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charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Rspamd-Queue-Id: 93638A0022 X-Rspamd-Server: rspam06 X-Rspam-User: X-Stat-Signature: dfwuq6rws8tjt5fagaxrorjfkihu1h4b X-HE-Tag: 1764953959-480789 X-HE-Meta: U2FsdGVkX1+TQR+lMMn5g/MOmVGykD8vIcqmqy0jgs+yPxRjLvAQQ4f3tPhmWm7Irdw0O2RQq9sZVKWtDEQirGPAVt5opOrqWz7wHfwC6dFCXpFbeWZl2WJimDdUcE3ZspQlzMNsrnrJAd9Fd7cYSzoLg4Y0Z2YW9BVlBVh7qyc0vwc2LhAV4wWjTLKS9J18qJgAl8htqFKNF/3iRTV4e2RhO2sEMRO6JNWQR0MS7SEh4ERadB/8I2un58cltWX4RL6l7+CJ0VRbecUjoeqkHkCK59SH+p+W9O0hq3Kc1vOeX7kBTEH2HoOyvGgCgePdxNeeqKA/NGWXWLTFpicusnSyk45qqdyxVV52pA2GbwL5VTSKJtyAkAt2jNbq9/Jn0AGOneuVuflsm4kklKLHIPy1GxtrTR32Gg1e6Re86XvIWwa3x88rOwY4oY0e3J/K9zzDW7vpvciO3CrI9hBUNiEFAIi9Bo3uZjuB4Fhtg/HaLrksFqIHd+tLOBSZMDTyJ/b+aQeSNtbsHlzRQ7oOxHKf1KpPqcRi5Nd6eyLjyLNx9DN2+wfZkr6yppeqyBXaMOLnpIjGB2H1JDIFsUvwn3PWySNQCChRFj30rzK7k8i87c9ZFXpiC5wfh2LgUTZvh3NVXboI/MeMEw84i/YznpQF1ueNpTt1qWredZA8B8IgnZfXFkqU1lXa+0wq5q7X8fZhDqTpvR6srtEK4rl1+oUezijXe1750FjzxdE49+JNRm68AiRMEKo8+jBJYOLLGhjldc7eWQHIPN82Qc4GAGYE2Lbq+hywNq+oGPoPCttryUICAYFU7Qg/fickNZTpv9rmF6H6oqJJ92aAn+ig97w//HjsxFxeO1ioT0O+Ve6xu2B8NQhEXrl8sosw9jWTfHAnLrYo3LeBhORPbsMHGljXhLivkAZN+gSZ10kUE2k4ex/y74IQVHtCPaFSMhUyEvU6NDr/iAcocgTYdZ7 0jDhDrow 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 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: 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..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=