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Diffstat (limited to 'hw/s390x/cpu-topology.c')
| -rw-r--r-- | hw/s390x/cpu-topology.c | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c new file mode 100644 index 0000000000..f16bdf65fa --- /dev/null +++ b/hw/s390x/cpu-topology.c @@ -0,0 +1,469 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * CPU Topology + * + * Copyright IBM Corp. 2022, 2023 + * Author(s): Pierre Morel <pmorel@linux.ibm.com> + * + * S390 topology handling can be divided in two parts: + * + * - The first part in this file is taking care of all common functions + * used by KVM and TCG to create and modify the topology. + * + * - The second part, building the topology information data for the + * guest with CPU and KVM specificity will be implemented inside + * the target/s390/kvm sub tree. + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "qemu/error-report.h" +#include "hw/qdev-properties.h" +#include "hw/boards.h" +#include "target/s390x/cpu.h" +#include "hw/s390x/s390-virtio-ccw.h" +#include "hw/s390x/cpu-topology.h" +#include "qapi/qapi-commands-machine-target.h" +#include "qapi/qapi-events-machine-target.h" + +/* + * s390_topology is used to keep the topology information. + * .cores_per_socket: tracks information on the count of cores + * per socket. + * .polarization: tracks machine polarization. + */ +S390Topology s390_topology = { + /* will be initialized after the CPU model is realized */ + .cores_per_socket = NULL, + .polarization = S390_CPU_POLARIZATION_HORIZONTAL, +}; + +/** + * s390_socket_nb: + * @cpu: s390x CPU + * + * Returns the socket number used inside the cores_per_socket array + * for a topology tree entry + */ +static int s390_socket_nb_from_ids(int drawer_id, int book_id, int socket_id) +{ + return (drawer_id * current_machine->smp.books + book_id) * + current_machine->smp.sockets + socket_id; +} + +/** + * s390_socket_nb: + * @cpu: s390x CPU + * + * Returns the socket number used inside the cores_per_socket array + * for a cpu. + */ +static int s390_socket_nb(S390CPU *cpu) +{ + return s390_socket_nb_from_ids(cpu->env.drawer_id, cpu->env.book_id, + cpu->env.socket_id); +} + +/** + * s390_has_topology: + * + * Return: true if the topology is supported by the machine. + */ +bool s390_has_topology(void) +{ + return s390_has_feat(S390_FEAT_CONFIGURATION_TOPOLOGY); +} + +/** + * s390_topology_init: + * @ms: the machine state where the machine topology is defined + * + * Keep track of the machine topology. + * + * Allocate an array to keep the count of cores per socket. + * The index of the array starts at socket 0 from book 0 and + * drawer 0 up to the maximum allowed by the machine topology. + */ +static void s390_topology_init(MachineState *ms) +{ + CpuTopology *smp = &ms->smp; + + s390_topology.cores_per_socket = g_new0(uint8_t, smp->sockets * + smp->books * smp->drawers); +} + +/* + * s390_handle_ptf: + * + * @register 1: contains the function code + * + * Function codes 0 (horizontal) and 1 (vertical) define the CPU + * polarization requested by the guest. + * + * Function code 2 is handling topology changes and is interpreted + * by the SIE. + */ +void s390_handle_ptf(S390CPU *cpu, uint8_t r1, uintptr_t ra) +{ + CpuS390Polarization polarization; + CPUS390XState *env = &cpu->env; + uint64_t reg = env->regs[r1]; + int fc = reg & S390_TOPO_FC_MASK; + + if (!s390_has_feat(S390_FEAT_CONFIGURATION_TOPOLOGY)) { + s390_program_interrupt(env, PGM_OPERATION, ra); + return; + } + + if (env->psw.mask & PSW_MASK_PSTATE) { + s390_program_interrupt(env, PGM_PRIVILEGED, ra); + return; + } + + if (reg & ~S390_TOPO_FC_MASK) { + s390_program_interrupt(env, PGM_SPECIFICATION, ra); + return; + } + + polarization = S390_CPU_POLARIZATION_VERTICAL; + switch (fc) { + case 0: + polarization = S390_CPU_POLARIZATION_HORIZONTAL; + /* fallthrough */ + case 1: + if (s390_topology.polarization == polarization) { + env->regs[r1] |= S390_PTF_REASON_DONE; + setcc(cpu, 2); + } else { + s390_topology.polarization = polarization; + s390_cpu_topology_set_changed(true); + qapi_event_send_cpu_polarization_change(polarization); + setcc(cpu, 0); + } + break; + default: + /* Note that fc == 2 is interpreted by the SIE */ + s390_program_interrupt(env, PGM_SPECIFICATION, ra); + } +} + +/** + * s390_topology_reset: + * + * Generic reset for CPU topology, calls s390_topology_reset() + * to reset the kernel Modified Topology Change Record. + */ +void s390_topology_reset(void) +{ + s390_cpu_topology_set_changed(false); + s390_topology.polarization = S390_CPU_POLARIZATION_HORIZONTAL; +} + +/** + * s390_topology_cpu_default: + * @cpu: pointer to a S390CPU + * @errp: Error pointer + * + * Setup the default topology if no attributes are already set. + * Passing a CPU with some, but not all, attributes set is considered + * an error. + * + * The function calculates the (drawer_id, book_id, socket_id) + * topology by filling the cores starting from the first socket + * (0, 0, 0) up to the last (smp->drawers, smp->books, smp->sockets). + * + * CPU type and dedication have defaults values set in the + * s390x_cpu_properties, entitlement must be adjust depending on the + * dedication. + * + * Returns false if it is impossible to setup a default topology + * true otherwise. + */ +static bool s390_topology_cpu_default(S390CPU *cpu, Error **errp) +{ + CpuTopology *smp = ¤t_machine->smp; + CPUS390XState *env = &cpu->env; + + /* All geometry topology attributes must be set or all unset */ + if ((env->socket_id < 0 || env->book_id < 0 || env->drawer_id < 0) && + (env->socket_id >= 0 || env->book_id >= 0 || env->drawer_id >= 0)) { + error_setg(errp, + "Please define all or none of the topology geometry attributes"); + return false; + } + + /* If one value is unset all are unset -> calculate defaults */ + if (env->socket_id < 0) { + env->socket_id = s390_std_socket(env->core_id, smp); + env->book_id = s390_std_book(env->core_id, smp); + env->drawer_id = s390_std_drawer(env->core_id, smp); + } + + /* + * When the user specifies the entitlement as 'auto' on the command line, + * QEMU will set the entitlement as: + * Medium when the CPU is not dedicated. + * High when dedicated is true. + */ + if (env->entitlement == S390_CPU_ENTITLEMENT_AUTO) { + if (env->dedicated) { + env->entitlement = S390_CPU_ENTITLEMENT_HIGH; + } else { + env->entitlement = S390_CPU_ENTITLEMENT_MEDIUM; + } + } + return true; +} + +/** + * s390_topology_check: + * @socket_id: socket to check + * @book_id: book to check + * @drawer_id: drawer to check + * @entitlement: entitlement to check + * @dedicated: dedication to check + * @errp: Error pointer + * + * The function checks if the topology + * attributes fits inside the system topology. + * + * Returns false if the specified topology does not match with + * the machine topology. + */ +static bool s390_topology_check(uint16_t socket_id, uint16_t book_id, + uint16_t drawer_id, uint16_t entitlement, + bool dedicated, Error **errp) +{ + CpuTopology *smp = ¤t_machine->smp; + + if (socket_id >= smp->sockets) { + error_setg(errp, "Unavailable socket: %d", socket_id); + return false; + } + if (book_id >= smp->books) { + error_setg(errp, "Unavailable book: %d", book_id); + return false; + } + if (drawer_id >= smp->drawers) { + error_setg(errp, "Unavailable drawer: %d", drawer_id); + return false; + } + if (entitlement >= S390_CPU_ENTITLEMENT__MAX) { + error_setg(errp, "Unknown entitlement: %d", entitlement); + return false; + } + if (dedicated && (entitlement == S390_CPU_ENTITLEMENT_LOW || + entitlement == S390_CPU_ENTITLEMENT_MEDIUM)) { + error_setg(errp, "A dedicated CPU implies high entitlement"); + return false; + } + return true; +} + +/** + * s390_topology_need_report + * @cpu: Current cpu + * @drawer_id: future drawer ID + * @book_id: future book ID + * @socket_id: future socket ID + * @entitlement: future entitlement + * @dedicated: future dedicated + * + * A modified topology change report is needed if the topology + * tree or the topology attributes change. + */ +static bool s390_topology_need_report(S390CPU *cpu, int drawer_id, + int book_id, int socket_id, + uint16_t entitlement, bool dedicated) +{ + return cpu->env.drawer_id != drawer_id || + cpu->env.book_id != book_id || + cpu->env.socket_id != socket_id || + cpu->env.entitlement != entitlement || + cpu->env.dedicated != dedicated; +} + +/** + * s390_update_cpu_props: + * @ms: the machine state + * @cpu: the CPU for which to update the properties from the environment. + * + */ +static void s390_update_cpu_props(MachineState *ms, S390CPU *cpu) +{ + CpuInstanceProperties *props; + + props = &ms->possible_cpus->cpus[cpu->env.core_id].props; + + props->socket_id = cpu->env.socket_id; + props->book_id = cpu->env.book_id; + props->drawer_id = cpu->env.drawer_id; +} + +/** + * s390_topology_setup_cpu: + * @ms: MachineState used to initialize the topology structure on + * first call. + * @cpu: the new S390CPU to insert in the topology structure + * @errp: the error pointer + * + * Called from CPU hotplug to check and setup the CPU attributes + * before the CPU is inserted in the topology. + * There is no need to update the MTCR explicitly here because it + * will be updated by KVM on creation of the new CPU. + */ +void s390_topology_setup_cpu(MachineState *ms, S390CPU *cpu, Error **errp) +{ + int entry; + + /* + * We do not want to initialize the topology if the CPU model + * does not support topology, consequently, we have to wait for + * the first CPU to be realized, which realizes the CPU model + * to initialize the topology structures. + * + * s390_topology_setup_cpu() is called from the CPU hotplug. + */ + if (!s390_topology.cores_per_socket) { + s390_topology_init(ms); + } + + if (!s390_topology_cpu_default(cpu, errp)) { + return; + } + + if (!s390_topology_check(cpu->env.socket_id, cpu->env.book_id, + cpu->env.drawer_id, cpu->env.entitlement, + cpu->env.dedicated, errp)) { + return; + } + + /* Do we still have space in the socket */ + entry = s390_socket_nb(cpu); + if (s390_topology.cores_per_socket[entry] >= ms->smp.cores) { + error_setg(errp, "No more space on this socket"); + return; + } + + /* Update the count of cores in sockets */ + s390_topology.cores_per_socket[entry] += 1; + + /* topology tree is reflected in props */ + s390_update_cpu_props(ms, cpu); +} + +static void s390_change_topology(uint16_t core_id, + bool has_socket_id, uint16_t socket_id, + bool has_book_id, uint16_t book_id, + bool has_drawer_id, uint16_t drawer_id, + bool has_entitlement, + CpuS390Entitlement entitlement, + bool has_dedicated, bool dedicated, + Error **errp) +{ + MachineState *ms = current_machine; + int old_socket_entry; + int new_socket_entry; + bool report_needed; + S390CPU *cpu; + + cpu = s390_cpu_addr2state(core_id); + if (!cpu) { + error_setg(errp, "Core-id %d does not exist!", core_id); + return; + } + + /* Get attributes not provided from cpu and verify the new topology */ + if (!has_socket_id) { + socket_id = cpu->env.socket_id; + } + if (!has_book_id) { + book_id = cpu->env.book_id; + } + if (!has_drawer_id) { + drawer_id = cpu->env.drawer_id; + } + if (!has_dedicated) { + dedicated = cpu->env.dedicated; + } + + /* + * When the user specifies the entitlement as 'auto' on the command line, + * QEMU will set the entitlement as: + * Medium when the CPU is not dedicated. + * High when dedicated is true. + */ + if (!has_entitlement || entitlement == S390_CPU_ENTITLEMENT_AUTO) { + if (dedicated) { + entitlement = S390_CPU_ENTITLEMENT_HIGH; + } else { + entitlement = S390_CPU_ENTITLEMENT_MEDIUM; + } + } + + if (!s390_topology_check(socket_id, book_id, drawer_id, + entitlement, dedicated, errp)) { + return; + } + + /* Check for space on new socket */ + old_socket_entry = s390_socket_nb(cpu); + new_socket_entry = s390_socket_nb_from_ids(drawer_id, book_id, socket_id); + + if (new_socket_entry != old_socket_entry) { + if (s390_topology.cores_per_socket[new_socket_entry] >= + ms->smp.cores) { + error_setg(errp, "No more space on this socket"); + return; + } + /* Update the count of cores in sockets */ + s390_topology.cores_per_socket[new_socket_entry] += 1; + s390_topology.cores_per_socket[old_socket_entry] -= 1; + } + + /* Check if we will need to report the modified topology */ + report_needed = s390_topology_need_report(cpu, drawer_id, book_id, + socket_id, entitlement, + dedicated); + + /* All checks done, report new topology into the vCPU */ + cpu->env.drawer_id = drawer_id; + cpu->env.book_id = book_id; + cpu->env.socket_id = socket_id; + cpu->env.dedicated = dedicated; + cpu->env.entitlement = entitlement; + + /* topology tree is reflected in props */ + s390_update_cpu_props(ms, cpu); + + /* Advertise the topology change */ + if (report_needed) { + s390_cpu_topology_set_changed(true); + } +} + +void qmp_set_cpu_topology(uint16_t core, + bool has_socket, uint16_t socket, + bool has_book, uint16_t book, + bool has_drawer, uint16_t drawer, + bool has_entitlement, CpuS390Entitlement entitlement, + bool has_dedicated, bool dedicated, + Error **errp) +{ + if (!s390_has_topology()) { + error_setg(errp, "This machine doesn't support topology"); + return; + } + + s390_change_topology(core, has_socket, socket, has_book, book, + has_drawer, drawer, has_entitlement, entitlement, + has_dedicated, dedicated, errp); +} + +CpuPolarizationInfo *qmp_query_s390x_cpu_polarization(Error **errp) +{ + CpuPolarizationInfo *info = g_new0(CpuPolarizationInfo, 1); + + info->polarization = s390_topology.polarization; + return info; +} |