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);
>> +
>> + 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.
Thanks,
Gavin
>
>Alex
>
