From nobody Thu Dec 18 22:02:55 2025 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (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 F05EB1C863C for ; Thu, 13 Feb 2025 16:22:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739463744; cv=none; b=C9/Sxh8y3ZI4j+2VXxyJsIfKOmx1BKCKqj69DUTqSAjfZRoFgMzhwNq7QVlM1+Wx/YefSbjuBP2DpfyfrxElD0AJrdNn+JozsKgFc3SiNHj+qRE32xpv1EUwwUc8xSZQYd+daQYO0DglLWH1s7wrnkQ5oFaWkJpUs8q5cjDapVA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739463744; c=relaxed/simple; bh=OultV2gf7z66EDxvE90LeulSf2nCT8KBuXJ7wGnhneQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u3ioXaEmDoXDdqb3kuFs2SRc8RUNjhJ0mD+V7jkOm1mmsn5ijJ5NHih5PaBchvKP4guII9btn6dxJaKvJSCSM4IxRmXDrThviMkkyajL6Ououeb4PXdLbithc0XakytRu1Qoypob+AJ8NAWynWioQbLJM9aDhxdLoo0g5ajVqSc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=shelob.surriel.com; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shelob.surriel.com Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1tibr7-000000003xx-0qLG; Thu, 13 Feb 2025 11:14:25 -0500 From: Rik van Riel To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, bp@alien8.de, peterz@infradead.org, dave.hansen@linux.intel.com, zhengqi.arch@bytedance.com, nadav.amit@gmail.com, thomas.lendacky@amd.com, kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, jackmanb@google.com, jannh@google.com, mhklinux@outlook.com, andrew.cooper3@citrix.com, Rik van Riel , Manali Shukla Subject: [PATCH v11 06/12] x86/mm: use INVLPGB for kernel TLB flushes Date: Thu, 13 Feb 2025 11:13:57 -0500 Message-ID: <20250213161423.449435-7-riel@surriel.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250213161423.449435-1-riel@surriel.com> References: <20250213161423.449435-1-riel@surriel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: riel@surriel.com Content-Type: text/plain; charset="utf-8" Use broadcast TLB invalidation for kernel addresses when available. Remove the need to send IPIs for kernel TLB flushes. Signed-off-by: Rik van Riel Reviewed-by: Nadav Amit Tested-by: Manali Shukla Tested-by: Brendan Jackman Tested-by: Michael Kelley --- arch/x86/mm/tlb.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 924ac2263725..ce9df82754ce 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -1077,6 +1077,28 @@ void flush_tlb_all(void) on_each_cpu(do_flush_tlb_all, NULL, 1); } =20 +static bool broadcast_kernel_range_flush(struct flush_tlb_info *info) +{ + unsigned long addr; + unsigned long nr; + + if (!cpu_feature_enabled(X86_FEATURE_INVLPGB)) + return false; + + if (info->end =3D=3D TLB_FLUSH_ALL) { + invlpgb_flush_all(); + return true; + } + + for (addr =3D info->start; addr < info->end; addr +=3D nr << PAGE_SHIFT) { + nr =3D (info->end - addr) >> PAGE_SHIFT; + nr =3D clamp_val(nr, 1, invlpgb_count_max); + invlpgb_flush_addr_nosync(addr, nr); + } + tlbsync(); + return true; +} + static void do_kernel_range_flush(void *info) { struct flush_tlb_info *f =3D info; @@ -1096,7 +1118,9 @@ void flush_tlb_kernel_range(unsigned long start, unsi= gned long end) info =3D get_flush_tlb_info(NULL, start, end, PAGE_SHIFT, false, TLB_GENERATION_INVALID); =20 - if (info->end =3D=3D TLB_FLUSH_ALL) + if (broadcast_kernel_range_flush(info)) + ; /* Fall through. */ + else if (info->end =3D=3D TLB_FLUSH_ALL) on_each_cpu(do_flush_tlb_all, NULL, 1); else on_each_cpu(do_kernel_range_flush, info, 1); --=20 2.47.1