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 A4C1947ACD7; Thu, 20 Aug 2026 16:28:20 +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=1787243301; cv=none; b=cyBJPZaAU2G+3KH5OzEjDk4mCRmMqrwwebx69hduzj0TwMWKtSXLmYt49IlSZj5nsor4KMJDoZk1gmy4FUYApV/dhzDUwOyna4jtarpkZZYFndnbFIy1lCXrFCfgg1uMbo2Em3rGSzuc9Xw3NCobmAMxf1q8u9wM4Hq6jWRwfko= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787243301; c=relaxed/simple; bh=rduTiLR8dQJeQyyRhGAQHf8h3ouHS1MeWk7YCv9DXuY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B0hvn34gKoGtbAFFkYKLYzPexA9wKBLrRR3ADGCUVMdzy5Ia7bWBJrvKiFj/ewYcCWAKmK/XFfoVndncLJS9qgs6mqh26V2qN5pMv+Z3Ng0+LsOYUmPVotuXq6PNIotHF6W9+oCDkdSwyxTHxzHCjvOHEx7DmPEj7eQftsmw8vY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TY4rdHH4; 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="TY4rdHH4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD6531F000E9; Thu, 20 Aug 2026 16:28:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787243300; bh=GLyjanNRdaXMlWCfmId7ehhipjANhNSY0Jgz//LbPCg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TY4rdHH4/2BGRD3c3zGIOb71kAXKi2sEmn3PF+eFuW/rK3FWP1YYA1YTTMxNNHwMD ozP1sDVUo+JKcfT8I2vlznHGStiS90w/dXXhJXa0GAVHm2lt3wOoP8mJxIs/AX3aQd eeAdy+4pG/d1lO4yOCz92TfvriEX4HW53IS8MSCw= 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 , Sasha Levin Subject: [PATCH 5.15 048/272] iommu/amd: Dont split flush for amd_iommu_domain_flush_all() Date: Thu, 20 Aug 2026 16:53:52 +0200 Message-ID: <20260820145232.664880667@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145231.229664293@linuxfoundation.org> References: <20260820145231.229664293@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weinan Liu [ Upstream commit 69fe699afe1afcb730164b86c228483c2da05f94 ] 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: Sasha Levin 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 @@ -1284,7 +1284,8 @@ static void __domain_flush_pages(struct static void domain_flush_pages(struct protection_domain *domain, u64 address, size_t size, int pde) { - if (likely(!amd_iommu_np_cache)) { + if (likely(!amd_iommu_np_cache) || + size >= (1ULL<<52)) { __domain_flush_pages(domain, address, size, pde); return; }