Commit e7f1be40 authored by Yu Zhang's avatar Yu Zhang Committed by Greg Kroah-Hartman

KVM: MMU: record maximum physical address width in kvm_mmu_extended_role

commit de3ccd26 upstream.

Previously, commit 7dcd5755 ("x86/kvm/mmu: check if tdp/shadow
MMU reconfiguration is needed") offered some optimization to avoid
the unnecessary reconfiguration. Yet one scenario is broken - when
cpuid changes VM's maximum physical address width, reconfiguration
is needed to reset the reserved bits.  Also, the TDP may need to
reset its shadow_root_level when this value is changed.

To fix this, a new field, maxphyaddr, is introduced in the extended
role structure to keep track of the configured guest physical address
Signed-off-by: 's avatarYu Zhang <>
Signed-off-by: 's avatarPaolo Bonzini <>
Signed-off-by: 's avatarGreg Kroah-Hartman <>
parent 1b983c69
......@@ -299,6 +299,7 @@ union kvm_mmu_extended_role {
unsigned int cr4_smap:1;
unsigned int cr4_smep:1;
unsigned int cr4_la57:1;
unsigned int maxphyaddr:6;
......@@ -4731,6 +4731,7 @@ static union kvm_mmu_extended_role kvm_calc_mmu_role_ext(struct kvm_vcpu *vcpu)
ext.cr4_pse = !!is_pse(vcpu);
ext.cr4_pke = !!kvm_read_cr4_bits(vcpu, X86_CR4_PKE);
ext.cr4_la57 = !!kvm_read_cr4_bits(vcpu, X86_CR4_LA57);
ext.maxphyaddr = cpuid_maxphyaddr(vcpu);
ext.valid = 1;
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