From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7B45C072A2 for ; Wed, 22 Nov 2023 05:46:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233558AbjKVFqJ (ORCPT ); Wed, 22 Nov 2023 00:46:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229631AbjKVFqF (ORCPT ); Wed, 22 Nov 2023 00:46:05 -0500 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3970185; Tue, 21 Nov 2023 21:45:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1700631960; x=1732167960; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/7/2023 11:00 PM, isaku.yamahata@intel.com wrote: > From: Xiaoyao Li > > When mapping the shared page for TDX, it needs to zap private alias. > > In the case that private page is mapped as large page (2MB), it can be > removed directly only when the whole 2MB is converted to shared. > Otherwise, it has to split 2MB page into 512 4KB page, and only remove > the pages that converted to shared. > > When a present large leaf spte switches to present non-leaf spte, TDX needs > to split the corresponding SEPT page to reflect it. > > Signed-off-by: Xiaoyao Li > Signed-off-by: Isaku Yamahata > --- > arch/x86/include/asm/kvm-x86-ops.h | 1 + > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/kvm/mmu/tdp_mmu.c | 21 ++++++++++++++++----- > arch/x86/kvm/vmx/tdx.c | 25 +++++++++++++++++++++++-- > arch/x86/kvm/vmx/tdx_arch.h | 1 + > arch/x86/kvm/vmx/tdx_ops.h | 7 +++++++ > 6 files changed, 50 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h > index 8ef0ed217f6e..3deb6ab4f291 100644 > --- a/arch/x86/include/asm/kvm-x86-ops.h > +++ b/arch/x86/include/asm/kvm-x86-ops.h > @@ -103,6 +103,7 @@ KVM_X86_OP_OPTIONAL_RET0(get_mt_mask) > KVM_X86_OP(load_mmu_pgd) > KVM_X86_OP_OPTIONAL(link_private_spt) > KVM_X86_OP_OPTIONAL(free_private_spt) > +KVM_X86_OP_OPTIONAL(split_private_spt) > KVM_X86_OP_OPTIONAL(set_private_spte) > KVM_X86_OP_OPTIONAL(remove_private_spte) > KVM_X86_OP_OPTIONAL(zap_private_spte) > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index c16823f3326e..e75a461bdea7 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1753,6 +1753,8 @@ struct kvm_x86_ops { > void *private_spt); > int (*free_private_spt)(struct kvm *kvm, gfn_t gfn, enum pg_level level, > void *private_spt); > + int (*split_private_spt)(struct kvm *kvm, gfn_t gfn, enum pg_level level, > + void *private_spt); > int (*set_private_spte)(struct kvm *kvm, gfn_t gfn, enum pg_level level, > kvm_pfn_t pfn); > int (*remove_private_spte)(struct kvm *kvm, gfn_t gfn, enum pg_level level, > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index a209a67decae..734ee822b43c 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -599,23 +599,34 @@ static int __must_check __set_private_spte_present(struct kvm *kvm, tdp_ptep_t s > { > bool was_present = is_shadow_present_pte(old_spte); > bool is_present = is_shadow_present_pte(new_spte); > + bool was_leaf = was_present && is_last_spte(old_spte, level); > bool is_leaf = is_present && is_last_spte(new_spte, level); > kvm_pfn_t new_pfn = spte_to_pfn(new_spte); > + void *private_spt; > int ret = 0; > > lockdep_assert_held(&kvm->mmu_lock); > - /* TDP MMU doesn't change present -> present */ > - KVM_BUG_ON(was_present, kvm); > > /* > * Use different call to either set up middle level > * private page table, or leaf. > */ > - if (is_leaf) > + if (level > PG_LEVEL_4K && was_leaf && !is_leaf) { > + /* > + * splitting large page into 4KB. > + * tdp_mmu_split_huage_page() => tdp_mmu_link_sp() Typo, tdp_mmu_split_huage_page -> tdp_mmu_split_huge_page > + */ > + private_spt = get_private_spt(gfn, new_spte, level); > + KVM_BUG_ON(!private_spt, kvm); > + ret = static_call(kvm_x86_zap_private_spte)(kvm, gfn, level); > + kvm_flush_remote_tlbs(kvm); > + if (!ret) > + ret = static_call(kvm_x86_split_private_spt)(kvm, gfn, > + level, private_spt); > + } else if (is_leaf) > ret = static_call(kvm_x86_set_private_spte)(kvm, gfn, level, new_pfn); > else { > - void *private_spt = get_private_spt(gfn, new_spte, level); > - > + private_spt = get_private_spt(gfn, new_spte, level); > KVM_BUG_ON(!private_spt, kvm); > ret = static_call(kvm_x86_link_private_spt)(kvm, gfn, level, private_spt); > } > diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c > index c614ab20c191..91eca578a7da 100644 > --- a/arch/x86/kvm/vmx/tdx.c > +++ b/arch/x86/kvm/vmx/tdx.c > @@ -1662,6 +1662,28 @@ static int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn, > return 0; > } > > +static int tdx_sept_split_private_spt(struct kvm *kvm, gfn_t gfn, > + enum pg_level level, void *private_spt) > +{ > + int tdx_level = pg_level_to_tdx_sept_level(level); > + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); > + gpa_t gpa = gfn_to_gpa(gfn) & KVM_HPAGE_MASK(level); > + hpa_t hpa = __pa(private_spt); > + struct tdx_module_args out; > + u64 err; > + > + /* See comment in tdx_sept_set_private_spte() */ Do you mean the comment about the pages are pinned to prevent migration part? Can you add some specific short information in this comment, in case tdx_sept_set_private_spte() is extended to have more comments in the future? > + err = tdh_mem_page_demote(kvm_tdx->tdr_pa, gpa, tdx_level, hpa, &out); > + if (unlikely(err == TDX_ERROR_SEPT_BUSY)) > + return -EAGAIN; > + if (KVM_BUG_ON(err, kvm)) { > + pr_tdx_error(TDH_MEM_PAGE_DEMOTE, err, &out); > + return -EIO; > + } > + > + return 0; > +} > + > static int tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn, > enum pg_level level) > { > @@ -1675,8 +1697,6 @@ static int tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn, > if (unlikely(!is_hkid_assigned(kvm_tdx))) > return 0; > > - /* For now large page isn't supported yet. */ > - WARN_ON_ONCE(level != PG_LEVEL_4K); > err = tdh_mem_range_block(kvm_tdx->tdr_pa, gpa, tdx_level, &out); > if (unlikely(err == TDX_ERROR_SEPT_BUSY)) > return -EAGAIN; > @@ -3183,6 +3203,7 @@ int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops) > > x86_ops->link_private_spt = tdx_sept_link_private_spt; > x86_ops->free_private_spt = tdx_sept_free_private_spt; > + x86_ops->split_private_spt = tdx_sept_split_private_spt; > x86_ops->set_private_spte = tdx_sept_set_private_spte; > x86_ops->remove_private_spte = tdx_sept_remove_private_spte; > x86_ops->zap_private_spte = tdx_sept_zap_private_spte; > diff --git a/arch/x86/kvm/vmx/tdx_arch.h b/arch/x86/kvm/vmx/tdx_arch.h > index ba41fefa47ee..cab6a74446a0 100644 > --- a/arch/x86/kvm/vmx/tdx_arch.h > +++ b/arch/x86/kvm/vmx/tdx_arch.h > @@ -21,6 +21,7 @@ > #define TDH_MNG_CREATE 9 > #define TDH_VP_CREATE 10 > #define TDH_MNG_RD 11 > +#define TDH_MEM_PAGE_DEMOTE 15 > #define TDH_MR_EXTEND 16 > #define TDH_MR_FINALIZE 17 > #define TDH_VP_FLUSH 18 > diff --git a/arch/x86/kvm/vmx/tdx_ops.h b/arch/x86/kvm/vmx/tdx_ops.h > index 0f2df7198bde..38ab0ab1509c 100644 > --- a/arch/x86/kvm/vmx/tdx_ops.h > +++ b/arch/x86/kvm/vmx/tdx_ops.h > @@ -183,6 +183,13 @@ static inline u64 tdh_mng_rd(hpa_t tdr, u64 field, struct tdx_module_args *out) > return tdx_seamcall(TDH_MNG_RD, tdr, field, 0, 0, out); > } > > +static inline u64 tdh_mem_page_demote(hpa_t tdr, gpa_t gpa, int level, hpa_t page, > + struct tdx_module_args *out) > +{ > + tdx_clflush_page(page, PG_LEVEL_4K); > + return tdx_seamcall_sept(TDH_MEM_PAGE_DEMOTE, gpa | level, tdr, page, 0, out); > +} > + > static inline u64 tdh_mr_extend(hpa_t tdr, gpa_t gpa, > struct tdx_module_args *out) > {