From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Christopherson Date: Thu, 2 Nov 2023 08:44:52 -0700 Subject: [PATCH v13 09/35] KVM: Add KVM_EXIT_MEMORY_FAULT exit to report faults to userspace In-Reply-To: <496b78bb-ad12-4eed-a62c-8c2fd725ec61@redhat.com> References: <20231027182217.3615211-1-seanjc@google.com> <20231027182217.3615211-10-seanjc@google.com> <482bfea6f54ea1bb7d1ad75e03541d0ba0e5be6f.camel@intel.com> <64e3764e36ba7a00d94cc7db1dea1ef06b620aaf.camel@intel.com> <32cb71700aedcbd1f65276cf44a601760ffc364b.camel@intel.com> <496b78bb-ad12-4eed-a62c-8c2fd725ec61@redhat.com> Message-ID: List-Id: To: kvm-riscv@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Thu, Nov 02, 2023, Paolo Bonzini wrote: > On 11/2/23 10:35, Huang, Kai wrote: > > IIUC KVM can already handle the case of poisoned > > page by sending signal to user app: > > > > static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct > > kvm_page_fault *fault) { > > ... > > > > if (fault->pfn == KVM_PFN_ERR_HWPOISON) { > > kvm_send_hwpoison_signal(fault->slot, fault->gfn); No, this doesn't work, because that signals the host virtual address unsigned long hva = gfn_to_hva_memslot(slot, gfn); send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); which is the *shared* page. > > return RET_PF_RETRY; > > } > > } > > EHWPOISON is not implemented by this series, so it should be left out of the > documentation. EHWPOISON *is* implemented. kvm_gmem_get_pfn() returns -EWPOISON as appropriate, and kvm_faultin_pfn() returns that directly without going through kvm_handle_error_pfn(). kvm_faultin_pfn_private() | |-> kvm_gmem_get_pfn() | |-> if (folio_test_hwpoison(folio)) { r = -EHWPOISON; goto out_unlock; } | |-> r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn, &max_order); if (r) { kvm_mmu_prepare_memory_fault_exit(vcpu, fault); return r; } | |-> ret = __kvm_faultin_pfn(vcpu, fault); if (ret != RET_PF_CONTINUE) return ret; if (unlikely(is_error_pfn(fault->pfn))) return kvm_handle_error_pfn(vcpu, fault); From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DAB9D3C16 for ; Thu, 2 Nov 2023 15:44:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; 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Thu, 02 Nov 2023 08:44:53 -0700 (PDT) Date: Thu, 2 Nov 2023 08:44:52 -0700 In-Reply-To: <496b78bb-ad12-4eed-a62c-8c2fd725ec61@redhat.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231027182217.3615211-1-seanjc@google.com> <20231027182217.3615211-10-seanjc@google.com> <482bfea6f54ea1bb7d1ad75e03541d0ba0e5be6f.camel@intel.com> <64e3764e36ba7a00d94cc7db1dea1ef06b620aaf.camel@intel.com> <32cb71700aedcbd1f65276cf44a601760ffc364b.camel@intel.com> <496b78bb-ad12-4eed-a62c-8c2fd725ec61@redhat.com> Message-ID: Subject: Re: [PATCH v13 09/35] KVM: Add KVM_EXIT_MEMORY_FAULT exit to report faults to userspace From: Sean Christopherson To: Paolo Bonzini Cc: Kai Huang , Xiaoyao Li , "kvm-riscv@lists.infradead.org" , "mic@digikod.net" , "liam.merwick@oracle.com" , "kvm@vger.kernel.org" , Isaku Yamahata , "viro@zeniv.linux.org.uk" , "kirill.shutemov@linux.intel.com" , "david@redhat.com" , "linux-mips@vger.kernel.org" , "amoorthy@google.com" , "linuxppc-dev@lists.ozlabs.org" , "tabba@google.com" , "kvmarm@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "oliver.upton@linux.dev" , "michael.roth@amd.com" , "chao.p.peng@linux.intel.com" , "palmer@dabbelt.com" , "chenhuacai@kernel.org" , "aou@eecs.berkeley.edu" , "mpe@ellerman.id.au" , Vishal Annapurve , "vbabka@suse.cz" , "mail@maciej.szmigiero.name" , "linux-riscv@lists.infradead.org" , "maz@kernel.org" , "willy@infradead.org" , "dmatlack@google.com" , "anup@brainfault.org" , "yu.c.zhang@linux.intel.com" , Yilun Xu , "qperret@google.com" , "brauner@kernel.org" , "isaku.yamahata@gmail.com" , "ackerleytng@google.com" , "jarkko@kernel.org" , "paul.walmsley@sifive.com" , "linux-arm-kernel@lists.infradead.org" , "linux-mm@kvack.org" , Wei W Wang , "akpm@linux-foundation.org" Content-Type: text/plain; charset="us-ascii" On Thu, Nov 02, 2023, Paolo Bonzini wrote: > On 11/2/23 10:35, Huang, Kai wrote: > > IIUC KVM can already handle the case of poisoned > > page by sending signal to user app: > > > > static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct > > kvm_page_fault *fault) { > > ... > > > > if (fault->pfn == KVM_PFN_ERR_HWPOISON) { > > kvm_send_hwpoison_signal(fault->slot, fault->gfn); No, this doesn't work, because that signals the host virtual address unsigned long hva = gfn_to_hva_memslot(slot, gfn); send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); which is the *shared* page. > > return RET_PF_RETRY; > > } > > } > > EHWPOISON is not implemented by this series, so it should be left out of the > documentation. EHWPOISON *is* implemented. kvm_gmem_get_pfn() returns -EWPOISON as appropriate, and kvm_faultin_pfn() returns that directly without going through kvm_handle_error_pfn(). kvm_faultin_pfn_private() | |-> kvm_gmem_get_pfn() | |-> if (folio_test_hwpoison(folio)) { r = -EHWPOISON; goto out_unlock; } | |-> r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn, &max_order); if (r) { kvm_mmu_prepare_memory_fault_exit(vcpu, fault); return r; } | |-> ret = __kvm_faultin_pfn(vcpu, fault); if (ret != RET_PF_CONTINUE) return ret; if (unlikely(is_error_pfn(fault->pfn))) return kvm_handle_error_pfn(vcpu, fault); 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 0B90AC4332F for ; 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Thu, 02 Nov 2023 08:44:53 -0700 (PDT) Date: Thu, 2 Nov 2023 08:44:52 -0700 In-Reply-To: <496b78bb-ad12-4eed-a62c-8c2fd725ec61@redhat.com> Mime-Version: 1.0 References: <20231027182217.3615211-1-seanjc@google.com> <20231027182217.3615211-10-seanjc@google.com> <482bfea6f54ea1bb7d1ad75e03541d0ba0e5be6f.camel@intel.com> <64e3764e36ba7a00d94cc7db1dea1ef06b620aaf.camel@intel.com> <32cb71700aedcbd1f65276cf44a601760ffc364b.camel@intel.com> <496b78bb-ad12-4eed-a62c-8c2fd725ec61@redhat.com> Message-ID: Subject: Re: [PATCH v13 09/35] KVM: Add KVM_EXIT_MEMORY_FAULT exit to report faults to userspace From: Sean Christopherson To: Paolo Bonzini Cc: Kai Huang , Xiaoyao Li , "kvm-riscv@lists.infradead.org" , "mic@digikod.net" , "liam.merwick@oracle.com" , "kvm@vger.kernel.org" , Isaku Yamahata , "viro@zeniv.linux.org.uk" , "kirill.shutemov@linux.intel.com" , "david@redhat.com" , "linux-mips@vger.kernel.org" , "amoorthy@google.com" , "linuxppc-dev@lists.ozlabs.org" , "tabba@google.com" , "kvmarm@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "oliver.upton@linux.dev" , "michael.roth@amd.com" , "chao.p.peng@linux.intel.com" , "palmer@dabbelt.com" , "chenhuacai@kernel.org" , "aou@eecs.berkeley.edu" , "mpe@ellerman.id.au" , Vishal Annapurve , "vbabka@suse.cz" , "mail@maciej.szmigiero.name" , "linux-riscv@lists.infradead.org" , "maz@kernel.org" , "willy@infradead.org" , "dmatlack@google.com" , "anup@brainfault.org" , "yu.c.zhang@linux.intel.com" , Yilun Xu , "qperret@google.com" , "brauner@kernel.org" , "isaku.yamahata@gmail.com" , "ackerleytng@google.com" , "jarkko@kernel.org" , "paul.walmsley@sifive.com" , "linux-arm-kernel@lists.infradead.org" , "linux-mm@kvack.org" , Wei W Wang , "akpm@linux-foundation.org" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231102_084459_580628_CA817A63 X-CRM114-Status: GOOD ( 14.25 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, Nov 02, 2023, Paolo Bonzini wrote: > On 11/2/23 10:35, Huang, Kai wrote: > > IIUC KVM can already handle the case of poisoned > > page by sending signal to user app: > > > > static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct > > kvm_page_fault *fault) { > > ... > > > > if (fault->pfn == KVM_PFN_ERR_HWPOISON) { > > kvm_send_hwpoison_signal(fault->slot, fault->gfn); No, this doesn't work, because that signals the host virtual address unsigned long hva = gfn_to_hva_memslot(slot, gfn); send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); which is the *shared* page. > > return RET_PF_RETRY; > > } > > } > > EHWPOISON is not implemented by this series, so it should be left out of the > documentation. EHWPOISON *is* implemented. kvm_gmem_get_pfn() returns -EWPOISON as appropriate, and kvm_faultin_pfn() returns that directly without going through kvm_handle_error_pfn(). kvm_faultin_pfn_private() | |-> kvm_gmem_get_pfn() | |-> if (folio_test_hwpoison(folio)) { r = -EHWPOISON; goto out_unlock; } | |-> r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn, &max_order); if (r) { kvm_mmu_prepare_memory_fault_exit(vcpu, fault); return r; } | |-> ret = __kvm_faultin_pfn(vcpu, fault); if (ret != RET_PF_CONTINUE) return ret; if (unlikely(is_error_pfn(fault->pfn))) return kvm_handle_error_pfn(vcpu, fault); _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 0C113C0018A for ; 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charset="us-ascii" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "kvm@vger.kernel.org" , "david@redhat.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "mic@digikod.net" , Kai Huang , "chao.p.peng@linux.intel.com" , "linux-riscv@lists.infradead.org" , "isaku.yamahata@gmail.com" , "chenhuacai@kernel.org" , Xiaoyao Li , "willy@infradead.org" , Wei W Wang , "vbabka@suse.cz" , "yu.c.zhang@linux.intel.com" , "linux-arm-kernel@lists.infradead.org" , "mail@maciej.szmigiero.name" , "aou@eecs.berkeley.edu" , "michael.roth@amd.com" , "ackerleytng@google.com" , "viro@ zeniv.linux.org.uk" , "paul.walmsley@sifive.com" , "kvmarm@lists.linux.dev" , "tabba@google.com" , Isaku Yamahata , "brauner@kernel.org" , "qperret@google.com" , "anup@brainfault.org" , "linux-mips@vger.kernel.org" , "oliver.upton@linux.dev" , "dmatlack@google.com" , "jarkko@kernel.org" , "palmer@dabbelt.com" , "kirill.shutemov@linux.intel.com" , "kvm-riscv@lists.infradead.org" , "maz@kernel.org" , "linux-fsdevel@vger.kernel.org" , "liam.merwick@oracle.com" , "akpm@linux-foundation.org" , Vishal Annapurve , "linux ppc-dev@lists.ozlabs.org" , Yilun Xu , "amoorthy@google.com" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Nov 02, 2023, Paolo Bonzini wrote: > On 11/2/23 10:35, Huang, Kai wrote: > > IIUC KVM can already handle the case of poisoned > > page by sending signal to user app: > > > > static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct > > kvm_page_fault *fault) { > > ... > > > > if (fault->pfn == KVM_PFN_ERR_HWPOISON) { > > kvm_send_hwpoison_signal(fault->slot, fault->gfn); No, this doesn't work, because that signals the host virtual address unsigned long hva = gfn_to_hva_memslot(slot, gfn); send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); which is the *shared* page. > > return RET_PF_RETRY; > > } > > } > > EHWPOISON is not implemented by this series, so it should be left out of the > documentation. EHWPOISON *is* implemented. kvm_gmem_get_pfn() returns -EWPOISON as appropriate, and kvm_faultin_pfn() returns that directly without going through kvm_handle_error_pfn(). kvm_faultin_pfn_private() | |-> kvm_gmem_get_pfn() | |-> if (folio_test_hwpoison(folio)) { r = -EHWPOISON; goto out_unlock; } | |-> r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn, &max_order); if (r) { kvm_mmu_prepare_memory_fault_exit(vcpu, fault); return r; } | |-> ret = __kvm_faultin_pfn(vcpu, fault); if (ret != RET_PF_CONTINUE) return ret; if (unlikely(is_error_pfn(fault->pfn))) return kvm_handle_error_pfn(vcpu, fault); 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 79B99C4332F for ; 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Thu, 02 Nov 2023 08:44:53 -0700 (PDT) Date: Thu, 2 Nov 2023 08:44:52 -0700 In-Reply-To: <496b78bb-ad12-4eed-a62c-8c2fd725ec61@redhat.com> Mime-Version: 1.0 References: <20231027182217.3615211-1-seanjc@google.com> <20231027182217.3615211-10-seanjc@google.com> <482bfea6f54ea1bb7d1ad75e03541d0ba0e5be6f.camel@intel.com> <64e3764e36ba7a00d94cc7db1dea1ef06b620aaf.camel@intel.com> <32cb71700aedcbd1f65276cf44a601760ffc364b.camel@intel.com> <496b78bb-ad12-4eed-a62c-8c2fd725ec61@redhat.com> Message-ID: Subject: Re: [PATCH v13 09/35] KVM: Add KVM_EXIT_MEMORY_FAULT exit to report faults to userspace From: Sean Christopherson To: Paolo Bonzini Cc: Kai Huang , Xiaoyao Li , "kvm-riscv@lists.infradead.org" , "mic@digikod.net" , "liam.merwick@oracle.com" , "kvm@vger.kernel.org" , Isaku Yamahata , "viro@zeniv.linux.org.uk" , "kirill.shutemov@linux.intel.com" , "david@redhat.com" , "linux-mips@vger.kernel.org" , "amoorthy@google.com" , "linuxppc-dev@lists.ozlabs.org" , "tabba@google.com" , "kvmarm@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "oliver.upton@linux.dev" , "michael.roth@amd.com" , "chao.p.peng@linux.intel.com" , "palmer@dabbelt.com" , "chenhuacai@kernel.org" , "aou@eecs.berkeley.edu" , "mpe@ellerman.id.au" , Vishal Annapurve , "vbabka@suse.cz" , "mail@maciej.szmigiero.name" , "linux-riscv@lists.infradead.org" , "maz@kernel.org" , "willy@infradead.org" , "dmatlack@google.com" , "anup@brainfault.org" , "yu.c.zhang@linux.intel.com" , Yilun Xu , "qperret@google.com" , "brauner@kernel.org" , "isaku.yamahata@gmail.com" , "ackerleytng@google.com" , "jarkko@kernel.org" , "paul.walmsley@sifive.com" , "linux-arm-kernel@lists.infradead.org" , "linux-mm@kvack.org" , Wei W Wang , "akpm@linux-foundation.org" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231102_084459_456095_819ABC91 X-CRM114-Status: GOOD ( 15.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Nov 02, 2023, Paolo Bonzini wrote: > On 11/2/23 10:35, Huang, Kai wrote: > > IIUC KVM can already handle the case of poisoned > > page by sending signal to user app: > > > > static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct > > kvm_page_fault *fault) { > > ... > > > > if (fault->pfn == KVM_PFN_ERR_HWPOISON) { > > kvm_send_hwpoison_signal(fault->slot, fault->gfn); No, this doesn't work, because that signals the host virtual address unsigned long hva = gfn_to_hva_memslot(slot, gfn); send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); which is the *shared* page. > > return RET_PF_RETRY; > > } > > } > > EHWPOISON is not implemented by this series, so it should be left out of the > documentation. EHWPOISON *is* implemented. kvm_gmem_get_pfn() returns -EWPOISON as appropriate, and kvm_faultin_pfn() returns that directly without going through kvm_handle_error_pfn(). kvm_faultin_pfn_private() | |-> kvm_gmem_get_pfn() | |-> if (folio_test_hwpoison(folio)) { r = -EHWPOISON; goto out_unlock; } | |-> r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn, &max_order); if (r) { kvm_mmu_prepare_memory_fault_exit(vcpu, fault); return r; } | |-> ret = __kvm_faultin_pfn(vcpu, fault); if (ret != RET_PF_CONTINUE) return ret; if (unlikely(is_error_pfn(fault->pfn))) return kvm_handle_error_pfn(vcpu, fault); _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel