We introduce a datatype for a tolerance with respect to a given cpreg migration issue. The tolerance applies to a given cpreg kvm index, and can be of different types: - ToleranceNotOnBothEnds (cpreg index is allowed to be only on one end) - ToleranceDiffInMask (value differences are allowed only within a mask) - ToleranceFieldLT (incoming field value must be less than a given value) - ToleranceFieldGT (incoming field value must be greater than a given value)
A QLIST of such tolerances can be populated using a new helper: arm_register_cpreg_mig_tolerance() and arm_cpu_cpreg_has_mig_tolerance() allows to check whether a tolerance exists for a given kvm index. callers for those helpers will be introduced in subsequent patches. Signed-off-by: Eric Auger <[email protected]> --- target/arm/cpu.h | 32 +++++++++++++++++++++ target/arm/cpu.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 107 insertions(+) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 657ff4ab20b..9dcc838f611 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -843,6 +843,21 @@ struct ARMELChangeHook { QLIST_ENTRY(ARMELChangeHook) node; }; +typedef enum { + ToleranceNotOnBothEnds, + ToleranceDiffInMask, + ToleranceFieldLT, + ToleranceFieldGT, +} ARMCPUCPREGMigToleranceType; + +typedef struct ARMCPUCPREGMigTolerance { + uint64_t kvmidx; + uint64_t mask; + uint64_t value; + ARMCPUCPREGMigToleranceType type; + QLIST_ENTRY(ARMCPUCPREGMigTolerance) node; +} ARMCPUCPREGMigTolerance; + /* These values map onto the return values for * QEMU_PSCI_0_2_FN_AFFINITY_INFO */ typedef enum ARMPSCIState { @@ -1139,6 +1154,7 @@ struct ArchCPU { QLIST_HEAD(, ARMELChangeHook) pre_el_change_hooks; QLIST_HEAD(, ARMELChangeHook) el_change_hooks; + QLIST_HEAD(, ARMCPUCPREGMigTolerance) cpreg_mig_tolerances; int32_t node_id; /* NUMA node this CPU belongs to */ @@ -2632,6 +2648,22 @@ void arm_register_pre_el_change_hook(ARMCPU *cpu, ARMELChangeHookFn *hook, void arm_register_el_change_hook(ARMCPU *cpu, ARMELChangeHookFn *hook, void *opaque); +/** + * arm_register_cpreg_mig_tolerance: + * Register a migration tolerance wrt one given cpreg identified by its + * @kvmidx. Only one tolerance can be registered by kvm reg idx. + */ +void arm_register_cpreg_mig_tolerance(ARMCPU *cpu, uint64_t kvmidx, + uint64_t mask, uint64_t value, + ARMCPUCPREGMigToleranceType type); + +/** + * arm_cpu_cpreg_has_mig_tolerance: + * Check whether a tolerance of type @type exists for a given @kvmidx + */ +bool arm_cpu_cpreg_has_mig_tolerance(ARMCPU *cpu, uint64_t kvmidx, + uint64_t vmstate_value, uint64_t local_value, + ARMCPUCPREGMigToleranceType type); /** * arm_rebuild_hflags: * Rebuild the cached TBFLAGS for arbitrary changed processor state. diff --git a/target/arm/cpu.c b/target/arm/cpu.c index 10f8280eef2..167f78cee13 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -181,6 +181,75 @@ void arm_register_el_change_hook(ARMCPU *cpu, ARMELChangeHookFn *hook, QLIST_INSERT_HEAD(&cpu->el_change_hooks, entry, node); } +void arm_register_cpreg_mig_tolerance(ARMCPU *cpu, uint64_t kvmidx, + uint64_t mask, uint64_t value, + ARMCPUCPREGMigToleranceType type) +{ + ARMCPUCPREGMigTolerance *t, *entry; + + /* make sure the kvmidx has not tolerance already registered */ + QLIST_FOREACH(t, &cpu->cpreg_mig_tolerances, node) { + if (t->kvmidx == kvmidx) { + g_assert_not_reached(); + } + } + entry = g_new0(ARMCPUCPREGMigTolerance, 1); + + entry->kvmidx = kvmidx; + entry->mask = mask; + entry->value = value; + entry->type = type; + + QLIST_INSERT_HEAD(&cpu->cpreg_mig_tolerances, entry, node); +} + +bool arm_cpu_cpreg_has_mig_tolerance(ARMCPU *cpu, uint64_t kvmidx, + uint64_t vmstate_value, uint64_t local_value, + ARMCPUCPREGMigToleranceType type) +{ + ARMCPUCPREGMigTolerance *t; + uint64_t diff, diff_outside_mask, field; + bool found = false; + + QLIST_FOREACH(t, &cpu->cpreg_mig_tolerances, node) { + if (t->kvmidx == kvmidx) { + found = true; + break; + } + } + if (!found) { + return false; + } + + /* we found one tolerance associated to the @kvmidx */ + + if (type == ToleranceNotOnBothEnds) { + return true; + } + + /* Need to check mask */ + diff = vmstate_value ^ local_value; + diff_outside_mask = diff & ~t->mask; + + if (diff_outside_mask) { + /* there are differences outside of the mask */ + return false; + } + if (type == ToleranceDiffInMask) { + /* differences only in the field, tolerance granted */ + return true; + } + /* need to compare field value against authorized ones */ + field = vmstate_value & t->mask; + if (type == ToleranceFieldLT && (field < t->value)) { + return true; + } + if (type == ToleranceFieldGT && (field > t->value)) { + return true; + } + return false; +} + static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque) { /* Reset a single ARMCPRegInfo register */ @@ -1106,6 +1175,7 @@ static void arm_cpu_initfn(Object *obj) QLIST_INIT(&cpu->pre_el_change_hooks); QLIST_INIT(&cpu->el_change_hooks); + QLIST_INIT(&cpu->cpreg_mig_tolerances); #ifdef CONFIG_USER_ONLY # ifdef TARGET_AARCH64 @@ -1548,6 +1618,7 @@ static void arm_cpu_finalizefn(Object *obj) { ARMCPU *cpu = ARM_CPU(obj); ARMELChangeHook *hook, *next; + ARMCPUCPREGMigTolerance *t, *n; g_hash_table_destroy(cpu->cp_regs); @@ -1559,6 +1630,10 @@ static void arm_cpu_finalizefn(Object *obj) QLIST_REMOVE(hook, node); g_free(hook); } + QLIST_FOREACH_SAFE(t, &cpu->cpreg_mig_tolerances, node, n) { + QLIST_REMOVE(t, node); + g_free(t); + } #ifndef CONFIG_USER_ONLY if (cpu->pmu_timer) { timer_free(cpu->pmu_timer); -- 2.53.0
