From: Xin Li <xin3.li@xxxxxxxxx> The CR4.FRED bit, i.e., CR4[32], is no longer a reserved bit when guest cpu cap has FRED, i.e., 1) All of FRED KVM support is in place. 2) Guest enumerates FRED. Otherwise it is still a reserved bit. Signed-off-by: Xin Li <xin3.li@xxxxxxxxx> Signed-off-by: Xin Li (Intel) <xin@xxxxxxxxx> Tested-by: Shan Kang <shan.kang@xxxxxxxxx> Tested-by: Xuelian Guo <xuelian.guo@xxxxxxxxx> --- Change in v5: * Add TB from Xuelian Guo. Change in v4: * Rebase on top of "guest_cpu_cap". Change in v3: * Don't allow CR4.FRED=1 before all of FRED KVM support is in place (Sean Christopherson). --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/x86.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7549e5143249..0b5857997b22 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -142,7 +142,7 @@ | X86_CR4_OSXSAVE | X86_CR4_SMEP | X86_CR4_FSGSBASE \ | X86_CR4_OSXMMEXCPT | X86_CR4_LA57 | X86_CR4_VMXE \ | X86_CR4_SMAP | X86_CR4_PKE | X86_CR4_UMIP \ - | X86_CR4_LAM_SUP | X86_CR4_CET)) + | X86_CR4_LAM_SUP | X86_CR4_CET | X86_CR4_FRED)) #define CR8_RESERVED_BITS (~(unsigned long)X86_CR8_TPR) diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 685eb710b1f2..c9f010862b2a 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -688,6 +688,8 @@ static inline bool __kvm_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) if (!__cpu_has(__c, X86_FEATURE_SHSTK) && \ !__cpu_has(__c, X86_FEATURE_IBT)) \ __reserved_bits |= X86_CR4_CET; \ + if (!__cpu_has(__c, X86_FEATURE_FRED)) \ + __reserved_bits |= X86_CR4_FRED; \ __reserved_bits; \ }) -- 2.50.1
