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authorMichael Roth <michael.roth@amd.com>2021-07-07 19:36:23 -0500
committerEduardo Habkost <ehabkost@redhat.com>2021-07-13 09:13:29 -0400
commita7a0da844d299971bdbf99665bd63398668dde83 (patch)
tree5f037a3755255de83a7c4f788cec7a5889ad77e9 /target/i386
parentcce087f628c651e905f5e2097d9bb9f678689669 (diff)
target/i386: suppress CPUID leaves not defined by the CPU vendor
Currently all built-in CPUs report cache information via CPUID leaves 2 and 4, but these have never been defined for AMD. In the case of SEV-SNP this can cause issues with CPUID enforcement. Address this by allowing CPU types to suppress these via a new "x-vendor-cpuid-only" CPU property, which is true by default, but switched off for older machine types to maintain compatibility. Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: zhenwei pi <pizhenwei@bytedance.com> Suggested-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Message-Id: <20210708003623.18665-1-michael.roth@amd.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Diffstat (limited to 'target/i386')
-rw-r--r--target/i386/cpu.c6
-rw-r--r--target/i386/cpu.h3
2 files changed, 9 insertions, 0 deletions
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 46befde387..6b7043e425 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5155,6 +5155,9 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
if (cpu->cache_info_passthrough) {
host_cpuid(index, 0, eax, ebx, ecx, edx);
break;
+ } else if (cpu->vendor_cpuid_only && IS_AMD_CPU(env)) {
+ *eax = *ebx = *ecx = *edx = 0;
+ break;
}
*eax = 1; /* Number of CPUID[EAX=2] calls required */
*ebx = 0;
@@ -5176,6 +5179,8 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
if ((*eax & 31) && cs->nr_cores > 1) {
*eax |= (cs->nr_cores - 1) << 26;
}
+ } else if (cpu->vendor_cpuid_only && IS_AMD_CPU(env)) {
+ *eax = *ebx = *ecx = *edx = 0;
} else {
*eax = 0;
switch (count) {
@@ -6651,6 +6656,7 @@ static Property x86_cpu_properties[] = {
DEFINE_PROP_BOOL("full-cpuid-auto-level", X86CPU, full_cpuid_auto_level, true),
DEFINE_PROP_STRING("hv-vendor-id", X86CPU, hyperv_vendor),
DEFINE_PROP_BOOL("cpuid-0xb", X86CPU, enable_cpuid_0xb, true),
+ DEFINE_PROP_BOOL("x-vendor-cpuid-only", X86CPU, vendor_cpuid_only, true),
DEFINE_PROP_BOOL("lmce", X86CPU, enable_lmce, false),
DEFINE_PROP_BOOL("l3-cache", X86CPU, enable_l3_cache, true),
DEFINE_PROP_BOOL("kvm-no-smi-migration", X86CPU, kvm_no_smi_migration,
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 8f3747dd28..950a991a71 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1748,6 +1748,9 @@ struct X86CPU {
/* Enable auto level-increase for all CPUID leaves */
bool full_cpuid_auto_level;
+ /* Only advertise CPUID leaves defined by the vendor */
+ bool vendor_cpuid_only;
+
/* Enable auto level-increase for Intel Processor Trace leave */
bool intel_pt_auto_level;