From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36430) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrW2e-0003Ut-Kr for qemu-devel@nongnu.org; Mon, 02 Jun 2014 13:29:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WrW2X-0000IP-5R for qemu-devel@nongnu.org; Mon, 02 Jun 2014 13:29:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61459) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrW2W-0000IH-Te for qemu-devel@nongnu.org; Mon, 02 Jun 2014 13:28:53 -0400 From: Alex Williamson Date: Mon, 02 Jun 2014 11:28:50 -0600 Message-ID: <20140602172811.13457.57010.stgit@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH] kvm: Enable -cpu option to hide KVM List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, kvm@vger.kernel.org The latest Nvidia driver (337.88) specifically checks for KVM as the hypervisor and reports Code 43 for the driver in a Windows guest when found. Removing or changing the KVM signature is sufficient for the driver to load and work. This patch adds an option to easily allow the KVM hypervisor signature to be hidden using '-cpu kvm=off'. We continue to expose KVM via the cpuid value by default. The state of this option does not supercede or replace -enable-kvm or the accel=kvm machine option. This only changes the visibility of KVM to the guest and paravirtual features specifically tied to the KVM cpuid. Signed-off-by: Alex Williamson --- target-i386/cpu-qom.h | 1 + target-i386/cpu.c | 1 + target-i386/kvm.c | 28 +++++++++++++++------------- 3 files changed, 17 insertions(+), 13 deletions(-) diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h index e9b3d57..0808cfc 100644 --- a/target-i386/cpu-qom.h +++ b/target-i386/cpu-qom.h @@ -87,6 +87,7 @@ typedef struct X86CPU { bool hyperv_time; bool check_cpuid; bool enforce_cpuid; + bool expose_kvm; /* if true the CPUID code directly forward host cache leaves to the guest */ bool cache_info_passthrough; diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 042a48d..cbf1d97 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -2792,6 +2792,7 @@ static Property x86_cpu_properties[] = { DEFINE_PROP_BOOL("hv-time", X86CPU, hyperv_time, false), DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, false), DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false), + DEFINE_PROP_BOOL("kvm", X86CPU, expose_kvm, true), DEFINE_PROP_END_OF_LIST() }; diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 0d894ef..b2295d2 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -528,23 +528,25 @@ int kvm_arch_init_vcpu(CPUState *cs) has_msr_hv_hypercall = true; } - memcpy(signature, "KVMKVMKVM\0\0\0", 12); - c = &cpuid_data.entries[cpuid_i++]; - c->function = KVM_CPUID_SIGNATURE | kvm_base; - c->eax = 0; - c->ebx = signature[0]; - c->ecx = signature[1]; - c->edx = signature[2]; + if (cpu->expose_kvm) { + memcpy(signature, "KVMKVMKVM\0\0\0", 12); + c = &cpuid_data.entries[cpuid_i++]; + c->function = KVM_CPUID_SIGNATURE | kvm_base; + c->eax = 0; + c->ebx = signature[0]; + c->ecx = signature[1]; + c->edx = signature[2]; - c = &cpuid_data.entries[cpuid_i++]; - c->function = KVM_CPUID_FEATURES | kvm_base; - c->eax = env->features[FEAT_KVM]; + c = &cpuid_data.entries[cpuid_i++]; + c->function = KVM_CPUID_FEATURES | kvm_base; + c->eax = env->features[FEAT_KVM]; - has_msr_async_pf_en = c->eax & (1 << KVM_FEATURE_ASYNC_PF); + has_msr_async_pf_en = c->eax & (1 << KVM_FEATURE_ASYNC_PF); - has_msr_pv_eoi_en = c->eax & (1 << KVM_FEATURE_PV_EOI); + has_msr_pv_eoi_en = c->eax & (1 << KVM_FEATURE_PV_EOI); - has_msr_kvm_steal_time = c->eax & (1 << KVM_FEATURE_STEAL_TIME); + has_msr_kvm_steal_time = c->eax & (1 << KVM_FEATURE_STEAL_TIME); + } cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);