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spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/rwWfpqaYa6/+hKaGeHYUz/6b6fvLe05qyhVUF6oE1M=; b=qS4anAGoCfSLLeyu+Q0gz8g16 wWSNITu72BRVXARq6i0VreeFNPPOYA6xvwE+/H5GqTweNiLrfQRLFgQFVoPkCdj+wZtH4LMBqcLp4 M3lxz1EAnERGABVv6BokbgI2YJQHvMijTi3MLVljq9QwLuq2FaFDVH+BI/Jo6nH9Gfx2nWGyOUEQT bG/LP8AAQ5ETKCRRoVtuck6t6Vn1Ek28w3rs2W2OR90BkPRCTUq+2J59l8V909ka1Tsdzda8bg3nb 3orDF557649SDPhwc9WnJBW5s9XKY36vkezPbog5+1UFqTEmaQzNRluN/fizxsl0E8lWXT0JtCF7f yyTSnqXOg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lMtPf-005SOU-GE; Thu, 18 Mar 2021 14:14:11 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lMtPa-005SNQ-1D for linux-arm-kernel@lists.infradead.org; Thu, 18 Mar 2021 14:14:08 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4DE7464E01; Thu, 18 Mar 2021 14:14:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616076844; bh=aUVF0Ydr7cFuRiZVzu9loYt6i7SML2c2a9mIIBakwxs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XffV7mEr8cWu7NBXBLOufsNJUerPiVzf6ncfT+/kpr+PJChg1Io5bvtS036WzRaF6 HbloftOXtPrFEKvbjOnaas3BiPyBf6bHzDmOJcC/GOIvdnn/kXRs//4JZLfYdiSXzL vHDGgsH05fJqFJbAh9I2ox/dCANiytHXoGUyAHenReMUnxktogaenPEXMJUuQm74yY XOhmBOrKmqHILKnmJrSOOAvVIlgDrxNQh37XYft851Y6hJjgKH0+yGY8usdokklTlU F8h5GuqDACqlfK6VS2gtP+NcrwPsSa2mjhENjemy3Zz3M3WAuGD3vLiHBw2G5/a9na FNR6nuH3RyUFg== Date: Thu, 18 Mar 2021 14:13:58 +0000 From: Will Deacon To: Marc Zyngier Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, dave.martin@arm.com, daniel.kiss@arm.com, Catalin Marinas , James Morse , Julien Thierry , Suzuki K Poulose , broonie@kernel.org, ascull@google.com, qperret@google.com, kernel-team@android.com Subject: Re: [PATCH v2 10/11] KVM: arm64: Save/restore SVE state for nVHE Message-ID: <20210318141358.GF7055@willie-the-truck> References: <20210318122532.505263-1-maz@kernel.org> <20210318122532.505263-11-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210318122532.505263-11-maz@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210318_141406_323340_D1A947AB X-CRM114-Status: GOOD ( 20.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Mar 18, 2021 at 12:25:31PM +0000, Marc Zyngier wrote: > Implement the SVE save/restore for nVHE, following a similar > logic to that of the VHE implementation: > > - the SVE state is switched on trap from EL1 to EL2 > > - no further changes to ZCR_EL2 occur as long as the guest isn't > preempted or exit to userspace > > - ZCR_EL2 is reset to its default value on the first SVE access from > the host EL1, and ZCR_EL1 restored to the default guest value in > vcpu_put() > > Signed-off-by: Marc Zyngier > --- > arch/arm64/kvm/fpsimd.c | 10 +++++-- > arch/arm64/kvm/hyp/include/hyp/switch.h | 37 +++++++++---------------- > arch/arm64/kvm/hyp/nvhe/switch.c | 4 +-- > 3 files changed, 23 insertions(+), 28 deletions(-) > > diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c > index 14ea05c5134a..5621020b28de 100644 > --- a/arch/arm64/kvm/fpsimd.c > +++ b/arch/arm64/kvm/fpsimd.c > @@ -121,11 +121,17 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) > local_irq_save(flags); > > if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { > - if (guest_has_sve) > + if (guest_has_sve) { > __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR); > > + /* Restore the VL that was saved when bound to the CPU */ > + if (!has_vhe()) > + sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, > + SYS_ZCR_EL1); You end up reading ZCR_EL1 twice here, but it's probably not the end of the world. Anyway: Acked-by: Will Deacon Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel