From patchwork Mon Jun 17 17:39:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrew Cooper X-Patchwork-Id: 13701119 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 66A21C27C79 for ; Mon, 17 Jun 2024 17:39:42 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.742542.1149408 (Exim 4.92) (envelope-from ) id 1sJGKL-0004V6-Ij; Mon, 17 Jun 2024 17:39:33 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 742542.1149408; Mon, 17 Jun 2024 17:39:33 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sJGKL-0004UF-Dw; Mon, 17 Jun 2024 17:39:33 +0000 Received: by outflank-mailman (input) for mailman id 742542; Mon, 17 Jun 2024 17:39:31 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sJGKJ-00036g-LD for xen-devel@lists.xenproject.org; Mon, 17 Jun 2024 17:39:31 +0000 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [2a00:1450:4864:20::634]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 8c77ddd1-2cd0-11ef-b4bb-af5377834399; Mon, 17 Jun 2024 19:39:29 +0200 (CEST) Received: by mail-ej1-x634.google.com with SMTP id a640c23a62f3a-a6f176c5c10so549351266b.2 for ; Mon, 17 Jun 2024 10:39:29 -0700 (PDT) Received: from andrewcoop.eng.citrite.net ([160.101.139.1]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a6f56da4496sm532010666b.8.2024.06.17.10.39.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Jun 2024 10:39:28 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 8c77ddd1-2cd0-11ef-b4bb-af5377834399 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1718645968; x=1719250768; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=iaQNeWXVPJOBqi4Jz3ws3Uw0UDtY4Ak6EMg/xM7DVZo=; b=VrFGtfmSSLW8DVJ5vvTBz2Ob+XtmWvZSEd+RK64X477iC0lyGg6e8MOS/E/x1tFjL8 vBZ+VV4H2fmzcDJ3m0IJJic2VpzyGLF4v87hqB8V6gqv7Ke7bWUm9LfLX6H2QBR9sY9K qz0VkGNmcAZox1QtsBWdCcajvFyb5OTTaosdE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718645968; x=1719250768; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iaQNeWXVPJOBqi4Jz3ws3Uw0UDtY4Ak6EMg/xM7DVZo=; b=lWTsItn18jIuVvLUXWJdvK8FVMNg+abRB24p3G5pyfdFRMXW5Q06JAnF4bZVZ8EdHH UQUf2aNgsjTKorAwnScTsIbLbsxtNugB4aFEjGJJi00LbL7x1Rjd7YWU4imRSug7zDfq k2YkXiPhjvJvYEqIQtkuupXHa1lTTkjViCvmGhM7tRowjuCGzIdhfGPDhFSgL142ue1F A1HX96teIC9qCk83ylPKj4aaJIDpk54dJO6rd4pOH5Qt9WgkeKnG5fsjfR5CIaOE1XmY ZHmMBJTeR8qIo71HnuGMGvYZgoOTXjc1+0TPrSq7DodVVO/nVwEVFhAJZQvXnPaumqio OPMQ== X-Gm-Message-State: AOJu0YyVFnU7tWum9jhfb4wyW9VSasNcuyw+y3nRAY9pLwahK+IRMuHV bC8Xn1Knl8SIoluP/2PLel9UzA2SdoaKT8SdJL//QnZpggxlAzyUEQjRYCkYMgl/LIIbwFmWcyW KO1U= X-Google-Smtp-Source: AGHT+IGKrdBfI9Nm+aHZ6UkUA5/JNpbfFSVehqAWMLC2Ni5M753x4xlQAZiw4qCHY7guT4Ih8WAYvg== X-Received: by 2002:a17:906:2c0d:b0:a64:a091:91f2 with SMTP id a640c23a62f3a-a6f60d40c99mr732397266b.37.1718645968592; Mon, 17 Jun 2024 10:39:28 -0700 (PDT) From: Andrew Cooper To: Xen-devel Cc: Andrew Cooper , Jan Beulich , Jan Beulich , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Oleksii Kurochko Subject: [PATCH v4 6/7] x86/cpuid: Fix handling of XSAVE dynamic leaves Date: Mon, 17 Jun 2024 18:39:20 +0100 Message-Id: <20240617173921.1755439-7-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240617173921.1755439-1-andrew.cooper3@citrix.com> References: <20240617173921.1755439-1-andrew.cooper3@citrix.com> MIME-Version: 1.0 First, if XSAVE is available in hardware but not visible to the guest, the dynamic leaves shouldn't be filled in. Second, the comment concerning XSS state is wrong. VT-x doesn't manage host/guest state automatically, but there is provision for "host only" bits to be set, so the implications are still accurate. Introduce xstate_compressed_size() to mirror the uncompressed one. Cross check it at boot. Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- CC: Jan Beulich CC: Roger Pau Monné CC: Oleksii Kurochko v3: * Adjust commit message about !XSAVE guests * Rebase over boot time cross check * Use raw policy v4: * Drop the TODO comment. The CPUID path is always liable to pass 0 here. * ASSERT() a nonzero c->size like we do in the uncompressed helper. --- xen/arch/x86/cpuid.c | 24 +++++++-------------- xen/arch/x86/include/asm/xstate.h | 1 + xen/arch/x86/xstate.c | 36 +++++++++++++++++++++++++++++++ 3 files changed, 45 insertions(+), 16 deletions(-) diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c index 7a38e032146a..a822e80c7ea7 100644 --- a/xen/arch/x86/cpuid.c +++ b/xen/arch/x86/cpuid.c @@ -330,23 +330,15 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf, case XSTATE_CPUID: switch ( subleaf ) { - case 1: - if ( !p->xstate.xsavec && !p->xstate.xsaves ) - break; - - /* - * TODO: Figure out what to do for XSS state. VT-x manages host - * vs guest MSR_XSS automatically, so as soon as we start - * supporting any XSS states, the wrong XSS will be in context. - */ - BUILD_BUG_ON(XSTATE_XSAVES_ONLY != 0); - fallthrough; case 0: - /* - * Read CPUID[0xD,0/1].EBX from hardware. They vary with enabled - * XSTATE, and appropriate XCR0|XSS are in context. - */ - res->b = cpuid_count_ebx(leaf, subleaf); + if ( p->basic.xsave ) + res->b = xstate_uncompressed_size(v->arch.xcr0); + break; + + case 1: + if ( p->xstate.xsavec ) + res->b = xstate_compressed_size(v->arch.xcr0 | + v->arch.msrs->xss.raw); break; } break; diff --git a/xen/arch/x86/include/asm/xstate.h b/xen/arch/x86/include/asm/xstate.h index bfb66dd766b6..da1d89d2f416 100644 --- a/xen/arch/x86/include/asm/xstate.h +++ b/xen/arch/x86/include/asm/xstate.h @@ -109,6 +109,7 @@ void xstate_free_save_area(struct vcpu *v); int xstate_alloc_save_area(struct vcpu *v); void xstate_init(struct cpuinfo_x86 *c); unsigned int xstate_uncompressed_size(uint64_t xcr0); +unsigned int xstate_compressed_size(uint64_t xstates); static inline uint64_t xgetbv(unsigned int index) { diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c index 8edc4792a8fd..31bf2dc95f57 100644 --- a/xen/arch/x86/xstate.c +++ b/xen/arch/x86/xstate.c @@ -619,6 +619,36 @@ unsigned int xstate_uncompressed_size(uint64_t xcr0) return size; } +unsigned int xstate_compressed_size(uint64_t xstates) +{ + unsigned int i, size = XSTATE_AREA_MIN_SIZE; + + if ( xstates == 0 ) + return 0; + + if ( xstates <= (X86_XCR0_SSE | X86_XCR0_FP) ) + return size; + + /* + * For the compressed size, every non-legacy component matters. Some + * componenets require aligning to 64 first. + */ + xstates &= ~(X86_XCR0_SSE | X86_XCR0_FP); + for_each_set_bit ( i, &xstates, 63 ) + { + const struct xstate_component *c = &raw_cpu_policy.xstate.comp[i]; + + ASSERT(c->size); + + if ( c->align ) + size = ROUNDUP(size, 64); + + size += c->size; + } + + return size; +} + struct xcheck_state { uint64_t states; uint32_t uncomp_size; @@ -681,6 +711,12 @@ static void __init check_new_xstate(struct xcheck_state *s, uint64_t new) s->states, &new, hw_size, s->comp_size); s->comp_size = hw_size; + + xen_size = xstate_compressed_size(s->states); + + if ( xen_size != hw_size ) + panic("XSTATE 0x%016"PRIx64", compressed hw size %#x != xen size %#x\n", + s->states, hw_size, xen_size); } else if ( hw_size ) /* Compressed size reported, but no XSAVEC ? */ {