From fa13680f5668cff05302a2f4753c49334a83a064 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 21 Apr 2021 19:11:13 -0700 Subject: [PATCH] KVM: SVM: Disable SEV/SEV-ES if NPT is disabled Disable SEV and SEV-ES if NPT is disabled. While the APM doesn't clearly state that NPT is mandatory, it's alluded to by: The guest page tables, managed by the guest, may mark data memory pages as either private or shared, thus allowing selected pages to be shared outside the guest. And practically speaking, shadow paging can't work since KVM can't read the guest's page tables. Fixes: e9df09428996 ("KVM: SVM: Add sev module_param") Cc: Brijesh Singh Signed-off-by: Sean Christopherson Message-Id: <20210422021125.3417167-4-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/svm.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 8bd30df..b854b13 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -982,21 +982,6 @@ static __init int svm_hardware_setup(void) kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE); } - if (IS_ENABLED(CONFIG_KVM_AMD_SEV) && sev) { - sev_hardware_setup(); - } else { - sev = false; - sev_es = false; - } - - svm_adjust_mmio_mask(); - - for_each_possible_cpu(cpu) { - r = svm_cpu_init(cpu); - if (r) - goto err; - } - /* * KVM's MMU doesn't support using 2-level paging for itself, and thus * NPT isn't supported if the host is using 2-level paging since host @@ -1011,6 +996,21 @@ static __init int svm_hardware_setup(void) kvm_configure_mmu(npt_enabled, get_max_npt_level(), PG_LEVEL_1G); pr_info("kvm: Nested Paging %sabled\n", npt_enabled ? "en" : "dis"); + if (IS_ENABLED(CONFIG_KVM_AMD_SEV) && sev && npt_enabled) { + sev_hardware_setup(); + } else { + sev = false; + sev_es = false; + } + + svm_adjust_mmio_mask(); + + for_each_possible_cpu(cpu) { + r = svm_cpu_init(cpu); + if (r) + goto err; + } + if (nrips) { if (!boot_cpu_has(X86_FEATURE_NRIPS)) nrips = false; -- 2.7.4