Quoting Gavin Shan (2015-02-15 23:32:09)
> On Mon, Feb 16, 2015 at 12:52:48PM +1100, David Gibson wrote:
> >On Mon, Feb 16, 2015 at 10:16:01AM +1100, 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
> >> callbacks sPAPRPHBClass::{eeh_set_option, eeh_get_state, eeh_reset,
> >> eeh_configure}, which are going to be used as follows:
> >>
> >> * 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 the corresponding sPAPRPHBClass callback is
> >> defined, it is called.
> >> * Those callbacks are only implemented for VFIO now. They do ioctl()
> >> to the IOMMU container fd to complete the calls. 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 | 281
> >> ++++++++++++++++++++++++++++++++++++++++++++
> >> include/hw/pci-host/spapr.h | 4 +
> >> include/hw/ppc/spapr.h | 43 ++++++-
> >> 3 files changed, 326 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> >> index cebdeb3..29b071d 100644
> >> --- a/hw/ppc/spapr_pci.c
> >> +++ b/hw/ppc/spapr_pci.c
> >> @@ -406,6 +406,268 @@ static void
> >> rtas_ibm_query_interrupt_source_number(PowerPCCPU *cpu,
> >> rtas_st(rets, 2, 1);/* 0 == level; 1 == edge */
> >> }
> >>
> >> +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)
> >> +{
> >> + sPAPRPHBState *sphb;
> >> + sPAPRPHBClass *spc;
> >> + uint32_t addr, option;
> >> + uint64_t buid;
> >> + int ret;
> >> +
> >> + if ((nargs != 4) || (nret != 1)) {
> >> + goto param_error_exit;
> >> + }
> >> +
> >> + buid = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args, 2);
> >> + addr = rtas_ld(args, 0);
> >> + option = rtas_ld(args, 3);
> >> +
> >> + sphb = find_phb(spapr, buid);
> >> + if (!sphb) {
> >> + goto param_error_exit;
> >> + }
> >> +
> >> + spc = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
> >> + if (!spc->eeh_set_option) {
> >> + goto param_error_exit;
> >> + }
> >> +
> >> + /*
> >> + * The EEH functionality is enabled on basis of PCI device,
> >> + * instead of PE. We need check the validity of the PCI
> >> + * device address.
> >> + */
> >> + if (option == RTAS_EEH_ENABLE &&
> >> + !find_dev(spapr, buid, addr)) {
> >> + goto param_error_exit;
> >> + }
> >
> >You're still breaking your layering by doing checks dependent on the
> >specific option both here and in the callback.
> >
> >What I meant by my comments on the previous version was that this
> >find_dev() test should also move into the eeh_set_option callback.
> >Obviously that means adding addr into the parameters - but surely if
> >the addr has any meaning whatsoever, it must be at least potentially
> >needed by the callback anyway.
> >
>
> Ok. Either simply dropping the check here, or moving find_dev() to
> sPAPRPHBClass::eeh_set_option() as you suggested. However, there're more
> things needed for sPAPRPHBClass::eeh_set_option() to do the check as follows.
> David, could you help to confirm which way you prefer?
>
> - Rename find_dev() to spapr_find_pci_dev() and make it public. It will be
> called in spapr_pci_vfio.c
> - Add one field sPAPRPHBState::spapr to reference the associated
> sPAPREnvironment,
> which is required by spapr_find_pci_dev(). Otherwise, we have to pass
> sPAPREnvironment
> to sPAPRPHBClass::eeh_set_option().
AFAICT spapr_pci.c:find_dev() only needs sPAPREnvironment to look up the phb
given a buid, but in your case you already have the phb and pass it on to
eeh_set_option(), so within eeh_set_option() you can call pci_find_device()
just like spapr_pci.c:find_dev() does to do the validation.
The validation seems to assume the addr value is a config_addr for the device
though, isn't it possible we might recieve a pe_addr of the form returned
by rtas_ibm_get_config_addr_info2? That value would happen to correspond to
bus:n,device:0,func:0,reg:1, and find_dev in that case would just mask off
the reg value and verify there's a device in PCI slot 0, instead of whatever
actually needs to be validated in that situation (which isn't clear to me).
>
> Thanks,
> Gavin
>
> >Apart from that,
> >
> >Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
> >
> >--
> >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
