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authorBabu Moger <babu.moger@amd.com>2018-06-13 21:18:22 -0400
committerEduardo Habkost <ehabkost@redhat.com>2018-06-22 15:01:15 -0300
commitf98bbd8304112187cafc3e636c31b2a3865d2717 (patch)
treed432efb88458ef55408c96786450b5d8cb5a3ec7 /target
parent254790a909a2f153d689bfa7d8e8f0386cda870d (diff)
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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 <babu.moger@amd.com> Message-Id: <1528939107-17193-2-git-send-email-babu.moger@amd.com> [ehabkost: rewrite comment and commit message] Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Diffstat (limited to 'target')
-rw-r--r--target/i386/kvm.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 445e0e0..2d174f3 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: