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charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Stat-Signature: z4hi9jxfwgswjwazwkj7x8qh3jx9qoks X-Rspam-User: X-Rspamd-Queue-Id: 6C6F1180003 X-Rspamd-Server: rspam04 X-HE-Tag: 1757668671-429377 X-HE-Meta: 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 K0X4R0LX 3yuDYtL/qubdex7mtA+d7lHnfBpJIPEFIxQn1SWAI9OgjIJ8gy2jdiK1EufnKLOe4C8TulSw45G5Z4hJ4feBb9lWbEoqN01FFSYdQFzPJTyHjZGlPFcFftWy7Cr9Ia6E9v4qhjBuo+NZ6VPbOYaQPs6Lo7xlhSPJUF4UKXRD/QR4Fj/j2d++W0o2TCofbua5I/ykZrY6cM9nONBDVSW5D+DKoud6EHVslpfg18CYg/d/BXaJAc47TR2t5XdduBIt2L8VCV9crrM2w/vZAYuvoF9KazPcv2dHxiNk4dqJVCy/1sWnwuGZKVZaO/kedfTRQQ+O3S+b6DyeGkAxVOK1ay1fPIV4urrRaVmq7XTzle60D7fqmBddWid9ORWl374b75gsXXCyf18oRtC17TWER/eYFJ0Oab6Lj1XjogIakiYeJoqqrgZOYZXZxtXjURYDxDYk3AOC7fcHMYGODRa8CPnlfKFvNNwR45n32fZ3/G8wRTcuXWDTcFALSJPZ8kplQ4PYt6gTsCEKy0wJwJFsa7FnBxc4DS3F3yUpW1EahW+PNVwEqU5iMRRHFiPWNnAHYdbRAFBsGSW9KmpJH6tXTSh8sRTjTm/dCl3INkwNGBkJbHWR2TqBvqRBl58YU0wP2XZM+YDXCkDyqUxCCRx3FmCqLr7iRUTzSz9EibH0VTVOceYvFmUvIeqhIb3eF+KTfi2eN13t+0y8NHMFFMX3nOfFI2plCUTxTPZdogl3+ZnAlr5iYOtwfQnwVifYhRa4UdN8njll8+S/rR3QkzzCQ49CSb4wkNUdwmpukqwtfWPXfFZFvxAr0jgfk3Q== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: If guest memory is backed using a VMA that does not allow GUP (e.g. a=0A= userspace mapping of guest_memfd when the fd was allocated using=0A= KVM_GMEM_NO_DIRECT_MAP), then directly loading the test ELF binary into=0A= it via read(2) potentially does not work. To nevertheless support=0A= loading binaries in this cases, do the read(2) syscall using a bounce=0A= buffer, and then memcpy from the bounce buffer into guest memory.=0A= =0A= Signed-off-by: Patrick Roy =0A= ---=0A= .../testing/selftests/kvm/include/test_util.h | 1 +=0A= tools/testing/selftests/kvm/lib/elf.c | 8 +++----=0A= tools/testing/selftests/kvm/lib/io.c | 23 +++++++++++++++++++=0A= 3 files changed, 28 insertions(+), 4 deletions(-)=0A= =0A= diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testin= g/selftests/kvm/include/test_util.h=0A= index c6ef895fbd9a..0409b7b96c94 100644=0A= --- a/tools/testing/selftests/kvm/include/test_util.h=0A= +++ b/tools/testing/selftests/kvm/include/test_util.h=0A= @@ -46,6 +46,7 @@ do { \=0A= =0A= ssize_t test_write(int fd, const void *buf, size_t count);=0A= ssize_t test_read(int fd, void *buf, size_t count);=0A= +ssize_t test_read_bounce(int fd, void *buf, size_t count);=0A= int test_seq_read(const char *path, char **bufp, size_t *sizep);=0A= =0A= void __printf(5, 6) test_assert(bool exp, const char *exp_str,=0A= diff --git a/tools/testing/selftests/kvm/lib/elf.c b/tools/testing/selftest= s/kvm/lib/elf.c=0A= index f34d926d9735..e829fbe0a11e 100644=0A= --- a/tools/testing/selftests/kvm/lib/elf.c=0A= +++ b/tools/testing/selftests/kvm/lib/elf.c=0A= @@ -31,7 +31,7 @@ static void elfhdr_get(const char *filename, Elf64_Ehdr *= hdrp)=0A= * the real size of the ELF header.=0A= */=0A= unsigned char ident[EI_NIDENT];=0A= - test_read(fd, ident, sizeof(ident));=0A= + test_read_bounce(fd, ident, sizeof(ident));=0A= TEST_ASSERT((ident[EI_MAG0] =3D=3D ELFMAG0) && (ident[EI_MAG1] =3D=3D ELF= MAG1)=0A= && (ident[EI_MAG2] =3D=3D ELFMAG2) && (ident[EI_MAG3] =3D=3D ELFMAG3),= =0A= "ELF MAGIC Mismatch,\n"=0A= @@ -79,7 +79,7 @@ static void elfhdr_get(const char *filename, Elf64_Ehdr *= hdrp)=0A= offset_rv =3D lseek(fd, 0, SEEK_SET);=0A= TEST_ASSERT(offset_rv =3D=3D 0, "Seek to ELF header failed,\n"=0A= " rv: %zi expected: %i", offset_rv, 0);=0A= - test_read(fd, hdrp, sizeof(*hdrp));=0A= + test_read_bounce(fd, hdrp, sizeof(*hdrp));=0A= TEST_ASSERT(hdrp->e_phentsize =3D=3D sizeof(Elf64_Phdr),=0A= "Unexpected physical header size,\n"=0A= " hdrp->e_phentsize: %x\n"=0A= @@ -146,7 +146,7 @@ void kvm_vm_elf_load(struct kvm_vm *vm, const char *fil= ename)=0A= =0A= /* Read in the program header. */=0A= Elf64_Phdr phdr;=0A= - test_read(fd, &phdr, sizeof(phdr));=0A= + test_read_bounce(fd, &phdr, sizeof(phdr));=0A= =0A= /* Skip if this header doesn't describe a loadable segment. */=0A= if (phdr.p_type !=3D PT_LOAD)=0A= @@ -187,7 +187,7 @@ void kvm_vm_elf_load(struct kvm_vm *vm, const char *fil= ename)=0A= " expected: 0x%jx",=0A= n1, errno, (intmax_t) offset_rv,=0A= (intmax_t) phdr.p_offset);=0A= - test_read(fd, addr_gva2hva(vm, phdr.p_vaddr),=0A= + test_read_bounce(fd, addr_gva2hva(vm, phdr.p_vaddr),=0A= phdr.p_filesz);=0A= }=0A= }=0A= diff --git a/tools/testing/selftests/kvm/lib/io.c b/tools/testing/selftests= /kvm/lib/io.c=0A= index fedb2a741f0b..74419becc8bc 100644=0A= --- a/tools/testing/selftests/kvm/lib/io.c=0A= +++ b/tools/testing/selftests/kvm/lib/io.c=0A= @@ -155,3 +155,26 @@ ssize_t test_read(int fd, void *buf, size_t count)=0A= =0A= return num_read;=0A= }=0A= +=0A= +/* Test read via intermediary buffer=0A= + *=0A= + * Same as test_read, except read(2)s happen into a bounce buffer that is = memcpy'd=0A= + * to buf. For use with buffers that cannot be GUP'd (e.g. guest_memfd VMA= s if=0A= + * guest_memfd was created with GUEST_MEMFD_FLAG_NO_DIRECT_MAP).=0A= + */=0A= +ssize_t test_read_bounce(int fd, void *buf, size_t count)=0A= +{=0A= + void *bounce_buffer;=0A= + ssize_t num_read;=0A= +=0A= + TEST_ASSERT(count >=3D 0, "Unexpected count, count: %li", count);=0A= +=0A= + bounce_buffer =3D malloc(count);=0A= + TEST_ASSERT(bounce_buffer !=3D NULL, "Failed to allocate bounce buffer");= =0A= +=0A= + num_read =3D test_read(fd, bounce_buffer, count);=0A= + memcpy(buf, bounce_buffer, num_read);=0A= + free(bounce_buffer);=0A= +=0A= + return num_read;=0A= +}=0A= -- =0A= 2.50.1=0A= =0A=