On Wed, Sep 21, 2022 at 10:35:39AM -0700,
David Matlack <dmatlack@xxxxxxxxxx> wrote:
> Grab mmu_invalidate_seq in kvm_faultin_pfn() and stash it in struct
> kvm_page_fault. The eliminates duplicate code and reduces the amount of
> parameters needed for is_page_fault_stale().
>
> Preemptively split out __kvm_faultin_pfn() to a separate function for
> use in subsequent commits.
>
> No functional change intended.
>
> Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
> ---
> arch/x86/kvm/mmu/mmu.c | 21 ++++++++++++---------
> arch/x86/kvm/mmu/mmu_internal.h | 1 +
> arch/x86/kvm/mmu/paging_tmpl.h | 6 +-----
> 3 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index dd261cd2ad4e..31b835d20762 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -4129,7 +4129,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
> kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true);
> }
>
> -static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
> +static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
> {
> struct kvm_memory_slot *slot = fault->slot;
> bool async;
> @@ -4185,12 +4185,20 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
> return RET_PF_CONTINUE;
> }
>
> +static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
> +{
> + fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq;
> + smp_rmb();
> +
> + return __kvm_faultin_pfn(vcpu, fault);
> +}
> +
> /*
> * Returns true if the page fault is stale and needs to be retried, i.e. if the
> * root was invalidated by a memslot update or a relevant mmu_notifier fired.
> */
> static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
> - struct kvm_page_fault *fault, int mmu_seq)
> + struct kvm_page_fault *fault)
> {
> struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa);
>
> @@ -4210,14 +4218,12 @@ static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
> return true;
>
> return fault->slot &&
> - mmu_invalidate_retry_hva(vcpu->kvm, mmu_seq, fault->hva);
> + mmu_invalidate_retry_hva(vcpu->kvm, fault->mmu_seq, fault->hva);
> }
>
> static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
> {
> bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
> -
> - unsigned long mmu_seq;
> int r;
>
> fault->gfn = fault->addr >> PAGE_SHIFT;
> @@ -4234,9 +4240,6 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
> if (r)
> return r;
>
> - mmu_seq = vcpu->kvm->mmu_invalidate_seq;
> - smp_rmb();
> -
> r = kvm_faultin_pfn(vcpu, fault);
> if (r != RET_PF_CONTINUE)
> return r;
> @@ -4252,7 +4255,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
> else
> write_lock(&vcpu->kvm->mmu_lock);
>
> - if (is_page_fault_stale(vcpu, fault, mmu_seq))
> + if (is_page_fault_stale(vcpu, fault))
> goto out_unlock;
>
> r = make_mmu_pages_available(vcpu);
> diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
> index 582def531d4d..1c0a1e7c796d 100644
> --- a/arch/x86/kvm/mmu/mmu_internal.h
> +++ b/arch/x86/kvm/mmu/mmu_internal.h
> @@ -221,6 +221,7 @@ struct kvm_page_fault {
> struct kvm_memory_slot *slot;
>
> /* Outputs of kvm_faultin_pfn. */
> + unsigned long mmu_seq;
> kvm_pfn_t pfn;
> hva_t hva;
> bool map_writable;
> diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
> index 39e0205e7300..98f4abce4eaf 100644
> --- a/arch/x86/kvm/mmu/paging_tmpl.h
> +++ b/arch/x86/kvm/mmu/paging_tmpl.h
> @@ -791,7 +791,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
> {
> struct guest_walker walker;
> int r;
> - unsigned long mmu_seq;
> bool is_self_change_mapping;
>
> pgprintk("%s: addr %lx err %x\n", __func__, fault->addr, fault->error_code);
> @@ -838,9 +837,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
> else
> fault->max_level = walker.level;
>
> - mmu_seq = vcpu->kvm->mmu_invalidate_seq;
> - smp_rmb();
> -
> r = kvm_faultin_pfn(vcpu, fault);
> if (r != RET_PF_CONTINUE)
> return r;
> @@ -871,7 +867,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
> r = RET_PF_RETRY;
> write_lock(&vcpu->kvm->mmu_lock);
>
> - if (is_page_fault_stale(vcpu, fault, mmu_seq))
> + if (is_page_fault_stale(vcpu, fault))
> goto out_unlock;
>
> r = make_mmu_pages_available(vcpu);
> --
> 2.37.3.998.g577e59143f-goog
>
Reviewed-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
