Commit a16e8dbc authored by Moger, Babu's avatar Moger, Babu Committed by Eduardo Habkost
Browse files

i386: Add missing cpu feature bits in EPYC model 



Adds the following missing CPUID bits:
perfctr-core : core performance counter extensions support. Enables the VM
               to use extended performance counter support. It enables six
               programmable counters instead of 4 counters.
clzero       : instruction zeroes out the 64 byte cache line specified in RAX.
xsaveerptr   : XSAVE, XSAVE, FXSAVEOPT, XSAVEC, XSAVES always save error
               pointers and FXRSTOR, XRSTOR, XRSTORS always restore error
               pointers.
ibpb         : Indirect Branch Prediction Barrie.
xsaves       : XSAVES, XRSTORS and IA32_XSS supported.

Depends on following kernel commits:
40bc47b08b6e ("kvm: x86: Enumerate support for CLZERO instruction")
504ce1954fba ("KVM: x86: Expose XSAVEERPTR to the guest")
52297436199d ("kvm: svm: Update svm_xsaves_supported")

These new features will be added in EPYC-v3. The -cpu help output after the change.
x86 EPYC-v1               AMD EPYC Processor
x86 EPYC-v2               AMD EPYC Processor (with IBPB)
x86 EPYC-v3               AMD EPYC Processor

Signed-off-by: default avatarBabu Moger <babu.moger@amd.com>
Message-Id: <157314965662.23828.3063243729449408327.stgit@naples-babu.amd.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent c63938df

target/i386/cpu.c

+13 −4
Original line number Diff line number Diff line
@@ -3942,10 +3942,6 @@ static X86CPUDefinition builtin_x86_defs[] = { 
            CPUID_7_0_EBX_SMEP | CPUID_7_0_EBX_BMI2 | CPUID_7_0_EBX_RDSEED |

            CPUID_7_0_EBX_ADX | CPUID_7_0_EBX_SMAP | CPUID_7_0_EBX_CLFLUSHOPT |

            CPUID_7_0_EBX_SHA_NI,

        /* Missing: XSAVES (not supported by some Linux versions,

         * including v4.1 to v4.12).

         * KVM doesn't yet expose any XSAVES state save component.

         */

        .features[FEAT_XSAVE] =

            CPUID_XSAVE_XSAVEOPT | CPUID_XSAVE_XSAVEC |

            CPUID_XSAVE_XGETBV1,
@@ -3968,6 +3964,19 @@ static X86CPUDefinition builtin_x86_defs[] = { 
                    { /* end of list */ }

                }

            },

            {

                .version = 3,

                .props = (PropValue[]) {

                    { "ibpb", "on" },

                    { "perfctr-core", "on" },

                    { "clzero", "on" },

                    { "xsaveerptr", "on" },

                    { "xsaves", "on" },

                    { "model-id",

                      "AMD EPYC Processor" },

                    { /* end of list */ }

                }

            },

            { /* end of list */ }

        }

    },