in spapr_pci.c, sanity check is done
>>>>>>> there.
>>>>>>> * RTAS handlers handle what they can. If there is something it
>>>>>>> cannot handle and sPAPRPHBClass::eeh_handler callback is defined,
>>>>>>> it is called.
>>>>>>> * sPAPRPHBClass::eeh_handler is only implemented for VFIO now. It
>>>>>>> does ioctl() to the IOMMU container fd to complete the call. Error
>>>>>>> codes from that ioctl() are transferred back to the guest.
>>>>>>>
>>>>>>> [aik: defined RTAS tokens for EEH RTAS calls]
>>>>>>> Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
>>>>>>> ---
>>>>>>> hw/ppc/spapr_pci.c | 246
>>>>>>> ++++++++++++++++++++++++++++++++++++++++++++
>>>>>>> include/hw/pci-host/spapr.h | 7 ++
>>>>>>> include/hw/ppc/spapr.h | 43 +++++++-
>>>>>>> 3 files changed, 294 insertions(+), 2 deletions(-)
>>>>>>>
>>>>>>> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
>>>>>>> index 3d70efe..3bb1971 100644
>>>>>>> --- a/hw/ppc/spapr_pci.c
>>>>>>> +++ b/hw/ppc/spapr_pci.c
>>>>>>> @@ -406,6 +406,233 @@ static void
>>>>>>> rtas_ibm_query_interrupt_source_number(PowerPCCPU *cpu,
>>>>>>> rtas_st(rets, 2, 1);/* 0 == level; 1 == edge */
>>>>>>> }
>>>>>>>
>>>>>>> +static int rtas_handle_eeh_request(sPAPREnvironment *spapr,
>>>>>>> + uint64_t buid, uint32_t req,
>>>>>>> uint32_t opt)
>>>>>>> +{
>>>>>>> + sPAPRPHBState *sphb = spapr_pci_find_phb(spapr, buid);
>>>>>>> + sPAPRPHBClass *info = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
>>>>>>
>>>>>> What happens when you try to cast NULL? Could a guest process invoke a
>>>>>> host assert() through this and abort the whole VM?
>>>>>>
>>>>>
>>>>> Yes, it would cause core dump. I had one experiment to force assigning
>>>>> NULL to "sphb" before doing the cast, the whole VM is aborted. So I
>>>>> guess you're happy to have something as follows. If you're not suggesting
>>>>> something else, I'll update the code as follows in next version:
>>>>>
>>>>> sPAPRPHBState *sphb = spapr_pci_find_phb(spapr, buid);
>>>>> sPAPRPHBClass *info;
>>>>>
>>>>> if (!sphb) {
>>>>> return -ENODEV;
>>>>> }
>>>>>
>>>>> info = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
>>>>> if (!info->eeh_handler) {
>>>>> return -ENOENT;
>>>>> }
>>>>>
>>>>> return info->eeh_handler(sphb, req, opt);
>>>>
>>>> Yes, I think this is a lot safer. And yes, the other patch looks sane to
>>>> me.
>>>>
>>>
>>> Thank you for your time reviewing this. Will update in next version.
>>>
>>>>>
>>>>>>> +
>>>>>>> + if (!sphb || !info->eeh_handler) {
>>>>>>> + return -ENOENT;
>>>>>>> + }
>>>>>>> +
>>>>>>> + return info->eeh_handler(sphb, req, opt);
>>>>>>> +}
>>>>>>> +
>>>>>>> +static void rtas_ibm_set_eeh_option(PowerPCCPU *cpu,
>>>>>>> + sPAPREnvironment *spapr,
>>>>>>> + uint32_t token, uint32_t nargs,
>>>>>>> + target_ulong args, uint32_t nret,
>>>>>>> + target_ulong rets)
>>>>>>> +{
>>>>>>> + uint32_t addr, option;
>>>>>>> + uint64_t buid = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args,
>>>>>>> 2);
>>>>>>> + int ret;
>>>>>>> +
>>>>>>> + if ((nargs != 4) || (nret != 1)) {
>>>>>>> + goto param_error_exit;
>>>>>>> + }
>>>>>>> +
>>>>>>> + addr = rtas_ld(args, 0);
>>>>>>> + option = rtas_ld(args, 3);
>>>>>>> + switch (option) {
>>>>>>> + case RTAS_EEH_ENABLE:
>>>>>>> + if (!spapr_pci_find_dev(spapr, buid, addr)) {
>>>>>>> + goto param_error_exit;
>>>>>>> + }
>>>>>>> + break;
>>>>>>> + case RTAS_EEH_DISABLE:
>>>>>>> + case RTAS_EEH_THAW_IO:
>>>>>>> + case RTAS_EEH_THAW_DMA:
>>>>>>
>>>>>> So these don't use the addr hint?
>>>>>>
>>>>>
>>>>> No, there're no address as argument of this RTAS call
>>>>> "ibm,set-eeh-option".
>>>>> The RTAS call has 4 arguments, all of them are 32-bits: BUID high part,
>>>>> BUID
>>>>> low part, PE address, option. The option could be one of: enable/disable
>>>>> EEH
>>>>> functionality, enable IO path, enable DMA path.
>>>>
>>>> Well, I'm just wondering that ENABLE wants to make sure there's a device
>>>> and the others don't.
>>>>
>>>
>>> Oh, I misunderstood your question. Yes, you're correct. All options
>>> except ENABLE will have address check in rtas_handle_eeh_request()
>>> where we check on "BUID" since each PHB and PE have one-to-one
>>> relationship.
>>>
>>> ENABLE and other options are using different address: enable
>>> uses config address of one specific device, but other options use PE
>>> address. From guest's sides, it enables EEH capability on basis
>>> of PCI device and left options are supported on basis of PE. Each
>>> PE could contain one or multiple PCI devices.
>>>
>>> DISABLE option isn't used until now.
>>
>> So would DISABLE also take effect on devfn basis or would it ignore the
>> first parameter?
>>
>> If it behaves the same as ENABLE (which would be logical), please move
>> it into the same case group.
>>
>
> DISABLE takes effect on PE basis. We don't have devfn for the case and
> code needn't changes. Here's the concise procedures if DISABLE needs to be
> involved:
>
> - ENABLE on basis of PCI device
> - RTAS call "ibm,get-config-addr-info2" to get the PE address
> - DISABLE on basis of PE, with PE address as argument.
>
> If you don't have anything else, I would like to change the code and
> send new version to you. Thanks again for your time.
Sounds great :). Just wanted to double-check that the above was correct.
Alex
