From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZpBuL6ClcBC9NgZzO1x0EieTkxm7Tg4iEesFfckh2b0WRLtq7fixauN2g6weFAUFGof/zGr ARC-Seal: i=1; a=rsa-sha256; t=1524823040; cv=none; d=google.com; s=arc-20160816; b=nblmhKS3E3a0dekPG9BFnoHMwm05e4p0joNjQFy2890kS7CrWAfIBNQoE0eSPww4Y8 UnLaJ6qAvp8Eyjdb/+4YNp8twVwl6T/3MIJd/Jm1+XIW82S+Mtj99gzdfp45szd1gYCL xNetOfiFZgzYKhzlHHBnsoYJOSAjR9D7FfzJr1tC71vb8eyLKvsq0RRUoT6/MWLFPW+b Ce7BRGw3BNPWgMFzt5h9NomjLTTHCG8xoE55siEd0ufngw+lkcnhZLP7egQyyfTvU2+A aNtqwheNN9zGp/h7TJCJKLvmCpB85W84m7FQ1WjTbq2snvfHyEOodks9ifn90m33j7Hd ajJg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:delivered-to:delivered-to :list-id:list-subscribe:list-unsubscribe:list-help:list-post :precedence:mailing-list:arc-authentication-results; bh=2MjfCulBrV4pTZsJoyumoQ04d6D6hybe8s1QQ9+KkMk=; b=Oxf2qCODr0cmkAEPB5HL31uWsndHNyzfKTz1/Iro2pxTnq6lBjkFSQqXlE8w0p9bI8 HwYbL3J8IDHsjJFttEc1EoWUzb6koo/wPlga/9yPbgoIqguPFgncatVXzqiuXNQH/W1r 8Goxcsq/IfMt7PaFj6W+lSEZ5KwRwhArAmXA46+EYk6/RvJXY2Efhqnx0cGqZmrkxvmx g0EOi+1CXCqrRgei4l6Zu54EwSwtzSlEkaI4MgBeutVzbHD5Gz57N00fYfcJ9DxbbYTp yMCQTz9U82V6YVWr1Vep7VNhekk9zkJZNyFRRraQ+4JTJevuCw/TJN2bCVa883zm5AP0 WrZg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-13147-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-13147-gregkh=linuxfoundation.org@lists.openwall.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-13147-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-13147-gregkh=linuxfoundation.org@lists.openwall.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: Date: Fri, 27 Apr 2018 11:52:05 +0200 From: Christoffer Dall To: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, arnd@arndb.de, marc.zyngier@arm.com, catalin.marinas@arm.com, awallis@codeaurora.org, kernel-hardening@lists.openwall.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, ramana.radhakrishnan@arm.com, kvmarm@lists.cs.columbia.edu Subject: Re: [PATCHv3 04/11] arm64: Don't trap host pointer auth use to EL2 Message-ID: <20180427095205.GJ13249@C02W217FHV2R.local> References: <20180417183735.56985-1-mark.rutland@arm.com> <20180417183735.56985-5-mark.rutland@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180417183735.56985-5-mark.rutland@arm.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1598019703538856592?= X-GMAIL-MSGID: =?utf-8?q?1598892844558812505?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Tue, Apr 17, 2018 at 07:37:28PM +0100, Mark Rutland wrote: > To allow EL0 (and/or EL1) to use pointer authentication functionality, > we must ensure that pointer authentication instructions and accesses to > pointer authentication keys are not trapped to EL2. > > This patch ensures that HCR_EL2 is configured appropriately when the > kernel is booted at EL2. For non-VHE kernels we set HCR_EL2.{API,APK}, > ensuring that EL1 can access keys and permit EL0 use of instructions. > For VHE kernels host EL0 (TGE && E2H) is unaffected by these settings, > and it doesn't matter how we configure HCR_EL2.{API,APK}, so we don't > bother setting them. > > This does not enable support for KVM guests, since KVM manages HCR_EL2 > itself when running VMs. > > Signed-off-by: Mark Rutland > Cc: Christoffer Dall > Cc: Catalin Marinas > Cc: Marc Zyngier > Cc: Will Deacon > Cc: kvmarm@lists.cs.columbia.edu FWIW: Acked-by: Christoffer Dall > --- > arch/arm64/include/asm/kvm_arm.h | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > index 89b3dda7e3cb..4d57e1e58323 100644 > --- a/arch/arm64/include/asm/kvm_arm.h > +++ b/arch/arm64/include/asm/kvm_arm.h > @@ -23,6 +23,8 @@ > #include > > /* Hyp Configuration Register (HCR) bits */ > +#define HCR_API (UL(1) << 41) > +#define HCR_APK (UL(1) << 40) > #define HCR_TEA (UL(1) << 37) > #define HCR_TERR (UL(1) << 36) > #define HCR_TLOR (UL(1) << 35) > @@ -86,7 +88,7 @@ > HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR | \ > HCR_FMO | HCR_IMO) > #define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF) > -#define HCR_HOST_NVHE_FLAGS (HCR_RW) > +#define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK) > #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) > > /* TCR_EL2 Registers bits */ > -- > 2.11.0 > > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm