On 10/24/2016 02:58 PM, Paolo Bonzini wrote: > > > On 24/10/2016 14:49, Haozhong Zhang wrote: >> Commit d2f39ad "exec.c: Ensure right alignment also for file backed ram" >> added an additional alignment requirement on the size of backend file >> besides the previous page size. On x86, the alignment is changed from >> 4KB in QEMU 2.6 to 2MB in QEMU 2.7. >> >> This change breaks certain usages in QEMU 2.7 on x86, e.g. >> -object memory-backend-file,id=mem1,mem-path=/tmp/,size=$SZ >> -device pc-dimm,id=dimm1,memdev=mem1 >> where $SZ is multiple of 4KB but not 2MB (e.g. 1023M). QEMU 2.7 >> reports the following error message and aborts: >> qemu-system-x86_64: -device pc-dimm,memdev=mem1,id=nv1: backend memory size >> must be multiple of 0x200000 >> >> The same regression may also happen in other platforms as indicated by >> Igor Mammedov. This change is however necessary for s390 according to >> the commit message of d2f39ad, so we workaround the regression by taking >> the change only on s390. >> >> Signed-off-by: Haozhong Zhang <[email protected]> >> Reported-by: "Xu, Anthony" <[email protected]> >> --- >> exec.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/exec.c b/exec.c >> index e63c5a1..55915ea 100644 >> --- a/exec.c >> +++ b/exec.c >> @@ -1254,7 +1254,11 @@ static void *file_ram_alloc(RAMBlock *block, >> } >> >> block->page_size = qemu_fd_getpagesize(fd); >> +#if defined(__s390x__) >> block->mr->align = MAX(block->page_size, QEMU_VMALLOC_ALIGN); >> +#else >> + block->mr->align = block->page_size; >> +#endif > > Better: > > block->mr->align = block->page_size; > #ifdef __s390x__ > if (kvm_enabled()) { > block->mr->align = MAX(block->mr->align, QEMU_VMALLOC_ALIGN); > } > #endif > > Queued with this change.
Thanks. Acked-by: Christian Borntraeger <[email protected]> > > Paolo > >> >> if (memory < block->page_size) { >> error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to " >> > >
