Forcefully turn off SEV if NPT is disabled, e.g. via module param. SEV
requires NPT as the C-bit only exists if NPT is active.
Fixes: e9df09428996f ("KVM: SVM: Add sev module_param")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
RFC as it's entirely possible that I am completely misunderstanding how
SEV works. Compile tested only.
arch/x86/kvm/svm/svm.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 783330d0e7b88..e30629593458b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -860,8 +860,14 @@ static __init int svm_hardware_setup(void)
kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
}
+ if (!boot_cpu_has(X86_FEATURE_NPT))
+ npt_enabled = false;
+
+ if (npt_enabled && !npt)
+ npt_enabled = false;
+
if (sev) {
- if (boot_cpu_has(X86_FEATURE_SEV) &&
+ if (boot_cpu_has(X86_FEATURE_SEV) && npt_enabled &&
IS_ENABLED(CONFIG_KVM_AMD_SEV)) {
r = sev_hardware_setup();
if (r)
@@ -879,12 +885,6 @@ static __init int svm_hardware_setup(void)
goto err;
}
- if (!boot_cpu_has(X86_FEATURE_NPT))
- npt_enabled = false;
-
- if (npt_enabled && !npt)
- npt_enabled = false;
-
kvm_configure_mmu(npt_enabled, PG_LEVEL_1G);
pr_info("kvm: Nested Paging %sabled\n", npt_enabled ? "en" : "dis");
--
2.28.0
