| Message ID | 20230522161249.800829-3-aleksandr.mikhalitsyn@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: SVM: small tweaks for sev_hardware_setup | expand |
On Mon, May 22, 2023, Alexander Mikhalitsyn wrote: > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > index cc832a8d1bca..fff63d1f2a34 100644 > --- a/arch/x86/kvm/svm/sev.c > +++ b/arch/x86/kvm/svm/sev.c > @@ -2224,7 +2224,6 @@ void __init sev_hardware_setup(void) > goto out; > } > > - pr_info("SEV supported: %u ASIDs\n", sev_asid_count); > sev_supported = true; > > /* SEV-ES support requested? */ > @@ -2252,10 +2251,16 @@ void __init sev_hardware_setup(void) > if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count)) > goto out; > > - pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count); > sev_es_supported = true; > > out: > + if (boot_cpu_has(X86_FEATURE_SEV)) > + pr_info("SEV %s (ASIDs %u - %u)\n", > + sev_supported ? "enabled" : "disabled", min_sev_asid, max_sev_asid); > + if (boot_cpu_has(X86_FEATURE_SEV_ES)) > + pr_info("SEV-ES %s (ASIDs %u - %u)\n", > + sev_es_supported ? "enabled" : "disabled", 1, min_sev_asid - 1); The min should print '0' if min_sev_asid<=1, otherwise the output will be SEV-ES disabled (ASIDs 1 - 0) which is confusing. That would also align with what gets printed out for SEV when it's not supported at all (min==max=0). No need for v3, I'll fixup when applying.
On Tue, Jun 6, 2023 at 8:46 PM Sean Christopherson <seanjc@google.com> wrote: > > On Mon, May 22, 2023, Alexander Mikhalitsyn wrote: > > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > > index cc832a8d1bca..fff63d1f2a34 100644 > > --- a/arch/x86/kvm/svm/sev.c > > +++ b/arch/x86/kvm/svm/sev.c > > @@ -2224,7 +2224,6 @@ void __init sev_hardware_setup(void) > > goto out; > > } > > > > - pr_info("SEV supported: %u ASIDs\n", sev_asid_count); > > sev_supported = true; > > > > /* SEV-ES support requested? */ > > @@ -2252,10 +2251,16 @@ void __init sev_hardware_setup(void) > > if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count)) > > goto out; > > > > - pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count); > > sev_es_supported = true; > > > > out: > > + if (boot_cpu_has(X86_FEATURE_SEV)) > > + pr_info("SEV %s (ASIDs %u - %u)\n", > > + sev_supported ? "enabled" : "disabled", min_sev_asid, max_sev_asid); > > + if (boot_cpu_has(X86_FEATURE_SEV_ES)) > > + pr_info("SEV-ES %s (ASIDs %u - %u)\n", > > + sev_es_supported ? "enabled" : "disabled", 1, min_sev_asid - 1); > > The min should print '0' if min_sev_asid<=1, otherwise the output will be > > SEV-ES disabled (ASIDs 1 - 0) > > which is confusing. That would also align with what gets printed out for SEV > when it's not supported at all (min==max=0). > > No need for v3, I'll fixup when applying. Got it. Ok! Thanks again for looking into that. Kind regards, Alex
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index cc832a8d1bca..fff63d1f2a34 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2224,7 +2224,6 @@ void __init sev_hardware_setup(void) goto out; } - pr_info("SEV supported: %u ASIDs\n", sev_asid_count); sev_supported = true; /* SEV-ES support requested? */ @@ -2252,10 +2251,16 @@ void __init sev_hardware_setup(void) if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count)) goto out; - pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count); sev_es_supported = true; out: + if (boot_cpu_has(X86_FEATURE_SEV)) + pr_info("SEV %s (ASIDs %u - %u)\n", + sev_supported ? "enabled" : "disabled", min_sev_asid, max_sev_asid); + if (boot_cpu_has(X86_FEATURE_SEV_ES)) + pr_info("SEV-ES %s (ASIDs %u - %u)\n", + sev_es_supported ? "enabled" : "disabled", 1, min_sev_asid - 1); + sev_enabled = sev_supported; sev_es_enabled = sev_es_supported; #endif
Let's print available ASID ranges for SEV/SEV-ES guests. This information can be useful for system administrator to debug if SEV/SEV-ES fails to enable. There are a few reasons. SEV: - NPT is disabled (module parameter) - CPU lacks some features (sev, decodeassists) - Maximum SEV ASID is 0 SEV-ES: - mmio_caching is disabled (module parameter) - CPU lacks sev_es feature - Minimum SEV ASID value is 1 (can be adjusted in BIOS/UEFI) Cc: Sean Christopherson <seanjc@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stéphane Graber <stgraber@ubuntu.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> --- v2: - print only the ASID ranges according to Sean's suggestion --- arch/x86/kvm/svm/sev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)