diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 81 |
3 files changed, 85 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 0558ff8c32a..26a74b7bb6b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -809,4 +809,7 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu); int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu); int kvm_cpu_get_interrupt(struct kvm_vcpu *v); +void kvm_define_shared_msr(unsigned index, u32 msr); +void kvm_set_shared_msr(unsigned index, u64 val); + #endif /* _ASM_X86_KVM_HOST_H */ diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index b84e571f417..4cd49833246 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -28,6 +28,7 @@ config KVM select HAVE_KVM_IRQCHIP select HAVE_KVM_EVENTFD select KVM_APIC_ARCHITECTURE + select USER_RETURN_NOTIFIER ---help--- Support hosting fully virtualized guest machines using hardware virtualization extensions. You will need a fairly recent diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e16cdc9ec0c..58c5cddf363 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -37,6 +37,7 @@ #include <linux/iommu.h> #include <linux/intel-iommu.h> #include <linux/cpufreq.h> +#include <linux/user-return-notifier.h> #include <trace/events/kvm.h> #undef TRACE_INCLUDE_FILE #define CREATE_TRACE_POINTS @@ -87,6 +88,25 @@ EXPORT_SYMBOL_GPL(kvm_x86_ops); int ignore_msrs = 0; module_param_named(ignore_msrs, ignore_msrs, bool, S_IRUGO | S_IWUSR); +#define KVM_NR_SHARED_MSRS 16 + +struct kvm_shared_msrs_global { + int nr; + struct kvm_shared_msr { + u32 msr; + u64 value; + } msrs[KVM_NR_SHARED_MSRS]; +}; + +struct kvm_shared_msrs { + struct user_return_notifier urn; + bool registered; + u64 current_value[KVM_NR_SHARED_MSRS]; +}; + +static struct kvm_shared_msrs_global __read_mostly shared_msrs_global; +static DEFINE_PER_CPU(struct kvm_shared_msrs, shared_msrs); + struct kvm_stats_debugfs_item debugfs_entries[] = { { "pf_fixed", VCPU_STAT(pf_fixed) }, { "pf_guest", VCPU_STAT(pf_guest) }, @@ -123,6 +143,64 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { NULL } }; +static void kvm_on_user_return(struct user_return_notifier *urn) +{ + unsigned slot; + struct kvm_shared_msr *global; + struct kvm_shared_msrs *locals + = container_of(urn, struct kvm_shared_msrs, urn); + + for (slot = 0; slot < shared_msrs_global.nr; ++slot) { + global = &shared_msrs_global.msrs[slot]; + if (global->value != locals->current_value[slot]) { + wrmsrl(global->msr, global->value); + locals->current_value[slot] = global->value; + } + } + locals->registered = false; + user_return_notifier_unregister(urn); +} + +void kvm_define_shared_msr(unsigned slot, u32 msr) +{ + int cpu; + u64 value; + + if (slot >= shared_msrs_global.nr) + shared_msrs_global.nr = slot + 1; + shared_msrs_global.msrs[slot].msr = msr; + rdmsrl_safe(msr, &value); + shared_msrs_global.msrs[slot].value = value; + for_each_online_cpu(cpu) + per_cpu(shared_msrs, cpu).current_value[slot] = value; +} +EXPORT_SYMBOL_GPL(kvm_define_shared_msr); + +static void kvm_shared_msr_cpu_online(void) +{ + unsigned i; + struct kvm_shared_msrs *locals = &__get_cpu_var(shared_msrs); + + for (i = 0; i < shared_msrs_global.nr; ++i) + locals->current_value[i] = shared_msrs_global.msrs[i].value; +} + +void kvm_set_shared_msr(unsigned slot, u64 value) +{ + struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs); + + if (value == smsr->current_value[slot]) + return; + smsr->current_value[slot] = value; + wrmsrl(shared_msrs_global.msrs[slot].msr, value); + if (!smsr->registered) { + smsr->urn.on_user_return = kvm_on_user_return; + user_return_notifier_register(&smsr->urn); + smsr->registered = true; + } +} +EXPORT_SYMBOL_GPL(kvm_set_shared_msr); + unsigned long segment_base(u16 selector) { struct descriptor_table gdt; @@ -4815,6 +4893,9 @@ int kvm_arch_hardware_enable(void *garbage) int cpu = raw_smp_processor_id(); per_cpu(cpu_tsc_khz, cpu) = 0; } + + kvm_shared_msr_cpu_online(); + return kvm_x86_ops->hardware_enable(garbage); } |