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 EBD0D1A2863; Sun, 24 Mar 2024 22:43:14 +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=1711320195; cv=none; b=GnGMZ0IBLKNx15ClPRRo3RO4smsOMUTWCgeXg/ejgi1wDktuh8YW2MZxKe5O/cuMLci4Ndc0sSUsievqNhp/WhobxrydXVMc3nRIRvxuB3sQnK1ys7EJ+Y6R4FTrddIeDWbCYI61wqyLZD5VrhG1as19jiIljxY09Fl++PO/H2c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711320195; c=relaxed/simple; bh=LOo3lC22VEDvJtM2gwHrvZYeaT0SOw4YiVKbCdHHZVk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QN7RGZ2lhqoI8FV9fRrIC3etprvjW9BvF2WuyoguxVrZISIS5KgU8McTy+LbKF10Vn5H+SCIS4VjL02bz7rKJXH5hw4wydX28ututcqa0MA9u5vz3bATVztmfjTQFMV5PsC8Ut4NP2edXelG6D8vmMdIavilkDRlbVBXcTkCgeM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B9tjrqX2; 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="B9tjrqX2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C73B1C433F1; Sun, 24 Mar 2024 22:43:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711320194; bh=LOo3lC22VEDvJtM2gwHrvZYeaT0SOw4YiVKbCdHHZVk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B9tjrqX2UJIC7Z5V4i2k6rqYRRLexTV7ayS5E9HBwIgbHUG1M25HtV6c/UMUX/+G4 jC8G0qUeRBnrm7OFv69Zx/7MrLdQB9/hanlcOiE6YFQGZM49ejACThT6OyUzDS0YBx WapQr/sYhCrwzCpvrpesArA7jE/pv2oEOOVwH/WUzdCS0jGI63R4ngq3SKPNGIDX8D pfDlFYEB8UNP4kuCQNGmzcLPPwpWHAJoVBwlyij0/aNyPTevwpBGHfMra+/pz07EoB bPeRNPzGT+Dt87h98dV0nw8xuPog7oomhogvXDnLkejDPkxQdQ+n9ZOe8O6/qgAFME HT48lItOfE/lg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kajol Jain , Akanksha J N , Michael Ellerman , Sasha Levin Subject: [PATCH 6.8 502/715] powerpc/hv-gpci: Fix the H_GET_PERF_COUNTER_INFO hcall return value checks Date: Sun, 24 Mar 2024 18:31:21 -0400 Message-ID: <20240324223455.1342824-503-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324223455.1342824-1-sashal@kernel.org> References: <20240324223455.1342824-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Kajol Jain [ Upstream commit ad86d7ee43b22aa2ed60fb982ae94b285c1be671 ] Running event hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ in one of the system throws below error: ---Logs--- # perf list | grep hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=?/[Kernel PMU event] # perf stat -v -e hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ sleep 2 Using CPUID 00800200 Control descriptor is not initialized Warning: hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ event is not supported by the kernel. failed to read counter hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ Performance counter stats for 'system wide': hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ 2.000700771 seconds time elapsed The above error is because of the hcall failure as required permission "Enable Performance Information Collection" is not set. Based on current code, single_gpci_request function did not check the error type incase hcall fails and by default returns EINVAL. But we can have other reasons for hcall failures like H_AUTHORITY/H_PARAMETER with detail_rc as GEN_BUF_TOO_SMALL, for which we need to act accordingly. Fix this issue by adding new checks in the single_gpci_request and h_gpci_event_init functions. Result after fix patch changes: # perf stat -e hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ sleep 2 Error: No permission to enable hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ event. Fixes: 220a0c609ad1 ("powerpc/perf: Add support for the hv gpci (get performance counter info) interface") Reported-by: Akanksha J N Signed-off-by: Kajol Jain Signed-off-by: Michael Ellerman Link: https://msgid.link/20240229122847.101162-1-kjain@linux.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/perf/hv-gpci.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c index 27f18119fda17..241551d1282f8 100644 --- a/arch/powerpc/perf/hv-gpci.c +++ b/arch/powerpc/perf/hv-gpci.c @@ -695,6 +695,20 @@ static unsigned long single_gpci_request(u32 req, u32 starting_index, ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO, virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE); + + /* + * ret value as 'H_PARAMETER' with detail_rc as 'GEN_BUF_TOO_SMALL', + * specifies that the current buffer size cannot accommodate + * all the information and a partial buffer returned. + * Since in this function we are only accessing data for a given starting index, + * we don't need to accommodate whole data and can get required count by + * accessing first entry data. + * Hence hcall fails only incase the ret value is other than H_SUCCESS or + * H_PARAMETER with detail_rc value as GEN_BUF_TOO_SMALL(0x1B). + */ + if (ret == H_PARAMETER && be32_to_cpu(arg->params.detail_rc) == 0x1B) + ret = 0; + if (ret) { pr_devel("hcall failed: 0x%lx\n", ret); goto out; @@ -759,6 +773,7 @@ static int h_gpci_event_init(struct perf_event *event) { u64 count; u8 length; + unsigned long ret; /* Not our event */ if (event->attr.type != event->pmu->type) @@ -789,13 +804,23 @@ static int h_gpci_event_init(struct perf_event *event) } /* check if the request works... */ - if (single_gpci_request(event_get_request(event), + ret = single_gpci_request(event_get_request(event), event_get_starting_index(event), event_get_secondary_index(event), event_get_counter_info_version(event), event_get_offset(event), length, - &count)) { + &count); + + /* + * ret value as H_AUTHORITY implies that partition is not permitted to retrieve + * performance information, and required to set + * "Enable Performance Information Collection" option. + */ + if (ret == H_AUTHORITY) + return -EPERM; + + if (ret) { pr_devel("gpci hcall failed\n"); return -EINVAL; } -- 2.43.0