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.
> ---
> 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
>
