On Fri, May 10, 2019 at 11:06:04AM +0200, Greg Kurz wrote:
> On Mon, 22 Apr 2019 12:32:58 +0530
> Aravinda Prasad <aravi...@linux.vnet.ibm.com> wrote:
>
> > This patch adds support in QEMU to handle "ibm,nmi-register"
> > and "ibm,nmi-interlock" RTAS calls.
> >
> > The machine check notification address is saved when the
> > OS issues "ibm,nmi-register" RTAS call.
> >
> > This patch also handles the case when multiple processors
> > experience machine check at or about the same time by
> > handling "ibm,nmi-interlock" call. In such cases, as per
> > PAPR, subsequent processors serialize waiting for the first
> > processor to issue the "ibm,nmi-interlock" call. The second
> > processor that also received a machine check error waits
> > till the first processor is done reading the error log.
> > The first processor issues "ibm,nmi-interlock" call
> > when the error log is consumed. This patch implements the
> > releasing part of the error-log while subsequent patch
> > (which builds error log) handles the locking part.
> >
> > Signed-off-by: Aravinda Prasad <aravi...@linux.vnet.ibm.com>
> > ---
> > hw/ppc/spapr.c | 18 ++++++++++++++
> > hw/ppc/spapr_rtas.c | 61
> > ++++++++++++++++++++++++++++++++++++++++++++++++
> > include/hw/ppc/spapr.h | 9 ++++++-
> > 3 files changed, 87 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index c56939a..6642cb5 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -1805,6 +1805,11 @@ static void spapr_machine_reset(void)
> > first_ppc_cpu->env.gpr[5] = 0;
> >
> > spapr->cas_reboot = false;
> > +
> > + spapr->guest_machine_check_addr = -1;
> > +
> > + /* Signal all vCPUs waiting on this condition */
> > + qemu_cond_broadcast(&spapr->mc_delivery_cond);
> > }
> >
> > static void spapr_create_nvram(SpaprMachineState *spapr)
> > @@ -2095,6 +2100,16 @@ static const VMStateDescription vmstate_spapr_dtb = {
> > },
> > };
> >
> > +static const VMStateDescription vmstate_spapr_machine_check = {
> > + .name = "spapr_machine_check",
> > + .version_id = 1,
> > + .minimum_version_id = 1,
> > + .fields = (VMStateField[]) {
> > + VMSTATE_UINT64(guest_machine_check_addr, SpaprMachineState),
> > + VMSTATE_END_OF_LIST()
> > + },
>
> This VMState descriptor is missing a .needed field because we only want
> to migrate the subsection if the guest has called NMI register, ie.
> spapr->guest_machine_check_addr != (target_ulong) -1.
>
> > +};
> > +
> > static const VMStateDescription vmstate_spapr = {
> > .name = "spapr",
> > .version_id = 3,
> > @@ -2127,6 +2142,7 @@ static const VMStateDescription vmstate_spapr = {
> > &vmstate_spapr_dtb,
> > &vmstate_spapr_cap_large_decr,
> > &vmstate_spapr_cap_ccf_assist,
> > + &vmstate_spapr_machine_check,
> > NULL
> > }
> > };
> > @@ -3068,6 +3084,8 @@ static void spapr_machine_init(MachineState *machine)
> >
> > kvmppc_spapr_enable_inkernel_multitce();
> > }
> > +
> > + qemu_cond_init(&spapr->mc_delivery_cond);
> > }
> >
> > static int spapr_kvm_type(MachineState *machine, const char *vm_type)
> > diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> > index ee24212..c2f3991 100644
> > --- a/hw/ppc/spapr_rtas.c
> > +++ b/hw/ppc/spapr_rtas.c
> > @@ -348,6 +348,39 @@ static void rtas_get_power_level(PowerPCCPU *cpu,
> > SpaprMachineState *spapr,
> > rtas_st(rets, 1, 100);
> > }
> >
> > +static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
> > + SpaprMachineState *spapr,
> > + uint32_t token, uint32_t nargs,
> > + target_ulong args,
> > + uint32_t nret, target_ulong rets)
> > +{
> > + uint64_t rtas_addr = spapr_get_rtas_addr();
> > +
> > + if (!rtas_addr) {
> > + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> > + return;
> > + }
> > +
> > + spapr->guest_machine_check_addr = rtas_ld(args, 1);
> > + rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> > +}
> > +
> > +static void rtas_ibm_nmi_interlock(PowerPCCPU *cpu,
> > + SpaprMachineState *spapr,
> > + uint32_t token, uint32_t nargs,
> > + target_ulong args,
> > + uint32_t nret, target_ulong rets)
> > +{
> > + if (!spapr->guest_machine_check_addr) {
>
> Hmm... the default value is -1. It looks like the check should rather be:
>
> if (spapr->guest_machine_check_addr == (target_ulong) -1) {
>
>
> > + /* NMI register not called */
> > + rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
> > + } else {
> > + qemu_cond_signal(&spapr->mc_delivery_cond);
> > + rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> > + }
> > +}
> > +
> > +
> > static struct rtas_call {
> > const char *name;
> > spapr_rtas_fn fn;
> > @@ -466,6 +499,30 @@ void spapr_load_rtas(SpaprMachineState *spapr, void
> > *fdt, hwaddr addr)
> > }
> > }
> >
> > +uint64_t spapr_get_rtas_addr(void)
>
> Shouldn't this be hwaddr instead of uint64_t ?
>
> > +{
> > + SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> > + int rtas_node;
> > + const struct fdt_property *rtas_addr_prop;
> > + void *fdt = spapr->fdt_blob;
> > + uint32_t rtas_addr;
> > +
> > + /* fetch rtas addr from fdt */
> > + rtas_node = fdt_path_offset(fdt, "/rtas");
> > + if (rtas_node == 0) {
> > + return 0;
> > + }
> > +
> > + rtas_addr_prop = fdt_get_property(fdt, rtas_node, "linux,rtas-base",
> > NULL);
> > + if (!rtas_addr_prop) {
>
> Just for curiosity: this is ok for linux, but what about other OSes (eg. AIX)
> ?
>
> > + return 0;
> > + }
> > +
> > + rtas_addr = fdt32_to_cpu(*(uint32_t *)rtas_addr_prop->data);
>
> Also this assumes the OS called RTAS instantiate-rtas, but some other
> OS might have called RTAS instantiate-rtas-64 instead. I guess it is
> ok for now because SLOF only provides the 32-bit variant, but a
> comment would certainly help IMHO.
I have a feeling kvm-unit-tests may not call instantiate-rtas at all.
--
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
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