From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40238) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vkfmj-0007Oq-AR for qemu-devel@nongnu.org; Sun, 24 Nov 2013 14:56:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Vkfmd-0003Bo-7P for qemu-devel@nongnu.org; Sun, 24 Nov 2013 14:56:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2746) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vkfmc-0003Be-Uc for qemu-devel@nongnu.org; Sun, 24 Nov 2013 14:55:55 -0500 From: Eduardo Habkost Date: Sun, 24 Nov 2013 17:55:36 -0200 Message-Id: <1385322940-27325-5-git-send-email-ehabkost@redhat.com> In-Reply-To: <1385322940-27325-1-git-send-email-ehabkost@redhat.com> References: <1385322940-27325-1-git-send-email-ehabkost@redhat.com> Subject: [Qemu-devel] [PATCH 4/8] target-i386: kvm_cpu_fill_host(): No need to check xlevel2 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Igor Mammedov , =?UTF-8?q?Andreas=20F=C3=A4rber?= There's no need to check CPU xlevel2 before calling kvm_arch_get_supported_cpuid(s, 0xC0000001, 0, R_EDX), because: * The kernel won't return any entry for 0xC0000000 if host CPU vendor is not Centaur (See kvm_dev_ioctl_get_supported_cpuid() on the kernel code) * Similarly, the kernel won't return any entry for 0xC0000001 if CPUID[0xC0000000].EAX is < 0xC0000001 * kvm_arch_get_supported_cpuid() will return 0 if no entry is returned by the kernel for the requested leaf For similar reasons, we can simply set x86_cpu_def->xlevel2 directly instead of making it conditional, because it will be set to 0 CPU vendor is not Centaur. This will simplify the kvm_cpu_fill_host() code a little. Signed-off-by: Eduardo Habkost --- target-i386/cpu.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 41726f8..9731493 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -1176,13 +1176,11 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) cpu_x86_fill_model_id(x86_cpu_def->model_id); /* Call Centaur's CPUID instruction. */ - eax = kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX); - if (eax >= 0xC0000001) { - /* Support VIA max extended level */ - x86_cpu_def->xlevel2 = eax; - x86_cpu_def->features[FEAT_C000_0001_EDX] = - kvm_arch_get_supported_cpuid(s, 0xC0000001, 0, R_EDX); - } + x86_cpu_def->xlevel2 = + kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX); + /* Support VIA max extended level */ + x86_cpu_def->features[FEAT_C000_0001_EDX] = + kvm_arch_get_supported_cpuid(s, 0xC0000001, 0, R_EDX); /* Other KVM-specific feature fields: */ x86_cpu_def->features[FEAT_SVM] = -- 1.8.3.1