From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E1DD2FF885E for ; Mon, 27 Apr 2026 13:49:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8PYGlOXEG6E9/P2t0qYpdnkfCSnyFBuw0mLKh5MPI4E=; b=bnkeO1ujoS0yt1CnWbFXdj5x68 V1AClHyrr1gsYrA+W6TREjDnPyNu/teJVGgcDmf237+DBprKhIcMQM4LozvF7+xJsJpinDVS7bV1q 2Q3RfDRFRDIkvmmgImzL6lDnRHKD+eOrX0OAuFEr7IbG/llTgmmdk0hcBiO8HmcNscvwG2o87/Udh xooIVMIkT4lS5B4e+Xe0OfAHhZqC3x/e1+nfI9lb8qUs57jtrAGyFZbIm2fJw3dbHqzlynYi8k+u9 IyvLmE/kk+xJr+MogfJDoNsyTb4NrP/qpE91SbdH1T1d68AfsmusDHYj0YVR7GIEhvJJ+ipctpjr1 2RAu5HqQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHMKk-0000000H1fb-0K4X; Mon, 27 Apr 2026 13:49:10 +0000 Received: from mail-qv1-xf34.google.com ([2607:f8b0:4864:20::f34]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHMKh-0000000H1fD-1k6m for linux-arm-kernel@lists.infradead.org; Mon, 27 Apr 2026 13:49:08 +0000 Received: by mail-qv1-xf34.google.com with SMTP id 6a1803df08f44-8a5800772f3so75623946d6.2 for ; Mon, 27 Apr 2026 06:49:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1777297745; x=1777902545; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=8PYGlOXEG6E9/P2t0qYpdnkfCSnyFBuw0mLKh5MPI4E=; b=GgpcP1qL1GRU44YXJ6EYxs/mK6Xlwv7tPqw6PkkFaz2YCO3iw31FWQzKqdkQZMnGRr 26R3tl2ijoDh9O4RlwwKyR4JlA6uuDsZLKJk7R7Zka1BWUFyeDgajrNVlV9G03I9wUtQ H4iIkD9kd2FSYSQ329Zby5/bDSXnky587dh9kaTBcy4ML0exNQri3U6PNvbG+12Lzut2 LgD6R4YfwmVLvIR/sgljLtIAYWUf0bTkQPrfd+5Oe6RzzF52JmFg8puipAmfS7Wy5KmN FwXyc0NLeOGonow9Ydmz5aZ+Fs1OoaPdftnlUsNJDwYvQJcpORTMLJ90gBnLNEJOPNXR roKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777297745; x=1777902545; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=8PYGlOXEG6E9/P2t0qYpdnkfCSnyFBuw0mLKh5MPI4E=; b=NjUlhkBz+d6U8TTmJJ9xFP8gJzYeLxFeTSweCxsm0BV05KZt+SuI1+RYudkCqFelOk s2no46uWGHvEkB6iyK7SwOCNGAqF4YBGeRxOoR/6ySX5n04+Iy41j1pJdCT+tXRHeL99 3V+QWv03nosV1il19cPSUa9GToFKuge/z5dUtkqZYDfTcQEys+7k83useWvOEZKsSvLe Zrz++V5+5AyVko14SFsX9yazlgYZzVNqDQukd3Nzs35X3n31IzRfNDDagCtSd5Eh8eE1 Uf4oltFeAOsA3w878OGIqFv+5Sox045tlWk88ILYev43ypvQkXKULL2XOHuSZxnkgn7b wkEQ== X-Forwarded-Encrypted: i=1; AFNElJ88Q/uDGY0cQqPPD+sUEBi+MKQzIrVSVjwfdzvbcDi//2LBt232rd9iABzpp+dEpmM3T3zxN03VPqa8VRK74Vlg@lists.infradead.org X-Gm-Message-State: AOJu0Yxwwyct3+IDYbnofpoOh0XpvoRBrjAh9hIfATY/6vIQwzZ7lOWO 9ZjMofAzV8UEuXg16ad9/1zvR8jNvLs69edkTrE1xfAqyfq8wshbzicBJM/qhtYE5rQ= X-Gm-Gg: AeBDievbszs3OmUJZlp1gprZBAiUKm/b3BZQunxmVLmPcHUqm2S7xvzsiWdbvSD5HMQ aIBSfRtJWugbOF5Nbsx/O4krCf7sW7BbMlM8Uuoz7Qu/m52gg0UID/icFBKi3OFyqGbASlGNIVF DstY3kTR+B6TapA7fQzfseZDwp+gUYUk2MyQASD8FXw5PNobPbP3h6bxFVGKbwGB4pQ6zsNzkNX GKeON8Dfclomx+q3mIRBdTx3qQ30pi/3JdafznPmHdLcEjh8SCNmiD2lH+jXjgDDawZgHI+V4SW 9wAvHFDwGE4WGcqVlKaDbnrWR9MLu8s08ZUU7T7h35BDAzew11q55ldFUB7F55U8OoNmtLRa8OZ fdE4ECC8+HOyF/uuvplJ/+0QFYj1Bd2sBaosowMqoiI0hvEFHthSsSKjyJz9Y/rzxukgw0g5fN6 xtfrw9jGUatPMXCtlaPLtNipD4/QkbTjMTeE9u2z/E4ZdNFXeKRdKNVQSASAMgMzaWcCNnwJ3l8 6fKkxNK71zouztP X-Received: by 2002:a05:6214:6107:b0:8a5:bd5b:e5f with SMTP id 6a1803df08f44-8b02817a4a5mr537295746d6.51.1777297745279; Mon, 27 Apr 2026 06:49:05 -0700 (PDT) Received: from ziepe.ca (crbknf0213w-47-54-130-67.pppoe-dynamic.high-speed.nl.bellaliant.net. [47.54.130.67]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8b02aa4f1f9sm257474006d6.0.2026.04.27.06.49.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Apr 2026 06:49:04 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wHMKd-00000003T5r-43dX; Mon, 27 Apr 2026 10:49:03 -0300 Date: Mon, 27 Apr 2026 10:49:03 -0300 From: Jason Gunthorpe To: "Aneesh Kumar K.V (Arm)" Cc: linux-kernel@vger.kernel.org, iommu@lists.linux.dev, linux-coco@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, Catalin Marinas , Marc Zyngier , Marek Szyprowski , Robin Murphy , Steven Price , Suzuki K Poulose , Thomas Gleixner , Will Deacon Subject: Re: [PATCH v4 2/3] swiotlb: dma: its: Enforce host page-size alignment for shared buffers Message-ID: <20260427134903.GA740385@ziepe.ca> References: <20260427063108.909019-1-aneesh.kumar@kernel.org> <20260427063108.909019-3-aneesh.kumar@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260427063108.909019-3-aneesh.kumar@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260427_064907_650085_E9FBE209 X-CRM114-Status: GOOD ( 23.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Apr 27, 2026 at 12:01:07PM +0530, Aneesh Kumar K.V (Arm) wrote: > When running private-memory guests, the guest kernel must apply additional > constraints when allocating buffers that are shared with the hypervisor. This patch has way too much stuff in it. I think your patch structure should be changed around 1) Patch to add mem_decrypt_granule_size(), and explain it as the alignment & size of what can be passed to set_memory_encrypted/decrypted() 2) Add support for mem_decrypt_granule_size() to ARM Then patches going caller by caller of set_memory_decrypted() to make them follow the new rule: 3) its 4) swiotlb 3) dma_alloc_coherent etc. don't forget about the new dma buf heaps too: drivers/dma-buf/heaps/system_heap.c: ret = set_memory_decrypted(addr, nr_pages); It is worth calling out in the cover letter that all the ARM CCA relevant places are fixed but drivers/hv/ is left for future. > @@ -33,18 +32,30 @@ int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops) > > int set_memory_encrypted(unsigned long addr, int numpages) > { > - if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr))) > + if (likely(!crypt_ops)) > return 0; > > + if (WARN_ON(!IS_ALIGNED(addr, mem_decrypt_granule_size()))) > + return -EINVAL; > + > + if (WARN_ON(!IS_ALIGNED(numpages << PAGE_SHIFT, mem_decrypt_granule_size()))) > + return -EINVAL; > + > return crypt_ops->encrypt(addr, numpages); > } > EXPORT_SYMBOL_GPL(set_memory_encrypted); > > int set_memory_decrypted(unsigned long addr, int numpages) > { > - if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr))) > + if (likely(!crypt_ops)) > return 0; > > + if (WARN_ON(!IS_ALIGNED(addr, mem_decrypt_granule_size()))) > + return -EINVAL; > + > + if (WARN_ON(!IS_ALIGNED(numpages << PAGE_SHIFT, mem_decrypt_granule_size()))) > + return -EINVAL; > + > return crypt_ops->decrypt(addr, numpages); > } > EXPORT_SYMBOL_GPL(set_memory_decrypted); This should go in the ARM patch adding mem_decrypt_granule_size() to CCA > diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h > index 07584c5e36fb..1e01c9ac697f 100644 > --- a/include/linux/mem_encrypt.h > +++ b/include/linux/mem_encrypt.h > @@ -11,6 +11,8 @@ > #define __MEM_ENCRYPT_H__ > > #ifndef __ASSEMBLY__ > +#include > +#include > > #ifdef CONFIG_ARCH_HAS_MEM_ENCRYPT > > @@ -54,6 +56,18 @@ > #define dma_addr_canonical(x) (x) > #endif > > +#ifndef mem_decrypt_granule_size > +static inline size_t mem_decrypt_granule_size(void) > +{ > + return PAGE_SIZE; > +} > +#endif > + > +static inline size_t mem_decrypt_align(size_t size) > +{ > + return ALIGN(size, mem_decrypt_granule_size()); > +} > + > #endif /* __ASSEMBLY__ */ > > #endif /* __MEM_ENCRYPT_H__ */ I know it seems a bit small, but put this in its own patch and explain how it works. I'd also like to see a kdoc here, and add a kdoc to set_memory_decrypted() that links back so people have a better chance to know about this. Jason