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KVM: x86: use guest maxphyaddr to check MTRR values

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The check introduced in commit d7a2a246a1 (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>
This commit is contained in:
Paolo Bonzini 2014-08-29 18:56:01 +02:00
parent 13a34e067e
commit fd2752352b
1 changed files with 2 additions and 3 deletions
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5
arch/x86/kvm/x86.c
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@ -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))