From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E8B5F606A31D for ; Sun, 25 Oct 2026 07:52:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=QbK5C3VP; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=cTdjI3+Q DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=kd+dIHLAZ0VbjKhoBYhi5STIRTNamR3vQAK0UqVJG5I=; b=QbK5C3VPTUQQbv 7++X/eFnzY6Chd3HE08JIrPhv5wujLwVg1NubFGQTVkqO0/dcdBokAAmZsIvJ2DLzcIzm9B59AxYa gsqEGsHpvzlkC4m1d2IG1v6j8Y+jPHPpBkB+zXdvm1CzP5KLrSZQ7K+CkyVe5bGx/JERvQfu8txA0 2XeS6XopC5FXQN6JVImIt7/VjKMseL3LoQgzdyzq7rN/7k0sm6ICqDpbib3deAyODp5gRcY7JC62s KExDZFrt1Fc1OJk0enywNAt5viw4G7rPBbuDfCLf3FOIJMWCZf0s3HWDnDj3uqMzFDFYXRL6OTL2H IwbaThf4DX1Zk0gdgCCQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xKt1P-00000000qvS-0oEV; Sun, 25 Oct 2026 07:52:03 +0000 Received: from out-102.mta1.migadu.com ([95.215.58.102] helo=mta1.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xKt1N-00000000qts-0A6E for linux-arm-kernel@lists.infradead.org; Sun, 25 Oct 2026 07:52:02 +0000 X-Envelope-To: linux-arm-kernel@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=Z2sHLhxFVy/B5w9Rnnrt3uG5g0JTtJ0jVUFIyN0gxO0=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792914719; v=1; x=1793519519; b=cTdjI3+QvXqk4cYmtvjSsIsx9AxR1NBU4tX5SFFx5IrPusBpErbKSqfMj5ku4tEGygh1et58 ue4XDPxhIWPAdl2lwzx6C515AB+AtoBJ6458fpVGROXWsONM9z5hBaSBTaaG4AHGLJe3qTzsUq5 YoUvKQzENrNc7s3wYu7O1IIA= X-Envelope-To: linux-arm-kernel@lists.infradead.org Received: by smtp.migadu.com with ESMTPS id 48f71797eadf8a7f; Sun, 25 Oct 2026 07:51:59 +0000 X-Mizu-Trace-ID: 48f71797eadf8a7f X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: Catalin Marinas , Will Deacon , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Steffen Eiden , Mark Rutland , Yicong Yang , Zhou Wang , Arnd Bergmann , Fuad Tabba , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 3/5] KVM: arm64: Add context-switch of ACCDATA_EL1 Date: Sun, 25 Oct 2026 07:51:36 +0000 Message-ID: <20261025075138.2919734-4-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261025075138.2919734-1-fuad.tabba@linux.dev> References: <20261025075138.2919734-1-fuad.tabba@linux.dev> X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261025_005201_227356_BD2C1E96 X-CRM114-Status: GOOD ( 15.01 ) X-Spam-Score: -2.8 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 From: Marc Zyngier Add ACCDATA_EL1 save/restore as part of the EL0 context. This is conditioned on the guest's view of ID_AA64ISAR1_EL1.LS64 reporting that this register is supported. Signed-off-by: Marc Zyngier Fixes: 58ce78667a641 ("arm64: Add support for FEAT_{LS64, LS64_V}") Link: https://lore.kernel.org/r/20240815125959.2097734-5-maz@kernel.org Cc: stable@vger.kernel.org [Fuad: rebased; switch ACCDATA_EL1 for guests only, as the host never uses it; gate it on a new ARM64_HAS_LS64_ACCDATA capability, since in pKVM the host controls a non-protected guest's ID registers, and an EL2 access to ACCDATA_EL1 on a CPU without the feature is UNDEFINED] Signed-off-by: Fuad Tabba --- arch/arm64/kernel/cpufeature.c | 7 +++++++ arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 23 ++++++++++++++++++++++ arch/arm64/tools/cpucaps | 1 + 3 files changed, 31 insertions(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 32102c3912fa7..b5720c56eebc9 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -3225,6 +3225,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .cpu_enable = cpu_enable_ls64_v, ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, LS64, LS64_V) }, + { + .desc = "LS64_ACCDATA", + .capability = ARM64_HAS_LS64_ACCDATA, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA) + }, #ifdef CONFIG_ARM64_LSUI { .desc = "Unprivileged Load Store Instructions (LSUI)", diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h index c382848d31947..4a008c8a696ba 100644 --- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h +++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h @@ -17,6 +17,7 @@ #include static inline bool ctxt_has_s1poe(struct kvm_cpu_context *ctxt); +static inline bool ctxt_has_accdata(struct kvm_cpu_context *ctxt); static inline struct kvm_vcpu *ctxt_to_vcpu(struct kvm_cpu_context *ctxt) { @@ -67,6 +68,13 @@ static inline void __sysreg_save_user_state(struct kvm_cpu_context *ctxt) { ctxt_sys_reg(ctxt, TPIDR_EL0) = read_sysreg(tpidr_el0); ctxt_sys_reg(ctxt, TPIDRRO_EL0) = read_sysreg(tpidrro_el0); + + /* + * Despite the appearances, ACCDATA_EL1 is part of the EL0 + * context, as it can only be used using ST64BV0. + */ + if (ctxt_has_accdata(ctxt)) + ctxt_sys_reg(ctxt, ACCDATA_EL1) = read_sysreg_s(SYS_ACCDATA_EL1); } static inline bool ctxt_has_mte(struct kvm_cpu_context *ctxt) @@ -131,6 +139,18 @@ static inline bool ctxt_has_sctlr2(struct kvm_cpu_context *ctxt) return kvm_has_sctlr2(kern_hyp_va(vcpu->kvm)); } +static inline bool ctxt_has_accdata(struct kvm_cpu_context *ctxt) +{ + struct kvm_vcpu *vcpu; + + /* The host never uses ACCDATA_EL1 */ + if (!cpus_have_final_cap(ARM64_HAS_LS64_ACCDATA) || !ctxt_is_guest(ctxt)) + return false; + + vcpu = ctxt_to_vcpu(ctxt); + return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA); +} + static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) { ctxt_sys_reg(ctxt, SCTLR_EL1) = read_sysreg_el1(SYS_SCTLR); @@ -210,6 +230,9 @@ static inline void __sysreg_restore_user_state(struct kvm_cpu_context *ctxt) { write_sysreg(ctxt_sys_reg(ctxt, TPIDR_EL0), tpidr_el0); write_sysreg(ctxt_sys_reg(ctxt, TPIDRRO_EL0), tpidrro_el0); + + if (ctxt_has_accdata(ctxt)) + write_sysreg_s(ctxt_sys_reg(ctxt, ACCDATA_EL1), SYS_ACCDATA_EL1); } static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt, diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 2775ba3359cfe..f01719bbd6037 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -49,6 +49,7 @@ HAS_LPA2 HAS_LSE_ATOMICS HAS_LS64 HAS_LS64_V +HAS_LS64_ACCDATA HAS_LSUI HAS_MOPS HAS_NESTED_VIRT -- 2.47.3