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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2022-08-30 16:37:34 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-09-26 19:02:59 +0300 |
| commit | 66a329be4b0abc81ee3d9a7e4f77f5f33f435362 (patch) | |
| tree | 262749eb0b4908e3b410aa93211513fb7ffbb44c /arch/x86/kvm/vmx/nested.c | |
| parent | 9d78d6fb186bc4aff41b5d6c4726b76649d3cb53 (diff) | |
| download | linux-66a329be4b0abc81ee3d9a7e4f77f5f33f435362.tar.xz | |
KVM: nVMX: Always set required-1 bits of pinbased_ctls to PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR
Similar to exit_ctls_low, entry_ctls_low, and procbased_ctls_low,
pinbased_ctls_low should be set to PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR
and not host's MSR_IA32_VMX_PINBASED_CTLS value |=
PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR.
The commit eabeaaccfca0 ("KVM: nVMX: Clean up and fix pin-based
execution controls") which introduced '|=' doesn't mention anything
about why this is needed, the change seems rather accidental.
Note: normally, required-1 portion of MSR_IA32_VMX_PINBASED_CTLS should
be equal to PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR so no behavioral change
is expected, however, it is (in theory) possible to observe something
different there when e.g. KVM is running as a nested hypervisor. Hope
this doesn't happen in practice.
Reported-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220830133737.1539624-31-vkuznets@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/nested.c')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index e836f4439452..9b261423fb50 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -6589,7 +6589,7 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps) rdmsr(MSR_IA32_VMX_PINBASED_CTLS, msrs->pinbased_ctls_low, msrs->pinbased_ctls_high); - msrs->pinbased_ctls_low |= + msrs->pinbased_ctls_low = PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR; msrs->pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK | |