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=1794418593; b=VJsnEb3IkTXdZiVEeTHv5cyNyVPXqHlo+Oq+pgXlx3OQzpzUE+xgboZisM5fZuOaDxpA 4nLOMtqww5EGyMXT0L78tAF0dPGYBtdI2uAFfmFYC4fPR1mNynHSrMM4DFePQ4qrg5pKr nqcC7PwCUZDjI6OVyhlda0Dsf0z+OJb53GjLD2tj4Oy/xLsRt0t0xWXx1lPVKNYYVh8eP 0NF1Xus5/kSrsP+wCMX0Xl0G9+cyMZEMoZaIyx46HkNjvjmMvqnC8DP2mKUEckMvtoplC 8vrOOEAuOvgclnhG1UJ7Ri1ZLbqidETPrh8U27VwfHOvBs7G3Ip4BU82IqSLv+lY1+A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794418593; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=vmfAY/utTC21Xke8G/BtbtuvSG6zizmCdl20fZax2h8=; b=Jo+R3Amdkl/VbYP7oqCstaZlDCtLjd+apFUlAR4mDutndmC86xx7z2s247hKRdscILho 4q3Ng0Kk4eaR/StfKqPJZoIgfhPsif3ZbNEsFAccvVAGPPUU2dZQMCgVWS4QeD4aU/6On RpLtDhcbshROG9aYCiWByf3q/X5+mDrrarAMkWO5v77T9GBwn2XyOJgK4AXFfDhzOO2ZQ mLSEUJ0pn5jI0OrnteNWIrjRWhrYtw7WMJFVE/qnOUY3skc7C8c5ppdI++GixpJ5Dekot YaMcW9Sg1AYH5bITkFTkDdFvi6v7X3Oc6S7BDfgbIXZlj+nciEjTSHZ/P130LP2rJqA== 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=ds3VVQvE; 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 237AD606A31C for ; Wed, 11 Nov 2026 17:36:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ds3VVQvE Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFF461F00A05; Wed, 11 Nov 2026 17:36:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794418593; bh=vmfAY/utTC21Xke8G/BtbtuvSG6zizmCdl20fZax2h8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=ds3VVQvEHO+F8/vIWH7Gg+KT2hQxy74WCqKn9INT5Bq09mLOVi6gles/LCZWACao/ elkvCjdBStJAPPDCn6b7d3FD9DCv0PwyKoYng5mfuo/y2b2LcVsaoNM3H3aKEJz0Dd mA3O+egP9AXgd1zbapgZYzW3kuvIFOt0RZJIM++dlpRqhla/L5jKNs8bG24FcTxFAn zOO1N98pD5l2yOWrIUwoNgM5gzV+KT06g0Rgo2EAR+3zobfH0Puz7ZR4vdqiuMwPEP kypmDDfxcSTd+abxdqJjQwNc8nDm+1CUhHNz01Xufr4lbJbnkc56zTXbSdkwKcB2BW hUlSasd8ge9Hg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v13 4/5] s390/pci: Fence FMB enable/disable via debugfs for passthrough devices Reply-To: sashiko-reviews@lists.linux.dev To: "Omar Elghoul" , linux-s390@vger.kernel.org Cc: "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261111162758.9792-5-oelghoul@linux.ibm.com> References: <20261111162758.9792-1-oelghoul@linux.ibm.com> <20261111162758.9792-5-oelghoul@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 11 Nov 2026 17:36:32 +0000 X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Introduce a fence over enabling or disabling FMB via debugfs when the zPCI > device is associated with a KVM. This will prevent processes on the host > from tampering with the FMB while the guest is still using it, which may > cause partial counter resets and inconsistent reads which have no parallel > in the architecture. >=20 > For VFIO devices that are not associated with a KVM (i.e., for userspace > drivers other than QEMU), this fence does not take effect. >=20 > Signed-off-by: Omar Elghoul Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261111162758.9792= -1-oelghoul@linux.ibm.com?part=3D4