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Commit d7a2a246 authored by Wanpeng Li's avatar Wanpeng Li Committed by Paolo Bonzini
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KVM: x86: #GP when attempts to write reserved bits of Variable Range MTRRs 



Section 11.11.2.3 of the SDM mentions "All other bits in the IA32_MTRR_PHYSBASEn
and IA32_MTRR_PHYSMASKn registers are reserved; the processor generates a
general-protection exception(#GP) if software attempts to write to them". This
patch do it in kvm.

Signed-off-by: default avatarWanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent adfb5d27

arch/x86/kvm/x86.c

+15 −3
Original line number Diff line number Diff line
@@ -1726,6 +1726,7 @@ static bool valid_mtrr_type(unsigned t) 
static bool mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data)

{

	int i;

	u64 mask = 0;



	if (!msr_mtrr_valid(msr))

		return false;
@@ -1749,10 +1750,21 @@ static bool mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data) 
	/* variable MTRRs */

	WARN_ON(!(msr >= 0x200 && msr < 0x200 + 2 * KVM_NR_VAR_MTRR));



	if ((msr & 1) == 0)

	for (i = 63; i > boot_cpu_data.x86_phys_bits; i--)

		mask |= (1ULL << i);

	if ((msr & 1) == 0) {

		/* MTRR base */

		return valid_mtrr_type(data & 0xff);

		if (!valid_mtrr_type(data & 0xff))

			return false;

		mask |= 0xf00;

	} else

		/* MTRR mask */

		mask |= 0x7ff;

	if (data & mask) {

		kvm_inject_gp(vcpu, 0);

		return false;

	}



	return true;

}