From 499c2933a848699a80edd44308e1c4f7497a8a66 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Thu, 26 Jul 2018 15:25:35 +0200 Subject: [PATCH 10/15] i386: Allow TOPOEXT to be enabled on older kernels RH-Author: Eduardo Habkost Message-id: <20180726152535.4493-2-ehabkost@redhat.com> Patchwork-id: 81513 O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH 1/1] i386: Allow TOPOEXT to be enabled on older kernels Bugzilla: 1608698 RH-Acked-by: Laurent Vivier RH-Acked-by: Paolo Bonzini RH-Acked-by: Igor Mammedov From: Babu Moger Enabling TOPOEXT feature might cause compatibility issues if older kernels does not set this feature. Lets set this feature unconditionally. Signed-off-by: Babu Moger Message-Id: <1528939107-17193-2-git-send-email-babu.moger@amd.com> [ehabkost: rewrite comment and commit message] Signed-off-by: Eduardo Habkost (cherry picked from commit f98bbd8304112187cafc3e636c31b2a3865d2717) Signed-off-by: Eduardo Habkost Signed-off-by: Miroslav Rezanina --- target/i386/kvm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 447215b..00f2141 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -372,6 +372,13 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (host_tsx_blacklisted()) { ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE); } + } else if (function == 0x80000001 && reg == R_ECX) { + /* + * It's safe to enable TOPOEXT even if it's not returned by + * GET_SUPPORTED_CPUID. Unconditionally enabling TOPOEXT here allows + * us to keep CPU models including TOPOEXT runnable on older kernels. + */ + ret |= CPUID_EXT3_TOPOEXT; } 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: -- 1.8.3.1