From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8715F1B81CE; Fri, 30 Aug 2024 15:54:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725033295; cv=none; b=hWo3vswH12IdIuZJThvqZ0V0FtS0K9ZxUHJG7g9/AbrsT7aAWYEDUyb2hTAhKMPMrsagen6iD5z7SV7iUrehQS+5bJvtf1J48/go63QIRHaBoFBoJU+Ln9lau9BZ0EBnsIzfg48NVY1GcTJzuFZk7H9FeHW8WoX5D4ud/Sjj65A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725033295; c=relaxed/simple; bh=MRRYMjFn7aWtSBHCAj+sJCDuQyVpbXGWsKlTveW1QRw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nQX02PD7ou3P11FmiEG5VQNY+zy7nXBQhs6BLb5IRwEhwfKe7vBD+rD96J9n41ltTJFlmvyfqnKLBtJfZTnEF6zmZIuha1iGbnxIzFjx/RVaCYuFvfKH9WykVXE+mEdfVq8FkPAANF1c5j+xMasCSLSAh0p4QY1qXA/irYWOqCQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 18A4D1477; Fri, 30 Aug 2024 08:55:19 -0700 (PDT) Received: from [10.1.30.22] (e122027.cambridge.arm.com [10.1.30.22]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EB3A13F762; Fri, 30 Aug 2024 08:54:48 -0700 (PDT) Message-ID: Date: Fri, 30 Aug 2024 16:54:45 +0100 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 10/19] arm64: Override set_fixmap_io To: Suzuki K Poulose , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun References: <20240819131924.372366-1-steven.price@arm.com> <20240819131924.372366-11-steven.price@arm.com> <13bc77b7-5f68-44ca-93ce-578ffe029437@arm.com> From: Steven Price Content-Language: en-GB In-Reply-To: <13bc77b7-5f68-44ca-93ce-578ffe029437@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 19/08/2024 15:13, Suzuki K Poulose wrote: > On 19/08/2024 14:19, Steven Price wrote: >> From: Suzuki K Poulose >> >> Override the set_fixmap_io to set shared permission for the host >> in case of a CC guest. For now we mark it shared unconditionally. >> >> If/when support for device assignment and device emulation in the realm >> is added in the future then this will need to filter the physical >> address and make the decision accordingly. >> >> Signed-off-by: Suzuki K Poulose >> Signed-off-by: Steven Price >> --- >> New patch for v5 >> --- >>   arch/arm64/include/asm/fixmap.h |  2 ++ >>   arch/arm64/mm/mmu.c             | 17 +++++++++++++++++ >>   2 files changed, 19 insertions(+) >> >> diff --git a/arch/arm64/include/asm/fixmap.h >> b/arch/arm64/include/asm/fixmap.h >> index 87e307804b99..2c20da3a468c 100644 >> --- a/arch/arm64/include/asm/fixmap.h >> +++ b/arch/arm64/include/asm/fixmap.h >> @@ -108,6 +108,8 @@ void __init early_fixmap_init(void); >>   #define __late_clear_fixmap(idx) __set_fixmap((idx), 0, >> FIXMAP_PAGE_CLEAR) >>     extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t >> phys, pgprot_t prot); >> +#define set_fixmap_io set_fixmap_io >> +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys); >>     #include >>   diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c >> index 353ea5dc32b8..06b66c23c124 100644 >> --- a/arch/arm64/mm/mmu.c >> +++ b/arch/arm64/mm/mmu.c >> @@ -1193,6 +1193,23 @@ void vmemmap_free(unsigned long start, unsigned >> long end, >>   } >>   #endif /* CONFIG_MEMORY_HOTPLUG */ >>   +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys) >> +{ >> +    pgprot_t prot = FIXMAP_PAGE_IO; >> + >> +    /* >> +     * The set_fixmap_io maps a single Page covering phys. >> +     * To make better decision, we stick to the smallest page >> +     * size supported (4K). >> +     */ >> +    if (!arm64_is_iomem_private(phys, SZ_4K)) >> +        prot = pgprot_decrypted(prot); >> +    else >> +        prot = pgprot_encrypted(prot); > > With the ioremap_prot_hook introduction, this one looks like should use > that, instead of open coding the same thing. Thoughts ? I can see the logic, but it's not quite that simple to implement. Either the ioremap_prot_hook needs moving out (and presumably) renaming to be a more generic "override device pgprot" mechanism, we it would be a horrid hack to put ioremap code in arch/arm64/mm/ioremap.c to handle this. Given that we're not even sure that the set_fixmap hack is a good idea, I'll leave this alone for now - the open coding is clear even if it's a duplicate. Thanks, Steve