From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37856) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZyYhY-0001qZ-Jv for qemu-devel@nongnu.org; Tue, 17 Nov 2015 00:21:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZyYhV-0006bB-Ha for qemu-devel@nongnu.org; Tue, 17 Nov 2015 00:21:08 -0500 Received: from mga01.intel.com ([192.55.52.88]:12755) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZyYhV-0006b6-CE for qemu-devel@nongnu.org; Tue, 17 Nov 2015 00:21:05 -0500 From: Haozhong Zhang Date: Tue, 17 Nov 2015 13:20:38 +0800 Message-Id: <1447737639-6139-3-git-send-email-haozhong.zhang@intel.com> In-Reply-To: <1447737639-6139-1-git-send-email-haozhong.zhang@intel.com> References: <1447737639-6139-1-git-send-email-haozhong.zhang@intel.com> Subject: [Qemu-devel] [PATCH v5 2/3] target-i386: reorganize TSC rate setting code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, Eduardo Habkost , "Dr. David Alan Gilbert" Cc: Haozhong Zhang , kvm@vger.kernel.org, "Michael S. Tsirkin" , Marcelo Tosatti , Paolo Bonzini , afaerber@suse.de, Richard Henderson Following two changes are made to the TSC rate setting code in kvm_arch_init_vcpu(): * The code is moved to a new function kvm_arch_set_tsc_khz(). * If setting user-specified TSC rate fails and the host TSC rate is inconsistent with the user-specified one, print a warning message. Signed-off-by: Haozhong Zhang --- target-i386/kvm.c | 45 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 38 insertions(+), 7 deletions(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 9e4d27f..6a1acb4 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -524,6 +524,41 @@ static bool hyperv_enabled(X86CPU *cpu) cpu->hyperv_runtime); } +/** + * Ask KVM to set vcpu's TSC rate to X86_CPU(cs)->env.tsc_khz. + * + * Returns: 0 if successful; + * -ENOTSUP if KVM_CAP_TSC_CONTROL is unavailable; + * -EIO if KVM_SET_TSC_KHZ fails. + */ +static int kvm_arch_set_tsc_khz(CPUState *cs) +{ + X86CPU *cpu = X86_CPU(cs); + CPUX86State *env = &cpu->env; + int has_tsc_control, r = 0; + + if (!env->tsc_khz) { + return 0; + } + + has_tsc_control = kvm_check_extension(cs->kvm_state, KVM_CAP_TSC_CONTROL); + if (has_tsc_control) { + r = kvm_vcpu_ioctl(cs, KVM_SET_TSC_KHZ, env->tsc_khz); + } + + if (!has_tsc_control || r < 0) { + r = kvm_check_extension(cs->kvm_state, KVM_CAP_GET_TSC_KHZ) ? + kvm_vcpu_ioctl(cs, KVM_GET_TSC_KHZ) : -ENOTSUP; + if (r <= 0 || r != env->tsc_khz) { + error_report("warning: TSC frequency mismatch between " + "VM and host, and TSC scaling unavailable"); + return has_tsc_control ? -EIO : -ENOTSUP; + } + } + + return 0; +} + static Error *invtsc_mig_blocker; #define KVM_MAX_CPUID_ENTRIES 100 @@ -823,13 +858,9 @@ int kvm_arch_init_vcpu(CPUState *cs) return r; } - r = kvm_check_extension(cs->kvm_state, KVM_CAP_TSC_CONTROL); - if (r && env->tsc_khz) { - r = kvm_vcpu_ioctl(cs, KVM_SET_TSC_KHZ, env->tsc_khz); - if (r < 0) { - fprintf(stderr, "KVM_SET_TSC_KHZ failed\n"); - return r; - } + if (kvm_arch_set_tsc_khz(cs) == -EIO) { + fprintf(stderr, "KVM_SET_TSC_KHZ failed\n"); + return -EIO; } /* -- 2.4.8