This introduces stub implementations of the H_RESIZE_HPT_PREPARE and H_RESIZE_HPT_COMMIT hypercalls which we hope to add in a PAPR extension to allow run time resizing of a guest's hash page table. It also adds a new machine property for controlling whether this new facility is available, and logic to check that against availability with KVM (only supported with KVM PR for now).
Finally, it adds a new string to the hypertas property in the device tree, advertising to the guest the availability of the HPT resizing hypercalls. This is a tentative suggested value, and would need to be standardized by PAPR before being merged. Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> --- hw/ppc/spapr.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++ hw/ppc/spapr_hcall.c | 36 ++++++++++++++++++++++++ hw/ppc/trace-events | 2 ++ include/hw/ppc/spapr.h | 11 ++++++++ target-ppc/kvm.c | 25 +++++++++++++++++ target-ppc/kvm_ppc.h | 5 ++++ 6 files changed, 154 insertions(+) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 0f25e83..846ce51 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -760,6 +760,11 @@ static void spapr_dt_rtas(sPAPRMachineState *spapr, void *fdt) if (!kvm_enabled() || kvmppc_spapr_use_multitce()) { add_str(hypertas, "hcall-multi-tce"); } + + if (spapr->resize_hpt != SPAPR_RESIZE_HPT_DISABLED) { + add_str(hypertas, "hcall-hpt-resize"); + } + _FDT(fdt_setprop(fdt, rtas, "ibm,hypertas-functions", hypertas->str, hypertas->len)); g_string_free(hypertas, TRUE); @@ -1839,11 +1844,40 @@ static void ppc_spapr_init(MachineState *machine) long load_limit, fw_size; char *filename; int smt = kvmppc_smt_threads(); + Error *resize_hpt_err = NULL; msi_nonbroken = true; QLIST_INIT(&spapr->phbs); + /* Check HPT resizing availability */ + kvmppc_check_papr_resize_hpt(&resize_hpt_err); + if (spapr->resize_hpt == SPAPR_RESIZE_HPT_DEFAULT) { + /* + * If the user explicitly requested a mode we should either + * supply it, or fail completely (which we do below). But if + * it's not set explicitly, we reset our mode to something + * that works + */ + if (resize_hpt_err) { + spapr->resize_hpt = SPAPR_RESIZE_HPT_DISABLED; + error_free(resize_hpt_err); + resize_hpt_err = NULL; + } else { + spapr->resize_hpt = smc->resize_hpt_default; + } + } + + assert(spapr->resize_hpt != SPAPR_RESIZE_HPT_DEFAULT); + + if ((spapr->resize_hpt != SPAPR_RESIZE_HPT_DISABLED) && resize_hpt_err) { + /* + * User requested HPT resize, but this host can't supply it. Bail out + */ + error_report_err(resize_hpt_err); + exit(1); + } + /* Allocate RMA if necessary */ rma_alloc_size = kvmppc_alloc_rma(&rma); @@ -2236,6 +2270,40 @@ static void spapr_set_modern_hotplug_events(Object *obj, bool value, spapr->use_hotplug_event_source = value; } +static char *spapr_get_resize_hpt(Object *obj, Error **errp) +{ + sPAPRMachineState *spapr = SPAPR_MACHINE(obj); + + switch (spapr->resize_hpt) { + case SPAPR_RESIZE_HPT_DEFAULT: + return g_strdup("default"); + case SPAPR_RESIZE_HPT_DISABLED: + return g_strdup("disabled"); + case SPAPR_RESIZE_HPT_ENABLED: + return g_strdup("enabled"); + case SPAPR_RESIZE_HPT_REQUIRED: + return g_strdup("required"); + } + assert(0); +} + +static void spapr_set_resize_hpt(Object *obj, const char *value, Error **errp) +{ + sPAPRMachineState *spapr = SPAPR_MACHINE(obj); + + if (strcmp(value, "default") == 0) { + spapr->resize_hpt = SPAPR_RESIZE_HPT_DEFAULT; + } else if (strcmp(value, "disabled") == 0) { + spapr->resize_hpt = SPAPR_RESIZE_HPT_DISABLED; + } else if (strcmp(value, "enabled") == 0) { + spapr->resize_hpt = SPAPR_RESIZE_HPT_ENABLED; + } else if (strcmp(value, "required") == 0) { + spapr->resize_hpt = SPAPR_RESIZE_HPT_REQUIRED; + } else { + error_setg(errp, "Bad value for \"resize-hpt\" property"); + } +} + static void spapr_machine_initfn(Object *obj) { sPAPRMachineState *spapr = SPAPR_MACHINE(obj); @@ -2256,6 +2324,12 @@ static void spapr_machine_initfn(Object *obj) " place of standard EPOW events when possible" " (required for memory hot-unplug support)", NULL); + + object_property_add_str(obj, "resize-hpt", + spapr_get_resize_hpt, spapr_set_resize_hpt, NULL); + object_property_set_description(obj, "resize-hpt", + "Resizing of the Hash Page Table (enabled, disabled, required)", + NULL); } static void spapr_machine_finalizefn(Object *obj) @@ -2707,6 +2781,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data) smc->dr_lmb_enabled = true; smc->tcg_default_cpu = "POWER8"; + smc->resize_hpt_default = SPAPR_RESIZE_HPT_DISABLED; mc->query_hotpluggable_cpus = spapr_query_hotpluggable_cpus; fwc->get_dev_path = spapr_get_fw_dev_path; nc->nmi_monitor_handler = spapr_nmi; diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c index fd9f1d4..72a9c4d 100644 --- a/hw/ppc/spapr_hcall.c +++ b/hw/ppc/spapr_hcall.c @@ -355,6 +355,38 @@ static target_ulong h_read(PowerPCCPU *cpu, sPAPRMachineState *spapr, return H_SUCCESS; } +static target_ulong h_resize_hpt_prepare(PowerPCCPU *cpu, + sPAPRMachineState *spapr, + target_ulong opcode, + target_ulong *args) +{ + target_ulong flags = args[0]; + target_ulong shift = args[1]; + + if (spapr->resize_hpt == SPAPR_RESIZE_HPT_DISABLED) { + return H_AUTHORITY; + } + + trace_spapr_h_resize_hpt_prepare(flags, shift); + return H_HARDWARE; +} + +static target_ulong h_resize_hpt_commit(PowerPCCPU *cpu, + sPAPRMachineState *spapr, + target_ulong opcode, + target_ulong *args) +{ + target_ulong flags = args[0]; + target_ulong shift = args[1]; + + if (spapr->resize_hpt == SPAPR_RESIZE_HPT_DISABLED) { + return H_AUTHORITY; + } + + trace_spapr_h_resize_hpt_commit(flags, shift); + return H_HARDWARE; +} + static target_ulong h_set_sprg0(PowerPCCPU *cpu, sPAPRMachineState *spapr, target_ulong opcode, target_ulong *args) { @@ -1134,6 +1166,10 @@ static void hypercall_register_types(void) /* hcall-bulk */ spapr_register_hypercall(H_BULK_REMOVE, h_bulk_remove); + /* hcall-hpt-resize */ + spapr_register_hypercall(H_RESIZE_HPT_PREPARE, h_resize_hpt_prepare); + spapr_register_hypercall(H_RESIZE_HPT_COMMIT, h_resize_hpt_commit); + /* hcall-splpar */ spapr_register_hypercall(H_REGISTER_VPA, h_register_vpa); spapr_register_hypercall(H_CEDE, h_cede); diff --git a/hw/ppc/trace-events b/hw/ppc/trace-events index 2297ead..bf59a8f 100644 --- a/hw/ppc/trace-events +++ b/hw/ppc/trace-events @@ -16,6 +16,8 @@ spapr_cas_continue(unsigned long n) "Copy changes to the guest: %ld bytes" # hw/ppc/spapr_hcall.c spapr_cas_pvr_try(uint32_t pvr) "%x" spapr_cas_pvr(uint32_t cur_pvr, bool cpu_match, uint32_t new_pvr, uint64_t pcr) "current=%x, cpu_match=%u, new=%x, compat flags=%"PRIx64 +spapr_h_resize_hpt_prepare(uint64_t flags, uint64_t shift) "flags=0x%"PRIx64", shift=%"PRIu64 +spapr_h_resize_hpt_commit(uint64_t flags, uint64_t shift) "flags=0x%"PRIx64", shift=%"PRIu64 # hw/ppc/spapr_iommu.c spapr_iommu_put(uint64_t liobn, uint64_t ioba, uint64_t tce, uint64_t ret) "liobn=%"PRIx64" ioba=0x%"PRIx64" tce=0x%"PRIx64" ret=%"PRId64 diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h index a2d8964..d2c758b 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -31,6 +31,13 @@ typedef struct sPAPRMachineState sPAPRMachineState; #define SPAPR_MACHINE_CLASS(klass) \ OBJECT_CLASS_CHECK(sPAPRMachineClass, klass, TYPE_SPAPR_MACHINE) +typedef enum { + SPAPR_RESIZE_HPT_DEFAULT = 0, + SPAPR_RESIZE_HPT_DISABLED, + SPAPR_RESIZE_HPT_ENABLED, + SPAPR_RESIZE_HPT_REQUIRED, +} sPAPRResizeHPT; + /** * sPAPRMachineClass: */ @@ -46,6 +53,7 @@ struct sPAPRMachineClass { uint64_t *buid, hwaddr *pio, hwaddr *mmio32, hwaddr *mmio64, unsigned n_dma, uint32_t *liobns, Error **errp); + sPAPRResizeHPT resize_hpt_default; }; /** @@ -61,6 +69,7 @@ struct sPAPRMachineState { XICSState *xics; DeviceState *rtc; + sPAPRResizeHPT resize_hpt; void *htab; uint32_t htab_shift; hwaddr rma_size; @@ -347,6 +356,8 @@ struct sPAPRMachineState { #define H_XIRR_X 0x2FC #define H_RANDOM 0x300 #define H_SET_MODE 0x31C +#define H_RESIZE_HPT_PREPARE 0x36C +#define H_RESIZE_HPT_COMMIT 0x370 #define H_SIGNAL_SYS_RESET 0x380 #define MAX_HCALL_OPCODE H_SIGNAL_SYS_RESET diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index 15e12f3..39e5753 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -22,6 +22,7 @@ #include <linux/kvm.h> #include "qemu-common.h" +#include "qapi/error.h" #include "qemu/error-report.h" #include "cpu.h" #include "qemu/timer.h" @@ -2672,3 +2673,27 @@ int kvmppc_enable_hwrng(void) return kvmppc_enable_hcall(kvm_state, H_RANDOM); } + +void kvmppc_check_papr_resize_hpt(Error **errp) +{ + if (!kvm_enabled()) { + return; + } + + /* TODO: Check specific capabilities for HPT resize aware host kernels */ + + /* + * It's tempting to try to check directly if the HPT is under our + * control or KVM's, which is what's really relevant here. + * Unfortunately, in order to correctly size the HPT, we need to + * know if we can do resizing, _before_ we attempt to allocate it + * with KVM. Before that point, we don't officially know whether + * we'll control the HPT or not. So we have to use a fallback + * test for PR vs HV KVM to predict that. + */ + if (kvmppc_is_pr(kvm_state)) { + return; + } + + error_setg(errp, "Hash page table resizing not available with this KVM version"); +} diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h index 841a29b..3e852ba 100644 --- a/target-ppc/kvm_ppc.h +++ b/target-ppc/kvm_ppc.h @@ -59,6 +59,7 @@ bool kvmppc_has_cap_htm(void); int kvmppc_enable_hwrng(void); int kvmppc_put_books_sregs(PowerPCCPU *cpu); PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void); +void kvmppc_check_papr_resize_hpt(Error **errp); #else @@ -270,6 +271,10 @@ static inline PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void) return NULL; } +static inline void kvmppc_check_papr_resize_hpt(Error **errp) +{ + return; +} #endif #ifndef CONFIG_KVM -- 2.9.3