queue-6.1/kvm-svm-enhance-info-printk-s-in-sev-init.patch

   1 From 6688ee674bc40eb0df66195e870205542c8ae100 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Mon, 22 May 2023 18:12:48 +0200
   4 Subject: KVM: SVM: enhance info printk's in SEV init
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 From: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
  10
  11 [ Upstream commit 6d1bc9754b04075d938b47cf7f7800814b8911a7 ]
  12
  13 Let's print available ASID ranges for SEV/SEV-ES guests.
  14 This information can be useful for system administrator
  15 to debug if SEV/SEV-ES fails to enable.
  16
  17 There are a few reasons.
  18 SEV:
  19 - NPT is disabled (module parameter)
  20 - CPU lacks some features (sev, decodeassists)
  21 - Maximum SEV ASID is 0
  22
  23 SEV-ES:
  24 - mmio_caching is disabled (module parameter)
  25 - CPU lacks sev_es feature
  26 - Minimum SEV ASID value is 1 (can be adjusted in BIOS/UEFI)
  27
  28 Cc: Sean Christopherson <seanjc@google.com>
  29 Cc: Paolo Bonzini <pbonzini@redhat.com>
  30 Cc: Stéphane Graber <stgraber@ubuntu.com>
  31 Cc: kvm@vger.kernel.org
  32 Cc: linux-kernel@vger.kernel.org
  33 Suggested-by: Sean Christopherson <seanjc@google.com>
  34 Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
  35 Link: https://lore.kernel.org/r/20230522161249.800829-3-aleksandr.mikhalitsyn@canonical.com
  36 [sean: print '0' for min SEV-ES ASID if there are no available ASIDs]
  37 Signed-off-by: Sean Christopherson <seanjc@google.com>
  38 Stable-dep-of: 0aa6b90ef9d7 ("KVM: SVM: Add support for allowing zero SEV ASIDs")
  39 Signed-off-by: Sasha Levin <sashal@kernel.org>
  40 ---
  41  arch/x86/kvm/svm/sev.c | 11 +++++++++--
  42  1 file changed, 9 insertions(+), 2 deletions(-)
  43
  44 diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
  45 index 3dc0ee1fe9db9..1fe9257d87b2d 100644
  46 --- a/arch/x86/kvm/svm/sev.c
  47 +++ b/arch/x86/kvm/svm/sev.c
  48 @@ -2217,7 +2217,6 @@ void __init sev_hardware_setup(void)
  49         if (misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count))
  50                 goto out;
  51
  52 -       pr_info("SEV supported: %u ASIDs\n", sev_asid_count);
  53         sev_supported = true;
  54
  55         /* SEV-ES support requested? */
  56 @@ -2245,10 +2244,18 @@ void __init sev_hardware_setup(void)
  57         if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count))
  58                 goto out;
  59
  60 -       pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count);
  61         sev_es_supported = true;
  62
  63  out:
  64 +       if (boot_cpu_has(X86_FEATURE_SEV))
  65 +               pr_info("SEV %s (ASIDs %u - %u)\n",
  66 +                       sev_supported ? "enabled" : "disabled",
  67 +                       min_sev_asid, max_sev_asid);
  68 +       if (boot_cpu_has(X86_FEATURE_SEV_ES))
  69 +               pr_info("SEV-ES %s (ASIDs %u - %u)\n",
  70 +                       sev_es_supported ? "enabled" : "disabled",
  71 +                       min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);
  72 +
  73         sev_enabled = sev_supported;
  74         sev_es_enabled = sev_es_supported;
  75  #endif
  76 --
  77 2.43.0
  78