From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5698A145A03 for ; Sat, 9 Nov 2024 22:37:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731191874; cv=none; b=a7YGx3INnM1xN3++PF4xB4ha82N60H23OLLPyT2DdpSZ5gHMdtDYkf9LzgLF5OzxK5b/oh34J1YWnCnfX/RuPC4jCVq0anvxDhXc1D+b6hXsJRLNCvAkKlXXp4mWCe2jKO2Rrd9hlc/pDnm98go6ELhkNHyiCrn2VEW408ksUm8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731191874; c=relaxed/simple; bh=+p9aF/4Dxh80rw+Nr6orHPCQmEGpZCusRg/Tb1GRujQ=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=dyXFHWjXwZZZCMww2bzn5rhMxL+IufN0Kt3WboqVX3sU2xngBW6UXlD+1oFYlCr0wtBFfrLO+wDWXB4+N0ndlEzVn0kgf8dYcXQ8rLkggjJ3Nq6FNC4O2t6ZLGjbDGWkKZ02b1OclqnCE61VrK67PwMhMwEqgCzR261cvvHmnFU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V9/ylEjG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V9/ylEjG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD3E1C4CECE; Sat, 9 Nov 2024 22:37:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731191873; bh=+p9aF/4Dxh80rw+Nr6orHPCQmEGpZCusRg/Tb1GRujQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=V9/ylEjG2zYKDlzqZZTd2ai5rF0U6x6bKpvqfrWMj/gdkDaFLAw4UBSX8lloqZKm1 IlNUMnkECymugTAcbTNIRoTEQOmwD6UEAo9u6rn/DXnvXWWf9EEIIJXUCDYEo4iWPJ kHP8szW6xSy95W9NSHfMT1i15hvZMyqCFjUd+caB5p/6XcT+6GxhenQC07qPdWB2/Q VhUl7ZFpD8v0XwfQUPQi8+9dqRiYFGXbT0NRPG8fBZwR10VsK5nGutx6xwvwuKljwT Mdp2uoJ5W8+QNI/gvc5O5LHjleJQIsK7p+ASQACOhSPlahLeJEXCiMNQmIps+gLigC cN+vw5dyv3eEA== Received: from sofa.misterjones.org ([185.219.108.64] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1t9u5X-00BV5v-JT; Sat, 09 Nov 2024 22:37:51 +0000 Date: Sat, 09 Nov 2024 22:37:49 +0000 Message-ID: <87bjyot4n6.wl-maz@kernel.org> From: Marc Zyngier To: Oliver Upton Cc: kvmarm@lists.linux.dev, Joey Gouly , Suzuki K Poulose , Zenghui Yu , Mingwei Zhang , Colton Lewis , Alexandru Elisei Subject: Re: [PATCH 11/15] KVM: arm64: Use debug_owner to track if debug regs need save/restore In-Reply-To: References: <20241108222418.1677420-1-oliver.upton@linux.dev> <20241108222418.1677420-12-oliver.upton@linux.dev> <86y11szjwk.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.4 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: oliver.upton@linux.dev, kvmarm@lists.linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, mizhang@google.com, coltonlewis@google.com, alexandru.elisei@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Sat, 09 Nov 2024 17:18:38 +0000, Oliver Upton wrote: > > On Sat, Nov 09, 2024 at 12:11:39PM +0000, Marc Zyngier wrote: > > > static bool trap_debug_regs(struct kvm_vcpu *vcpu, > > > struct sys_reg_params *p, > > > const struct sys_reg_desc *r) > > > { > > > access_rw(vcpu, p, r); > > > if (p->is_write) > > > - vcpu_set_flag(vcpu, DEBUG_DIRTY); > > > > > > kvm_handle_debug_access(vcpu); > > > > Something has gone wrong here, and I don't think you wanted to make > > the ownership conditional on the access being only a write. > > That's very much intentional (probably not clear enough in changelog). I > don't think there's any value in special-casing this to writes. Look again. You *are* special-casing it by only dropping the vcpu_set_flag() call. Hint, the indentation is misleading. M. -- Without deviation from the norm, progress is not possible.