| Message ID | 20161024124937.17239-1-haozhong.zhang@intel.com |
|---|---|
| State | New |
| Headers | show |
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 $SZ is multiple of 4KB but not 2MB (e.g. 1023M). QEMU 2.7 > reports the following error message and aborts: > qemu-system-x86_64: -device pc-dimm,memdev=mem1,id=nv1: backend memory size must be multiple of 0x200000 > > The same regression may also happen in other platforms as indicated by > Igor Mammedov. This change is however necessary for s390 according to > the commit message of d2f39ad, so we workaround the regression by taking > the change only on s390. > > Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> > Reported-by: "Xu, Anthony" <anthony.xu@intel.com> > --- > exec.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/exec.c b/exec.c > index e63c5a1..55915ea 100644 > --- a/exec.c > +++ b/exec.c > @@ -1254,7 +1254,11 @@ static void *file_ram_alloc(RAMBlock *block, > } > > block->page_size = qemu_fd_getpagesize(fd); > +#if defined(__s390x__) > block->mr->align = MAX(block->page_size, QEMU_VMALLOC_ALIGN); > +#else > + block->mr->align = block->page_size; > +#endif Better: block->mr->align = block->page_size; #ifdef __s390x__ if (kvm_enabled()) { block->mr->align = MAX(block->mr->align, QEMU_VMALLOC_ALIGN); } #endif Queued with this change. Paolo > > if (memory < block->page_size) { > error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to " >
On 10/24/2016 02:58 PM, Paolo Bonzini wrote: > > > On 24/10/2016 14:49, Haozhong Zhang wrote: >> Commit d2f39ad "exec.c: Ensure right alignment also for file backed ram" >> added an additional alignment requirement on the size of backend file >> besides the previous page size. On x86, the alignment is changed from >> 4KB in QEMU 2.6 to 2MB in QEMU 2.7. >> >> This change breaks certain usages in QEMU 2.7 on x86, e.g. >> -object memory-backend-file,id=mem1,mem-path=/tmp/,size=$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 <haozhong.zhang@intel.com> >> Reported-by: "Xu, Anthony" <anthony.xu@intel.com> >> --- >> 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 <borntraeger@de.ibm.com> > > Paolo > >> >> if (memory < block->page_size) { >> error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to " >> > >
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 if (memory < block->page_size) { error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to "
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 <haozhong.zhang@intel.com> Reported-by: "Xu, Anthony" <anthony.xu@intel.com> --- exec.c | 4 ++++ 1 file changed, 4 insertions(+)