On Mon, Nov 22, 2021 at 10:55 AM Ben Gardon <bgardon@xxxxxxxxxx> wrote:
>
> On Fri, Nov 19, 2021 at 3:58 PM David Matlack <dmatlack@xxxxxxxxxx> wrote:
> >
> > Move the kvm_mmu_memory_cache structs into a separate wrapper struct.
> > This is in preparation for eagerly splitting all large pages during
> > VM-ioctls (i.e. not in the vCPU fault path) which will require adding
> > kvm_mmu_memory_cache structs to struct kvm_arch.
> >
> > Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
>
> Reviewed-by: Ben Gardon
>
> I don't think this patch creates any functional change. If that's the
> intent, it'd be worth noting.
Will do!
>
>
> > ---
> > arch/x86/include/asm/kvm_host.h | 12 ++++---
> > arch/x86/kvm/mmu/mmu.c | 59 ++++++++++++++++++++++-----------
> > arch/x86/kvm/mmu/tdp_mmu.c | 7 ++--
> > 3 files changed, 52 insertions(+), 26 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> > index 1fcb345bc107..2a7564703ea6 100644
> > --- a/arch/x86/include/asm/kvm_host.h
> > +++ b/arch/x86/include/asm/kvm_host.h
> > @@ -612,6 +612,13 @@ struct kvm_vcpu_xen {
> > u64 runstate_times[4];
> > };
> >
> > +struct kvm_mmu_memory_caches {
> > + struct kvm_mmu_memory_cache pte_list_desc_cache;
> > + struct kvm_mmu_memory_cache shadow_page_cache;
> > + struct kvm_mmu_memory_cache gfn_array_cache;
> > + struct kvm_mmu_memory_cache page_header_cache;
> > +};
> > +
> > struct kvm_vcpu_arch {
> > /*
> > * rip and regs accesses must go through
> > @@ -681,10 +688,7 @@ struct kvm_vcpu_arch {
> > */
> > struct kvm_mmu *walk_mmu;
> >
> > - struct kvm_mmu_memory_cache mmu_pte_list_desc_cache;
> > - struct kvm_mmu_memory_cache mmu_shadow_page_cache;
> > - struct kvm_mmu_memory_cache mmu_gfn_array_cache;
> > - struct kvm_mmu_memory_cache mmu_page_header_cache;
> > + struct kvm_mmu_memory_caches mmu_caches;
> >
> > /*
> > * QEMU userspace and the guest each have their own FPU state.
> > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> > index 1146f87044a6..537952574211 100644
> > --- a/arch/x86/kvm/mmu/mmu.c
> > +++ b/arch/x86/kvm/mmu/mmu.c
> > @@ -732,38 +732,60 @@ static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu)
> >
> > static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect)
> > {
> > + struct kvm_mmu_memory_caches *mmu_caches;
> > int r;
> >
> > + mmu_caches = &vcpu->arch.mmu_caches;
> > +
> > /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */
> > - r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache,
> > + r = kvm_mmu_topup_memory_cache(&mmu_caches->pte_list_desc_cache,
> > 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM);
> > if (r)
> > return r;
> > - r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache,
> > + r = kvm_mmu_topup_memory_cache(&mmu_caches->shadow_page_cache,
> > PT64_ROOT_MAX_LEVEL);
> > if (r)
> > return r;
> > if (maybe_indirect) {
> > - r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_cache,
> > + r = kvm_mmu_topup_memory_cache(&mmu_caches->gfn_array_cache,
> > PT64_ROOT_MAX_LEVEL);
> > if (r)
> > return r;
> > }
> > - return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
> > + return kvm_mmu_topup_memory_cache(&mmu_caches->page_header_cache,
> > PT64_ROOT_MAX_LEVEL);
> > }
> >
> > static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
> > {
> > - kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache);
> > - kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache);
> > - kvm_mmu_free_memory_cache(&vcpu->arch.mmu_gfn_array_cache);
> > - kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
> > + struct kvm_mmu_memory_caches *mmu_caches;
> > +
> > + mmu_caches = &vcpu->arch.mmu_caches;
> > +
> > + kvm_mmu_free_memory_cache(&mmu_caches->pte_list_desc_cache);
> > + kvm_mmu_free_memory_cache(&mmu_caches->shadow_page_cache);
> > + kvm_mmu_free_memory_cache(&mmu_caches->gfn_array_cache);
> > + kvm_mmu_free_memory_cache(&mmu_caches->page_header_cache);
> > +}
> > +
> > +static void mmu_init_memory_caches(struct kvm_mmu_memory_caches *caches)
> > +{
> > + caches->pte_list_desc_cache.kmem_cache = pte_list_desc_cache;
> > + caches->pte_list_desc_cache.gfp_zero = __GFP_ZERO;
> > +
> > + caches->page_header_cache.kmem_cache = mmu_page_header_cache;
> > + caches->page_header_cache.gfp_zero = __GFP_ZERO;
> > +
> > + caches->shadow_page_cache.gfp_zero = __GFP_ZERO;
> > }
> >
> > static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu)
> > {
> > - return kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_list_desc_cache);
> > + struct kvm_mmu_memory_caches *mmu_caches;
> > +
> > + mmu_caches = &vcpu->arch.mmu_caches;
> > +
> > + return kvm_mmu_memory_cache_alloc(&mmu_caches->pte_list_desc_cache);
> > }
> >
> > static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc)
> > @@ -1071,7 +1093,7 @@ static bool rmap_can_add(struct kvm_vcpu *vcpu)
> > {
> > struct kvm_mmu_memory_cache *mc;
> >
> > - mc = &vcpu->arch.mmu_pte_list_desc_cache;
> > + mc = &vcpu->arch.mmu_caches.pte_list_desc_cache;
> > return kvm_mmu_memory_cache_nr_free_objects(mc);
> > }
> >
> > @@ -1742,12 +1764,15 @@ static void drop_parent_pte(struct kvm_mmu_page *sp,
> >
> > static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct)
> > {
> > + struct kvm_mmu_memory_caches *mmu_caches;
> > struct kvm_mmu_page *sp;
> >
> > - sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
> > - sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
> > + mmu_caches = &vcpu->arch.mmu_caches;
> > +
> > + sp = kvm_mmu_memory_cache_alloc(&mmu_caches->page_header_cache);
> > + sp->spt = kvm_mmu_memory_cache_alloc(&mmu_caches->shadow_page_cache);
> > if (!direct)
> > - sp->gfns = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache);
> > + sp->gfns = kvm_mmu_memory_cache_alloc(&mmu_caches->gfn_array_cache);
> > set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
> >
> > /*
> > @@ -5544,13 +5569,7 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu)
> > {
> > int ret;
> >
> > - vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache;
> > - vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO;
> > -
> > - vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache;
> > - vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO;
> > -
> > - vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO;
> > + mmu_init_memory_caches(&vcpu->arch.mmu_caches);
> >
> > vcpu->arch.mmu = &vcpu->arch.root_mmu;
> > vcpu->arch.walk_mmu = &vcpu->arch.root_mmu;
> > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> > index 9ee3f4f7fdf5..b70707a7fe87 100644
> > --- a/arch/x86/kvm/mmu/tdp_mmu.c
> > +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> > @@ -175,10 +175,13 @@ static union kvm_mmu_page_role page_role_for_level(struct kvm_vcpu *vcpu,
> > static struct kvm_mmu_page *alloc_tdp_mmu_page(struct kvm_vcpu *vcpu, gfn_t gfn,
> > int level)
> > {
> > + struct kvm_mmu_memory_caches *mmu_caches;
> > struct kvm_mmu_page *sp;
> >
> > - sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
> > - sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
> > + mmu_caches = &vcpu->arch.mmu_caches;
> > +
> > + sp = kvm_mmu_memory_cache_alloc(&mmu_caches->page_header_cache);
> > + sp->spt = kvm_mmu_memory_cache_alloc(&mmu_caches->shadow_page_cache);
> > set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
> >
> > sp->role.word = page_role_for_level(vcpu, level).word;
> > --
> > 2.34.0.rc2.393.gf8c9666880-goog
> >
