Yu Zhang <[email protected]> writes: > Previously, commit 7dcd57552008 ("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 > width. > > Signed-off-by: Yu Zhang <[email protected]> > --- > Cc: Paolo Bonzini <[email protected]> > Cc: "Radim Krčmář" <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Borislav Petkov <[email protected]> > Cc: "H. Peter Anvin" <[email protected]> > Cc: [email protected] > --- > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/mmu.c | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 4660ce9..be87f71 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -299,6 +299,7 @@ struct kvm_mmu_memory_cache { > unsigned int cr4_smap:1; > unsigned int cr4_smep:1; > unsigned int cr4_la57:1; > + unsigned int maxphyaddr:6; > }; > }; > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index ce770b4..2b74505 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -4769,6 +4769,7 @@ 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;
It seems that we can now drop 'valid' from role_ext as maxphyaddr can't be 0. Reviewed-by: Vitaly Kuznetsov <[email protected]> -- Vitaly
