From 4cb88c3c378ae8c86c0ba53619caf6924f72239c Mon Sep 17 00:00:00 2001 From: Dominik Dingel Date: Fri, 11 Apr 2014 13:47:40 +0200 Subject: s390x/kvm: enable/reset cmma via vm attributes Exploit the new api for userspace-controlled cmma. If supported, enable cmma during kvm initialization and register a reset handler for cmma, which is also called directly from the load IPL code. The reset functionality is needed to reset the cmma state of the guest pages, e.g. if a system reset is triggered via qemu monitor; otherwise this could result in data corruption. A guest triggered reboot may now lead to multiple cmma resets; this is OK, however, as this is slowpath anyway and the simplest way to achieve the intended effects. Signed-off-by: Dominik Dingel Acked-by: Christian Borntraeger Acked-by: Cornelia Huck Signed-off-by: Cornelia Huck --- target-s390x/cpu.h | 12 ++++++++++ target-s390x/kvm.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++ target-s390x/misc_helper.c | 2 ++ 3 files changed, 72 insertions(+) (limited to 'target-s390x') diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h index 06454d6da5..808b906861 100644 --- a/target-s390x/cpu.h +++ b/target-s390x/cpu.h @@ -1074,6 +1074,7 @@ void kvm_s390_enable_css_support(S390CPU *cpu); int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch, int vq, bool assign); int kvm_s390_cpu_restart(S390CPU *cpu); +void kvm_s390_clear_cmma_callback(void *opaque); #else static inline void kvm_s390_io_interrupt(S390CPU *cpu, uint16_t subchannel_id, @@ -1098,8 +1099,19 @@ static inline int kvm_s390_cpu_restart(S390CPU *cpu) { return -ENOSYS; } +static inline void kvm_s390_clear_cmma_callback(void *opaque) +{ +} #endif +static inline void cmma_reset(S390CPU *cpu) +{ + if (kvm_enabled()) { + CPUState *cs = CPU(cpu); + kvm_s390_clear_cmma_callback(cs->kvm_state); + } +} + static inline int s390_cpu_restart(S390CPU *cpu) { if (kvm_enabled()) { diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c index 7a07f9d753..0a2a2052ee 100644 --- a/target-s390x/kvm.c +++ b/target-s390x/kvm.c @@ -32,6 +32,7 @@ #include "qemu/timer.h" #include "sysemu/sysemu.h" #include "sysemu/kvm.h" +#include "hw/hw.h" #include "cpu.h" #include "sysemu/device_tree.h" #include "qapi/qmp/qjson.h" @@ -104,10 +105,67 @@ static int cap_async_pf; static void *legacy_s390_alloc(size_t size); +static int kvm_s390_check_clear_cmma(KVMState *s) +{ + struct kvm_device_attr attr = { + .group = KVM_S390_VM_MEM_CTRL, + .attr = KVM_S390_VM_MEM_CLR_CMMA, + }; + + return kvm_vm_ioctl(s, KVM_HAS_DEVICE_ATTR, &attr); +} + +static int kvm_s390_check_enable_cmma(KVMState *s) +{ + struct kvm_device_attr attr = { + .group = KVM_S390_VM_MEM_CTRL, + .attr = KVM_S390_VM_MEM_ENABLE_CMMA, + }; + + return kvm_vm_ioctl(s, KVM_HAS_DEVICE_ATTR, &attr); +} + +void kvm_s390_clear_cmma_callback(void *opaque) +{ + int rc; + KVMState *s = opaque; + struct kvm_device_attr attr = { + .group = KVM_S390_VM_MEM_CTRL, + .attr = KVM_S390_VM_MEM_CLR_CMMA, + }; + + rc = kvm_vm_ioctl(s, KVM_SET_DEVICE_ATTR, &attr); + trace_kvm_clear_cmma(rc); +} + +static void kvm_s390_enable_cmma(KVMState *s) +{ + int rc; + struct kvm_device_attr attr = { + .group = KVM_S390_VM_MEM_CTRL, + .attr = KVM_S390_VM_MEM_ENABLE_CMMA, + }; + + if (kvm_s390_check_enable_cmma(s) || kvm_s390_check_clear_cmma(s)) { + return; + } + + rc = kvm_vm_ioctl(s, KVM_SET_DEVICE_ATTR, &attr); + if (!rc) { + qemu_register_reset(kvm_s390_clear_cmma_callback, s); + } + trace_kvm_enable_cmma(rc); +} + int kvm_arch_init(KVMState *s) { cap_sync_regs = kvm_check_extension(s, KVM_CAP_SYNC_REGS); cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF); + + if (kvm_check_extension(s, KVM_CAP_VM_ATTRIBUTES)) { + kvm_s390_enable_cmma(s); + } + if (!kvm_check_extension(s, KVM_CAP_S390_GMAP) || !kvm_check_extension(s, KVM_CAP_S390_COW)) { phys_mem_set_alloc(legacy_s390_alloc); diff --git a/target-s390x/misc_helper.c b/target-s390x/misc_helper.c index 9dae0256fa..519edb81dd 100644 --- a/target-s390x/misc_helper.c +++ b/target-s390x/misc_helper.c @@ -136,6 +136,7 @@ static int modified_clear_reset(S390CPU *cpu) pause_all_vcpus(); cpu_synchronize_all_states(); cpu_full_reset_all(); + cmma_reset(cpu); io_subsystem_reset(); scc->load_normal(CPU(cpu)); cpu_synchronize_all_post_reset(); @@ -150,6 +151,7 @@ static int load_normal_reset(S390CPU *cpu) pause_all_vcpus(); cpu_synchronize_all_states(); cpu_reset_all(); + cmma_reset(cpu); io_subsystem_reset(); scc->initial_cpu_reset(CPU(cpu)); scc->load_normal(CPU(cpu)); -- cgit v1.2.1