Commit fd275235 authored Aug 29, 2014 by Paolo Bonzini

KVM: x86: use guest maxphyaddr to check MTRR values



The check introduced in commit d7a2a246 (KVM: x86: #GP when attempts to write reserved bits of Variable Range MTRRs, 2014-08-19)
will break if the guest maxphyaddr is higher than the host's (which
sometimes happens depending on your hardware and how QEMU is
configured).

To fix this, use cpuid_maxphyaddr similar to how the APIC_BASE MSR
does already.

Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 13a34e06

arch/x86/kvm/x86.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -1726,7 +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;
		u64 mask;

		if (!msr_mtrr_valid(msr))
		return false;
		@@ -1750,8 +1750,7 @@ 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));

		for (i = 63; i > boot_cpu_data.x86_phys_bits; i--)
		mask \|= (1ULL << i);
		mask = (~0ULL) << cpuid_maxphyaddr(vcpu);
		if ((msr & 1) == 0) {
		/* MTRR base */
		if (!valid_mtrr_type(data & 0xff))