From nobody Fri Dec 19 17:34:40 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass header.i=@intel.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=intel.com ARC-Seal: i=1; a=rsa-sha256; t=1709188789; cv=none; d=zohomail.com; s=zohoarc; b=iOLRq35cO8IWb+NxyYZjXRQCr+k/WuNEdFR7XeIG+5jYrypDj41O4VXWyJbYypbKjE5m70+E7/6dgU0e815/l5bW63D9N04LFYJl0EbIyCo+1QLcktglH0Gq6j8r28hr6Lu9fvb5EUid1wC1bb1clm2V34D+/0ic3VXy41kYSi8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1709188789; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=vaUt9WdJuGVgEY7lGfr7N/VEKJeZA1Ra9ErnLjsbLzw=; b=C5dB7UznnMsKp9e+vcFKOAKgQ7WZYTPvkuVzePs5m9I+r4eftMhZkEVAsceUs1KtNsnQSkPIUJ1tUgEHGxnae2u9nZRp4C1gFbRZWKCaPHbuaf61cyuWX3BZtt355WAihNwvcq3fxtcOYmOHslIt4wX2ccNv7Svd5PzcqQUOnXg= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=@intel.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1709188789689178.9371759198192; Wed, 28 Feb 2024 22:39:49 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rfa42-00014K-3l; Thu, 29 Feb 2024 01:38:44 -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 1rfa3r-0000sw-Js for qemu-devel@nongnu.org; Thu, 29 Feb 2024 01:38:34 -0500 Received: from mgamail.intel.com ([192.198.163.15]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rfa3o-0004LA-05 for qemu-devel@nongnu.org; Thu, 29 Feb 2024 01:38:30 -0500 Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Feb 2024 22:38:27 -0800 Received: from lxy-clx-4s.sh.intel.com ([10.239.48.52]) by orviesa007.jf.intel.com with ESMTP; 28 Feb 2024 22:38:21 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1709188708; x=1740724708; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=nHcrori2+xWCP40+Q6vPTJnv0Y0lUVOf729EXknihSo=; b=R7d0iHwzpYK/5h1ju/6WRMz/F2gjlK/4gYCgAsfQvG5jdgjIoSFm+QOH cY2jjgeVBGEa11wi08N+jfvinYnbwgk1JCf5Vc1zaNHENnc5EWKBv947e Si1m+VVrkHk2bXBXIrVL99xIACtwsZ010OKVsaRgVIyQQERRMcsThTXZw ebiso4Z0ol7Mq0kZzq0xcQVqUfI4iLe5d+soy5ooIb1UYzk5cdNymlIvV 5EbhzeZLtFE4p5tWA1U6igOIeqv4uvWLiFVMuuGanAqbd1daVwu7SWvUP 0Q0tRUrmWNXiMvPAcMI3DfR67StRPzovAun9BYCdr0Qfneu43je3RPZDF w==; X-IronPort-AV: E=McAfee;i="6600,9927,10998"; a="3802527" X-IronPort-AV: E=Sophos;i="6.06,192,1705392000"; d="scan'208";a="3802527" X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,192,1705392000"; d="scan'208";a="8074917" From: Xiaoyao Li To: Paolo Bonzini , David Hildenbrand , Igor Mammedov , Eduardo Habkost , Marcel Apfelbaum , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Yanan Wang , "Michael S. Tsirkin" , Richard Henderson , Ani Sinha , Peter Xu , Cornelia Huck , =?UTF-8?q?Daniel=20P=2E=20Berrang=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 , xiaoyao.li@intel.com Subject: [PATCH v5 08/65] kvm: handle KVM_EXIT_MEMORY_FAULT Date: Thu, 29 Feb 2024 01:36:29 -0500 Message-Id: <20240229063726.610065-9-xiaoyao.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240229063726.610065-1-xiaoyao.li@intel.com> References: <20240229063726.610065-1-xiaoyao.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=192.198.163.15; envelope-from=xiaoyao.li@intel.com; helo=mgamail.intel.com X-Spam_score_int: -5 X-Spam_score: -0.6 X-Spam_bar: / X-Spam_report: (-0.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.102, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HK_RANDOM_ENVFROM=0.596, HK_RANDOM_FROM=0.999, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no 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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @intel.com) X-ZM-MESSAGEID: 1709188790893100003 Content-Type: text/plain; charset="utf-8" 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 Reviewed-by: Isaku Yamahata --- 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)); } =20 +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 =3D -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 =3D memory_region_find(get_system_memory(), start, size); + mr =3D section.mr; + if (!mr) { + return -1; + } + + if (memory_region_has_guest_memfd(mr)) { + if (to_private) { + ret =3D kvm_set_memory_attributes_private(start, size); + } else { + ret =3D kvm_set_memory_attributes_shared(start, size); + } + + if (ret) { + memory_region_unref(section.mr); + return ret; + } + + addr =3D memory_region_get_ram_ptr(mr) + section.offset_within_reg= ion; + rb =3D qemu_ram_block_from_host(addr, false, &offset); + + if (to_private) { + if (rb->page_size !=3D 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 + */ + return 0; + } else { + ret =3D ram_block_discard_range(rb, offset, size); + } + } else { + ret =3D 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", + start, size, to_private ? "private" : "shared"); + } + + memory_region_unref(section.mr); + return ret; +} + int kvm_cpu_exec(CPUState *cpu) { struct kvm_run *run =3D cpu->kvm_run; @@ -2970,18 +3032,20 @@ int kvm_cpu_exec(CPUState *cpu) ret =3D EXCP_INTERRUPT; break; } - fprintf(stderr, "error: kvm run failed %s\n", - strerror(-run_ret)); + if (!(run_ret =3D=3D -EFAULT && run->exit_reason =3D=3D KVM_EX= IT_MEMORY_FAULT)) { + fprintf(stderr, "error: kvm run failed %s\n", + strerror(-run_ret)); #ifdef TARGET_PPC - if (run_ret =3D=3D -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 =3D=3D -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 =3D -1; - break; + ret =3D -1; + break; + } } =20 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%" PRI= x64, + (uint64_t)run->memory_fault.flags); + ret =3D -1; + break; + } + ret =3D kvm_convert_memory(run->memory_fault.gpa, run->memory_= fault.size, + run->memory_fault.flags & KVM_MEMORY_= EXIT_FLAG_PRIVATE); + break; default: ret =3D kvm_arch_handle_exit(cpu, run); break; --=20 2.34.1