| Message ID | 20201106032921.600200-16-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Mirror map JIT memory for TCG | expand |
Richard Henderson <richard.henderson@linaro.org> writes: > We cannot use a real temp file, because we would need to find > a filesystem that does not have noexec enabled. However, a > memfd is not associated with any filesystem. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> It looks like this breaks --enable-tcg-interpreter: FAILED: libqemu-ppc64-softmmu.fa.p/accel_tcg_translate-all.c.o cc -Ilibqemu-ppc64-softmmu.fa.p -I. -I../.. -Itarget/ppc -I../../target/ppc -I../../dtc/libfdt -I../../capstone/include/capstone -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/pixman-1 -I/usr/include/libdrm -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -fdiagnostics-color=auto -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -m64 -mcx16 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -DLEGACY_RDMA_REG_MR -isystem /home/alex/lsrc/qemu.git/linux-headers -isystem linux-headers -iquote /home/alex/lsrc/qemu.git/tcg/tci -iquote . -iquote /home/alex/lsrc/qemu.git -iquote /home/alex/lsrc/qemu.git/accel/tcg -iquote /home/alex/lsrc/qemu.git/include -iquote /home/alex/lsrc/qemu.git/disas/libvixl -pthread -fPIC -isystem../../linux-headers -isystemlinux-headers -DNEED_CPU_H '-DCONFIG_TARGET="ppc64-softmmu-config-target.h"' '-DCONFIG_DEVICES="ppc64-softmmu-config-devices.h"' -MD -MQ libqemu-ppc64-softmmu.fa.p/accel_tcg_translate-all.c.o -MF libqemu-ppc64-softmmu.fa.p/accel_tcg_translate-all.c.o.d -o libqemu-ppc64-softmmu.fa.p/accel_tcg_translate-all.c.o -c ../../accel/tcg/translate-all.c ../../accel/tcg/translate-all.c:1138:13: error: ‘alloc_code_gen_buffer_splitwx_memfd’ defined but not used [-Werror=unused-function] static bool alloc_code_gen_buffer_splitwx_memfd(size_t size, Error **errp) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors > --- > accel/tcg/translate-all.c | 84 +++++++++++++++++++++++++++++++++++---- > 1 file changed, 76 insertions(+), 8 deletions(-) > > diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c > index a29cb4a42e..1931e65365 100644 > --- a/accel/tcg/translate-all.c > +++ b/accel/tcg/translate-all.c > @@ -1078,17 +1078,11 @@ static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) > return true; > } > #else > -static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) > +static bool alloc_code_gen_buffer_anon(size_t size, int prot, > + int flags, Error **errp) > { > - int prot = PROT_WRITE | PROT_READ | PROT_EXEC; > - int flags = MAP_PRIVATE | MAP_ANONYMOUS; > void *buf; > > - if (splitwx > 0) { > - error_setg(errp, "jit split-wx not supported"); > - return false; > - } > - > buf = mmap(NULL, size, prot, flags, -1, 0); > if (buf == MAP_FAILED) { > error_setg_errno(errp, errno, > @@ -1137,6 +1131,80 @@ static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) > tcg_ctx->code_gen_buffer = buf; > return true; > } > + > +#ifdef CONFIG_POSIX > +#include "qemu/memfd.h" > + > +static bool alloc_code_gen_buffer_splitwx_memfd(size_t size, Error **errp) > +{ > + void *buf_rw, *buf_rx; > + int fd = -1; > + > + buf_rw = qemu_memfd_alloc("tcg-jit", size, 0, &fd, errp); > + if (buf_rw == NULL) { > + return false; > + } > + > + buf_rx = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_SHARED, fd, 0); > + if (buf_rx == MAP_FAILED) { > + error_setg_errno(errp, errno, > + "failed to map shared memory for execute"); > + munmap(buf_rw, size); > + close(fd); > + return false; > + } > + close(fd); > + > + tcg_ctx->code_gen_buffer = buf_rw; > + tcg_ctx->code_gen_buffer_size = size; > + tcg_splitwx_diff = buf_rx - buf_rw; > + > + /* Request large pages for the buffer and the splitwx. */ > + qemu_madvise(buf_rw, size, QEMU_MADV_HUGEPAGE); > + qemu_madvise(buf_rx, size, QEMU_MADV_HUGEPAGE); > + return true; > +} > +#endif /* CONFIG_POSIX */ > + > +static bool alloc_code_gen_buffer_splitwx(size_t size, Error **errp) > +{ > + if (TCG_TARGET_SUPPORT_MIRROR) { > +#ifdef CONFIG_POSIX > + return alloc_code_gen_buffer_splitwx_memfd(size, errp); > +#endif > + } > + error_setg(errp, "jit split-wx not supported"); > + return false; > +} > + > +static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) > +{ > + ERRP_GUARD(); > + int prot, flags; > + > + if (splitwx) { > + if (alloc_code_gen_buffer_splitwx(size, errp)) { > + return true; > + } > + /* > + * If splitwx force-on (1), fail; > + * if splitwx default-on (-1), fall through to splitwx off. > + */ > + if (splitwx > 0) { > + return false; > + } > + error_free_or_abort(errp); > + } > + > + prot = PROT_READ | PROT_WRITE | PROT_EXEC; > + flags = MAP_PRIVATE | MAP_ANONYMOUS; > +#ifdef CONFIG_TCG_INTERPRETER > + /* The tcg interpreter does not need execute permission. */ > + prot = PROT_READ | PROT_WRITE; > +#endif > + > + return alloc_code_gen_buffer_anon(size, prot, flags, errp); > +} > #endif /* USE_STATIC_CODE_GEN_BUFFER, WIN32, POSIX */ > > static bool tb_cmp(const void *ap, const void *bp) -- Alex Bennée
On 11/10/20 9:03 AM, Alex Bennée wrote: > > Richard Henderson <richard.henderson@linaro.org> writes: > >> We cannot use a real temp file, because we would need to find >> a filesystem that does not have noexec enabled. However, a >> memfd is not associated with any filesystem. >> >> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > > It looks like this breaks --enable-tcg-interpreter: > > FAILED: libqemu-ppc64-softmmu.fa.p/accel_tcg_translate-all.c.o > cc -Ilibqemu-ppc64-softmmu.fa.p -I. -I../.. -Itarget/ppc -I../../target/ppc -I../../dtc/libfdt -I../../capstone/include/capstone -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/pixman-1 -I/usr/include/libdrm -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -fdiagnostics-color=auto -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -m64 -mcx16 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -DLEGACY_RDMA_REG_MR -isystem /home/alex/lsrc/qemu.git/linux-headers -isystem linux-headers -iquote /home/alex/lsrc/qemu.git/tcg/tci -iquote . -iquote /home/alex/lsrc/qemu.git -iquote /home/alex/lsrc/qemu.git/accel/tcg -iquote /home/alex/lsrc/qemu.git/include -iquote /home/alex/lsrc/qemu.git/disas/libvixl -pthread -fPIC -isystem../../linux-headers -isystemlinux-headers -DNEED_CPU_H '-DCONFIG_TARGET="ppc64-softmmu-config-target.h"' '-DCONFIG_DEVICES="ppc64-softmmu-config-devices.h"' -MD -MQ libqemu-ppc64-softmmu.fa.p/accel_tcg_translate-all.c.o -MF libqemu-ppc64-softmmu.fa.p/accel_tcg_translate-all.c.o.d -o libqemu-ppc64-softmmu.fa.p/accel_tcg_translate-all.c.o -c ../../accel/tcg/translate-all.c > ../../accel/tcg/translate-all.c:1138:13: error: ‘alloc_code_gen_buffer_splitwx_memfd’ defined but not used [-Werror=unused-function] > static bool alloc_code_gen_buffer_splitwx_memfd(size_t size, Error **errp) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors Bah, this will actually be patch 39, where I switch from if to ifdef. I'll have to rearrange those. r~
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index a29cb4a42e..1931e65365 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -1078,17 +1078,11 @@ static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) return true; } #else -static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) +static bool alloc_code_gen_buffer_anon(size_t size, int prot, + int flags, Error **errp) { - int prot = PROT_WRITE | PROT_READ | PROT_EXEC; - int flags = MAP_PRIVATE | MAP_ANONYMOUS; void *buf; - if (splitwx > 0) { - error_setg(errp, "jit split-wx not supported"); - return false; - } - buf = mmap(NULL, size, prot, flags, -1, 0); if (buf == MAP_FAILED) { error_setg_errno(errp, errno, @@ -1137,6 +1131,80 @@ static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) tcg_ctx->code_gen_buffer = buf; return true; } + +#ifdef CONFIG_POSIX +#include "qemu/memfd.h" + +static bool alloc_code_gen_buffer_splitwx_memfd(size_t size, Error **errp) +{ + void *buf_rw, *buf_rx; + int fd = -1; + + buf_rw = qemu_memfd_alloc("tcg-jit", size, 0, &fd, errp); + if (buf_rw == NULL) { + return false; + } + + buf_rx = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_SHARED, fd, 0); + if (buf_rx == MAP_FAILED) { + error_setg_errno(errp, errno, + "failed to map shared memory for execute"); + munmap(buf_rw, size); + close(fd); + return false; + } + close(fd); + + tcg_ctx->code_gen_buffer = buf_rw; + tcg_ctx->code_gen_buffer_size = size; + tcg_splitwx_diff = buf_rx - buf_rw; + + /* Request large pages for the buffer and the splitwx. */ + qemu_madvise(buf_rw, size, QEMU_MADV_HUGEPAGE); + qemu_madvise(buf_rx, size, QEMU_MADV_HUGEPAGE); + return true; +} +#endif /* CONFIG_POSIX */ + +static bool alloc_code_gen_buffer_splitwx(size_t size, Error **errp) +{ + if (TCG_TARGET_SUPPORT_MIRROR) { +#ifdef CONFIG_POSIX + return alloc_code_gen_buffer_splitwx_memfd(size, errp); +#endif + } + error_setg(errp, "jit split-wx not supported"); + return false; +} + +static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) +{ + ERRP_GUARD(); + int prot, flags; + + if (splitwx) { + if (alloc_code_gen_buffer_splitwx(size, errp)) { + return true; + } + /* + * If splitwx force-on (1), fail; + * if splitwx default-on (-1), fall through to splitwx off. + */ + if (splitwx > 0) { + return false; + } + error_free_or_abort(errp); + } + + prot = PROT_READ | PROT_WRITE | PROT_EXEC; + flags = MAP_PRIVATE | MAP_ANONYMOUS; +#ifdef CONFIG_TCG_INTERPRETER + /* The tcg interpreter does not need execute permission. */ + prot = PROT_READ | PROT_WRITE; +#endif + + return alloc_code_gen_buffer_anon(size, prot, flags, errp); +} #endif /* USE_STATIC_CODE_GEN_BUFFER, WIN32, POSIX */ static bool tb_cmp(const void *ap, const void *bp)
We cannot use a real temp file, because we would need to find a filesystem that does not have noexec enabled. However, a memfd is not associated with any filesystem. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- accel/tcg/translate-all.c | 84 +++++++++++++++++++++++++++++++++++---- 1 file changed, 76 insertions(+), 8 deletions(-) -- 2.25.1