From patchwork Wed Apr 22 09:56:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 1274907 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 496bzW25f2z9sSJ for ; Wed, 22 Apr 2020 20:20:23 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=DCkjrSXv; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 496bzV6738zDqjY for ; Wed, 22 Apr 2020 20:20:22 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 496bx11RlNzDqR2 for ; Wed, 22 Apr 2020 20:18:13 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=DCkjrSXv; dkim-atps=neutral Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) by bilbo.ozlabs.org (Postfix) with ESMTP id 496bx06Zr6z8t9Z for ; Wed, 22 Apr 2020 20:18:12 +1000 (AEST) Received: by ozlabs.org (Postfix) id 496bx04xmMz9sV0; Wed, 22 Apr 2020 20:18:12 +1000 (AEST) Delivered-To: linuxppc-dev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linuxfoundation.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=gregkh@linuxfoundation.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=DCkjrSXv; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 496bx03QHFz9sTy; Wed, 22 Apr 2020 20:18:12 +1000 (AEST) Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8CE1B2075A; Wed, 22 Apr 2020 10:18:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550690; bh=ha+CAQ7iEhlPF52xa10ZLaHKRCJQ1ZS6XYdgwGYgaWw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DCkjrSXvni1A9F5d+K4eJ792g+miATOzt4tNRGV/CGV5RAOeBShKzy3hrWLfzv+6e snAK/LB3XCv6M+SLBLyKk/7JYtnWXlMX8ePTyLF2mPcTduWEwxdjtdPhjmeT3yx54P cR544kNxjmI7C+oUpl87vFhRgVl1qGS/gbKW8Ww0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Subject: [PATCH 5.4 054/118] KVM: PPC: Book3S HV: Fix H_CEDE return code for nested guests Date: Wed, 22 Apr 2020 11:56:55 +0200 Message-Id: <20200422095040.897701454@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095031.522502705@linuxfoundation.org> References: <20200422095031.522502705@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , Greg Kroah-Hartman , Michael Roth , stable@vger.kernel.org, linuxppc-dev@ozlabs.org, David Gibson Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Michael Roth [ Upstream commit 1f50cc1705350a4697923203fedd7d8fb1087fe2 ] The h_cede_tm kvm-unit-test currently fails when run inside an L1 guest via the guest/nested hypervisor. ./run-tests.sh -v ... TESTNAME=h_cede_tm TIMEOUT=90s ACCEL= ./powerpc/run powerpc/tm.elf -smp 2,threads=2 -machine cap-htm=on -append "h_cede_tm" FAIL h_cede_tm (2 tests, 1 unexpected failures) While the test relates to transactional memory instructions, the actual failure is due to the return code of the H_CEDE hypercall, which is reported as 224 instead of 0. This happens even when no TM instructions are issued. 224 is the value placed in r3 to execute a hypercall for H_CEDE, and r3 is where the caller expects the return code to be placed upon return. In the case of guest running under a nested hypervisor, issuing H_CEDE causes a return from H_ENTER_NESTED. In this case H_CEDE is specially-handled immediately rather than later in kvmppc_pseries_do_hcall() as with most other hcalls, but we forget to set the return code for the caller, hence why kvm-unit-test sees the 224 return code and reports an error. Guest kernels generally don't check the return value of H_CEDE, so that likely explains why this hasn't caused issues outside of kvm-unit-tests so far. Fix this by setting r3 to 0 after we finish processing the H_CEDE. RHBZ: 1778556 Fixes: 4bad77799fed ("KVM: PPC: Book3S HV: Handle hypercalls correctly when nested") Cc: linuxppc-dev@ozlabs.org Cc: David Gibson Cc: Paul Mackerras Signed-off-by: Michael Roth Reviewed-by: David Gibson Signed-off-by: Paul Mackerras Signed-off-by: Sasha Levin --- arch/powerpc/kvm/book3s_hv.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 36abbe3c346df..e2183fed947d4 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3623,6 +3623,7 @@ int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested && kvmppc_get_gpr(vcpu, 3) == H_CEDE) { kvmppc_nested_cede(vcpu); + kvmppc_set_gpr(vcpu, 3, 0); trap = 0; } } else {