From mboxrd@z Thu Jan 1 00:00:00 1970 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 BD1B654767 for ; Tue, 27 Aug 2024 16:40:36 +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=1724776836; cv=none; b=MFTa/ZPau2f/SNr8NZkU+nrkunqmRbv0RE6/8NE+1u85mIH0PsXQ7zAVdC3IP1ZGheuq7Q72AJ16KhlfXsqrYw0U8RQiR/QSI2DDZq/he/8HV57vl9OPPz4U8ocSir5BNAlmMdHxf23GQJAlyWS+EMHKdL2PLoVzmsAxJbLjICc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724776836; c=relaxed/simple; bh=YmFy6I+FOIp8e0gC/sd4B75E6JcawsEbBSOL+Wk2fQE=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=p/zYlLkfaWRvisB8TCFgDP3GczllKR/kJDFcQtfz+zIQLRrdP0vPY9yyJ9tD9morAP6IcMEzyCLHgxveKBaBZriKdVKVGFOCd1rB2x0uS1jOZL7fy8pVyte3WzxGPmMoeFI06NNjAIjfvC7hsbflr5CphKEZ2dYsYaUy+3/AfHM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n0mxmiXP; 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="n0mxmiXP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D695C4AF0C; Tue, 27 Aug 2024 16:40:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1724776836; bh=YmFy6I+FOIp8e0gC/sd4B75E6JcawsEbBSOL+Wk2fQE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=n0mxmiXPAeRRDPrpMitOZw/2o74O39e9jpbKN/92IzozJFbOikB5iRYuXrz9+SepW 7nt/4U6NHqL98AM4VmGxzpoAHkkDENaviM0flo7okqGN2OfQwMRGXLlY2Sxh4qKI4M ZZfDllJkeRkVPyRY2yS5ZEl7LgoLJbmt7Oau5BfnuuxYHTOVZwr0+sPUQnyHQvxGGR +pxQR+iab+OvlZ9eDpJEcI0d7h5xY8h34uVmwqcmYkOu0pDcJwVYuFzCoVKutY2q0a BqmoKZgc6pw3DHoBRuzCfVe01FYi2ZLZSdwzqsBTOYBRXX+CHw7EUE5M92Y3F49HwU CfeTIqIDSBWeQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1sizFC-007IhG-3c; Tue, 27 Aug 2024 17:40:34 +0100 Date: Tue, 27 Aug 2024 17:40:33 +0100 Message-ID: <86jzg1x6ke.wl-maz@kernel.org> From: Marc Zyngier To: Oliver Upton Cc: kvmarm@lists.linux.dev, James Morse , Suzuki K Poulose , Zenghui Yu , Ganapatrao Kulkarni Subject: Re: [PATCH v2 09/12] KVM: arm64: nv: Advertise support for FEAT_HPMN0 In-Reply-To: <20240827002235.1753237-10-oliver.upton@linux.dev> References: <20240827002235.1753237-1-oliver.upton@linux.dev> <20240827002235.1753237-10-oliver.upton@linux.dev> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: oliver.upton@linux.dev, kvmarm@lists.linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, gankulkarni@os.amperecomputing.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Tue, 27 Aug 2024 01:22:32 +0100, Oliver Upton wrote: > > Everything is in place now for KVM to actually handle MDCR_EL2.HPMN. Not > only that, the emulation is capable of doing FEAT_HPMN0. Advertise > support for the feature in the VM's ID registers. > > Signed-off-by: Oliver Upton > --- > arch/arm64/kvm/nested.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c > index de789e0f1ae9..206aff3d88f7 100644 > --- a/arch/arm64/kvm/nested.c > +++ b/arch/arm64/kvm/nested.c > @@ -910,12 +910,13 @@ static void limit_nv_id_regs(struct kvm *kvm) > ID_AA64MMFR4_EL1_E2H0_NI_NV1); > kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR4_EL1, val); > > - /* Only limited support for PMU, Debug, BPs and WPs */ > + /* Only limited support for PMU, Debug, BPs, WPs, and HPMN0 */ > val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1); > val &= (NV_FTR(DFR0, PMUVer) | > NV_FTR(DFR0, WRPs) | > NV_FTR(DFR0, BRPs) | > - NV_FTR(DFR0, DebugVer)); > + NV_FTR(DFR0, DebugVer) | > + NV_FTR(DFR0, HPMN0)); I don't think it does what you say it does! ;-) What you probably want is something like val |= FIELD_PREP(NV_FTR(DFR0, HPMN0), ID_AA64DFR0_EL1_HPMN0_DEF); instead. M. -- Without deviation from the norm, progress is not possible.