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 C0855606A32E for ; Fri, 6 Nov 2026 18:59:14 +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=lwHW9Izc; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lRWqtfp+ 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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=hh1wVIGhMUtDEqA1RGRXhLPsq4X7xlZOf5Yg/x7bTfA=; b=lwHW9IzcTJD9JmPGwI7uTeN0dK V/SVYV8qjl8NVT+i1cjeeMuxYPs4D8Vnb4rdxIInuvxa/q0vOeFcz0uBu/V5oDpCBolBBGLg3OQTf NeJQyIHNMLMPTp+S3jUgZGchaC/vT5UNv7O/y8aFiKYZ1iwhcXIbqQVa6a6PWehZqiYx5k8cAeneV N1sq8IjjoLbosH6M1jbd0rR7xlzG+gtB47IL1OLh5xS38+GxaM6DveBAaaamA0jxcLJ9mfJA6qmNc GWp30PPmtfR5eIVKzSH2xXLPIUpZWoHQFOmJFm9TacFVxu1NYAoY++TtxefkBv5z9oBGGu/cp8+ZL 4RMBDn0A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xPP9Y-0000000DTaG-3LNQ; Fri, 06 Nov 2026 18:59:08 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xPP9Y-0000000DTa8-0W7u for linux-arm-kernel@lists.infradead.org; Fri, 06 Nov 2026 18:59:08 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 3D1E0601E1; Fri, 6 Nov 2026 18:59:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDC261F0089F; Fri, 6 Nov 2026 18:59:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793991547; bh=hh1wVIGhMUtDEqA1RGRXhLPsq4X7xlZOf5Yg/x7bTfA=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=lRWqtfp+1D498aBxxNnJJyG9ECqg+f/OfZ3IbBN3x25p6pxG/EdBJjp5O3EH94agq G4S0/LF+z79xECrP3fyX7gwClgYK0RzJw9f9N3wi0e0o5s3jvO7ePlzSAmsak8VDRD cUAdhEjJNEeQNF9q55IQx6OW5BBMj3KUGC7Vi2Sms6yntczCqpkTI4QcgPvgc0I1bk zsTMLn/IvdjcnbQ3thc+emgG+L4sMVxWznkDRqMTFCVLh+O0aQo9ygdXuBfAX5QygY XjXntwjXrnaRLax/wGU7yepiBQjqQ+XjzW3GXqjj4bp31h0zvRrYlfnNosyp/tcgJt Y06IpJ3ja+I/A== Date: Fri, 6 Nov 2026 10:59:05 -0800 From: Oliver Upton To: Vincent Donnefort Cc: Fuad Tabba , Marc Zyngier , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Joey Gouly , Suzuki K Poulose , Zenghui Yu , Steffen Eiden , Catalin Marinas , Will Deacon , Mark Rutland , Fuad Tabba , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] KVM: arm64: Allocate a protected vCPU's SVE state at EL2 Message-ID: References: <20261105130456.1617185-1-fuad.tabba@linux.dev> <20261105130456.1617185-3-fuad.tabba@linux.dev> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 On Fri, Nov 06, 2026 at 05:51:44PM +0000, Vincent Donnefort wrote: > > @@ -1243,6 +1253,9 @@ int pkvm_reset_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) > > PSCI_0_2_AFFINITY_LEVEL_ON) != PSCI_0_2_AFFINITY_LEVEL_ON_PENDING) > > return -ECANCELED; > > > > + if (vcpu_has_sve(&hyp_vcpu->vcpu)) > > + memset(hyp_vcpu->vcpu.arch.sve_state, 0, vcpu_sve_state_size(&hyp_vcpu->vcpu)); > > + > > Why wasn't this line around before? Prior to this series SVE was only supported in non-protected guests, so the host was responsible for resetting SVE state. Now that we have pVM support we need to reset state for protected vCPUs. Thanks, Oliver > > kvm_reset_vcpu_core(&hyp_vcpu->vcpu); > > kvm_reset_pvm_sys_regs(&hyp_vcpu->vcpu); > > > > diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c > > index 32e82653ebf7e..06ea91415ad8b 100644 > > --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c > > +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c > > @@ -570,6 +570,7 @@ static const struct sys_reg_desc_reset pvm_sys_reg_reset_vals[] = { > > RESET_UNKNOWN(MAIR_EL1), > > RESET_ZERO(AMAIR_EL1), > > RESET_ZERO(MDSCR_EL1), > > + RESET_ZERO(ZCR_EL1), > > RESET_ZERO(CNTV_CTL_EL0), > > RESET_UNKNOWN(TTBR0_EL1), > > RESET_UNKNOWN(TTBR1_EL1), > > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > > index 10eb7249aa9e8..aaaa1b8634ba4 100644 > > --- a/arch/arm64/kvm/reset.c > > +++ b/arch/arm64/kvm/reset.c > > @@ -52,6 +52,8 @@ int __init kvm_arm_init_sve(void) > > if (WARN_ON(kvm_sve_max_vl > VL_ARCH_MAX)) > > kvm_sve_max_vl = VL_ARCH_MAX; > > > > + kvm_nvhe_sym(kvm_sve_max_vl) = kvm_sve_max_vl; > > + > > /* > > * Don't even try to make use of vector lengths that > > * aren't available on all CPUs, for now: > > -- > > 2.47.3 > > > > -- > Vincent