From patchwork Mon Feb 19 09:20:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13562409 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 5C58724B39; Mon, 19 Feb 2024 09:20:25 +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=1708334425; cv=none; b=iuVfcsjnmoBPaEZXCPnXF1x4AGWiEG4RYoPgxtJk+nBzVl6IxPmzy8bqRM8ogsi5BqfUhoatgwhoNq3d4lA1w2n2r9aNj2ZaKrIjtKyi1Gqb9yiEzjCZfsMPp4RPraRMVMt4QvRx9c58E6JXeEDk/Mg+FQbxhK81id//hiFIn2s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708334425; c=relaxed/simple; bh=BXb8tAm/95vFkuq3D2jCOy3oGWf70BBXrMbsz1oxJZA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=OpIUEdNvr8RmwvzjV1VjNXcYSFg5y64lZ42/ZzT+SFAeQf1XytJeDrq2L/MrwrdZgOpiGud6M8D6PB51I4UvYYqzgR6ieWLAO6p499TIGKLff7D/EtF2C2UWcD8Njmwuwnk5DsKZeyT3HCgEmVtp+OGBZSY3B/oUVfuB3BQQPFw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q89F6BMS; 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="Q89F6BMS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E64B8C433C7; Mon, 19 Feb 2024 09:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708334425; bh=BXb8tAm/95vFkuq3D2jCOy3oGWf70BBXrMbsz1oxJZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q89F6BMSPF9NqMX3WsGiaqpVAB7KuAYncda0xr3oHsn202hR2L14VOCLek7xUEJXE jOIvqFsgUWFGNTM7nVWRai+EWBEcPy5vL00ptNeFFmnoMu273eMSD/i1GGJaTRkYZB hD32hpeGpX6RbRCkL1fpqD6Xa1LXvHNduHKMdSYJaJXyDaLsZNO+IEiVCg67dVvZRu sBhlSWXdZeKdtNn0VsrO2bpO7OXgwyJRxYx9nUa51Q+SxlLDVLPCQ4V1r5bNDjyZmd GFN4sanp2XNEdS8TxEsU7eVCgYhl+oiQOdQO8mk6dhuXr5ybpxZzoS9uDrrCdKjH37 35N5dhn7zp+qg== 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 1rbzp1-004WBZ-5B; Mon, 19 Feb 2024 09:20:23 +0000 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 , Will Deacon , Catalin Marinas Subject: [PATCH 09/13] KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 Date: Mon, 19 Feb 2024 09:20:10 +0000 Message-Id: <20240219092014.783809-10-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240219092014.783809-1-maz@kernel.org> References: <20240219092014.783809-1-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, 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 1ccdfe40c691..556af771a9e9 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; }