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charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Rspamd-Queue-Id: 110B8140007 X-Rspamd-Server: rspam07 X-Stat-Signature: p391fug5reftbmqam7h9nag4wimhhuns X-Rspam-User: X-HE-Tag: 1773756769-648654 X-HE-Meta: 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 /1AQgqZn 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Patrick Roy =0A= =0A= 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= GUEST_MEMFD_FLAG_NO_DIRECT_MAP), then directly loading the test ELF=0A= binary into it via read(2) potentially does not work. To nevertheless=0A= support loading binaries in this cases, do the read(2) syscall using a=0A= bounce buffer, and then memcpy from the bounce buffer into guest memory.=0A= =0A= Signed-off-by: Patrick Roy =0A= Signed-off-by: Nikita Kalyazin =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 b4872ba8ed12..8140e59b59e5 100644=0A= --- a/tools/testing/selftests/kvm/include/test_util.h=0A= +++ b/tools/testing/selftests/kvm/include/test_util.h=0A= @@ -48,6 +48,7 @@ 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..60613dce6cfd 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 > 0, "Unexpected count, count: %zu", 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=