From mboxrd@z Thu Jan 1 00:00:00 1970 From: Haozhong Zhang Subject: [PATCH 11/13] vmx: Use scaled host TSC to calculate TSC offset Date: Mon, 28 Sep 2015 15:13:56 +0800 Message-ID: <1443424438-13404-12-git-send-email-haozhong.zhang@intel.com> References: <1443424438-13404-1-git-send-email-haozhong.zhang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1443424438-13404-1-git-send-email-haozhong.zhang@intel.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: Haozhong Zhang , Kevin Tian , Wei Liu , Ian Campbell , Stefano Stabellini , Jun Nakajima , Andrew Cooper , Ian Jackson , Aravind Gopalakrishnan , Jan Beulich , Keir Fraser , Boris Ostrovsky , Suravee Suthikulpanit List-Id: xen-devel@lists.xenproject.org If VMX TSC scaling is enabled and no TSC emulation is used, vmx_set_tsc_offset() will calculate the TSC offset by substracting the scaled host TSC from the current guest TSC. Signed-off-by: Haozhong Zhang --- xen/arch/x86/hvm/vmx/vmx.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 454440e..163974d 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -1102,11 +1102,26 @@ static void vmx_handle_cd(struct vcpu *v, unsigned long value) static void vmx_set_tsc_offset(struct vcpu *v, u64 offset, u64 at_tsc) { + uint64_t host_tsc, guest_tsc; + struct domain *d = v->domain; + + guest_tsc = hvm_get_guest_tsc_fixed(v, at_tsc); + + if ( cpu_has_vmx_tsc_scaling && !d->arch.vtsc ) + { + host_tsc = at_tsc ? at_tsc : rdtsc(); + offset = guest_tsc - hvm_scale_tsc(v, host_tsc); + } + vmx_vmcs_enter(v); + if ( !nestedhvm_enabled(d) ) + goto out; + if ( nestedhvm_vcpu_in_guestmode(v) ) offset += nvmx_get_tsc_offset(v); +out: __vmwrite(TSC_OFFSET, offset); vmx_vmcs_exit(v); } -- 2.4.8