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 DDA172EC54D; Fri, 9 Jan 2026 12:23:17 +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=1767961397; cv=none; b=U+d6c1zTVula6T0ozJDxKrmq9ny+PDyc5YDmsYN4jUWomPU9PqSMTo8LdnEL9Uu1LkKogITV0rf2WGCxIFu6DUr3WGL5I48E3RL1mtOHx8T0iir4r0jt3L0c6lN8pnrW/MIrRSMHhaPpD50HVlihg0X9sQi/oeKYaAGi8yiYy8A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767961397; c=relaxed/simple; bh=s9vJBTZtdOhHIRzUYPCK/ZjsolTsGXmCI17rqQ2YOUs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VwEuJomr+6ze8pMtqeG4JuXEsaYlU3si0PfpzuiRgDLg7W84MFDYYaff9fdW6oQl03V4LubH4A8qUmEL2zylOAQ0lGtFKBZuvHEWfLxCvlM7Drb4h3OYcxPZ4u/xN+jV8XmReJE57M1Pnid//5ftwo+mZkbX3etkFG7i0tvl528= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VW9xgJW/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="VW9xgJW/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66FD8C4CEF1; Fri, 9 Jan 2026 12:23:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767961397; bh=s9vJBTZtdOhHIRzUYPCK/ZjsolTsGXmCI17rqQ2YOUs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VW9xgJW/h/yhjMojt2TjA9AmRSFK3peZm8c2FwECPvcla1dEfM3p4BGQbXTVaWur0 ErAO+37udbFy/69xJ/EvfhPVd1uIk0MeaNaEDuWXEC7hgQzZ7ZJ3agUnuiMnw7Xuje V/uVFiez+9tmgM779Hmi0kX/maC3zPNtFFJBBRC8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ashish Kalra , Vasant Hegde , Sairaj Kodilkar , Joerg Roedel , Sasha Levin Subject: [PATCH 6.6 737/737] Revert "iommu/amd: Skip enabling command/event buffers for kdump" Date: Fri, 9 Jan 2026 12:44:36 +0100 Message-ID: <20260109112201.830855236@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260109112133.973195406@linuxfoundation.org> References: <20260109112133.973195406@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman This reverts commit 44a764aec64b3f3235b9cbac2525222f69685418 which is commit 9be15fbfc6c5c89c22cf6e209f66ea43ee0e58bb upstream. This causes problems in older kernel trees as SNP host kdump is not supported in them, so drop it from the stable branches. Reported-by: Ashish Kalra Link: https://lore.kernel.org/r/dacdff7f-0606-4ed5-b056-2de564404d51@amd.com Cc: Vasant Hegde Cc: Sairaj Kodilkar Cc: Joerg Roedel Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/amd/init.c | 28 +++++++++------------------- 1 file changed, 9 insertions(+), 19 deletions(-) --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -840,16 +840,11 @@ static void iommu_enable_command_buffer( BUG_ON(iommu->cmd_buf == NULL); - if (!is_kdump_kernel()) { - /* - * Command buffer is re-used for kdump kernel and setting - * of MMIO register is not required. - */ - entry = iommu_virt_to_phys(iommu->cmd_buf); - entry |= MMIO_CMD_SIZE_512; - memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET, - &entry, sizeof(entry)); - } + entry = iommu_virt_to_phys(iommu->cmd_buf); + entry |= MMIO_CMD_SIZE_512; + + memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET, + &entry, sizeof(entry)); amd_iommu_reset_cmd_buffer(iommu); } @@ -898,15 +893,10 @@ static void iommu_enable_event_buffer(st BUG_ON(iommu->evt_buf == NULL); - if (!is_kdump_kernel()) { - /* - * Event buffer is re-used for kdump kernel and setting - * of MMIO register is not required. - */ - entry = iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK; - memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET, - &entry, sizeof(entry)); - } + entry = iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK; + + memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET, + &entry, sizeof(entry)); /* set head and tail to zero manually */ writel(0x00, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);