On Tue, Jun 04, 2019 at 12:15:26PM +0530, Aravinda Prasad wrote: > > > On Monday 03 June 2019 08:55 PM, Greg Kurz wrote: > > On Wed, 29 May 2019 11:10:49 +0530 > > Aravinda Prasad <aravi...@linux.vnet.ibm.com> wrote: > > > >> Enable the KVM capability KVM_CAP_PPC_FWNMI so that > >> the KVM causes guest exit with NMI as exit reason > >> when it encounters a machine check exception on the > >> address belonging to a guest. Without this capability > >> enabled, KVM redirects machine check exceptions to > >> guest's 0x200 vector. > >> > >> This patch also deals with the case when a guest with > >> the KVM_CAP_PPC_FWNMI capability enabled is attempted > >> to migrate to a host that does not support this > >> capability. > >> > >> Signed-off-by: Aravinda Prasad <aravi...@linux.vnet.ibm.com> > >> --- > > > > As suggested in another mail, it may be worth introducing the sPAPR cap > > in its own patch, earlier in the series. > > Sure, also as a workaround mentioned in the reply to that mail, I am > thinking of returning RTAS_OUT_NOT_SUPPORTED to rtas nmi register call > until the entire functionality is implemented. This will help solve > spapr cap issue as well.
Not registering the RTAS call at all is the correct way to handle that
case.
>
> >
> > Anyway, I have some comments below.
> >
> >> hw/ppc/spapr.c | 1 +
> >> hw/ppc/spapr_caps.c | 24 ++++++++++++++++++++++++
> >> hw/ppc/spapr_rtas.c | 18 ++++++++++++++++++
> >> include/hw/ppc/spapr.h | 4 +++-
> >> target/ppc/kvm.c | 19 +++++++++++++++++++
> >> target/ppc/kvm_ppc.h | 12 ++++++++++++
> >> 6 files changed, 77 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> >> index c97f6a6..e8a77636 100644
> >> --- a/hw/ppc/spapr.c
> >> +++ b/hw/ppc/spapr.c
> >> @@ -4364,6 +4364,7 @@ static void spapr_machine_class_init(ObjectClass
> >> *oc, void *data)
> >> smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
> >> smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
> >> smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
> >> + smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;
> >> spapr_caps_add_properties(smc, &error_abort);
> >> smc->irq = &spapr_irq_dual;
> >> smc->dr_phb_enabled = true;
> >> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> >> index 31b4661..ef9e612 100644
> >> --- a/hw/ppc/spapr_caps.c
> >> +++ b/hw/ppc/spapr_caps.c
> >> @@ -479,6 +479,20 @@ static void cap_ccf_assist_apply(SpaprMachineState
> >> *spapr, uint8_t val,
> >> }
> >> }
> >>
> >> +static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val,
> >> + Error **errp)
> >> +{
> >> + if (!val) {
> >> + return; /* Disabled by default */
> >> + }
> >> +
> >> + if (tcg_enabled()) {
> >> + error_setg(errp, "No fwnmi support in TCG, try
> >> cap-fwnmi-mce=off");
> >
> > Maybe expand "fwnmi" to "Firmware Assisted Non-Maskable Interrupts" ?
>
> sure..
>
> >
> >> + } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
> >> + error_setg(errp, "Requested fwnmi capability not support by
> >> KVM");
> >
> > Maybe reword and add a hint:
> >
> > "KVM implementation does not support Firmware Assisted Non-Maskable
> > Interrupts, try cap-fwnmi-mce=off"
>
> sure..
>
> >
> >
> >> + }
> >> +}
> >> +
> >> SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> >> [SPAPR_CAP_HTM] = {
> >> .name = "htm",
> >> @@ -578,6 +592,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] =
> >> {
> >> .type = "bool",
> >> .apply = cap_ccf_assist_apply,
> >> },
> >> + [SPAPR_CAP_FWNMI_MCE] = {
> >> + .name = "fwnmi-mce",
> >> + .description = "Handle fwnmi machine check exceptions",
> >> + .index = SPAPR_CAP_FWNMI_MCE,
> >> + .get = spapr_cap_get_bool,
> >> + .set = spapr_cap_set_bool,
> >> + .type = "bool",
> >> + .apply = cap_fwnmi_mce_apply,
> >> + },
> >> };
> >>
> >> static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
> >> @@ -717,6 +740,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize,
> >> SPAPR_CAP_HPT_MAXPAGESIZE);
> >> SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
> >> SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
> >> SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
> >> +SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI_MCE);
> >>
> >> void spapr_caps_init(SpaprMachineState *spapr)
> >> {
> >> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> >> index e0bdfc8..91a7ab9 100644
> >> --- a/hw/ppc/spapr_rtas.c
> >> +++ b/hw/ppc/spapr_rtas.c
> >> @@ -49,6 +49,7 @@
> >> #include "hw/ppc/fdt.h"
> >> #include "target/ppc/mmu-hash64.h"
> >> #include "target/ppc/mmu-book3s-v3.h"
> >> +#include "kvm_ppc.h"
> >>
> >> static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState
> >> *spapr,
> >> uint32_t token, uint32_t nargs,
> >> @@ -358,6 +359,7 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
> >> target_ulong args,
> >> uint32_t nret, target_ulong rets)
> >> {
> >> + int ret;
> >> hwaddr rtas_addr = spapr_get_rtas_addr();
> >>
> >> if (!rtas_addr) {
> >> @@ -365,6 +367,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
> >> return;
> >> }
> >>
> >> + if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == 0) {
> >> + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> >> + return;
> >> + }
> >> +
> >> + ret = kvmppc_fwnmi_enable(cpu);
> >> + if (ret == 1) {
> >
> > I have the impression that this should really not happen,
> > otherwise something has gone terribly wrong in QEMU or
> > in KVM... this maybe deserves an error message as well ?
> > No big deal.
>
> I think so.. will add an error message.
Right, and because this is essentially a host side error,
RTAS_OUT_HW_ERROR would be more appropriate.
>
> Also I should check for non zero return value, not just ret == 1, as
> kvmppc_fwnmi_enable() returns the error value from ioctl().
>
>
> >
> >> + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> >> + return;
> >> + }
> >> +
> >> + if (ret < 0) {
> >> + rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
> >> + return;
> >> + }
> >> +
> >> spapr->guest_machine_check_addr = rtas_ld(args, 1);
> >> rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> >> }
> >> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> >> index c717ab2..bd75d4b 100644
> >> --- a/include/hw/ppc/spapr.h
> >> +++ b/include/hw/ppc/spapr.h
> >> @@ -78,8 +78,10 @@ typedef enum {
> >> #define SPAPR_CAP_LARGE_DECREMENTER 0x08
> >> /* Count Cache Flush Assist HW Instruction */
> >> #define SPAPR_CAP_CCF_ASSIST 0x09
> >> +/* FWNMI machine check handling */
> >> +#define SPAPR_CAP_FWNMI_MCE 0x0A
> >> /* Num Caps */
> >> -#define SPAPR_CAP_NUM (SPAPR_CAP_CCF_ASSIST + 1)
> >> +#define SPAPR_CAP_NUM (SPAPR_CAP_FWNMI_MCE + 1)
> >>
> >> /*
> >> * Capability Values
> >> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> >> index 39f1a73..368ec6e 100644
> >> --- a/target/ppc/kvm.c
> >> +++ b/target/ppc/kvm.c
> >> @@ -84,6 +84,7 @@ static int cap_ppc_safe_indirect_branch;
> >> static int cap_ppc_count_cache_flush_assist;
> >> static int cap_ppc_nested_kvm_hv;
> >> static int cap_large_decr;
> >> +static int cap_ppc_fwnmi;
> >>
> >> static uint32_t debug_inst_opcode;
> >>
> >> @@ -152,6 +153,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> >> kvmppc_get_cpu_characteristics(s);
> >> cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s,
> >> KVM_CAP_PPC_NESTED_HV);
> >> cap_large_decr = kvmppc_get_dec_bits();
> >> + cap_ppc_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
> >> /*
> >> * Note: setting it to false because there is not such capability
> >> * in KVM at this moment.
> >> @@ -2119,6 +2121,18 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int
> >> mpic_proxy)
> >> }
> >> }
> >>
> >> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> >> +{
> >> + CPUState *cs = CPU(cpu);
> >> +
> >> + if (!cap_ppc_fwnmi) {
> >> + return 1;
> >> + }
> >> +
> >> + return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
> >> +}
> >> +
> >> +
> >> int kvmppc_smt_threads(void)
> >> {
> >> return cap_ppc_smt ? cap_ppc_smt : 1;
> >> @@ -2419,6 +2433,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
> >> return cap_mmu_hash_v3;
> >> }
> >>
> >> +bool kvmppc_has_cap_ppc_fwnmi(void)
> >> +{
> >> + return cap_ppc_fwnmi;
> >> +}
> >> +
> >> static bool kvmppc_power8_host(void)
> >> {
> >> bool ret = false;
> >> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
> >> index 18693f1..3d9f0b4 100644
> >> --- a/target/ppc/kvm_ppc.h
> >> +++ b/target/ppc/kvm_ppc.h
> >> @@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void);
> >> void kvmppc_set_papr(PowerPCCPU *cpu);
> >> int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr);
> >> void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
> >> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu);
> >> +bool kvmppc_has_cap_ppc_fwnmi(void);
> >> int kvmppc_smt_threads(void);
> >> void kvmppc_hint_smt_possible(Error **errp);
> >> int kvmppc_set_smt_threads(int smt);
> >> @@ -160,6 +162,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU
> >> *cpu, int mpic_proxy)
> >> {
> >> }
> >>
> >> +static inline int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> >> +{
> >> + return 1;
> >> +}
> >> +
> >> +static inline bool kvmppc_has_cap_ppc_fwnmi(void)
> >> +{
> >> + return false;
> >> +}
> >> +
> >> static inline int kvmppc_smt_threads(void)
> >> {
> >> return 1;
> >>
> >>
> >
> >
>
--
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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