pve-kernel-lowlatency-qoup/patches/kernel/0014-KVM-x86-SVM-don-t-save-SVM-state-to-SMRAM-when-VM-is.patch
Thomas Lamprecht 9fde3ef1c6 wireless: Add Debian wireless-regdb certificates
so that plain Debian crda + wireless-regdb can work, alternatively we
could disable CRDA and bake in the regdb directly in the kernel,
using the CFG80211_INTERNAL_REGDB KConfig.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
2023-02-10 12:48:20 +01:00

45 lines
1.5 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@redhat.com>
Date: Wed, 3 Aug 2022 18:50:10 +0300
Subject: [PATCH] KVM: x86: SVM: don't save SVM state to SMRAM when VM is not
long mode capable
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
When the guest CPUID doesn't have support for long mode, 32 bit SMRAM
layout is used and it has no support for preserving EFER and/or SVM
state.
Note that this isn't relevant to running 32 bit guests on VM which is
long mode capable - such VM can still run 32 bit guests in compatibility
mode.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---
arch/x86/kvm/svm/svm.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index bfacbef667d7..6b02f99fe70c 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4394,6 +4394,15 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, union kvm_smram *smram)
if (!is_guest_mode(vcpu))
return 0;
+ /*
+ * 32 bit SMRAM format doesn't preserve EFER and SVM state.
+ * SVM should not be enabled by the userspace without marking
+ * the CPU as at least long mode capable.
+ */
+
+ if (!guest_cpuid_has(vcpu, X86_FEATURE_LM))
+ return 1;
+
smram->smram64.svm_guest_flag = 1;
smram->smram64.svm_guest_vmcb_gpa = svm->nested.vmcb12_gpa;