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KVM: x86: Add macro to ensure reserved cr4 bits checks stay in sync

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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 <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2019-12-10 14:44:16 -08:00 committed by Paolo Bonzini
parent 96be4e069c
commit 345599f9a2
1 changed files with 25 additions and 40 deletions
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65
arch/x86/kvm/x86.c
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@ -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;