From nobody Fri Nov 14 19:39:05 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=quarantine dis=none) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; t=1761648391; cv=none; d=zohomail.com; s=zohoarc; b=bMlmrbeRypk1t780kcqUWGu2uBnqFrvpQ8jjwmf4fpVgphh/kKKytNZ+YhZH890Z95ARy7xqOiAOfTxSDrxVvgM7zb3e0ZERAktjioNqvIEYYI5+6mZuNVTb95ei5KPMrQa5IzjiKvc6f4kD2sK23MFltzq+tWr2+aBc1BWpY4Y= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1761648391; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=7PXU0KudA4lCh1cHWJ2Z3Ek88d4g0GilUKcFYkuqxBU=; b=L8wfZ185SMXLKK+trUHwhp9y4AydAEMWXwPJvxs48X3ZKkGAzPhO9T3Cx8B/MS5kT2U2mtNusQPPVgcWsgelhGzxbtxc+DZ2EOz2BDhuNed1I04nx2QIscJQhIMHq9cbGHzkJwUklygj92ypu3+9eOgZ0PHW7u7nuHhiQ9skwD0= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1761648391412531.6784030093797; Tue, 28 Oct 2025 03:46:31 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vDhD4-0007PG-J2; Tue, 28 Oct 2025 06:45:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vDhCy-0007IL-Sm for qemu-devel@nongnu.org; Tue, 28 Oct 2025 06:45:46 -0400 Received: from sea.source.kernel.org ([172.234.252.31]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vDhCt-0005aa-Iq for qemu-devel@nongnu.org; Tue, 28 Oct 2025 06:45:44 -0400 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id CC81640195; Tue, 28 Oct 2025 10:45:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBA7AC4CEE7; Tue, 28 Oct 2025 10:45:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761648337; bh=5loEzMpfIdonqQFmPBZ630rSRFDUYBkaKtJLL1zfw3Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hUGbmm8PZGStITaZJsS9Td8Liin28iEbvewokKYQ26oBC/wPoP9gXJjQjo2waSb0o 45984r3uV8uDMNCzKiD+WSLJvNIo4gC8Kw31+UkWsW9lYj7/ZOk1poIhdmkv7qfq2S a3fq8+8HQ4ecEaq0u7aa2+DYHddhkK7TINE6Zuv4Plw2Hn7B9YA0b/9rc2DOGkne4K 1V67DfYACl3gMXaUTMFFCHhETpwboQlWLBdBR1qu/foN56AsYj9pmWMkIYv+hmOVKw EH3GbFnxkLstBQKUoZ8DXQaAfDQ2AL849+Vr04NOCWw2Dp8Fk5fclx7xjYYg9lg6Hn CJbjKFG5eb1QQ== From: "Naveen N Rao (AMD)" To: qemu-devel Cc: Paolo Bonzini , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Eduardo Habkost , Eric Blake , Markus Armbruster , Marcelo Tosatti , Zhao Liu , Nikunj A Dadhania , Tom Lendacky , Michael Roth , Roy Hopkins , Srikanth Aithal Subject: [PATCH v3 6/9] target/i386: SEV: Add support for enabling debug-swap SEV feature Date: Tue, 28 Oct 2025 16:13:31 +0530 Message-ID: <5fad4eec4386eba7a3aaa7fbc7b8ab3fa79dcdbd.1761648149.git.naveen@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=172.234.252.31; envelope-from=naveen@kernel.org; helo=sea.source.kernel.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @kernel.org) X-ZM-MESSAGEID: 1761648392350154100 Content-Type: text/plain; charset="utf-8" Add support for enabling debug-swap VMSA SEV feature in SEV-ES and SEV-SNP guests through a new "debug-swap" boolean property on SEV guest objects. Though the boolean property is available for plain SEV guests, check_sev_features() has a check that rejects attempts to enable any SEV feature for a plain SEV guest. Though this SEV feature is called "Debug virtualization" in the APM, KVM calls this "debug swap" so use the same name for consistency. Sample command-line: -machine q35,confidential-guest-support=3Dsev0 \ -object sev-snp-guest,id=3Dsev0,cbitpos=3D51,reduced-phys-bits=3D1,debug-= swap=3Don Reviewed-by: Tom Lendacky Signed-off-by: Naveen N Rao (AMD) --- target/i386/sev.h | 1 + target/i386/sev.c | 20 ++++++++++++++++++++ qapi/qom.json | 7 ++++++- 3 files changed, 27 insertions(+), 1 deletion(-) diff --git a/target/i386/sev.h b/target/i386/sev.h index 102546b112d6..8e09b2ce1976 100644 --- a/target/i386/sev.h +++ b/target/i386/sev.h @@ -45,6 +45,7 @@ bool sev_snp_enabled(void); #define SEV_SNP_POLICY_DBG 0x80000 =20 #define SVM_SEV_FEAT_SNP_ACTIVE BIT(0) +#define SVM_SEV_FEAT_DEBUG_SWAP BIT(5) =20 typedef struct SevKernelLoaderContext { char *setup_data; diff --git a/target/i386/sev.c b/target/i386/sev.c index 0508b8998997..2cea2661cc03 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -319,6 +319,11 @@ sev_set_guest_state(SevCommonState *sev_common, SevSta= te new_state) sev_common->state =3D new_state; } =20 +static bool is_sev_feature_set(SevCommonState *sev_common, uint64_t featur= e) +{ + return !!(sev_common->sev_features & feature); +} + static void sev_set_feature(SevCommonState *sev_common, uint64_t feature, = bool set) { if (set) { @@ -2745,6 +2750,16 @@ static int cgs_set_guest_policy(ConfidentialGuestPol= icyType policy_type, return 0; } =20 +static bool sev_common_get_debug_swap(Object *obj, Error **errp) +{ + return is_sev_feature_set(SEV_COMMON(obj), SVM_SEV_FEAT_DEBUG_SWAP); +} + +static void sev_common_set_debug_swap(Object *obj, bool value, Error **err= p) +{ + sev_set_feature(SEV_COMMON(obj), SVM_SEV_FEAT_DEBUG_SWAP, value); +} + static void sev_common_class_init(ObjectClass *oc, const void *data) { @@ -2762,6 +2777,11 @@ sev_common_class_init(ObjectClass *oc, const void *d= ata) sev_common_set_kernel_hashes); object_class_property_set_description(oc, "kernel-hashes", "add kernel hashes to guest firmware for measured Linux boot"); + object_class_property_add_bool(oc, "debug-swap", + sev_common_get_debug_swap, + sev_common_set_debug_swap); + object_class_property_set_description(oc, "debug-swap", + "enable virtualization of debug registers"); } =20 static void diff --git a/qapi/qom.json b/qapi/qom.json index 830cb2ffe781..e89d11ce45ad 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -1010,13 +1010,18 @@ # designated guest firmware page for measured boot with -kernel # (default: false) (since 6.2) # +# @debug-swap: enable virtualization of debug registers, +# only supported on SEV-ES and SEV-SNP guests +# (default: false) (since 10.2) +# # Since: 9.1 ## { 'struct': 'SevCommonProperties', 'data': { '*sev-device': 'str', '*cbitpos': 'uint32', 'reduced-phys-bits': 'uint32', - '*kernel-hashes': 'bool' } } + '*kernel-hashes': 'bool', + '*debug-swap': 'bool' } } =20 ## # @SevGuestProperties: --=20 2.51.0