From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 BA0A73CC9E8; Thu, 16 Jul 2026 14:33:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784212412; cv=none; b=t9/GiV/RiTsTWllt8S2XxaNS0gSa1Lnryyl/vAbgR3y76Izo1LMImVc6lYX7DkU6pUGD4SFBMdxsxZZ1aF2aI+ohwP15h+Y2zP3nyazj3UajuuatKwmZ+yB7lqr1Km8+5atjTZt7euoLR7SrUoYzDbhsrAn2IPdxaEKxgDXQrro= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784212412; c=relaxed/simple; bh=Pno6lJtAuQa+790X41hnj/eMKWa4zUjv0Q8mEH0i9dI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GYGovrCEzKnWRDibYgy4r/qfX70lOIQANLGYXUWEkPSvgZnQnEo6Vd/bTFF+PUXLJwxvY4a4Wk6GC3tamETnSA55GwccowIKS5vwnkZehCO1ynYJvVMAJCXSW8PxdmfBa4QWfWcfrxp7wcMC7QKrT04M3AIojuLCi4B+Rs5ELAA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fj2mMcy1; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="fj2mMcy1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 326E21F000E9; Thu, 16 Jul 2026 14:33:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784212410; bh=7u8rSh8F9v2esazYyNZoJiyS+K4cFKSc8TbfamHDCcg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fj2mMcy1gsPSon18uiG3ayM7+TMpoTq7Q+drVv4JOYeJ2FaXBQc4fMnYcfbpjuA8B L9VNaE8tXJIJLFmYfLpB71Vt9vDr4U+dKqOqlxFvw94j0ZLR33MdOvt00WmdyUTbtj 9fhQlKpAF9ACbf+8fW7I4QKTN5QSImK52ssDBWGo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josef Bacik , Jason Gunthorpe , Weinan Liu , Wei Wang , Samiullah Khawaja , Suravee Suthikulpanit , Vasant Hegde , Joerg Roedel Subject: [PATCH 6.12 316/349] iommu/amd: Dont split flush for amd_iommu_domain_flush_all() Date: Thu, 16 Jul 2026 15:34:10 +0200 Message-ID: <20260716133040.389804312@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133033.287196923@linuxfoundation.org> References: <20260716133033.287196923@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weinan Liu commit 69fe699afe1afcb730164b86c228483c2da05f94 upstream. We have observed multiple full invalidations occurring during device detach when we are done using the vfio-device. blocked_domain_attach_device() -> detach_device() -> amd_iommu_domain_flush_all() -> amd_iommu_domain_flush_pages(..., CMD_INV_IOMMU_ALL_PAGES_ADDRESS) while (size != 0) { -> __domain_flush_pages( flush_size /* power of 2 flush_size */) -> domain_flush_pages_v1() -> build_inv_iommu_pages() -> build_inv_address() } build_inv_address() will trigger a full invalidation if the chunk size > (1 << 51). Consequently, the guest will issue multiple full invalidations for a single call to amd_iommu_domain_flush_all() Without this patch, we will see 10 time instead of 1 time full invalidations for every amd_iommu_domain_flush_all(). Cc: stable@vger.kernel.org Fixes: a270be1b3fdf ("iommu/amd: Use only natural aligned flushes in a VM") Suggested-by: Josef Bacik Suggested-by: Jason Gunthorpe Signed-off-by: Weinan Liu Reviewed-by: Wei Wang Reviewed-by: Jason Gunthorpe Reviewed-by: Samiullah Khawaja Reviewed-by: Suravee Suthikulpanit Reviewed-by: Vasant Hegde Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/amd/iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -1702,7 +1702,8 @@ void amd_iommu_domain_flush_pages(struct { lockdep_assert_held(&domain->lock); - if (likely(!amd_iommu_np_cache)) { + if (likely(!amd_iommu_np_cache) || + size >= (1ULL<<52)) { __domain_flush_pages(domain, address, size); /* Wait until IOMMU TLB and all device IOTLB flushes are complete */