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 C5C233F39D8 for ; Mon, 18 May 2026 15:31:49 +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=1779118309; cv=none; b=KtIBngQcMp1IL0EQ595jD0+uupLbHwjMGrl1HEGwbstHoU8DPRjzUC7HVERVA5Pu5NSDYRn0MfLu8hVfapZ0CpbZVT0rVtGpJqj52ZsSk/SyE4YtqJvfSt474iHJf1oPL7p1SneMmMTTNfoa79sUFrWMzLCcPk+MYxz8iV4SRmk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779118309; c=relaxed/simple; bh=TaL0vGDEszMByRNDVpz/8GnVwTdL8YYz0VnNw2wxbGA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=qwgVMItMB5fmC++k+0Qs7Ag2hEfLALdziD7EG0C41XLyn7QQq/KcFIGWG39FolYBBz301Dvu3LvqDd79Pm/+zKgrLcG3dUsPYqZbyTtRyuznFtSPGwA25CKtxG/nUDwfLWdX9mcJAriixp7Ys3k35ndP6Kp4fo6870Nc37Ui00M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O4/mNYg1; 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="O4/mNYg1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03933C2BCC6; Mon, 18 May 2026 15:31:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779118309; bh=TaL0vGDEszMByRNDVpz/8GnVwTdL8YYz0VnNw2wxbGA=; h=From:To:Cc:Subject:Date:From; b=O4/mNYg1V5kkPZinsY4CrYsg0XLHAPWKJfdRL6SKHfgihCrOi8AI62nGNsFyWLRmr PuMIxhyshowGteayZnXXhRY4wdL+nxU1UNItNDjCUjREK5t357VzPAkYu5w6cSF3cw wLr3GpKJBZBOOxhPZPuVNVZPkScSdYWxFxd7DA2uSBO4JEMGiSbD9KwZz6PU2VTg1R apIVmw0tsobf7ClVKOuQuwERXoxXrkyAkpLZuAZlOGsBRw6Bw9zObwo+ttLar9aHpM o3JETNs0CC5sD74A4E0XfbkKWLTuaDFk+rZy1ZhWd+FYkKe8WUjWIXSC83sA6H8TAk s5cXhh3abM9YQ== From: Will Deacon To: kvmarm@lists.linux.dev Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Oliver Upton , Marc Zyngier , Catalin Marinas , Mark Rutland Subject: [PATCH v2] KVM: arm64: Don't populate TPIDR_EL2 in finalise_el2() Date: Mon, 18 May 2026 16:31:26 +0100 Message-ID: <20260518153127.6078-1-will@kernel.org> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Currently, it is not necessary for __finalise_el2() to configure TPIDR_EL2: * The hyp stub code does not consume the value of TPIDR_EL2. * On the boot cpu, TPIDR_EL1 is used for the percpu offset until the ARM64_HAS_VIRT_HOST_EXTN cpucap is detected and boot alternatives are patched. Before boot alternatives are patched, cpu_copy_el2regs() will copy TPIDR_EL1 into TPIDR_EL2. It is not necessary for __finalise_el2() to initialise TPIDR_EL2 before this. * Secondary CPUs are brought up after boot alternatives have been patched, and __secondary_switched() will initialize TPIDR_EL2 in 'init_cpu_task', after finalise_el2() calls __finalise_el2() * KVM hyp code which may consume TPIDR_EL2 is brought up after all secondaries have been booted, once TPIDR_El2 has been configured on all CPUs. Remove the redundant initialisation from __finalise_el2(). Cc: Oliver Upton Cc: Marc Zyngier Cc: Catalin Marinas Reviewed-by: Mark Rutland Signed-off-by: Will Deacon --- v2: Use Mark's commit message, add his R-b tag, rebase onto -rc4. Link to v1: https://lore.kernel.org/r/20260330152927.26300-1-will@kernel.org arch/arm64/kernel/hyp-stub.S | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 634ddc904244..37c6976e44a4 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -104,11 +104,9 @@ SYM_CODE_START_LOCAL(__finalise_el2) mov_q x0, HCR_HOST_VHE_FLAGS msr_hcr_el2 x0 - // Use the EL1 allocated stack, per-cpu offset + // Use the EL1 allocated stack mrs x0, sp_el1 mov sp, x0 - mrs x0, tpidr_el1 - msr tpidr_el2, x0 // FP configuration, vectors mrs_s x0, SYS_CPACR_EL12 -- 2.54.0.563.g4f69b47b94-goog