Re: [PATCH 08/54] Revert "KVM: MMU: record maximum physical address width in kvm_mmu_extended_role"

From: Yu Zhang
Date: Fri Jun 25 2021 - 04:52:14 EST


On Tue, Jun 22, 2021 at 10:56:53AM -0700, Sean Christopherson wrote:
> Drop MAXPHYADDR from mmu_role now that all MMUs have their role
> invalidated after a CPUID update. Invalidating the role forces all MMUs
> to re-evaluate the guest's MAXPHYADDR, and the guest's MAXPHYADDR can
> only be changed only through a CPUID update.
>
> This reverts commit de3ccd26fafc707b09792d9b633c8b5b48865315.
>
> Cc: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/include/asm/kvm_host.h | 1 -
> arch/x86/kvm/mmu/mmu.c | 1 -
> 2 files changed, 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 19c88b445ee0..cdaff399ed94 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -321,7 +321,6 @@ union kvm_mmu_extended_role {
> 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/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 8d97d21d5241..04cab330c445 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -4538,7 +4538,6 @@ 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;
>
> --
> 2.32.0.288.g62a8d224e6-goog
>

Reviewed-by: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>

Thanks
Yu