From patchwork Thu Feb 4 17:12:20 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 77121 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o14HUOVn001362 for ; Thu, 4 Feb 2010 17:30:24 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933317Ab0BDRWO (ORCPT ); Thu, 4 Feb 2010 12:22:14 -0500 Received: from kroah.org ([198.145.64.141]:34808 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933309Ab0BDRWM (ORCPT ); Thu, 4 Feb 2010 12:22:12 -0500 Received: from localhost (c-98-246-45-209.hsd1.or.comcast.net [98.246.45.209]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by coco.kroah.org (Postfix) with ESMTPSA id AC32948B19; Thu, 4 Feb 2010 09:22:11 -0800 (PST) X-Mailbox-Line: From linux@linux.site Thu Feb 4 09:15:16 2010 Message-Id: <20100204171515.880676617@linux.site> User-Agent: quilt/0.47-14.9 Date: Thu, 04 Feb 2010 09:12:20 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, Alexander Graf , Greg KH Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Avi Kivity , KVM list , Glauber Costa , Marcelo Tosatti Subject: [49/74] KVM: allow userspace to adjust kvmclock offset In-Reply-To: <20100204171850.GA16539@kroah.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Thu, 04 Feb 2010 17:30:24 +0000 (UTC) --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -412,6 +412,7 @@ struct kvm_arch{ unsigned long irq_sources_bitmap; unsigned long irq_states[KVM_IOAPIC_NUM_PINS]; u64 vm_init_tsc; + s64 kvmclock_offset; }; struct kvm_vm_stat { --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -680,7 +680,8 @@ static void kvm_write_guest_time(struct /* 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 @@ -1227,6 +1228,7 @@ int kvm_dev_ioctl_check_extension(long e case KVM_CAP_PIT2: case KVM_CAP_PIT_STATE2: case KVM_CAP_SET_IDENTITY_MAP_ADDR: + case KVM_CAP_ADJUST_CLOCK: r = 1; break; case KVM_CAP_COALESCED_MMIO: @@ -2424,6 +2426,44 @@ 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: ; } --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -593,6 +593,42 @@ struct kvm_irqchip { } chip; }; +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 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -439,6 +439,7 @@ struct kvm_ioeventfd { #endif #define KVM_CAP_IOEVENTFD 36 #define KVM_CAP_SET_IDENTITY_MAP_ADDR 37 +#define KVM_CAP_ADJUST_CLOCK 39 #ifdef KVM_CAP_IRQ_ROUTING @@ -501,6 +502,12 @@ struct kvm_irqfd { __u8 pad[20]; }; +struct kvm_clock_data { + __u64 clock; + __u32 flags; + __u32 pad[9]; +}; + /* * ioctls for VM fds */ @@ -550,6 +557,8 @@ struct kvm_irqfd { #define KVM_CREATE_PIT2 _IOW(KVMIO, 0x77, struct kvm_pit_config) #define KVM_SET_BOOT_CPU_ID _IO(KVMIO, 0x78) #define KVM_IOEVENTFD _IOW(KVMIO, 0x79, struct kvm_ioeventfd) +#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