From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792585351; b=MtjD3ysApN2PnfCIAYQ6rGQCyyjSf4KXnpiPjr+64WOsWATbHz6trKE5gs/p5XP8tp8/ JarrCbzxw0f4IYhs0lWErDZAt+di633AgpIahpEJsd1H6i7auXU3eP7EPdGDtXAmhhk0t 6UUOFVSmQq//oq9hZppfv8d5gJB8hdFs0cMvhrkdVvaYNnEDoMzgYfD8jIsMTfk/HlOPz +5Jh/0IJCGZ/w7tf0m+dHHuPDrlS/VAWFfxJF4Tk0lBNj+Qzoi5uRSFMJjlDQWLGRSCM4 IHJunBaiBwE4y7m3zDUxCU38VdAahERahpv9EHPotIOukE8fjOckZLNydUomhNcP3mg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792585351; h=Received:DKIM-Signature:Received:Date:Message-ID:From:To:Cc:Subject: In-Reply-To:References:User-Agent:MIME-Version:Content-Type: X-SA-Exim-Connect-IP:X-SA-Exim-Rcpt-To:X-SA-Exim-Mail-From: X-SA-Exim-Scanned; bh=IPJUymxjKiGCs/LHeM584g/BXjOFeySUOeJJNoSlY1w=; b=zKGgUXaDr8+A+KyQHRmZ+Fdv1hY8dQJtZtxSOAv+wm7m53GcIWl655/2Hn4EFZKho0MM ui1ozOZgGYJfvsVs4sleCVIlRtYYVcXqHjxvw46y60b94+VZnz0I40633MuAoC6ATJQ2M MwPXL+TJLsK+ttoA8J8vClQ+d8X+HA9L2Gz1+zdvOMIgD41R0ild2ulCmGLViT8M6FMOc p0E0RRmmhwe1hKx5tqb7WqhNGHkCHibdGDo3a8gs25wdorcuQDElKXiafq/Vq8c3ix2YZ 8x/aOSEjDJ9uMYsKo8eUYvlXrzxYL4UwblhA/9EvmTEhpRIwSSIMlEjkrrVZKZalsCg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=OMZTz62u; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 39D80606A319; Wed, 21 Oct 2026 12:22:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=OMZTz62u Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7D991F000C6; Wed, 21 Oct 2026 12:22:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792585350; bh=IPJUymxjKiGCs/LHeM584g/BXjOFeySUOeJJNoSlY1w=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=OMZTz62ums/EzYgkcLfkDHfXVmr9pFPoJ8Dwj4vD2T06tPR5bPP1njcDF5Oi9ewm1 qxbaufbPYNTTEtEv14nDLB4FuMVs9Jj1GZltLa4Mv40SwMde40CrOreI3ONQOFfJxQ jDrofnvfGatq6D/BP7k2jQFZK6qJa38IfAqSNHOkfRA6Vd0KFS1cyWtx6x9XfqoMc6 mmcMq+jh0DEsDMrI8rJxUszEkKt6kE6S+DqVygbWYtGyDhS/yww4QhRl16jFT2HF+Q 3sHErpEsxRN426ueQc+BcGX1fOigsLKmwkzga05TKzmnbm8IxDtTPesGAFIvBE7Xb4 8GYYi+Qbo2RxQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1xJVKu-00000005YGD-2Ld2; Wed, 21 Oct 2026 12:22:28 +0000 Date: Wed, 21 Oct 2026 13:22:28 +0100 Message-ID: <86qzhjz1iz.wl-maz@kernel.org> From: Marc Zyngier To: Vincent Donnefort Cc: oupton@kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, kernel-team@android.com, fuad.tabba@linux.dev, stable@vger.kernel.org Subject: Re: [PATCH v1] KVM: arm64: pkvm: Clear GICv3 LRs in the hypervisor In-Reply-To: <20261021110000.508827-1-vdonnefort@google.com> References: <20261021110000.508827-1-vdonnefort@google.com> 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/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list 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: vdonnefort@google.com, oupton@kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, kernel-team@android.com, fuad.tabba@linux.dev, stable@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Wed, 21 Oct 2026 12:00:00 +0100, Vincent Donnefort wrote: > > The LR registers are architecturally UNKNOWN when the CPU boots or > resumes. However, in protected mode, only the used ones are reset. > During boot the HVC __vgic_v3_init_lrs() is never called because > vgic_present is only set in init_subsystems(), after cpu_hyp_init() was > called. Why don't you fix this rather than making the init even more different? > Also, the PM notifier isn't registered for pKVM and the HVC > becomes unavailable after the host is deprivileged. Sanitising the LRs on PSCI_ON is probably the right thing to do, but I don't understand why resetting the LRs is out of reach from the host, given that the host is fully in charge of the interrupt injection, and therefore controls the LRs. Thanks, M. -- Without deviation from the norm, progress is not possible.