From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 12652C47071 for ; Thu, 16 Nov 2023 05:17:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r3UkR-0006Pj-LA; Thu, 16 Nov 2023 00:17:03 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3UkP-0006PC-CK for qemu-devel@nongnu.org; Thu, 16 Nov 2023 00:17:01 -0500 Received: from mgamail.intel.com ([192.55.52.136]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3UkM-0004pt-AJ for qemu-devel@nongnu.org; Thu, 16 Nov 2023 00:17:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1700111818; x=1731647818; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=/INa79jB8VKoRWQG9/d/TbWATffq3Wxzhda7N1BwDPc=; b=PaqqSkQlxVFc4u4WL33fua+tvxAfBl3DCS3Ej0CKxbuPtnj//8p0SAcT mnZ6+fwsFW8hNWNwy/A8Tnu2Tqzuo8jNlOoSyricNr07Wwc1ffo26Gx4C DG/1guZ8g8vkzPQG3GanKbsz5zd7YVAOstcVoLfIKCj9mpEJoQ5ERZc4Y 3rkp8ZDYGBEpebvJ8ehFCM50Qpepq74TAVWzNQKKPiy3d0BRFJzP1V2vM Lv94vHV/Lndvq16hrfr0ii1SuBEaUBR612Fe86xOQa1TN/Aej70lNvxTQ rHBnGeudgzGipxd4TtduGntvHwcuUCYIuqwFbakjcbisQaRAfc78t7KBG w==; X-IronPort-AV: E=McAfee;i="6600,9927,10895"; a="370374263" X-IronPort-AV: E=Sophos;i="6.03,307,1694761200"; d="scan'208";a="370374263" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Nov 2023 21:16:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.03,307,1694761200"; d="scan'208";a="13002025" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.93.6.77]) ([10.93.6.77]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Nov 2023 21:16:50 -0800 Message-ID: <727a54e6-9ab5-4329-b5fe-3d3abb72b3da@intel.com> Date: Thu, 16 Nov 2023 13:16:46 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 10/70] kvm: handle KVM_EXIT_MEMORY_FAULT Content-Language: en-US To: =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= Cc: Paolo Bonzini , David Hildenbrand , Igor Mammedov , "Michael S . Tsirkin" , Marcel Apfelbaum , Richard Henderson , Peter Xu , =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= , Cornelia Huck , Eric Blake , Markus Armbruster , Marcelo Tosatti , qemu-devel@nongnu.org, kvm@vger.kernel.org, Michael Roth , Sean Christopherson , Claudio Fontana , Gerd Hoffmann , Isaku Yamahata , Chenyi Qiang References: <20231115071519.2864957-1-xiaoyao.li@intel.com> <20231115071519.2864957-11-xiaoyao.li@intel.com> From: Xiaoyao Li In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=192.55.52.136; envelope-from=xiaoyao.li@intel.com; helo=mgamail.intel.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.099, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HK_RANDOM_ENVFROM=0.999, HK_RANDOM_FROM=0.999, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 11/15/2023 6:42 PM, Daniel P. Berrangé wrote: > On Wed, Nov 15, 2023 at 02:14:19AM -0500, Xiaoyao Li wrote: >> From: Chao Peng >> >> Currently only KVM_MEMORY_EXIT_FLAG_PRIVATE in flags is valid when >> KVM_EXIT_MEMORY_FAULT happens. It indicates userspace needs to do >> the memory conversion on the RAMBlock to turn the memory into desired >> attribute, i.e., private/shared. >> >> Note, KVM_EXIT_MEMORY_FAULT makes sense only when the RAMBlock has >> guest_memfd memory backend. >> >> Note, KVM_EXIT_MEMORY_FAULT returns with -EFAULT, so special handling is >> added. >> >> Signed-off-by: Chao Peng >> Co-developed-by: Xiaoyao Li >> Signed-off-by: Xiaoyao Li >> --- >> accel/kvm/kvm-all.c | 76 +++++++++++++++++++++++++++++++++++++++------ >> 1 file changed, 66 insertions(+), 10 deletions(-) >> >> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c >> index 76e2404d54d2..58abbcb6926e 100644 >> --- a/accel/kvm/kvm-all.c >> +++ b/accel/kvm/kvm-all.c >> @@ -2902,6 +2902,50 @@ static void kvm_eat_signals(CPUState *cpu) >> } while (sigismember(&chkset, SIG_IPI)); >> } >> >> +static int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private) >> +{ >> + MemoryRegionSection section; >> + ram_addr_t offset; >> + RAMBlock *rb; >> + void *addr; >> + int ret = -1; >> + >> + section = memory_region_find(get_system_memory(), start, size); >> + if (!section.mr) { >> + return ret; >> + } >> + >> + if (memory_region_has_guest_memfd(section.mr)) { >> + if (to_private) { >> + ret = kvm_set_memory_attributes_private(start, size); >> + } else { >> + ret = kvm_set_memory_attributes_shared(start, size); >> + } >> + >> + if (ret) { >> + memory_region_unref(section.mr); >> + return ret; >> + } >> + >> + addr = memory_region_get_ram_ptr(section.mr) + >> + section.offset_within_region; >> + rb = qemu_ram_block_from_host(addr, false, &offset); >> + /* >> + * With KVM_SET_MEMORY_ATTRIBUTES by kvm_set_memory_attributes(), >> + * operation on underlying file descriptor is only for releasing >> + * unnecessary pages. >> + */ >> + ram_block_convert_range(rb, offset, size, to_private); >> + } else { >> + warn_report("Convert non guest_memfd backed memory region " >> + "(0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") to %s", >> + start, size, to_private ? "private" : "shared"); > > Again, if you're returning '-1' to indicate error, then > using warn_report is wrong, it should be error_report. > > warn_report is for when you return success, indicating > the problem was non-fatal. Learned. Thanks! >> + } >> + >> + memory_region_unref(section.mr); >> + return ret; >> +} >> + >> int kvm_cpu_exec(CPUState *cpu) >> { >> struct kvm_run *run = cpu->kvm_run; >> @@ -2969,18 +3013,20 @@ int kvm_cpu_exec(CPUState *cpu) >> ret = EXCP_INTERRUPT; >> break; >> } >> - fprintf(stderr, "error: kvm run failed %s\n", >> - strerror(-run_ret)); >> + if (!(run_ret == -EFAULT && run->exit_reason == KVM_EXIT_MEMORY_FAULT)) { >> + fprintf(stderr, "error: kvm run failed %s\n", >> + strerror(-run_ret)); >> #ifdef TARGET_PPC >> - if (run_ret == -EBUSY) { >> - fprintf(stderr, >> - "This is probably because your SMT is enabled.\n" >> - "VCPU can only run on primary threads with all " >> - "secondary threads offline.\n"); >> - } >> + if (run_ret == -EBUSY) { >> + fprintf(stderr, >> + "This is probably because your SMT is enabled.\n" >> + "VCPU can only run on primary threads with all " >> + "secondary threads offline.\n"); >> + } >> #endif >> - ret = -1; >> - break; >> + ret = -1; >> + break; >> + } >> } >> >> trace_kvm_run_exit(cpu->cpu_index, run->exit_reason); >> @@ -3067,6 +3113,16 @@ int kvm_cpu_exec(CPUState *cpu) >> break; >> } >> break; >> + case KVM_EXIT_MEMORY_FAULT: >> + if (run->memory_fault.flags & ~KVM_MEMORY_EXIT_FLAG_PRIVATE) { >> + error_report("KVM_EXIT_MEMORY_FAULT: Unknown flag 0x%" PRIx64, >> + (uint64_t)run->memory_fault.flags); >> + ret = -1; >> + break; >> + } >> + ret = kvm_convert_memory(run->memory_fault.gpa, run->memory_fault.size, >> + run->memory_fault.flags & KVM_MEMORY_EXIT_FLAG_PRIVATE); >> + break; >> default: >> DPRINTF("kvm_arch_handle_exit\n"); >> ret = kvm_arch_handle_exit(cpu, run); >> -- >> 2.34.1 >> > > With regards, > Daniel