From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 446C243F8B4; Thu, 9 Jul 2026 18:41:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783622512; cv=none; b=QNmWQcmwYxUYSuspNcYZZKUpwXqXftCOG2gboe4Z5qkcaPEgacjCv0dvFtSG/kFLmN+rDgMqL9uK6lhd1MmJ/jOkK60w0+rRaGopBFHS0q066F7HIVyB3zioYzyPMatLA+3QgUs591ABTC97aH4WiUuSDAvNyCYeNlEvdzqc5L4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783622512; c=relaxed/simple; bh=x/XFPzNN5/J6G5E0oqhJf08B8/sFJa7dJ49zCMEJE/4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=q44wQOUejtiOeDeGuK4/9tdpJVRBsG9VdXbNmd8OaxPv4ScAkmQ8P92+mmryLdz03Em8zHKQjTgLYKFsFMebKzNCloBT3Ns1NfDKg5xys1Ic1/NluncbHlgRxyTB84f+rjnGoJdApMA8ZhsCRmPR3iA5xreC11Vsqepb3fnQwGg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QgMOA0S+; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QgMOA0S+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBB701F00A3A; Thu, 9 Jul 2026 18:41:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783622510; bh=lXCEStw7jpxbfMPkl2Z/72HpjmmD/RSWBvdz3qpCcgU=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=QgMOA0S+Y4eap5dVYMkcLnL/Ry5Xm/wsb+x1Cj4O6YRiaArIgeBcRxmDUbKTR2Xpf UUY83AMKg6kZWp5Re3DwHf4LyUxrAbjP5Isn+KafFjvzA6K4vYJWEo217zhnKq8ZGQ AUjtNh8sfi/ip2yWrJD23Gu8ptPYgMK8rMJBiMFk3cJGL/Hh7ttdo79mtPK6oo9y8U 8TWW5TNL1Agzy6nd+9ttMJi6RvuVtAkk2DvdAJREgJiTMKK9HglKo6JnccFQvDuZwU M7k6ZVYvP2WRQ8HdOUkiW51+LEJgGhV96INcGQ3awJ/hTIciHn21ljS95CSooVtFbg JBCzjGgyKR8TQ== From: Mark Brown Date: Thu, 09 Jul 2026 19:27:44 +0100 Subject: [PATCH v12 23/29] KVM: arm64: Handle SME exceptions Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260709-kvm-arm64-sme-v12-23-d0301d79ef58@kernel.org> References: <20260709-kvm-arm64-sme-v12-0-d0301d79ef58@kernel.org> In-Reply-To: <20260709-kvm-arm64-sme-v12-0-d0301d79ef58@kernel.org> To: Marc Zyngier , Joey Gouly , Catalin Marinas , Suzuki K Poulose , Will Deacon , Paolo Bonzini , Jonathan Corbet , Shuah Khan , Oliver Upton Cc: Dave Martin , Fuad Tabba , Mark Rutland , Ben Horgan , Jean-Philippe Brucker , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Peter Maydell , Eric Auger , Mark Brown X-Mailer: b4 0.16-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=6115; i=broonie@kernel.org; h=from:subject:message-id; bh=x/XFPzNN5/J6G5E0oqhJf08B8/sFJa7dJ49zCMEJE/4=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBqT+r8VGEq0Ppk21bwZmw/Ad5l8W+roobCEAC39 p/rAEneOFuJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCak/q/AAKCRAk1otyXVSH 0HAvB/9ZZ3LAZ0sJFynI6ylfiHczhjXwAbvQCmR2mK8S4I7ed29W8AD1V4vReLpAymk3bVXpug9 VJZrP3lzKlMTp/354zE/WGENmaWnAh2zLxGHKicNQummptbImVgMZP/6Wwzu5X5rrbAIeimpISB WmEZ2rX0xaMMhgy6vwgx/8lqEqF+dYmxo+A9U0ibDPSTBGjgjUMNtIXRz1/5k9NBF4ycOKpxJJL jf18L4y45ANVMuugAY/eY5VGhWZKrT5AGJZtPN9v4YLaOyyCCFkqL/OuX+KR+vY3zfVvpmykLKm EPdiLB+fCnc+BPGj5rihQdkIZGl/VB3v2SP8ske12xeMT5za X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB The access control for SME follows the same structure as for the base FP and SVE extensions, with control being via CPACR_ELx.SMEN and CPTR_EL2.TSM mirroring the equivalent FPSIMD and SVE controls in those registers. Add handling for these controls and exceptions mirroring the existing handling for FPSIMD and SVE. Reviewed-by: Fuad Tabba Signed-off-by: Mark Brown --- arch/arm64/kvm/handle_exit.c | 14 ++++++++++++++ arch/arm64/kvm/hyp/include/hyp/switch.h | 11 ++++++----- arch/arm64/kvm/hyp/nvhe/switch.c | 2 ++ arch/arm64/kvm/hyp/vhe/switch.c | 17 ++++++++++++----- 4 files changed, 34 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 54aedf93c78b..e69bdb87f19d 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -237,6 +237,19 @@ static int handle_sve(struct kvm_vcpu *vcpu) return 1; } +/* + * Guest access to SME registers should be routed to this handler only + * when the system doesn't support SME. + */ +static int handle_sme(struct kvm_vcpu *vcpu) +{ + if (guest_hyp_sme_traps_enabled(vcpu)) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + + kvm_inject_undefined(vcpu); + return 1; +} + /* * Two possibilities to handle a trapping ptrauth instruction: * @@ -390,6 +403,7 @@ static exit_handle_fn arm_exit_handlers[] = { [ESR_ELx_EC_SVC64] = handle_svc, [ESR_ELx_EC_SYS64] = kvm_handle_sys_reg, [ESR_ELx_EC_SVE] = handle_sve, + [ESR_ELx_EC_SME] = handle_sme, [ESR_ELx_EC_ERET] = kvm_handle_eret, [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort, [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort, diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 7c913da9babb..47f523a37cbe 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -67,11 +67,8 @@ static inline void __activate_cptr_traps_nvhe(struct kvm_vcpu *vcpu) { u64 val = CPTR_NVHE_EL2_RES1 | CPTR_EL2_TAM | CPTR_EL2_TTA; - /* - * Always trap SME since it's not supported in KVM. - * TSM is RES1 if SME isn't implemented. - */ - val |= CPTR_EL2_TSM; + if (!vcpu_has_sme(vcpu) || !guest_owns_fp_regs()) + val |= CPTR_EL2_TSM; if (!vcpu_has_sve(vcpu) || !guest_owns_fp_regs()) val |= CPTR_EL2_TZ; @@ -99,6 +96,8 @@ static inline void __activate_cptr_traps_vhe(struct kvm_vcpu *vcpu) val |= CPACR_EL1_FPEN; if (vcpu_has_sve(vcpu)) val |= CPACR_EL1_ZEN; + if (vcpu_has_sme(vcpu)) + val |= CPACR_EL1_SMEN; } if (!vcpu_has_nv(vcpu)) @@ -140,6 +139,8 @@ static inline void __activate_cptr_traps_vhe(struct kvm_vcpu *vcpu) val &= ~CPACR_EL1_FPEN; if (!(SYS_FIELD_GET(CPACR_EL1, ZEN, cptr) & BIT(0))) val &= ~CPACR_EL1_ZEN; + if (!(SYS_FIELD_GET(CPACR_EL1, SMEN, cptr) & BIT(0))) + val &= ~CPACR_EL1_SMEN; if (kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, S1POE, IMP)) val |= cptr & CPACR_EL1_E0POE; diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index 7318e3e6a5f3..2d5029dbfb00 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -196,6 +196,7 @@ static const exit_handler_fn hyp_exit_handlers[] = { [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, [ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg, [ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_SME] = kvm_hyp_handle_fpsimd, [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, @@ -208,6 +209,7 @@ static const exit_handler_fn pvm_exit_handlers[] = { [ESR_ELx_EC_HVC64] = kvm_handle_pvm_hvc64, [ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64, [ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted, + [ESR_ELx_EC_SME] = kvm_handle_pvm_restricted, [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index bbe9cebd3d9d..5fc677afcaf9 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -458,22 +458,28 @@ static bool kvm_hyp_handle_cpacr_el1(struct kvm_vcpu *vcpu, u64 *exit_code) return true; } -static bool kvm_hyp_handle_zcr_el2(struct kvm_vcpu *vcpu, u64 *exit_code) +static bool kvm_hyp_handle_vec_cr_el2(struct kvm_vcpu *vcpu, u64 *exit_code) { u32 sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu)); if (!vcpu_has_nv(vcpu)) return false; - if (sysreg != SYS_ZCR_EL2) + switch (sysreg) { + case SYS_ZCR_EL2: + case SYS_SMCR_EL2: + break; + default: return false; + } if (guest_owns_fp_regs()) return false; /* - * ZCR_EL2 traps are handled in the slow path, with the expectation - * that the guest's FP context has already been loaded onto the CPU. + * ZCR_EL2 and SMCR_EL2 traps are handled in the slow path, + * with the expectation that the guest's FP context has + * already been loaded onto the CPU. * * Load the guest's FP context and unconditionally forward to the * slow path for handling (i.e. return false). @@ -493,7 +499,7 @@ static bool kvm_hyp_handle_sysreg_vhe(struct kvm_vcpu *vcpu, u64 *exit_code) if (kvm_hyp_handle_cpacr_el1(vcpu, exit_code)) return true; - if (kvm_hyp_handle_zcr_el2(vcpu, exit_code)) + if (kvm_hyp_handle_vec_cr_el2(vcpu, exit_code)) return true; return kvm_hyp_handle_sysreg(vcpu, exit_code); @@ -522,6 +528,7 @@ static const exit_handler_fn hyp_exit_handlers[] = { [0 ... ESR_ELx_EC_MAX] = NULL, [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, [ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg_vhe, + [ESR_ELx_EC_SME] = kvm_hyp_handle_fpsimd, [ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd, [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, -- 2.47.3