From db3975717ac5e2c2761bae7b90c4f2e0abb5ef22 Mon Sep 17 00:00:00 2001 From: Andrey Smetanin Date: Tue, 10 Nov 2015 15:36:35 +0300 Subject: [PATCH] kvm/x86: Hyper-V kvm exit A new vcpu exit is introduced to notify the userspace of the changes in Hyper-V SynIC configuration triggered by guest writing to the corresponding MSRs. Changes v4: * exit into userspace only if guest writes into SynIC MSR's Changes v3: * added KVM_EXIT_HYPERV types and structs notes into docs Signed-off-by: Andrey Smetanin Reviewed-by: Roman Kagan Signed-off-by: Denis V. Lunev CC: Gleb Natapov CC: Paolo Bonzini CC: Roman Kagan CC: Denis V. Lunev CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/api.txt | 22 ++++++++++++++++++++++ arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/hyperv.c | 20 ++++++++++++++++++++ arch/x86/kvm/x86.c | 6 ++++++ include/linux/kvm_host.h | 1 + include/uapi/linux/kvm.h | 17 +++++++++++++++++ 6 files changed, 67 insertions(+) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 88af84675af0..053f613fc9a9 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3337,6 +3337,28 @@ the userspace IOAPIC should process the EOI and retrigger the interrupt if it is still asserted. Vector is the LAPIC interrupt vector for which the EOI was received. + struct kvm_hyperv_exit { +#define KVM_EXIT_HYPERV_SYNIC 1 + __u32 type; + union { + struct { + __u32 msr; + __u64 control; + __u64 evt_page; + __u64 msg_page; + } synic; + } u; + }; + /* KVM_EXIT_HYPERV */ + struct kvm_hyperv_exit hyperv; +Indicates that the VCPU exits into userspace to process some tasks +related to Hyper-V emulation. +Valid values for 'type' are: + KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about +Hyper-V SynIC state change. Notification is used to remap SynIC +event/message pages and to enable/disable SynIC messages/events processing +in userspace. + /* Fix the size of the union. */ char padding[256]; }; diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index bab47b61d2b0..f608e170ba3d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -393,6 +393,7 @@ struct kvm_vcpu_hv { u64 hv_vapic; s64 runtime_offset; struct kvm_vcpu_hv_synic synic; + struct kvm_hyperv_exit exit; }; struct kvm_vcpu_arch { diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 83a3c0c9b3de..41869a9d43f8 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -130,6 +130,20 @@ static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint) srcu_read_unlock(&kvm->irq_srcu, idx); } +static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr) +{ + struct kvm_vcpu *vcpu = synic_to_vcpu(synic); + struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv; + + hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC; + hv_vcpu->exit.u.synic.msr = msr; + hv_vcpu->exit.u.synic.control = synic->control; + hv_vcpu->exit.u.synic.evt_page = synic->evt_page; + hv_vcpu->exit.u.synic.msg_page = synic->msg_page; + + kvm_make_request(KVM_REQ_HV_EXIT, vcpu); +} + static int synic_set_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 data, bool host) { @@ -145,6 +159,8 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic, switch (msr) { case HV_X64_MSR_SCONTROL: synic->control = data; + if (!host) + synic_exit(synic, msr); break; case HV_X64_MSR_SVERSION: if (!host) { @@ -161,6 +177,8 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic, break; } synic->evt_page = data; + if (!host) + synic_exit(synic, msr); break; case HV_X64_MSR_SIMP: if (data & HV_SYNIC_SIMP_ENABLE) @@ -170,6 +188,8 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic, break; } synic->msg_page = data; + if (!host) + synic_exit(synic, msr); break; case HV_X64_MSR_EOM: { int i; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eb64377edcd3..036e4bc124f9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6482,6 +6482,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) r = 0; goto out; } + if (kvm_check_request(KVM_REQ_HV_EXIT, vcpu)) { + vcpu->run->exit_reason = KVM_EXIT_HYPERV; + vcpu->run->hyperv = vcpu->arch.hyperv.exit; + r = 0; + goto out; + } } /* diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index ebaf2f82f712..14f95969b0f3 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -143,6 +143,7 @@ static inline bool is_error_page(struct page *page) #define KVM_REQ_HV_CRASH 27 #define KVM_REQ_IOAPIC_EOI_EXIT 28 #define KVM_REQ_HV_RESET 29 +#define KVM_REQ_HV_EXIT 30 #define KVM_USERSPACE_IRQ_SOURCE_ID 0 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1 diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 27ce4602a072..6e32f7599081 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -154,6 +154,20 @@ struct kvm_s390_skeys { __u32 flags; __u32 reserved[9]; }; + +struct kvm_hyperv_exit { +#define KVM_EXIT_HYPERV_SYNIC 1 + __u32 type; + union { + struct { + __u32 msr; + __u64 control; + __u64 evt_page; + __u64 msg_page; + } synic; + } u; +}; + #define KVM_S390_GET_SKEYS_NONE 1 #define KVM_S390_SKEYS_MAX 1048576 @@ -184,6 +198,7 @@ struct kvm_s390_skeys { #define KVM_EXIT_SYSTEM_EVENT 24 #define KVM_EXIT_S390_STSI 25 #define KVM_EXIT_IOAPIC_EOI 26 +#define KVM_EXIT_HYPERV 27 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -338,6 +353,8 @@ struct kvm_run { struct { __u8 vector; } eoi; + /* KVM_EXIT_HYPERV */ + struct kvm_hyperv_exit hyperv; /* Fix the size of the union. */ char padding[256]; }; -- 2.39.2