From nobody Wed Sep 10 02:57:15 2025 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 DA221C001DC for ; Thu, 27 Jul 2023 19:55:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232599AbjG0Tzd (ORCPT ); Thu, 27 Jul 2023 15:55:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34744 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229995AbjG0TzA (ORCPT ); Thu, 27 Jul 2023 15:55:00 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4C6A030D4; Thu, 27 Jul 2023 12:54:59 -0700 (PDT) Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id 3D8EF2383EF5; Thu, 27 Jul 2023 12:54:57 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 3D8EF2383EF5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1690487697; bh=HPETpWBPXcktJiZxDGWrM7Bd3Q7E+nExHqjfNeCbApo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fTWMskoQmaiRKYdKSqF8KN7KIhXNYhlpbivfWu4+Oy1P7HYd9Z+BoDF38kI6TH7b6 KqqJ1TpASd3aeiNA2Mak+9sdTcFrsiLjjsPwTmYiP1WS/42I6mYZDf5lr7zmQYZZV9 S7qwQ8Z/HVglVTZKCWImoAOU4lsYLcQXP3OnRoiE= From: Nuno Das Neves To: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org Cc: mikelley@microsoft.com, kys@microsoft.com, wei.liu@kernel.org, haiyangz@microsoft.com, decui@microsoft.com, ssengar@linux.microsoft.com, mukeshrathor@microsoft.com, stanislav.kinsburskiy@gmail.com, jinankjain@linux.microsoft.com, apais@linux.microsoft.com, Tianyu.Lan@microsoft.com, vkuznets@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, will@kernel.org, catalin.marinas@arm.com Subject: [PATCH 08/15] Drivers: hv: Introduce per-cpu event ring tail Date: Thu, 27 Jul 2023 12:54:43 -0700 Message-Id: <1690487690-2428-9-git-send-email-nunodasneves@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1690487690-2428-1-git-send-email-nunodasneves@linux.microsoft.com> References: <1690487690-2428-1-git-send-email-nunodasneves@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Add a pointer hv_synic_eventring_tail to track the tail pointer for the SynIC event ring buffer for each SINT. This will be used by the mshv driver, but must be tracked independently since the driver module could be removed and re-inserted. Signed-off-by: Nuno Das Neves --- drivers/hv/hv_common.c | 25 +++++++++++++++++++++++++ include/asm-generic/mshyperv.h | 2 ++ 2 files changed, 27 insertions(+) diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index 9f9c3dc89bb2..99d9b262b8a7 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -61,6 +61,16 @@ static void hv_kmsg_dump_unregister(void); =20 static struct ctl_table_header *hv_ctl_table_hdr; =20 +/* + * Per-cpu array holding the tail pointer for the SynIC event ring buffer + * for each SINT. + * + * We cannot maintain this in mshv driver because the tail pointer should + * persist even if the mshv driver is unloaded. + */ +u8 __percpu **hv_synic_eventring_tail; +EXPORT_SYMBOL_GPL(hv_synic_eventring_tail); + /* * Hyper-V specific initialization and shutdown code that is * common across all architectures. Called from architecture @@ -332,6 +342,8 @@ int __init hv_common_init(void) if (hv_root_partition) { hyperv_pcpu_output_arg =3D alloc_percpu(void *); BUG_ON(!hyperv_pcpu_output_arg); + hv_synic_eventring_tail =3D alloc_percpu(u8 *); + BUG_ON(hv_synic_eventring_tail =3D=3D NULL); } =20 hv_vp_index =3D kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index), @@ -356,6 +368,7 @@ int __init hv_common_init(void) int hv_common_cpu_init(unsigned int cpu) { void **inputarg, **outputarg; + u8 **synic_eventring_tail; u64 msr_vp_index; gfp_t flags; int pgcount =3D hv_root_partition ? 2 : 1; @@ -371,6 +384,14 @@ int hv_common_cpu_init(unsigned int cpu) if (hv_root_partition) { outputarg =3D (void **)this_cpu_ptr(hyperv_pcpu_output_arg); *outputarg =3D (char *)(*inputarg) + HV_HYP_PAGE_SIZE; + synic_eventring_tail =3D (u8 **)this_cpu_ptr(hv_synic_eventring_tail); + *synic_eventring_tail =3D kcalloc(HV_SYNIC_SINT_COUNT, sizeof(u8), + flags); + + if (unlikely(!*synic_eventring_tail)) { + kfree(*inputarg); + return -ENOMEM; + } } =20 msr_vp_index =3D hv_get_register(HV_MSR_VP_INDEX); @@ -387,6 +408,7 @@ int hv_common_cpu_die(unsigned int cpu) { unsigned long flags; void **inputarg, **outputarg; + u8 **synic_eventring_tail; void *mem; =20 local_irq_save(flags); @@ -398,6 +420,9 @@ int hv_common_cpu_die(unsigned int cpu) if (hv_root_partition) { outputarg =3D (void **)this_cpu_ptr(hyperv_pcpu_output_arg); *outputarg =3D NULL; + synic_eventring_tail =3D (u8 **)this_cpu_ptr(hv_synic_eventring_tail); + kfree(*synic_eventring_tail); + *synic_eventring_tail =3D NULL; } =20 local_irq_restore(flags); diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index 0c94d20b4d44..9118d678b27a 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -73,6 +73,8 @@ extern bool hv_nested; extern void * __percpu *hyperv_pcpu_input_arg; extern void * __percpu *hyperv_pcpu_output_arg; =20 +extern u8 __percpu **hv_synic_eventring_tail; + extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr); extern u64 hv_do_fast_hypercall8(u16 control, u64 input8); extern bool hv_isolation_type_snp(void); --=20 2.25.1