From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 411AA4FD27B; Wed, 30 Sep 2026 18:34:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790793275; cv=none; b=loH+yoYQVD2IwKosxnTVvohktmTlyHq/KDywQtiax3jkJYVtF4J6yOfNvVoDHG5F22X/f2Rl316rZIBr2768HzqsPn0Bajrxpvb1sD/n4T8Ph8mmY1m+MFVE//L1PD82AFO8GREJxVqzX9/nxhwORrx9My+RXE/jF2d20GeLPl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790793275; c=relaxed/simple; bh=4ZHQC0FNvnEH1rvTVVQrUOL94LZ9n9+5aGzT4xHSXkI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JEKX2jWbYdVUhGBdVG+f/0TH6WaGGzfuQSbWT/6reL9JSDN/qIJdysA1kdA3mrbbc/CIVAl41wDPwbAsYvjL2mZqKv7UZLTPB/IRRNP3CAHRq0iwQBhuvBcnOunottTxDsLbVTyhidAx/YraTYPg9cMxs8pyOmxTmuS98f1ajMU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PasnwQ44; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PasnwQ44" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9CF001F000FF; Wed, 30 Sep 2026 18:34:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790793274; bh=CLbfbXIpH785DNE8FmJt7N/CxvzYS8lQ14bjJ3VK7yM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PasnwQ44nlzGpPTzINEJaxIa+1leSQtt28/DOAAx50JGgsmK4MPU2ug9aQLYoclxc FpBVfoxuMxrHumu6xHbYAMDBpXqlXGUlTB2m4w4zWVleaMMvfTHL51I3oKwm+1oNIO hv8w3UZ+BhvION3ub7JrZeYuOVzb+rV1bE4eM9m0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Christopherson , "Peter Zijlstra (Intel)" , Ingo Molnar , Dapeng Mi , Sasha Levin Subject: [PATCH 6.18 197/395] perf/x86/intel: Ensure KVM guest PEBS path doesnt set unwanted PERF_GLOBAL_CTRL bits Date: Wed, 30 Sep 2026 17:27:39 +0200 Message-ID: <20260930152344.922523068@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152340.591469096@linuxfoundation.org> References: <20260930152340.591469096@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson [ Upstream commit cec38d5c098a350dcf084d345025136ade7e6d1e ] When reinstating PEBS counters into PERF_GLOBAL_CTRL for a KVM guest, mask the value with perf's desired/original PERF_GLOBAL_CTRL value to ensure KVM doesn't unintentionally set reserved bits in PERF_GLOBAL_CTRL. E.g. if the guest's PEBS_ENABLE value had bit 63, "Enable Precise Store", set, then using the raw guest PEBS value would propagate bit 63 to the guest's PERF_GLOBAL_CTRL value (which thankfully would be a failed VM-Entry, not a VMX Abort). The only reason this bug isn't reachable is because KVM doesn't support "Enable Precise Store" (which is probably a KVM bug?), i.e. bit 63 can't be set in kvm_pmu->pebs_enable and thus not in arr[pebs_enable].guest. In other words, this _should_ be a glorified NOP in the current code base. Fixes: c59a1f106f5c ("KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS") Signed-off-by: Sean Christopherson Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Dapeng Mi Link: https://patch.msgid.link/20260921191418.950933-2-seanjc@google.com Signed-off-by: Sasha Levin --- arch/x86/events/intel/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 4dacbf664b303..8d283f44c55b1 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -4694,7 +4694,7 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data) arr[pebs_enable].guest &= ~kvm_pmu->host_cross_mapped_mask; arr[global_ctrl].guest &= ~kvm_pmu->host_cross_mapped_mask; /* Set hw GLOBAL_CTRL bits for PEBS counter when it runs for guest */ - arr[global_ctrl].guest |= arr[pebs_enable].guest; + arr[global_ctrl].guest |= intel_ctrl & arr[pebs_enable].guest; } return arr; -- 2.53.0