From patchwork Tue Jun 14 12:02:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 581763 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 6ECEBC433EF for ; Tue, 14 Jun 2022 12:03:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356803AbiFNMDq (ORCPT ); Tue, 14 Jun 2022 08:03:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244018AbiFNMCs (ORCPT ); Tue, 14 Jun 2022 08:02:48 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00F0C1C132; Tue, 14 Jun 2022 05:02:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655208167; x=1686744167; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=7oQeAKlAd2ATqVqYodMfjK9yYRqZpDnGTOvOo+Mth6U=; b=JI3RPK2CGISy7qAsjWiZmYrOGMmaCilDkFOKuOnPhNPk4BX15MYZ8xnl dfMNfxz6tpiBhMiaT/IJzMyleTT3Y7NhyiSXWKaaPeAbSLlh205kdPKga udEjnZaQY7oP7+OwdwH5X6mnjfS6Ben+RELL8ysfR8qr+9XA8gJXLHM38 go6dhJesjL6tnLVPS8AP+69ejcv76JRhiHjkzLJlBdkrM4Ayt3G0qr2E3 tSCes9uKPR3JQNOb1g+RKBiv98Ku4eNYtWuIjH/GrIOJJzS1LU9LShO5I rVHDTAehf1gQmrsMyscBVkPM/156v5cgF+u2O54KUTJIjIaw1RyTvOD/v w==; X-IronPort-AV: E=McAfee;i="6400,9594,10377"; a="258432288" X-IronPort-AV: E=Sophos;i="5.91,300,1647327600"; d="scan'208";a="258432288" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jun 2022 05:02:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,300,1647327600"; d="scan'208";a="640332833" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga008.fm.intel.com with ESMTP; 14 Jun 2022 05:02:36 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 0FCEDA3F; Tue, 14 Jun 2022 15:02:33 +0300 (EEST) From: "Kirill A. Shutemov" To: Borislav Petkov , Andy Lutomirski , Sean Christopherson , Andrew Morton , Joerg Roedel , Ard Biesheuvel Cc: Andi Kleen , Kuppuswamy Sathyanarayanan , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , Varad Gautam , Dario Faggioli , Dave Hansen , Mike Rapoport , David Hildenbrand , marcelo.cerri@canonical.com, tim.gardner@canonical.com, khalid.elmously@canonical.com, philip.cox@canonical.com, x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv7 14/14] x86/tdx: Add unaccepted memory support Date: Tue, 14 Jun 2022 15:02:31 +0300 Message-Id: <20220614120231.48165-15-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220614120231.48165-1-kirill.shutemov@linux.intel.com> References: <20220614120231.48165-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Hookup TDX-specific code to accept memory. Accepting the memory is the same process as converting memory from shared to private: kernel notifies VMM with MAP_GPA hypercall and then accept pages with ACCEPT_PAGE module call. The implementation in core kernel uses tdx_enc_status_changed(). It already used for converting memory to shared and back for I/O transactions. Boot stub provides own implementation of tdx_accept_memory(). It is similar in structure to tdx_enc_status_changed(), but only cares about converting memory to private. Signed-off-by: Kirill A. Shutemov --- arch/x86/Kconfig | 1 + arch/x86/boot/compressed/mem.c | 27 ++++++++++- arch/x86/boot/compressed/tdx.c | 78 +++++++++++++++++++++++++++++++ arch/x86/coco/tdx/tdx.c | 30 ++++++++---- arch/x86/include/asm/shared/tdx.h | 2 + arch/x86/mm/unaccepted_memory.c | 9 +++- 6 files changed, 136 insertions(+), 11 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9783ebc4e021..80683afa5749 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -892,6 +892,7 @@ config INTEL_TDX_GUEST select ARCH_HAS_CC_PLATFORM select X86_MEM_ENCRYPT select X86_MCE + select UNACCEPTED_MEMORY help Support running as a guest under Intel TDX. Without this support, the guest kernel can not boot or run under TDX. diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c index b45458af00ca..48e36e640da1 100644 --- a/arch/x86/boot/compressed/mem.c +++ b/arch/x86/boot/compressed/mem.c @@ -5,6 +5,8 @@ #include "error.h" #include "find.h" #include "math.h" +#include "tdx.h" +#include #define PMD_SHIFT 21 #define PMD_SIZE (_AC(1, UL) << PMD_SHIFT) @@ -12,10 +14,33 @@ extern struct boot_params *boot_params; +static bool is_tdx_guest(void) +{ + static bool once; + static bool is_tdx; + + if (!IS_ENABLED(CONFIG_INTEL_TDX_GUEST)) + return false; + + if (!once) { + u32 eax, sig[3]; + + cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, + &sig[0], &sig[2], &sig[1]); + is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig)); + once = true; + } + + return is_tdx; +} + static inline void __accept_memory(phys_addr_t start, phys_addr_t end) { /* Platform-specific memory-acceptance call goes here */ - error("Cannot accept memory"); + if (is_tdx_guest()) + tdx_accept_memory(start, end); + else + error("Cannot accept memory: unknown platform\n"); } /* diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c index 918a7606f53c..8518a75e5dd5 100644 --- a/arch/x86/boot/compressed/tdx.c +++ b/arch/x86/boot/compressed/tdx.c @@ -3,12 +3,15 @@ #include "../cpuflags.h" #include "../string.h" #include "../io.h" +#include "align.h" #include "error.h" +#include "pgtable_types.h" #include #include #include +#include /* Called from __tdx_hypercall() for unrecoverable failure */ void __tdx_hypercall_failed(void) @@ -75,3 +78,78 @@ void early_tdx_detect(void) pio_ops.f_outb = tdx_outb; pio_ops.f_outw = tdx_outw; } + +static unsigned long try_accept_one(phys_addr_t start, unsigned long len, + enum pg_level level) +{ + unsigned long accept_size = PAGE_SIZE << ((level - 1) * PTE_SHIFT); + u64 tdcall_rcx; + u8 page_size; + + if (!IS_ALIGNED(start, accept_size)) + return 0; + + if (len < accept_size) + return 0; + + /* + * Pass the page physical address to the TDX module to accept the + * pending, private page. + * + * Bits 2:0 of RCX encode page size: 0 - 4K, 1 - 2M, 2 - 1G. + */ + switch (level) { + case PG_LEVEL_4K: + page_size = 0; + break; + case PG_LEVEL_2M: + page_size = 1; + break; + case PG_LEVEL_1G: + page_size = 2; + break; + default: + return 0; + } + + tdcall_rcx = start | page_size; + if (__tdx_module_call(TDX_ACCEPT_PAGE, tdcall_rcx, 0, 0, 0, NULL)) + return 0; + + return accept_size; +} + +void tdx_accept_memory(phys_addr_t start, phys_addr_t end) +{ + /* + * Notify the VMM about page mapping conversion. More info about ABI + * can be found in TDX Guest-Host-Communication Interface (GHCI), + * section "TDG.VP.VMCALL" + */ + if (_tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0)) + error("Accepting memory failed\n"); + + /* + * For shared->private conversion, accept the page using + * TDX_ACCEPT_PAGE TDX module call. + */ + while (start < end) { + unsigned long len = end - start; + unsigned long accept_size; + + /* + * Try larger accepts first. It gives chance to VMM to keep + * 1G/2M Secure EPT entries where possible and speeds up + * process by cutting number of hypercalls (if successful). + */ + + accept_size = try_accept_one(start, len, PG_LEVEL_1G); + if (!accept_size) + accept_size = try_accept_one(start, len, PG_LEVEL_2M); + if (!accept_size) + accept_size = try_accept_one(start, len, PG_LEVEL_4K); + if (!accept_size) + error("Accepting memory failed\n"); + start += accept_size; + } +} diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index b10c95307f6e..8240f04d3646 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -664,16 +664,9 @@ static unsigned long try_accept_one(phys_addr_t start, unsigned long len, return accept_size; } -/* - * Inform the VMM of the guest's intent for this physical page: shared with - * the VMM or private to the guest. The VMM is expected to change its mapping - * of the page in response. - */ -static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) +static bool tdx_enc_status_changed_phys(phys_addr_t start, phys_addr_t end, + bool enc) { - phys_addr_t start = __pa(vaddr); - phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE); - if (!enc) { /* Set the shared (decrypted) bits: */ start |= cc_mkdec(0); @@ -719,6 +712,25 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) return true; } +void tdx_accept_memory(phys_addr_t start, phys_addr_t end) +{ + if (!tdx_enc_status_changed_phys(start, end, true)) + panic("Accepting memory failed: %#llx-%#llx\n", start, end); +} + +/* + * Inform the VMM of the guest's intent for this physical page: shared with + * the VMM or private to the guest. The VMM is expected to change its mapping + * of the page in response. + */ +static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) +{ + phys_addr_t start = __pa(vaddr); + phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE); + + return tdx_enc_status_changed_phys(start, end, enc); +} + void __init tdx_early_init(void) { u64 cc_mask; diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index 956ced04c3be..97534c334473 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -81,5 +81,7 @@ struct tdx_module_output { u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, struct tdx_module_output *out); +void tdx_accept_memory(phys_addr_t start, phys_addr_t end); + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_SHARED_TDX_H */ diff --git a/arch/x86/mm/unaccepted_memory.c b/arch/x86/mm/unaccepted_memory.c index 05e216716690..9ec2304272dc 100644 --- a/arch/x86/mm/unaccepted_memory.c +++ b/arch/x86/mm/unaccepted_memory.c @@ -7,6 +7,7 @@ #include #include +#include #include /* Protects unaccepted memory bitmap */ @@ -62,7 +63,13 @@ void accept_memory(phys_addr_t start, phys_addr_t end) unsigned long len = range_end - range_start; /* Platform-specific memory-acceptance call goes here */ - panic("Cannot accept memory: unknown platform\n"); + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { + tdx_accept_memory(range_start * PMD_SIZE, + range_end * PMD_SIZE); + } else { + panic("Cannot accept memory: unknown platform\n"); + } + bitmap_clear(bitmap, range_start, len); } spin_unlock_irqrestore(&unaccepted_memory_lock, flags);