From 345599f9a292899bf5474651f3cea9b7a0576436 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 10 Dec 2019 14:44:16 -0800 Subject: [PATCH] KVM: x86: Add macro to ensure reserved cr4 bits checks stay in sync Add a helper macro to generate the set of reserved cr4 bits for both host and guest to ensure that adding a check on guest capabilities is also added for host capabilities, and vice versa. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 65 ++++++++++++++++++---------------------------- 1 file changed, 25 insertions(+), 40 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 960b886e1e43..456fc131c95e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -881,31 +881,34 @@ int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr) } EXPORT_SYMBOL_GPL(kvm_set_xcr); +#define __cr4_reserved_bits(__cpu_has, __c) \ +({ \ + u64 __reserved_bits = CR4_RESERVED_BITS; \ + \ + if (!__cpu_has(__c, X86_FEATURE_XSAVE)) \ + __reserved_bits |= X86_CR4_OSXSAVE; \ + if (!__cpu_has(__c, X86_FEATURE_SMEP)) \ + __reserved_bits |= X86_CR4_SMEP; \ + if (!__cpu_has(__c, X86_FEATURE_SMAP)) \ + __reserved_bits |= X86_CR4_SMAP; \ + if (!__cpu_has(__c, X86_FEATURE_FSGSBASE)) \ + __reserved_bits |= X86_CR4_FSGSBASE; \ + if (!__cpu_has(__c, X86_FEATURE_PKU)) \ + __reserved_bits |= X86_CR4_PKE; \ + if (!__cpu_has(__c, X86_FEATURE_LA57)) \ + __reserved_bits |= X86_CR4_LA57; \ + __reserved_bits; \ +}) + static u64 kvm_host_cr4_reserved_bits(struct cpuinfo_x86 *c) { - u64 reserved_bits = CR4_RESERVED_BITS; + u64 reserved_bits = __cr4_reserved_bits(cpu_has, c); - if (!cpu_has(c, X86_FEATURE_XSAVE)) - reserved_bits |= X86_CR4_OSXSAVE; + if (cpuid_ecx(0x7) & bit(X86_FEATURE_LA57)) + reserved_bits &= ~X86_CR4_LA57; - if (!cpu_has(c, X86_FEATURE_SMEP)) - reserved_bits |= X86_CR4_SMEP; - - if (!cpu_has(c, X86_FEATURE_SMAP)) - reserved_bits |= X86_CR4_SMAP; - - if (!cpu_has(c, X86_FEATURE_FSGSBASE)) - reserved_bits |= X86_CR4_FSGSBASE; - - if (!cpu_has(c, X86_FEATURE_PKU)) - reserved_bits |= X86_CR4_PKE; - - if (!cpu_has(c, X86_FEATURE_LA57) && - !(cpuid_ecx(0x7) & bit(X86_FEATURE_LA57))) - reserved_bits |= X86_CR4_LA57; - - if (!cpu_has(c, X86_FEATURE_UMIP) && !kvm_x86_ops->umip_emulated()) - reserved_bits |= X86_CR4_UMIP; + if (kvm_x86_ops->umip_emulated()) + reserved_bits &= ~X86_CR4_UMIP; return reserved_bits; } @@ -915,25 +918,7 @@ static int kvm_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) if (cr4 & cr4_reserved_bits) return -EINVAL; - if (!guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && (cr4 & X86_CR4_OSXSAVE)) - return -EINVAL; - - if (!guest_cpuid_has(vcpu, X86_FEATURE_SMEP) && (cr4 & X86_CR4_SMEP)) - return -EINVAL; - - if (!guest_cpuid_has(vcpu, X86_FEATURE_SMAP) && (cr4 & X86_CR4_SMAP)) - return -EINVAL; - - if (!guest_cpuid_has(vcpu, X86_FEATURE_FSGSBASE) && (cr4 & X86_CR4_FSGSBASE)) - return -EINVAL; - - if (!guest_cpuid_has(vcpu, X86_FEATURE_PKU) && (cr4 & X86_CR4_PKE)) - return -EINVAL; - - if (!guest_cpuid_has(vcpu, X86_FEATURE_LA57) && (cr4 & X86_CR4_LA57)) - return -EINVAL; - - if (!guest_cpuid_has(vcpu, X86_FEATURE_UMIP) && (cr4 & X86_CR4_UMIP)) + if (cr4 & __cr4_reserved_bits(guest_cpuid_has, vcpu)) return -EINVAL; return 0;