Commit ec010c00 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by David Gibson
Browse files

ppc/spapr: KVM FWNMI should not be enabled until guest requests it 



The KVM FWNMI capability should be enabled with the "ibm,nmi-register"
rtas call. Although MCEs from KVM will be delivered as architected
interrupts to the guest before "ibm,nmi-register" is called, KVM has
different behaviour depending on whether the guest has enabled FWNMI
(it attempts to do more recovery on behalf of a non-FWNMI guest).

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Message-Id: <20200325142906.221248-2-npiggin@gmail.com>
Reviewed-by: default avatarGreg Kurz <groug@kaod.org>
Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
parent 79178edd

hw/ppc/spapr_caps.c

+4 −3
Original line number Diff line number Diff line
@@ -517,9 +517,10 @@ static void cap_fwnmi_apply(SpaprMachineState *spapr, uint8_t val, 
    }



    if (kvm_enabled()) {

        if (kvmppc_set_fwnmi() < 0) {

            error_setg(errp, "Firmware Assisted Non-Maskable Interrupts(FWNMI) "

                             "not supported by KVM");

        if (!kvmppc_get_fwnmi()) {

            error_setg(errp,

"Firmware Assisted Non-Maskable Interrupts(FWNMI) not supported by KVM.");

            error_append_hint(errp, "Try appending -machine cap-fwnmi=off\n");

        }

    }

}

hw/ppc/spapr_rtas.c

+7 −0
Original line number Diff line number Diff line
@@ -437,6 +437,13 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu, 
        return;

    }



    if (kvm_enabled()) {

        if (kvmppc_set_fwnmi() < 0) {

            rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);

            return;

        }

    }



    spapr->fwnmi_system_reset_addr = sreset_addr;

    spapr->fwnmi_machine_check_addr = mce_addr;

target/ppc/kvm.c

+7 −0
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ 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_fwnmi;



static uint32_t debug_inst_opcode;
@@ -136,6 +137,7 @@ 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_fwnmi = kvm_vm_check_extension(s, KVM_CAP_PPC_FWNMI);

    /*

     * Note: setting it to false because there is not such capability

     * in KVM at this moment.
@@ -2064,6 +2066,11 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy) 
    }

}



bool kvmppc_get_fwnmi(void)

{

    return cap_fwnmi;

}



int kvmppc_set_fwnmi(void)

{

    PowerPCCPU *cpu = POWERPC_CPU(first_cpu);

target/ppc/kvm_ppc.h

+6 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 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);

bool kvmppc_get_fwnmi(void);

int kvmppc_set_fwnmi(void);

int kvmppc_smt_threads(void);

void kvmppc_error_append_smt_possible_hint(Error *const *errp);
@@ -163,6 +164,11 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy) 
{

}



static inline bool kvmppc_get_fwnmi(void)

{

    return false;

}



static inline int kvmppc_set_fwnmi(void)

{

    return -1;