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| author | Sean Christopherson <seanjc@google.com> | 2023-08-25 04:36:19 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-08-25 19:00:40 +0300 |
| commit | 80d0f521d59e08eeaa0bc5d624da139448fb99b8 (patch) | |
| tree | fd8edcc490ee545e81543888adb6ee087b167055 /arch/x86/kvm/svm/svm.c | |
| parent | cb49631ad111570f1bad37702c11c2ae07fa2e3c (diff) | |
| download | linux-80d0f521d59e08eeaa0bc5d624da139448fb99b8.tar.xz | |
KVM: SVM: Require nrips support for SEV guests (and beyond)
Disallow SEV (and beyond) if nrips is disabled via module param, as KVM
can't read guest memory to partially emulate and skip an instruction. All
CPUs that support SEV support NRIPS, i.e. this is purely stopping the user
from shooting themselves in the foot.
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20230825013621.2845700-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index d7a474571ff1..5cf2380c89dd 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -203,7 +203,7 @@ static int nested = true; module_param(nested, int, S_IRUGO); /* enable/disable Next RIP Save */ -static int nrips = true; +int nrips = true; module_param(nrips, int, 0444); /* enable/disable Virtual VMLOAD VMSAVE */ @@ -5156,9 +5156,11 @@ static __init int svm_hardware_setup(void) svm_adjust_mmio_mask(); + nrips = nrips && boot_cpu_has(X86_FEATURE_NRIPS); + /* * Note, SEV setup consumes npt_enabled and enable_mmio_caching (which - * may be modified by svm_adjust_mmio_mask()). + * may be modified by svm_adjust_mmio_mask()), as well as nrips. */ sev_hardware_setup(); @@ -5170,11 +5172,6 @@ static __init int svm_hardware_setup(void) goto err; } - if (nrips) { - if (!boot_cpu_has(X86_FEATURE_NRIPS)) - nrips = false; - } - enable_apicv = avic = avic && avic_hardware_setup(); if (!enable_apicv) { |