From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792507225; b=J6rZjjwqe5tI9QdF9ajV6YyFq1qdkH7dXOt8ljtqL897BVx09jANDCWFmOWSyVBR+sAT jgKwuEVAdeTvrGgz5fkeoLoYv2zUyRVx4K1zd1KnOhIfHqyGW8NJIHCkoZ/QN9HY++MJO mOSLsYka6JGVh5AAcbNpvBOtRaQ18iWNQe/kfTe1Dvys+Z7ShskoAXblME51cb2FwjYfp 0VwXKz877nQ5mQgAMwnkMAS+HlFhWFBZ9qDWu2lLpfXWeI0GUW+o2iebkkOX1EoFUIcXg ovXBCAWlmf8BXWkeDJG6vtgiN07LOwyO8MclgXVDRXK2sigUpw3xejHUt/TUm0YCtDA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792507225; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=5ag2TWCXWR9uzwdO4FL54tkw6F6WUl4C1dUeOhZ1BMU=; b=KRh3E2tbarD7GTUXOvnIsz/h7/x+/lPTJ7roQYzGkMq66lKmpIKqpYsEfu7B97mGofVr PAu1QIWh6QVAlUtAmDnTNoNfUV+6XOLr0ATZ2+sDNSOjH3J1FG2VHlGISKD5ZszEgbRib uf4ckQLkeVwv+kVMgAh958LeJGPzXw71wzT9XC5DXi2SQEWr9oH81pCdjjjJ02ysa0A3c dm2qxwdg/TB9MgF8Ky+5eXCaavvCyItqIx9nDZJ/3f0XN+/WGNRrOwOgLTNUWOMWynu2F Sq545nbJJNmq47zhlArvYLInKYdLR/H+M7Onlc5Nu13vU6DTq5ERunZ9LrNNq9UEM5w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Cxn7Ofr1; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4BCE4606A319; Tue, 20 Oct 2026 14:40:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Cxn7Ofr1 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1CD01F000C8; Tue, 20 Oct 2026 14:40:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792507225; bh=5ag2TWCXWR9uzwdO4FL54tkw6F6WUl4C1dUeOhZ1BMU=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Cxn7Ofr1wvvUiUpg/R0YCV7YQ7xesgvqbIo4AzRbd11v2ij8B92lvDF9Hk0ikuocG pLIQvpRzAWRvcWpOBeSgqjKqtEy5OCSA5+RwXtcRn+FFf7CxaZfm0NfXcpmWfKparq rpT0MrjKnqspN75f+S3LlHHy/UmdyA5EQXMh0DHndukWRaXlWRQ/6DebnxVDk/DFhK XQB4odxaxRYZfVAVeAcjq5GSbgmzvfW5vy/Gmi620JuBaFsB7ai2VJM69PoNlQFIuX TmXZ6ZnkwjPvbCJX0mOmwRSX5ChBSyLD/8EkuxOZr9D72Hxbw3uarZmbctwgCVB1I5 yBqF1KeisXU8g== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 2/2] KVM: selftests: Test that KVM_RUN fails for unresolvable host faults Reply-To: sashiko-reviews@lists.linux.dev To: "Christian Borntraeger" Cc: KVM , linux-s390 , "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" In-Reply-To: <20261020143308.228328-3-borntraeger@linux.ibm.com> References: <20261020143308.228328-1-borntraeger@linux.ibm.com> <20261020143308.228328-3-borntraeger@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 20 Oct 2026 14:40:24 +0000 X-Mailing-List: kvm@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] KVM: selftests: missing gmem_flags argument to vm_mem_add() in m= ain() -- commit 3a1c0f90404979b6638dbd3c2769d7b78633b104 Author: Christian Borntraeger KVM: selftests: Test that KVM_RUN fails for unresolvable host faults This commit adds a selftest in which a guest writes to a shmem-backed memslot beyond the end of the file to verify that KVM_RUN fails with -EFAULT rather than retrying an asynchronous page fault indefinitely. > diff --git a/tools/testing/selftests/kvm/faultin_sigbus_test.c b/tools/te= sting/selftests/kvm/faultin_sigbus_test.c > new file mode 100644 > index 0000000000000..b9d673260ed5a > --- /dev/null > +++ b/tools/testing/selftests/kvm/faultin_sigbus_test.c > @@ -0,0 +1,168 @@ [ ... ] > +int main(void) > +{ > + struct sigaction sa =3D { .sa_handler =3D sig_alarm }; /* no SA_RESTART= */ > + struct userspace_mem_region *region; > + struct kvm_vcpu *vcpu; > + struct kvm_vm *vm; > + struct ucall uc; > + gpa_t gpa; > + gva_t gva; > + u64 npages; > + int r; > + > + vm =3D vm_create_with_one_vcpu(&vcpu, guest_code); > + > + /* After slot 0 and the page that some architectures use for ucalls. */ > + region =3D memslot2region(vm, 0); > + gpa =3D align_up(region->region.guest_phys_addr + > + region->region.memory_size + vm->page_size, TEST_SIZE); > + npages =3D TEST_SIZE / vm->page_size; > + > + vm_mem_add(vm, VM_MEM_SRC_SHMEM, gpa, TEST_SLOT, npages, 0, -1, 0); [Severity: Medium] Does this fail to build when compiling KVM selftests? In tools/testing/selftests/kvm/include/kvm_util.h (and tools/testing/selftests/kvm/lib/kvm_util.c), vm_mem_add() takes 9 arguments following commit ee455183c92be7: void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, gpa_t gpa, u32 slot, u64 npages, u32 flags, int gmem_fd, u64 gmem_offset, u64 gmem_flags); Calling vm_mem_add() in main() with only 8 arguments omits the final gmem_flags parameter and fails compilation with too few arguments to function vm_mem_add. Should this pass the 9th argument (0), or use the 6-argument helper vm_userspace_mem_region_add(vm, VM_MEM_SRC_SHMEM, gpa, TEST_SLOT, npages, 0) instead? > + region =3D memslot2region(vm, TEST_SLOT); > + /* Only the first host page is backed, everything behind it is SIGBUS. = */ > + TEST_ASSERT(!ftruncate(region->fd, getpagesize()), "ftruncate() failed"= ); [ ... ] --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261020143308.2283= 28-1-borntraeger@linux.ibm.com?part=3D2