From f98bbd8304112187cafc3e636c31b2a3865d2717 Mon Sep 17 00:00:00 2001 From: Babu Moger Date: Wed, 13 Jun 2018 21:18:22 -0400 Subject: [PATCH] i386: Allow TOPOEXT to be enabled on older kernels 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 --- target/i386/kvm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 445e0e0b11..2d174f3a91 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: -- GitLab