From mboxrd@z Thu Jan 1 00:00:00 1970 From: Haozhong Zhang Subject: [PATCH v4 03/10] svm: Remove redundant TSC scaling in svm_set_tsc_offset() Date: Mon, 18 Jan 2016 05:58:52 +0800 Message-ID: <1453067939-9121-4-git-send-email-haozhong.zhang@intel.com> References: <1453067939-9121-1-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: <1453067939-9121-1-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, Jan Beulich , Boris Ostrovsky , Kevin Tian Cc: Haozhong Zhang , Keir Fraser , Suravee Suthikulpanit , Andrew Cooper , Aravind Gopalakrishnan , Jun Nakajima List-Id: xen-devel@lists.xenproject.org Now every caller passes an already scaled offset to svm_set_tsc_offset(), so it's not necessary to recalculate a scaled TSC offset in svm_set_tsc_offset(). Signed-off-by: Haozhong Zhang Reviewed-by: Boris Ostrovsky --- Changes in v4: (addressing Jan Beulich's comments) * Fix code style. xen/arch/x86/hvm/svm/svm.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index a46bc98..953e0b5 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -823,19 +823,6 @@ static void svm_set_tsc_offset(struct vcpu *v, u64 offset, u64 at_tsc) struct vmcb_struct *n1vmcb, *n2vmcb; uint64_t n2_tsc_offset = 0; struct domain *d = v->domain; - uint64_t host_tsc, guest_tsc; - - guest_tsc = hvm_get_guest_tsc_fixed(v, at_tsc); - - /* Re-adjust the offset value when TSC_RATIO is available */ - if ( cpu_has_tsc_ratio && !d->arch.vtsc ) - { - if ( at_tsc ) - host_tsc = at_tsc; - else - host_tsc = rdtsc(); - offset = svm_get_tsc_offset(host_tsc, guest_tsc, vcpu_tsc_ratio(v)); - } if ( !nestedhvm_enabled(d) ) { vmcb_set_tsc_offset(vmcb, offset); @@ -849,10 +836,13 @@ static void svm_set_tsc_offset(struct vcpu *v, u64 offset, u64 at_tsc) struct nestedsvm *svm = &vcpu_nestedsvm(v); n2_tsc_offset = vmcb_get_tsc_offset(n2vmcb) - - vmcb_get_tsc_offset(n1vmcb); + vmcb_get_tsc_offset(n1vmcb); if ( svm->ns_tscratio != DEFAULT_TSC_RATIO ) { + uint64_t guest_tsc = hvm_get_guest_tsc_fixed(v, at_tsc); + n2_tsc_offset = svm_get_tsc_offset(guest_tsc, - guest_tsc + n2_tsc_offset, svm->ns_tscratio); + guest_tsc + n2_tsc_offset, + svm->ns_tscratio); } vmcb_set_tsc_offset(n1vmcb, offset); } -- 2.7.0