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 213D931D381; Thu, 16 Jul 2026 14:16:25 +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=1784211387; cv=none; b=d9e/xR0HTEDk2VNzHzzeiQ5kveHQJyUfmwkuZDfzRgnpLLYvhVApapOLvJ2fPpKT8lHdswY4I7qsC9VcS1yoAQN/8274UsBzwFVHntB9dLly78u12Fsi5fPsy2zYmlmaYvhDKzGOAbbbXFAV7GWoLWKlIQILB9ChqVwiDIn/cd4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211387; c=relaxed/simple; bh=6a9k8mRDj/+oQr0PB9yQFaDaRUdjnP6IulrdH1Cy/xM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IGeiFycsbDRWjrrDfpZZTflrZFC7/akZQRZRn0WJHZx83uIRDxDo6PATE9Lo8q4Md5/2b+N8ozoWpDuA78MdpHXZnhJKKHV2swbbpSOsnvDwqCnJ4aybSzsEkwLKkTv6Pb/Xjin7t4sGdfaLBHVgrTp9YEs0nq6id9Y6DxWevYw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=X1z1r5Ld; 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="X1z1r5Ld" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3798A1F00A3A; Thu, 16 Jul 2026 14:16:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784211385; bh=j83Is8w/spco17VRx+uJzsVCg0ik5KiABXw3AjjNYeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=X1z1r5LdC0vCCFyDKjCeSwEFRU+mrYAgrOOx15w2aKFjJy0VwLMdspOtXcTcYMQYE V0f1Zw5zUm3W2C8YGP1MrGxD8tHDzgUkXl+oLHZhhBj58M8ydflJIugnbuvA82ul06 EyiX4z6SsuUSvf1QQlNSV+6lCOoYqrGwReEgEMTI= 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 6.18 407/480] iommu/amd: Dont split flush for amd_iommu_domain_flush_all() Date: Thu, 16 Jul 2026 15:32:34 +0200 Message-ID: <20260716133053.616187940@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133044.672218725@linuxfoundation.org> References: <20260716133044.672218725@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 6.18-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 @@ -1689,7 +1689,8 @@ 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 */