From patchwork Fri May 13 14:23:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 572939 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0CA56C433F5 for ; Fri, 13 May 2022 14:27:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380744AbiEMO1U (ORCPT ); Fri, 13 May 2022 10:27:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381111AbiEMO0k (ORCPT ); Fri, 13 May 2022 10:26:40 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CA0D50B25; Fri, 13 May 2022 07:26:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 396056216D; Fri, 13 May 2022 14:26:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49833C36AE9; Fri, 13 May 2022 14:26:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652451997; bh=UpCcU25Xv82HILkYDgU1w77S6ZMW9ZRfx0gmJ332NVc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YomKhBjtFMi3CEd486NRv2gxQfGX+nfvLzx4H+l4JoBzkBeh8ocJwfRiQV0dbWvbL yspy6qc+0+oEgAtPpo4FI6g+FsgSfUofzrwd1IO+uWtXJGnQDtfia0MB/MTphQ0Cg4 VB+syeep60x8ekO7Y8Oyz7IEv0Pzjai7Ccq5ICio= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kyle Huey , Paolo Bonzini Subject: [PATCH 5.4 14/18] KVM: x86/svm: Account for family 17h event renumberings in amd_pmc_perf_hw_id Date: Fri, 13 May 2022 16:23:40 +0200 Message-Id: <20220513142229.569318882@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220513142229.153291230@linuxfoundation.org> References: <20220513142229.153291230@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kyle Huey commit 5eb849322d7f7ae9d5c587c7bc3b4f7c6872cd2f upstream. Zen renumbered some of the performance counters that correspond to the well known events in perf_hw_id. This code in KVM was never updated for that, so guest that attempt to use counters on Zen that correspond to the pre-Zen perf_hw_id values will silently receive the wrong values. This has been observed in the wild with rr[0] when running in Zen 3 guests. rr uses the retired conditional branch counter 00d1 which is incorrectly recognized by KVM as PERF_COUNT_HW_STALLED_CYCLES_BACKEND. [0] https://rr-project.org/ Signed-off-by: Kyle Huey Message-Id: <20220503050136.86298-1-khuey@kylehuey.com> Cc: stable@vger.kernel.org [Check guest family, not host. - Paolo] Signed-off-by: Paolo Bonzini [Backport to 5.15: adjusted context] Signed-off-by: Kyle Huey Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/pmu_amd.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) --- a/arch/x86/kvm/pmu_amd.c +++ b/arch/x86/kvm/pmu_amd.c @@ -44,6 +44,22 @@ static struct kvm_event_hw_type_mapping [7] = { 0xd1, 0x00, PERF_COUNT_HW_STALLED_CYCLES_BACKEND }, }; +/* duplicated from amd_f17h_perfmon_event_map. */ +static struct kvm_event_hw_type_mapping amd_f17h_event_mapping[] = { + [0] = { 0x76, 0x00, PERF_COUNT_HW_CPU_CYCLES }, + [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS }, + [2] = { 0x60, 0xff, PERF_COUNT_HW_CACHE_REFERENCES }, + [3] = { 0x64, 0x09, PERF_COUNT_HW_CACHE_MISSES }, + [4] = { 0xc2, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS }, + [5] = { 0xc3, 0x00, PERF_COUNT_HW_BRANCH_MISSES }, + [6] = { 0x87, 0x02, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND }, + [7] = { 0x87, 0x01, PERF_COUNT_HW_STALLED_CYCLES_BACKEND }, +}; + +/* amd_pmc_perf_hw_id depends on these being the same size */ +static_assert(ARRAY_SIZE(amd_event_mapping) == + ARRAY_SIZE(amd_f17h_event_mapping)); + static unsigned int get_msr_base(struct kvm_pmu *pmu, enum pmu_type type) { struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu); @@ -128,19 +144,25 @@ static inline struct kvm_pmc *get_gp_pmc static unsigned int amd_pmc_perf_hw_id(struct kvm_pmc *pmc) { + struct kvm_event_hw_type_mapping *event_mapping; u8 event_select = pmc->eventsel & ARCH_PERFMON_EVENTSEL_EVENT; u8 unit_mask = (pmc->eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8; int i; + if (guest_cpuid_family(pmc->vcpu) >= 0x17) + event_mapping = amd_f17h_event_mapping; + else + event_mapping = amd_event_mapping; + for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++) - if (amd_event_mapping[i].eventsel == event_select - && amd_event_mapping[i].unit_mask == unit_mask) + if (event_mapping[i].eventsel == event_select + && event_mapping[i].unit_mask == unit_mask) break; if (i == ARRAY_SIZE(amd_event_mapping)) return PERF_COUNT_HW_MAX; - return amd_event_mapping[i].event_type; + return event_mapping[i].event_type; } /* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */