Introduce 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 introduces fwnmi-mce capability to
deal 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>
---
hw/ppc/spapr.c | 1 +
hw/ppc/spapr_caps.c | 29 +++++++++++++++++++++++++++++
include/hw/ppc/spapr.h | 4 +++-
target/ppc/kvm.c | 26 ++++++++++++++++++++++++++
target/ppc/kvm_ppc.h | 12 ++++++++++++
5 files changed, 71 insertions(+), 1 deletion(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index ea56499..8288e8b 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -4487,6 +4487,7 @@ 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_OFF;
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 481dfd2..c11ff87 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -496,6 +496,25 @@ 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()) {
+ /*
+ * TCG support may not be correct in some conditions (e.g., in case
+ * of software injected faults like duplicate SLBs).
+ */
+ warn_report("Firmware Assisted Non-Maskable Interrupts not supported
in TCG");
+ } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
+ error_setg(errp,
+"Firmware Assisted Non-Maskable Interrupts not supported by KVM, try
cap-fwnmi-mce=off");
+ }
+}
+
SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
[SPAPR_CAP_HTM] = {
.name = "htm",
@@ -595,6 +614,15 @@ 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,
@@ -734,6 +762,7 @@ 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/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 03111fd..66049ac 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -79,8 +79,10 @@ 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 8c5b1f2..8b1ab78 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -85,6 +85,7 @@ 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;
@@ -2055,6 +2056,26 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int
mpic_proxy)
}
}
+int kvmppc_set_fwnmi(void)
+{
+ PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
+ CPUState *cs = CPU(cpu);
+ int ret;
+
+ ret = kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
+ if (ret) {
+ error_report("This KVM version does not support FWNMI");
+ return ret;
+ }
+
+ /*
+ * cap_ppc_fwnmi is set when FWNMI is available and enabled in KVM
+ * and not just when FWNMI is available in KVM
+ */
+ cap_ppc_fwnmi = 1;
+ return ret;
+}
+
int kvmppc_smt_threads(void)
{
return cap_ppc_smt ? cap_ppc_smt : 1;
@@ -2355,6 +2376,11 @@ 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 98bd7d5..ce5c1f9 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_set_fwnmi(void);
+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);
@@ -159,6 +161,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu,
int mpic_proxy)
{
}
+static inline int kvmppc_set_fwnmi(void)
+{
+ return -1;
+}
+
+static inline bool kvmppc_has_cap_ppc_fwnmi(void)
+{
+ return false;
+}
+
static inline int kvmppc_smt_threads(void)
{
return 1;
