From: David Matlack <dmatlack@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
seanjc@google.com, vkuznets@redhat.com
Subject: Re: [PATCH 07/23] KVM: MMU: remove kvm_mmu_calc_root_page_role
Date: Fri, 4 Feb 2022 19:32:55 +0000 [thread overview]
Message-ID: <Yf1/ZyrPufhHKEep@google.com> (raw)
In-Reply-To: <20220204115718.14934-8-pbonzini@redhat.com>
On Fri, Feb 04, 2022 at 06:57:02AM -0500, Paolo Bonzini wrote:
> Since the guest PGD is now loaded after the MMU has been set up
> completely, the desired role for a cache hit is simply the current
> mmu_role. There is no need to compute it again, so __kvm_mmu_new_pgd
> can be folded in kvm_mmu_new_pgd.
>
> As an aside, the !tdp_enabled case in the function was dead code,
> and that also gets mopped up as a side effect.
Couldn't the !tdp_enabled case be called via kvm_set_cr3() ->
kvm_mmu_new_pgd()?
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/kvm/mmu/mmu.c | 29 ++++-------------------------
> 1 file changed, 4 insertions(+), 25 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index b8ab16323629..42475e4c2a48 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -190,8 +190,6 @@ struct kmem_cache *mmu_page_header_cache;
> static struct percpu_counter kvm_total_used_mmu_pages;
>
> static void mmu_spte_set(u64 *sptep, u64 spte);
> -static union kvm_mmu_page_role
> -kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu);
>
> struct kvm_mmu_role_regs {
> const unsigned long cr0;
> @@ -4159,9 +4157,9 @@ static bool fast_pgd_switch(struct kvm_vcpu *vcpu, gpa_t new_pgd,
> return false;
> }
>
> -static void __kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd,
> - union kvm_mmu_page_role new_role)
> +void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd)
> {
> + union kvm_mmu_page_role new_role = vcpu->arch.mmu->mmu_role.base;
nit: Blank line after variable declarations.
> if (!fast_pgd_switch(vcpu, new_pgd, new_role)) {
> kvm_mmu_free_roots(vcpu, vcpu->arch.mmu, KVM_MMU_ROOT_CURRENT);
> return;
> @@ -4196,11 +4194,6 @@ static void __kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd,
> __clear_sp_write_flooding_count(
> to_shadow_page(vcpu->arch.mmu->root_hpa));
> }
> -
> -void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd)
> -{
> - __kvm_mmu_new_pgd(vcpu, new_pgd, kvm_mmu_calc_root_page_role(vcpu));
> -}
> EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd);
>
> static unsigned long get_cr3(struct kvm_vcpu *vcpu)
> @@ -4871,7 +4864,7 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
>
> shadow_mmu_init_context(vcpu, context, ®s, new_role);
> reset_shadow_zero_bits_mask(vcpu, context, is_efer_nx(context));
> - __kvm_mmu_new_pgd(vcpu, nested_cr3, new_role.base);
> + kvm_mmu_new_pgd(vcpu, nested_cr3);
> }
> EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu);
>
> @@ -4923,7 +4916,7 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
> reset_ept_shadow_zero_bits_mask(context, execonly);
> }
>
> - __kvm_mmu_new_pgd(vcpu, new_eptp, new_role.base);
> + kvm_mmu_new_pgd(vcpu, new_eptp);
> }
> EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu);
>
> @@ -5009,20 +5002,6 @@ void kvm_init_mmu(struct kvm_vcpu *vcpu)
> }
> EXPORT_SYMBOL_GPL(kvm_init_mmu);
>
> -static union kvm_mmu_page_role
> -kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu)
> -{
> - struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu);
> - union kvm_mmu_role role;
> -
> - if (tdp_enabled)
> - role = kvm_calc_tdp_mmu_root_page_role(vcpu, ®s, true);
> - else
> - role = kvm_calc_shadow_mmu_root_page_role(vcpu, ®s, true);
> -
> - return role.base;
> -}
> -
> void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu)
> {
> /*
> --
> 2.31.1
>
>
next prev parent reply other threads:[~2022-02-04 19:33 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-04 11:56 [PATCH 00/23] KVM: MMU: MMU role refactoring Paolo Bonzini
2022-02-04 11:56 ` [PATCH 01/23] KVM: MMU: pass uses_nx directly to reset_shadow_zero_bits_mask Paolo Bonzini
2022-02-04 17:59 ` David Matlack
2022-02-05 14:52 ` Paolo Bonzini
2022-02-07 16:09 ` Sean Christopherson
2022-02-07 21:50 ` David Matlack
2022-02-10 0:30 ` Sean Christopherson
2022-02-10 16:38 ` Paolo Bonzini
2022-02-04 11:56 ` [PATCH 02/23] KVM: MMU: nested EPT cannot be used in SMM Paolo Bonzini
2022-02-04 18:16 ` David Matlack
2022-02-09 22:43 ` Sean Christopherson
2022-02-04 11:56 ` [PATCH 03/23] KVM: MMU: remove valid from extended role Paolo Bonzini
2022-02-04 18:32 ` David Matlack
2022-02-05 14:50 ` Paolo Bonzini
2022-02-09 22:54 ` Sean Christopherson
2022-02-10 9:53 ` Paolo Bonzini
2022-02-04 11:56 ` [PATCH 04/23] KVM: MMU: constify uses of struct kvm_mmu_role_regs Paolo Bonzini
2022-02-04 18:41 ` David Matlack
2022-02-09 22:57 ` Sean Christopherson
2022-02-04 11:57 ` [PATCH 05/23] KVM: MMU: pull computation of kvm_mmu_role_regs to kvm_init_mmu Paolo Bonzini
2022-02-04 18:45 ` David Matlack
2022-02-04 11:57 ` [PATCH 06/23] KVM: MMU: load new PGD once nested two-dimensional paging is initialized Paolo Bonzini
2022-02-04 19:18 ` David Matlack
2022-02-07 13:50 ` Paolo Bonzini
2022-02-07 14:35 ` Paolo Bonzini
2022-02-09 12:34 ` Paolo Bonzini
2022-02-04 11:57 ` [PATCH 07/23] KVM: MMU: remove kvm_mmu_calc_root_page_role Paolo Bonzini
2022-02-04 19:32 ` David Matlack [this message]
2022-02-05 14:46 ` Paolo Bonzini
2022-02-10 0:47 ` Sean Christopherson
2022-02-10 9:52 ` Paolo Bonzini
2022-02-10 17:29 ` Sean Christopherson
2022-02-10 17:43 ` Paolo Bonzini
2022-02-04 11:57 ` [PATCH 08/23] KVM: MMU: rephrase unclear comment Paolo Bonzini
2022-02-04 19:38 ` David Matlack
2022-02-04 11:57 ` [PATCH 09/23] KVM: MMU: remove "bool base_only" arguments Paolo Bonzini
2022-02-04 19:41 ` David Matlack
2022-02-04 11:57 ` [PATCH 10/23] KVM: MMU: split cpu_role from mmu_role Paolo Bonzini
2022-02-04 21:57 ` David Matlack
2022-02-05 14:49 ` Paolo Bonzini
2022-02-07 21:38 ` David Matlack
2022-02-04 11:57 ` [PATCH 11/23] KVM: MMU: do not recompute root level from kvm_mmu_role_regs Paolo Bonzini
2022-02-07 22:10 ` David Matlack
2022-02-07 22:17 ` David Matlack
2022-02-04 11:57 ` [PATCH 12/23] KVM: MMU: remove ept_ad field Paolo Bonzini
2022-02-04 11:57 ` [PATCH 13/23] KVM: MMU: remove kvm_calc_shadow_root_page_role_common Paolo Bonzini
2022-02-07 22:25 ` David Matlack
2022-02-04 11:57 ` [PATCH 14/23] KVM: MMU: cleanup computation of MMU roles for two-dimensional paging Paolo Bonzini
2022-02-04 11:57 ` [PATCH 15/23] KVM: MMU: cleanup computation of MMU roles for shadow paging Paolo Bonzini
2022-02-04 11:57 ` [PATCH 16/23] KVM: MMU: remove extended bits from mmu_role Paolo Bonzini
2022-02-04 11:57 ` [PATCH 17/23] KVM: MMU: remove redundant bits from extended role Paolo Bonzini
2022-02-04 11:57 ` [PATCH 18/23] KVM: MMU: fetch shadow EFER.NX from MMU role Paolo Bonzini
2022-02-04 11:57 ` [PATCH 19/23] KVM: MMU: simplify and/or inline computation of shadow MMU roles Paolo Bonzini
2022-02-04 11:57 ` [PATCH 20/23] KVM: MMU: pull CPU role computation to kvm_init_mmu Paolo Bonzini
2022-02-07 22:42 ` David Matlack
2022-02-04 11:57 ` [PATCH 21/23] KVM: MMU: store shadow_root_level into mmu_role Paolo Bonzini
2022-02-07 23:00 ` David Matlack
2022-02-04 11:57 ` [PATCH 22/23] KVM: MMU: use cpu_role for root_level Paolo Bonzini
2022-02-07 23:01 ` David Matlack
2022-02-04 11:57 ` [PATCH 23/23] KVM: MMU: replace direct_map with mmu_role.direct Paolo Bonzini
2022-02-07 23:02 ` David Matlack
2022-02-07 23:08 ` [PATCH 00/23] KVM: MMU: MMU role refactoring David Matlack
2022-02-07 23:27 ` Sean Christopherson
2022-02-07 23:53 ` David Matlack
2022-02-10 1:11 ` Sean Christopherson
2022-02-10 11:58 ` Paolo Bonzini
2022-02-10 16:55 ` Sean Christopherson
2022-02-10 17:30 ` Paolo Bonzini
2022-02-10 19:28 ` Sean Christopherson
2022-02-09 22:31 ` Sean Christopherson
2022-02-10 9:54 ` Paolo Bonzini
2022-02-14 18:14 ` David Matlack
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