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 F02F28487 for ; Thu, 27 Oct 2022 17:01:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 756CBC433C1; Thu, 27 Oct 2022 17:01:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666890098; bh=ywL33qZItllB0cMnef9dhGze3pM9dYzaYuQO0eR+CS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mXLlPnjkieV71yIMtPzRIn60+HU3GfngKinkMQ1QMp6v7YO3XQXxN6H4e61DEdV8X JSzjPIAcwDY5pLZ55NAvBEvn3+BJQj8+J8Qn3I1twIi5nKLku2QM1KkN5dMT9tqr9t vAViscXgEvAIR/BIBhcR3Ias/HCnibJS0DyZ8y4o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stephane Eranian , Babu Moger , Borislav Petkov , Ingo Molnar , James Morse , Reinette Chatre , Fenghua Yu Subject: [PATCH 5.15 21/79] x86/resctrl: Fix min_cbm_bits for AMD Date: Thu, 27 Oct 2022 18:55:19 +0200 Message-Id: <20221027165055.667051644@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221027165054.917467648@linuxfoundation.org> References: <20221027165054.917467648@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Babu Moger commit 67bf6493449b09590f9f71d7df29efb392b12d25 upstream. AMD systems support zero CBM (capacity bit mask) for cache allocation. That is reflected in rdt_init_res_defs_amd() by: r->cache.arch_has_empty_bitmaps = true; However given the unified code in cbm_validate(), checking for: val == 0 && !arch_has_empty_bitmaps is not enough because of another check in cbm_validate(): if ((zero_bit - first_bit) < r->cache.min_cbm_bits) The default value of r->cache.min_cbm_bits = 1. Leading to: $ cd /sys/fs/resctrl $ mkdir foo $ cd foo $ echo L3:0=0 > schemata -bash: echo: write error: Invalid argument $ cat /sys/fs/resctrl/info/last_cmd_status Need at least 1 bits in the mask Initialize the min_cbm_bits to 0 for AMD. Also, remove the default setting of min_cbm_bits and initialize it separately. After the fix: $ cd /sys/fs/resctrl $ mkdir foo $ cd foo $ echo L3:0=0 > schemata $ cat /sys/fs/resctrl/info/last_cmd_status ok Fixes: 316e7f901f5a ("x86/resctrl: Add struct rdt_cache::arch_has_{sparse, empty}_bitmaps") Co-developed-by: Stephane Eranian Signed-off-by: Stephane Eranian Signed-off-by: Babu Moger Signed-off-by: Borislav Petkov Reviewed-by: Ingo Molnar Reviewed-by: James Morse Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Cc: Link: https://lore.kernel.org/lkml/20220517001234.3137157-1-eranian@google.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/resctrl/core.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -66,9 +66,6 @@ struct rdt_hw_resource rdt_resources_all .rid = RDT_RESOURCE_L3, .name = "L3", .cache_level = 3, - .cache = { - .min_cbm_bits = 1, - }, .domains = domain_init(RDT_RESOURCE_L3), .parse_ctrlval = parse_cbm, .format_str = "%d=%0*x", @@ -83,9 +80,6 @@ struct rdt_hw_resource rdt_resources_all .rid = RDT_RESOURCE_L2, .name = "L2", .cache_level = 2, - .cache = { - .min_cbm_bits = 1, - }, .domains = domain_init(RDT_RESOURCE_L2), .parse_ctrlval = parse_cbm, .format_str = "%d=%0*x", @@ -877,6 +871,7 @@ static __init void rdt_init_res_defs_int r->cache.arch_has_sparse_bitmaps = false; r->cache.arch_has_empty_bitmaps = false; r->cache.arch_has_per_cpu_cfg = false; + r->cache.min_cbm_bits = 1; } else if (r->rid == RDT_RESOURCE_MBA) { hw_res->msr_base = MSR_IA32_MBA_THRTL_BASE; hw_res->msr_update = mba_wrmsr_intel; @@ -897,6 +892,7 @@ static __init void rdt_init_res_defs_amd r->cache.arch_has_sparse_bitmaps = true; r->cache.arch_has_empty_bitmaps = true; r->cache.arch_has_per_cpu_cfg = true; + r->cache.min_cbm_bits = 0; } else if (r->rid == RDT_RESOURCE_MBA) { hw_res->msr_base = MSR_IA32_MBA_BW_BASE; hw_res->msr_update = mba_wrmsr_amd;