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| author | Sean Christopherson <seanjc@google.com> | 2021-06-15 19:45:34 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-06-18 13:24:50 +0300 |
| commit | 8bbed95d2cb6e5de8a342d761a89b0a04faed7be (patch) | |
| tree | b29d109013807d563aea7ff33c2b23e6a175a70a /arch/x86/kvm | |
| parent | b26a71a1a5b93531bd93305c9c0c7eae2d5cace1 (diff) | |
| download | linux-8bbed95d2cb6e5de8a342d761a89b0a04faed7be.tar.xz | |
KVM: x86: WARN and reject loading KVM if NX is supported but not enabled
WARN if NX is reported as supported but not enabled in EFER. All flavors
of the kernel, including non-PAE 32-bit kernels, set EFER.NX=1 if NX is
supported, even if NX usage is disable via kernel command line. KVM relies
on NX being enabled if it's supported, e.g. KVM will generate illegal NPT
entries if nx_huge_pages is enabled and NX is supported but not enabled.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210615164535.2146172-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8b898ec8d349..76dae88cf524 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10920,6 +10920,9 @@ int kvm_arch_hardware_setup(void *opaque) int r; rdmsrl_safe(MSR_EFER, &host_efer); + if (WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_NX) && + !(host_efer & EFER_NX))) + return -EIO; if (boot_cpu_has(X86_FEATURE_XSAVES)) rdmsrl(MSR_IA32_XSS, host_xss); |