| Message ID | 20240102015808.132373-26-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | linux-user: Improve host and guest page size handling | expand |
On Tue, Jan 02, 2024 at 12:58:00PM +1100, Richard Henderson wrote: > When guest page size > host page size, this test can fail > due to the SIGBUS protection hack. Avoid this by making > sure that the file size is at least one guest page. Maybe also mention PAGE_PASSTHROUGH? > Visible with alpha guest on x86_64 host. I had to apply (very hacky): --- a/linux-user/main.c +++ b/linux-user/main.c @@ -803,7 +803,7 @@ int main(int argc, char **argv, char **envp) * The most efficient setting is to match the host. */ host_page_size = qemu_real_host_page_size(); - set_preferred_target_page_bits(ctz32(host_page_size)); + set_preferred_target_page_bits(ctz32(host_page_size) + 1); finalize_target_page_bits(); in order to see this. Is there a way to set the guest page size from the command line? > Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > tests/tcg/multiarch/linux/linux-madvise.c | 2 ++ > 1 file changed, 2 insertions(+) Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
On 1/30/24 23:13, Ilya Leoshkevich wrote: > Is there a way to set the guest page size from > the command line? No. Before this patch set, guest page size was a compile-time constant. Afterward, it would be possible for any TARGET_PAGE_BITS_VARY target. I refrained from adding such a command-line switch because, other than selecting the host page size, it only leads to breakage. That doesn't seem helpful, even for developers. r~
diff --git a/tests/tcg/multiarch/linux/linux-madvise.c b/tests/tcg/multiarch/linux/linux-madvise.c index 29d0997e68..539fb3b772 100644 --- a/tests/tcg/multiarch/linux/linux-madvise.c +++ b/tests/tcg/multiarch/linux/linux-madvise.c @@ -42,6 +42,8 @@ static void test_file(void) assert(ret == 0); written = write(fd, &c, sizeof(c)); assert(written == sizeof(c)); + ret = ftruncate(fd, pagesize); + assert(ret == 0); page = mmap(NULL, pagesize, PROT_READ, MAP_PRIVATE, fd, 0); assert(page != MAP_FAILED);