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 C1B33611B for ; Sun, 28 May 2023 19:35:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4EB21C433EF; Sun, 28 May 2023 19:35:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1685302543; bh=Lk1VFpN1xRWamVmS76OW6veLC48QUYX42hDioYr1L0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iycCC+JxDyQ9JDBA4ZlY+JDBjSS3oOpPNCFaY4cOO94nW/IFvihm3FhUyaSmfQMtZ YqkbSyWANScslraUv8LsD/kryYZFL8faBN3CwbGlLmAEV/Vih21o6qXIrkwKZEyqd3 8piFbtghzj9ZnKRegsplh5Yp9+7VhlZ++00MMr00= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dave Hansen , Thomas Gleixner Subject: [PATCH 6.1 017/119] x86/mm: Avoid incomplete Global INVLPG flushes Date: Sun, 28 May 2023 20:10:17 +0100 Message-Id: <20230528190835.902657708@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230528190835.386670951@linuxfoundation.org> References: <20230528190835.386670951@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: Dave Hansen commit ce0b15d11ad837fbacc5356941712218e38a0a83 upstream. The INVLPG instruction is used to invalidate TLB entries for a specified virtual address. When PCIDs are enabled, INVLPG is supposed to invalidate TLB entries for the specified address for both the current PCID *and* Global entries. (Note: Only kernel mappings set Global=1.) Unfortunately, some INVLPG implementations can leave Global translations unflushed when PCIDs are enabled. As a workaround, never enable PCIDs on affected processors. I expect there to eventually be microcode mitigations to replace this software workaround. However, the exact version numbers where that will happen are not known today. Once the version numbers are set in stone, the processor list can be tweaked to only disable PCIDs on affected processors with affected microcode. Note: if anyone wants a quick fix that doesn't require patching, just stick 'nopcid' on your kernel command-line. Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/init.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -9,6 +9,7 @@ #include #include +#include #include #include #include @@ -260,6 +261,24 @@ static void __init probe_page_size_mask( } } +#define INTEL_MATCH(_model) { .vendor = X86_VENDOR_INTEL, \ + .family = 6, \ + .model = _model, \ + } +/* + * INVLPG may not properly flush Global entries + * on these CPUs when PCIDs are enabled. + */ +static const struct x86_cpu_id invlpg_miss_ids[] = { + INTEL_MATCH(INTEL_FAM6_ALDERLAKE ), + INTEL_MATCH(INTEL_FAM6_ALDERLAKE_L ), + INTEL_MATCH(INTEL_FAM6_ALDERLAKE_N ), + INTEL_MATCH(INTEL_FAM6_RAPTORLAKE ), + INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_P), + INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_S), + {} +}; + static void setup_pcid(void) { if (!IS_ENABLED(CONFIG_X86_64)) @@ -268,6 +287,12 @@ static void setup_pcid(void) if (!boot_cpu_has(X86_FEATURE_PCID)) return; + if (x86_match_cpu(invlpg_miss_ids)) { + pr_info("Incomplete global flushes, disabling PCID"); + setup_clear_cpu_cap(X86_FEATURE_PCID); + return; + } + if (boot_cpu_has(X86_FEATURE_PGE)) { /* * This can't be cr4_set_bits_and_update_boot() -- the