From e6f541bd5eea74185e34e41e628d52cfc5ab7b6a Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Thu, 26 Jul 2018 17:19:03 +0100 Subject: [PATCH 13/14] i386: Remove generic SMT thread check RH-Author: Eduardo Habkost Message-id: <20180726171904.27418-11-ehabkost@redhat.com> Patchwork-id: 81532 O-Subject: [qemu-kvm RHEL8/virt212 PATCH v2 10/11] i386: Remove generic SMT thread check Bugzilla: 1597739 RH-Acked-by: Paolo Bonzini RH-Acked-by: Laurent Vivier RH-Acked-by: Igor Mammedov From: Babu Moger Remove generic non-intel check while validating hyperthreading support. Certain AMD CPUs can support hyperthreading now. CPU family with TOPOEXT feature can support hyperthreading now. Signed-off-by: Babu Moger Tested-by: Geoffrey McRae Reviewed-by: Eduardo Habkost Message-Id: <1529443919-67509-4-git-send-email-babu.moger@amd.com> Signed-off-by: Eduardo Habkost (cherry picked from commit 6b2942f966d5e54c37d305c80f5f98d504c2bc55) Signed-off-by: Eduardo Habkost Signed-off-by: Danilo C. L. de Paula --- target/i386/cpu.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index fe2b2e8..8647109 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -4952,17 +4952,22 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) qemu_init_vcpu(cs); - /* Only Intel CPUs support hyperthreading. Even though QEMU fixes this - * issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX - * based on inputs (sockets,cores,threads), it is still better to gives + /* + * Most Intel and certain AMD CPUs support hyperthreading. Even though QEMU + * fixes this issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX + * based on inputs (sockets,cores,threads), it is still better to give * users a warning. * * NOTE: the following code has to follow qemu_init_vcpu(). Otherwise * cs->nr_threads hasn't be populated yet and the checking is incorrect. */ - if (!IS_INTEL_CPU(env) && cs->nr_threads > 1 && !ht_warned) { - error_report("AMD CPU doesn't support hyperthreading. Please configure" - " -smp options properly."); + if (IS_AMD_CPU(env) && + !(env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) && + cs->nr_threads > 1 && !ht_warned) { + error_report("This family of AMD CPU doesn't support " + "hyperthreading(%d). Please configure -smp " + "options properly or try enabling topoext feature.", + cs->nr_threads); ht_warned = true; } -- 1.8.3.1