From patchwork Thu Oct 4 20:49:01 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [09/15] i386: kvm: set CPUID_EXT_TSC_DEADLINE_TIMER on kvm_arch_get_supported_cpuid() From: Eduardo Habkost X-Patchwork-Id: 189330 Message-Id: <1349383747-19383-10-git-send-email-ehabkost@redhat.com> To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, Gleb Natapov , Marcelo Tosatti , Avi Kivity , Igor Mammedov , =?UTF-8?q?Andreas=20F=C3=A4rber?= Date: Thu, 4 Oct 2012 17:49:01 -0300 This moves the CPUID_EXT_TSC_DEADLINE_TIMER CPUID flag hacking from kvm_arch_init_vcpu() to kvm_arch_get_supported_cpuid(). Full git grep for kvm_arch_get_supported_cpuid: kvm.h:uint32_t kvm_arch_get_supported_cpuid(KVMState *env, uint32_t function, target-i386/cpu.c: x86_cpu_def->cpuid_7_0_ebx_features = kvm_arch_get_supported_cpuid(kvm_state, 0x7, 0, R_EBX); target-i386/cpu.c: *eax = kvm_arch_get_supported_cpuid(s, 0xA, count, R_EAX); target-i386/cpu.c: *ebx = kvm_arch_get_supported_cpuid(s, 0xA, count, R_EBX); target-i386/cpu.c: *ecx = kvm_arch_get_supported_cpuid(s, 0xA, count, R_ECX); target-i386/cpu.c: *edx = kvm_arch_get_supported_cpuid(s, 0xA, count, R_EDX); target-i386/cpu.c: *eax = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EAX); target-i386/cpu.c: *ebx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EBX); target-i386/cpu.c: *ecx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_ECX); target-i386/cpu.c: *edx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EDX); target-i386/kvm.c:uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, target-i386/kvm.c: cpuid_1_edx = kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX); target-i386/kvm.c: env->cpuid_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX); * target-i386/kvm.c: env->cpuid_ext_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_ECX); target-i386/kvm.c: env->cpuid_ext2_features &= kvm_arch_get_supported_cpuid(s, 0x80000001, target-i386/kvm.c: env->cpuid_ext3_features &= kvm_arch_get_supported_cpuid(s, 0x80000001, target-i386/kvm.c: env->cpuid_svm_features &= kvm_arch_get_supported_cpuid(s, 0x8000000A, target-i386/kvm.c: kvm_arch_get_supported_cpuid(s, KVM_CPUID_FEATURES, 0, R_EAX); target-i386/kvm.c: kvm_arch_get_supported_cpuid(s, 0xC0000001, 0, R_EDX); Note that there is only one call for CPUID[1].ECX above (*), and it is the one that gets hacked to include CPUID_EXT_TSC_DEADLINE_TIMER, so we can simply make kvm_arch_get_supported_cpuid() set it, to let the rest of the code know the flag can be safely set by QEMU. One thing I was worrying about when doing this is that now kvm_arch_get_supported_cpuid() depends on kvm_irqchip_in_kernel(). But the 'kvm_kernel_irqchip' global variable is initialized during kvm_init(), that is called very early, and kvm_init() is already a requirement to run the GET_SUPPORTED_CPUID ioctl() (as kvm_init() is the function that initializes the 'kvm_state' global variable). Signed-off-by: Eduardo Habkost --- target-i386/kvm.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 1f451e3..704ad33 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -201,6 +201,14 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, * GET_SUPPORTED_CPUID */ ret |= CPUID_EXT_HYPERVISOR; + /* tsc-deadline flag is not returned by GET_SUPPORTED_CPUID, but it + * can be enabled if the kernel has KVM_CAP_TSC_DEADLINE_TIMER, + * and the irqchip is in the kernel. + */ + if (kvm_irqchip_in_kernel() && + kvm_check_extension(s, KVM_CAP_TSC_DEADLINE_TIMER)) { + ret |= CPUID_EXT_TSC_DEADLINE_TIMER; + } } else if (function == 0x80000001 && reg == R_EDX) { /* On Intel, kvm returns cpuid according to the Intel spec, * so add missing bits according to the AMD spec: @@ -404,12 +412,7 @@ int kvm_arch_init_vcpu(CPUX86State *env) env->cpuid_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX); - j = env->cpuid_ext_features & CPUID_EXT_TSC_DEADLINE_TIMER; env->cpuid_ext_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_ECX); - if (j && kvm_irqchip_in_kernel() && - kvm_check_extension(s, KVM_CAP_TSC_DEADLINE_TIMER)) { - env->cpuid_ext_features |= CPUID_EXT_TSC_DEADLINE_TIMER; - } env->cpuid_ext2_features &= kvm_arch_get_supported_cpuid(s, 0x80000001, 0, R_EDX);