From patchwork Fri Apr 19 10:29:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13636183 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 44C8F7F48C; Fri, 19 Apr 2024 10:29:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713522593; cv=none; b=VzrhVIxPBaf13XAHtV3zx6c8Fwi5g1TpmHBdv9xVW8sqGi2Ri5xCFdv+EvTO1GoAcYtFRja7Z6xkvlkJ7eBoR4z1/41jew/m7+etd8PQ/gn1MK9I098dbDALw2CLQn3tNKH82f4Ts1j799DsaakA4X3+CrBfWb7YDXoUAUVLI8k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713522593; c=relaxed/simple; bh=Alk8DkWcPcruQ5um5KDrpSCEo4m97neZZIMYfFIrE54=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=KNmPts8YoV94V9oKO/ajM9Zbrq5/iSJKv9o+lR5KRHLmfl5/XKLTfwCL7p8WIzcyH5pUpKgUZZfi53SoJHGgOh6rENzfkwfPOvOa2GMlmv7dFLUr1ve8X90yTkON/jMVdkxfYjU2aVXmvEafkdUGuWjkGpb9NN2vP9hRmaU4km4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=skVSkIri; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="skVSkIri" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B504C3277B; Fri, 19 Apr 2024 10:29:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713522593; bh=Alk8DkWcPcruQ5um5KDrpSCEo4m97neZZIMYfFIrE54=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=skVSkIriuOpK0iffn+AxzWWeiOvNIqp8cRmSl+phTSJvg3xZ1vnADur2SZS8fdfuC 80NC+Q0E1fYXoJs+4Sh65nvu2jR3cOA70Hkfed4dZ6D4dzNWToQGW2IMtuNQt8f22z uCb+WVJ8HGTAZv1PpwgyXTG/HCBs4UxSGvxwO/Qet9TaXvFnUwxemCy35jUVy9vgk7 sB0vMLqseBifJPjK7ZWn4c6XDhpREIaB7ThQBtxLJQwKW6C9C/9M52nCGi5Vpm301w GRfH7AklBBfoghqid4/Jpnj3fVFmC6BuzzrcphQbq/A4SVzuQTk3Dji6znaiXZVvYQ rlBmlOJaLvvog== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1rxlV9-00636W-4p; Fri, 19 Apr 2024 11:29:51 +0100 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Joey Gouly , Fuad Tabba , Mostafa Saleh , Will Deacon , Catalin Marinas Subject: [PATCH v4 10/15] KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 Date: Fri, 19 Apr 2024 11:29:30 +0100 Message-Id: <20240419102935.1935571-11-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240419102935.1935571-1-maz@kernel.org> References: <20240419102935.1935571-1-maz@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, joey.gouly@arm.com, tabba@google.com, smostafa@google.com, will@kernel.org, catalin.marinas@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false In order for a L1 hypervisor to correctly handle PAuth instructions, it must observe traps caused by a L1 PAuth instruction when HCR_EL2.API==0. Since we already handle the case for API==1 as a fixup, only the exception injection case needs to be handled. Rework the kvm_handle_ptrauth() callback to reinject the trap in this case. Note that APK==0 is already handled by the exising triage_sysreg_trap() helper. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/handle_exit.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 6a88ec024e2f..1ba2f788b2c3 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -214,12 +214,34 @@ static int handle_sve(struct kvm_vcpu *vcpu) } /* - * Guest usage of a ptrauth instruction (which the guest EL1 did not turn into - * a NOP). If we get here, it is that we didn't fixup ptrauth on exit, and all - * that we can do is give the guest an UNDEF. + * Two possibilities to handle a trapping ptrauth instruction: + * + * - Guest usage of a ptrauth instruction (which the guest EL1 did not + * turn into a NOP). If we get here, it is that we didn't fixup + * ptrauth on exit, and all that we can do is give the guest an + * UNDEF (as the guest isn't supposed to use ptrauth without being + * told it could). + * + * - Running an L2 NV guest while L1 has left HCR_EL2.API==0, and for + * which we reinject the exception into L1. API==1 is handled as a + * fixup so the only way to get here is when API==0. + * + * Anything else is an emulation bug (hence the WARN_ON + UNDEF). */ static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu) { + if (!vcpu_has_ptrauth(vcpu)) { + kvm_inject_undefined(vcpu); + return 1; + } + + if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) { + kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + return 1; + } + + /* Really shouldn't be here! */ + WARN_ON_ONCE(1); kvm_inject_undefined(vcpu); return 1; }