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 49A2342C4E9; Fri, 31 Jul 2026 12:37:46 +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=1785501470; cv=none; b=mBG+Lrhf9xcBKmSdCnk+Jhu5dFV7ZomK8vsrfR+oNcn+Zla8Nn1IwvLK5xx+YX4H6iOJr0sTr96sEjTSbofxTxNesJJyz8qZ2XK3ag/23NhLE7uc0NJ+FiTThmCFpVWXJqN4hF1rXzNiAJkPS3x/wfT3jXRj5VkJ5zHNUpfh0sA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785501470; c=relaxed/simple; bh=rvtRV62usxvYDabRiDuT5QzOKER095ZOoLBRwH9Xwsc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=NPAdRJFFnguabX7m7rsM5HwZ1HJqI7u9SW/+/L1OKVTE/O7ECO8LBT0/fiaTwqLdHRX5RR17O9gylHtPvcbgBNZELREzcOdyQpvp0Ju4hEmCo2dYVU5mttTuZV/T1W7X5cPKRQLWGe0IPBXWNpta5pKZWGOumBCaWxsYWvZWc9M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MUVfliT8; 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="MUVfliT8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EED971F00A3E; Fri, 31 Jul 2026 12:37:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785501466; bh=2SztSUpbsqfIgO005x2FPAmHBQNw5E5n0LUq/NdA0HU=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=MUVfliT8oYhJnCj/BJ/J46GBwZX1YAo9xvIA4MuUIEZ/gptCvTGlpC4IEBXOTbdZb ob/In2Wk29Fw+ESbe+Gkrrt+OKF081D7z4WTsE8cZ6YESbkFduP6FegCDtO6NibPyz JTVHuqB5XJ9vl6b+bZr+rmiVoao/+LULhsGkx3n7qoOn13BboxqC2x6bDG4hrDRjRU Gi+ry+Ezi/E797AT5CkjNWhHtbvWuZi1XalDBfyFfuxkebar3cY8p/Nn6TjL1tAMlW tZ1Hne61MJmemJFTOAMGH+pn46KaSorMy9aVj3sWktq6G4ts5HIkpNfKkR1mEv8iTT QK30tQ3uRtz+w== From: Mark Brown Date: Fri, 31 Jul 2026 13:25:43 +0100 Subject: [PATCH v17 05/14] KVM: arm64: Set PSTATE.EXLOCK when entering an exception Precedence: bulk X-Mailing-List: linux-kernel@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: <20260731-arm64-gcs-v17-5-5e39ca01b14e@kernel.org> References: <20260731-arm64-gcs-v17-0-5e39ca01b14e@kernel.org> In-Reply-To: <20260731-arm64-gcs-v17-0-5e39ca01b14e@kernel.org> To: Catalin Marinas , Will Deacon , Marc Zyngier , Joey Gouly , Suzuki K Poulose , Shuah Khan , Fuad Tabba , Oliver Upton Cc: Peter Maydell , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Brown X-Mailer: b4 0.16-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2696; i=broonie@kernel.org; h=from:subject:message-id; bh=rvtRV62usxvYDabRiDuT5QzOKER095ZOoLBRwH9Xwsc=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBqbJb/AJFaS2DpkGvedgVJ9VYbHW8bMmiP0fPw7 ZEiXBwgikqJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCamyW/wAKCRAk1otyXVSH 0OuTB/97FhJlWUvMLrTaOyBT9B0gl7l0ec7Rp7QH+V2nKcB+6vFPfbo9QZy0y+QIMY623/IZ/NN 3rch/ho8F5zS7/uOWByUeL13H1YDc3cK0nZPRbWesfs28hgmLhXS7ioiwWr2k8O14P9v2zAxo10 836ejbS1cJ6dXxCenqTo64xHM/EtYw57f7MtQ55epF9vQ9ZM0yDcv4eDtY2C9ZB7RO3cYd8dEPo VnQPEel90VPuG1yheGBtJs/zxj7bJfC2xHumC1ptkSTWhHtbLCY+dZwYff8OZiTvTkBlGd+x9NB mjzHRZL36yQIfByPnetyTFYOZdEnwXB/8nZsparyCW6chXtP X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB As per DDI 0487 R_WTXBY we need to manage PSTATE.EXLOCK when entering an exception, when the exception is entered from a lower EL the bit is cleared while if entering from the same EL it is set to GCSCR_ELx.EXLOCKEN. Implement this behaviour in enter_exception64(). Signed-off-by: Mark Brown --- arch/arm64/include/uapi/asm/ptrace.h | 1 + arch/arm64/kvm/hyp/exception.c | 37 ++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h index 6fed93fb2536..6113b9f9771b 100644 --- a/arch/arm64/include/uapi/asm/ptrace.h +++ b/arch/arm64/include/uapi/asm/ptrace.h @@ -56,6 +56,7 @@ #define PSR_C_BIT 0x20000000 #define PSR_Z_BIT 0x40000000 #define PSR_N_BIT 0x80000000 +#define PSR_EXLOCK_BIT 0x400000000 #define PSR_BTYPE_SHIFT 10 diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c index bef40ddb16db..15b00e0ee1ec 100644 --- a/arch/arm64/kvm/hyp/exception.c +++ b/arch/arm64/kvm/hyp/exception.c @@ -65,6 +65,38 @@ static void __vcpu_write_spsr_und(struct kvm_vcpu *vcpu, u64 val) vcpu->arch.ctxt.spsr_und = val; } +static unsigned long compute_exlock(struct kvm_vcpu *vcpu, + unsigned long mode, + unsigned long target_mode) +{ + u64 gcscr; + + if (!kvm_has_gcs(kern_hyp_va(vcpu->kvm))) + return 0; + + /* GCS can't be enabled for 32 bit */ + if (mode & PSR_MODE32_BIT) + return 0; + + /* When taking an exception to a higher EL EXLOCK is cleared. */ + if ((mode | PSR_MODE_THREAD_BIT) != target_mode) + return 0; + + /* + * When taking an exception to the same EL EXLOCK is set to + * the effective value of GCSR_ELx.EXLOCKEN. + */ + if (is_hyp_ctxt(vcpu)) + gcscr = __vcpu_read_sys_reg(vcpu, GCSCR_EL2); + else + gcscr = __vcpu_read_sys_reg(vcpu, GCSCR_EL1); + + if (gcscr & GCSCR_ELx_EXLOCKEN) + return PSR_EXLOCK_BIT; + + return 0; +} + /* * This performs the exception entry at a given EL (@target_mode), stashing PC * and PSTATE into ELR and SPSR respectively, and compute the new PC/PSTATE. @@ -154,6 +186,11 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode, // PSTATE.BTYPE is set to zero upon any exception to AArch64 // See ARM DDI 0487E.a, pages D1-2293 to D1-2294. + // PSTATE.EXLOCK is set to 0 upon any exception to a higher + // EL, or to GCSCR_ELx.EXLOCKEN for an exception to the same + // exception level. See ARM DDI 0487 R_WTXBY. + new |= compute_exlock(vcpu, mode, target_mode); + new |= PSR_D_BIT; new |= PSR_A_BIT; new |= PSR_I_BIT; -- 2.47.3