diff options
| -rw-r--r-- | Documentation/kvm/api.txt | 36 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 42 | ||||
| -rw-r--r-- | include/linux/kvm.h | 10 |
4 files changed, 88 insertions, 1 deletions
diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index 3e8684e..36594ba 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -617,6 +617,42 @@ struct kvm_xen_hvm_config { __u8 pad2[30]; }; +4.27 KVM_GET_CLOCK + +Capability: KVM_CAP_ADJUST_CLOCK +Architectures: x86 +Type: vm ioctl +Parameters: struct kvm_clock_data (out) +Returns: 0 on success, -1 on error + +Gets the current timestamp of kvmclock as seen by the current guest. In +conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios +such as migration. + +struct kvm_clock_data { + __u64 clock; /* kvmclock current value */ + __u32 flags; + __u32 pad[9]; +}; + +4.28 KVM_SET_CLOCK + +Capability: KVM_CAP_ADJUST_CLOCK +Architectures: x86 +Type: vm ioctl +Parameters: struct kvm_clock_data (in) +Returns: 0 on success, -1 on error + +Sets the current timestamp of kvmclock to the valued specific in its parameter. +In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios +such as migration. + +struct kvm_clock_data { + __u64 clock; /* kvmclock current value */ + __u32 flags; + __u32 pad[9]; +}; + 5. The kvm_run structure Application code obtains a pointer to the kvm_run structure by diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4d994ad..0558ff8 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -413,6 +413,7 @@ struct kvm_arch{ unsigned long irq_sources_bitmap; u64 vm_init_tsc; + s64 kvmclock_offset; struct kvm_xen_hvm_config xen_hvm_config; }; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 13f30aac..e16cdc9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -680,7 +680,8 @@ static void kvm_write_guest_time(struct kvm_vcpu *v) /* With all the info we got, fill in the values */ vcpu->hv_clock.system_time = ts.tv_nsec + - (NSEC_PER_SEC * (u64)ts.tv_sec); + (NSEC_PER_SEC * (u64)ts.tv_sec) + v->kvm->arch.kvmclock_offset; + /* * The interface expects us to write an even number signaling that the * update is finished. Since the guest won't see the intermediate @@ -1262,6 +1263,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_PIT_STATE2: case KVM_CAP_SET_IDENTITY_MAP_ADDR: case KVM_CAP_XEN_HVM: + case KVM_CAP_ADJUST_CLOCK: r = 1; break; case KVM_CAP_COALESCED_MMIO: @@ -2468,6 +2470,44 @@ long kvm_arch_vm_ioctl(struct file *filp, r = 0; break; } + case KVM_SET_CLOCK: { + struct timespec now; + struct kvm_clock_data user_ns; + u64 now_ns; + s64 delta; + + r = -EFAULT; + if (copy_from_user(&user_ns, argp, sizeof(user_ns))) + goto out; + + r = -EINVAL; + if (user_ns.flags) + goto out; + + r = 0; + ktime_get_ts(&now); + now_ns = timespec_to_ns(&now); + delta = user_ns.clock - now_ns; + kvm->arch.kvmclock_offset = delta; + break; + } + case KVM_GET_CLOCK: { + struct timespec now; + struct kvm_clock_data user_ns; + u64 now_ns; + + ktime_get_ts(&now); + now_ns = timespec_to_ns(&now); + user_ns.clock = kvm->arch.kvmclock_offset + now_ns; + user_ns.flags = 0; + + r = -EFAULT; + if (copy_to_user(argp, &user_ns, sizeof(user_ns))) + goto out; + r = 0; + break; + } + default: ; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index b694c1d..6ed1a12 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -439,6 +439,7 @@ struct kvm_ioeventfd { #ifdef __KVM_HAVE_XEN_HVM #define KVM_CAP_XEN_HVM 38 #endif +#define KVM_CAP_ADJUST_CLOCK 39 #ifdef KVM_CAP_IRQ_ROUTING @@ -512,6 +513,12 @@ struct kvm_irqfd { __u8 pad[20]; }; +struct kvm_clock_data { + __u64 clock; + __u32 flags; + __u32 pad[9]; +}; + /* * ioctls for VM fds */ @@ -562,6 +569,9 @@ struct kvm_irqfd { #define KVM_SET_BOOT_CPU_ID _IO(KVMIO, 0x78) #define KVM_IOEVENTFD _IOW(KVMIO, 0x79, struct kvm_ioeventfd) #define KVM_XEN_HVM_CONFIG _IOW(KVMIO, 0x7a, struct kvm_xen_hvm_config) +#define KVM_SET_CLOCK _IOW(KVMIO, 0x7b, struct kvm_clock_data) +#define KVM_GET_CLOCK _IOR(KVMIO, 0x7c, struct kvm_clock_data) + /* * ioctls for vcpu fds |
