leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

KVM: x86: WARN and reject loading KVM if NX is supported but not enabled

Browse Source 
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>
This commit is contained in:
Sean Christopherson 2021-06-15 09:45:34 -07:00 committed by Paolo Bonzini
parent b26a71a1a5
commit 8bbed95d2c
1 changed files with 3 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/x86/kvm/x86.c
View File

@ -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);