Commit 6cb8f2a6 authored by Brijesh Singh's avatar Brijesh Singh Committed by Paolo Bonzini
Browse files

cpu/i386: populate CPUID 0x8000_001F when SEV is active 

When SEV is enabled, CPUID 0x8000_001F should provide additional
information regarding the feature (such as which page table bit is used
to mark the pages as encrypted etc).

The details for memory encryption CPUID is available in AMD APM
(https://support.amd.com/TechDocs/24594.pdf

) Section E.4.17

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 8fa4466d

target/i386/cpu.c

+13 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include "sysemu/hvf.h"

#include "sysemu/cpus.h"

#include "kvm_i386.h"

#include "sev_i386.h"



#include "qemu/error-report.h"

#include "qemu/option.h"
@@ -3612,6 +3613,13 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, 
        *ecx = 0;

        *edx = 0;

        break;

    case 0x8000001F:

        *eax = sev_enabled() ? 0x2 : 0;

        *ebx = sev_get_cbit_position();

        *ebx |= sev_get_reduced_phys_bits() << 6;

        *ecx = 0;

        *edx = 0;

        break;

    default:

        /* reserved values: zero */

        *eax = 0;
@@ -4042,6 +4050,11 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error **errp) 
        if (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_SVM) {

            x86_cpu_adjust_level(cpu, &env->cpuid_min_xlevel, 0x8000000A);

        }



        /* SEV requires CPUID[0x8000001F] */

        if (sev_enabled()) {

            x86_cpu_adjust_level(cpu, &env->cpuid_min_xlevel, 0x8000001F);

        }

    }



    /* Set cpuid_*level* based on cpuid_min_*level, if not explicitly set */