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 96F472C21E8; Sat, 4 Apr 2026 06:11:07 +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=1775283067; cv=none; b=Hu/5SsHC9oghmGLxb5ycSxiGDIUT9R9a60xYZxJ6qWG1HAh3bvuD0aNfaGTuygkFJUQ933QS1n/qzSej3b5a5AJ1JrGjlczkevjsStSaqd3BbOb7vqqO/Vc2DYRshAvdlUbWV/U28ljIEFnaSo7W7SFsk+vS+h8tKdoEnIDwMfM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775283067; c=relaxed/simple; bh=ZtzFClOB+Kj6ezVFI7LgGkgYWZlEzzMhdc7YAFHzGqw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=u631AlyzxnPzUWP2UDEYepL41tLWyr08yZRfGJQ+ObKZYCeXzDmL/s/4FU2R7S+u57TSANWy/jjV0eMjeuPKgR/iS+ZA+XPcXI47ux4SPIny3/iu7Kuq4524pCiYl8xxiEO/bm4Sb4rlRTCAwTRoGGLVu5u6OpoO/rb42yEMMcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vo6GC2Nz; 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="Vo6GC2Nz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD913C19423; Sat, 4 Apr 2026 06:11:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775283067; bh=ZtzFClOB+Kj6ezVFI7LgGkgYWZlEzzMhdc7YAFHzGqw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Vo6GC2Nz4+3PeA5uxcsZ/iYTvu9WTQFm/TdY1pLLupX5BSzX48LKxjLhnkrdlBKrR cahJeZUYKSIldD3qakqdE9desRKUMUBNVmigUKNOjbVznJY74BFIE6vEip5e5sy3Yl s1o/vw1lZm4AXhxeEZl5GxcizBnzOeXFHEG4pR194b5dHN4MQf9qRGlHjA59ueOzWh 22aGgrJm7Jor5bV4ZJ95quHndlnEmtvm9+8DgnLQLe+D6BIEzcnPBzUrJxL+ztoK/D uzS2BPlInQ8831HrblCw+Dur4sPS3uBC3uDCRhvtHBqG1HFkRon2bNMTRJ3MNEegPx 8N7EPpU8k/dzA== Date: Sat, 4 Apr 2026 06:11:05 +0000 From: Wei Liu To: mhklinux@outlook.com Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, longli@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, maz@kernel.org, bigeasy@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org Subject: Re: [PATCH 2/2] Drivers: hv: Move add_interrupt_randomness() to hypervisor callback sysvec Message-ID: <20260404061105.GC60588@liuwe-devbox-debian-v2.local> References: <20260402202400.1707-1-mhklkml@zohomail.com> <20260402202400.1707-3-mhklkml@zohomail.com> Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260402202400.1707-3-mhklkml@zohomail.com> On Thu, Apr 02, 2026 at 01:24:00PM -0700, Michael Kelley wrote: > From: Michael Kelley > > The Hyper-V ISRs, for normal guests and when running in the > hypervisor root patition, are calling add_interrupt_randomness() as a > primary source of entropy. The call is currently in the ISRs as a common > place to handle both x86/x64 and arm64. On x86/x64, hypervisor interrupts > come through a custom sysvec entry, and do not go through a generic > interrupt handler. On arm64, hypervisor interrupts come through an > emulated GICv3. GICv3 uses the generic handler handle_percpu_devid_irq(), > which does not do add_interrupt_randomness() -- unlike its counterpart > handle_percpu_irq(). But handle_percpu_devid_irq() is now updated to do > the add_interrupt_randomness(). So add_interrupt_randomness() is now > needed only in Hyper-V's x86/x64 custom sysvec path. > > Move add_interrupt_randomness() from the Hyper-V ISRs into the Hyper-V > x86/x64 custom sysvec path, matching the existing STIMER0 sysvec path. > With this change, add_interrupt_randomness() is no longer called from any > device drivers, which is appropriate. > > Signed-off-by: Michael Kelley Acked-by: Wei Liu