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 C2A1FC54E5D for ; Tue, 19 Mar 2024 02:15:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rmP0H-00018u-TF; Mon, 18 Mar 2024 22:15:01 -0400 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 1rmP0F-00018m-1r for qemu-devel@nongnu.org; Mon, 18 Mar 2024 22:14:59 -0400 Received: from mgamail.intel.com ([192.198.163.7]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rmP0D-0005qf-4V for qemu-devel@nongnu.org; Mon, 18 Mar 2024 22:14:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1710814497; x=1742350497; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=GLhds+4K7dc7u246W/UoQ0WN87K/fN2ZmsoMZyd0Dag=; b=n43E9lMI/aaA8pc+N8bVMuXKUscW07+LGsz/fg4AjYlJhQ/otlGrfG/J AtHUC9TPWx05B2SfADo7+aODRvICWcPiHeiPzKXqy1a0hwPpCbhs4jJZW G/YgmxR+4v/i2iLx5rVimPga4n0vobB8XeZeZOD7ZDdlFlqxt94lZ4Djh JAf8nfdfvKJlaTJmZMjtR5ib2/HB+ZwbAjvZccP9tIQhQRW+4C+N9WP8V ukJHkSvNhEcjKt8jEkU7WBxDHrLzMnuL/t7tig8YWBap2RoRkEo+5WgtT ET1lrR9O6FzZ4YlvsO4umbFtxptlaNhAws2yDhopSYt2Zp+D9/jZvAczr Q==; X-IronPort-AV: E=McAfee;i="6600,9927,11017"; a="31091304" X-IronPort-AV: E=Sophos;i="6.07,135,1708416000"; d="scan'208";a="31091304" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2024 19:14:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,135,1708416000"; d="scan'208";a="44718549" Received: from leiwang7-mobl.ccr.corp.intel.com (HELO [10.124.244.145]) ([10.124.244.145]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2024 19:14:49 -0700 Message-ID: <3d2655c7-74ad-49d9-a527-7648f8e565da@intel.com> Date: Tue, 19 Mar 2024 10:14:47 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 08/65] kvm: handle KVM_EXIT_MEMORY_FAULT Content-Language: en-US To: Xiaoyao Li , Paolo Bonzini , David Hildenbrand , Igor Mammedov , Eduardo Habkost , Marcel Apfelbaum , =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= , Yanan Wang , "Michael S. Tsirkin" , Richard Henderson , Ani Sinha , Peter Xu , Cornelia Huck , =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= , Eric Blake , Markus Armbruster , Marcelo Tosatti Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org, Michael Roth , Claudio Fontana , Gerd Hoffmann , Isaku Yamahata , Chenyi Qiang References: <20240229063726.610065-1-xiaoyao.li@intel.com> <20240229063726.610065-9-xiaoyao.li@intel.com> From: "Wang, Lei" In-Reply-To: <20240229063726.610065-9-xiaoyao.li@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=192.198.163.7; envelope-from=lei4.wang@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=-0.374, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, 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 2/29/2024 14:36, Xiaoyao Li wrote: > From: Chao Peng > > When geeting KVM_EXIT_MEMORY_FAULT exit, it indicates userspace needs to > do the memory conversion on the RAMBlock to turn the memory into desired > attribute, i.e., private/shared. > > Currently only KVM_MEMORY_EXIT_FLAG_PRIVATE in flags is valid when > KVM_EXIT_MEMORY_FAULT happens. > > 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. > > When page is converted from shared to private, the original shared > memory can be discarded via ram_block_discard_range(). Note, shared > memory can be discarded only when it's not back'ed by hugetlb because > hugetlb is supposed to be pre-allocated and no need for discarding. > > Signed-off-by: Chao Peng > Co-developed-by: Xiaoyao Li > Signed-off-by: Xiaoyao Li > > --- > Changes in v4: > - open-coded ram_block_discard logic; > - change warn_report() to error_report(); (Daniel) > --- > accel/kvm/kvm-all.c | 94 ++++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 84 insertions(+), 10 deletions(-) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index 70d482a2c936..87e4275932a7 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -2903,6 +2903,68 @@ 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; > + MemoryRegion *mr; > + RAMBlock *rb; > + void *addr; > + int ret = -1; > + > + if (!QEMU_PTR_IS_ALIGNED(start, qemu_host_page_size) || > + !QEMU_PTR_IS_ALIGNED(size, qemu_host_page_size)) { > + return -1; > + } > + > + if (!size) { > + return -1; > + } > + > + section = memory_region_find(get_system_memory(), start, size); > + mr = section.mr; > + if (!mr) { > + return -1; > + } > + > + if (memory_region_has_guest_memfd(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(mr) + section.offset_within_region; > + rb = qemu_ram_block_from_host(addr, false, &offset); > + > + if (to_private) { > + if (rb->page_size != qemu_host_page_size) { > + /* > + * shared memory is back'ed by hugetlb, which is supposed to be > + * pre-allocated and doesn't need to be discarded > + */ Nit: comment indentation is broken here. > + return 0; > + } else { > + ret = ram_block_discard_range(rb, offset, size); > + } > + } else { > + ret = ram_block_discard_guest_memfd_range(rb, offset, size); > + } > + } else { > + error_report("Convert non guest_memfd backed memory region " > + "(0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") to %s", Same as above. > + start, size, to_private ? "private" : "shared"); > + } > + > + memory_region_unref(section.mr); > + return ret; > +} > + > int kvm_cpu_exec(CPUState *cpu) > { > struct kvm_run *run = cpu->kvm_run; > @@ -2970,18 +3032,20 @@ 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); > @@ -3064,6 +3128,16 @@ 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: > ret = kvm_arch_handle_exit(cpu, run); > break;