On Fri, 29 Apr 2016 15:32:22 +0800 Fam Zheng <f...@redhat.com> wrote:
> On Mon, 04/25 13:55, Dominik Dingel wrote: > > While in the anonymous ram case we already take care of the right alignment > > such an alignment gurantee does not exist for file backed ram allocation. > > s/gurantee/guarantee/ > > Otherwise looks good to me, > > Reviewed-by: Fam Zheng <f...@redhat.com> Thank you very much! Paolo do you want me to fix the typo, add the r-b and resend the patch? > > > > Instead, pagesize is used for alignment. On s390 this is not enough for > > gmap, > > as we need to satisfy an alignment up to segments. > > > > Reported-by: Halil Pasic <pa...@linux.vnet.ibm.com> > > Signed-off-by: Dominik Dingel <din...@linux.vnet.ibm.com> > > > > --- > > > > v2 -> v3: > > Skipping additional variable and just use alignment of memory region. > > As memory will not be backpropagated it is enough to round up to page_sizes. > > > > v1 -> v2: > > While enforcing alignments we allow memory sizes on page_size. > > On mmap the memory size will be round up to alignments. > > > > I thought about moving this alignment into qemu_ram_mmap but the result > > was a lot of code churn, the other possibility was to create an additional > > define ending up with two defines with the same semantics. > > --- > > exec.c | 5 +++-- > > include/qemu/osdep.h | 13 +++++++++++++ > > util/oslib-posix.c | 13 ------------- > > 3 files changed, 16 insertions(+), 15 deletions(-) > > > > diff --git a/exec.c b/exec.c > > index c4f9036..fc75266 100644 > > --- a/exec.c > > +++ b/exec.c > > @@ -1296,7 +1296,7 @@ static void *file_ram_alloc(RAMBlock *block, > > } > > > > page_size = qemu_fd_getpagesize(fd); > > - block->mr->align = page_size; > > + block->mr->align = MAX(page_size, QEMU_VMALLOC_ALIGN); > > > > if (memory < page_size) { > > error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to " > > @@ -1317,7 +1317,8 @@ static void *file_ram_alloc(RAMBlock *block, > > perror("ftruncate"); > > } > > > > - area = qemu_ram_mmap(fd, memory, page_size, block->flags & RAM_SHARED); > > + area = qemu_ram_mmap(fd, memory, block->mr->align, > > + block->flags & RAM_SHARED); > > if (area == MAP_FAILED) { > > error_setg_errno(errp, errno, > > "unable to map backing store for guest RAM"); > > diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h > > index 408783f..783270f 100644 > > --- a/include/qemu/osdep.h > > +++ b/include/qemu/osdep.h > > @@ -247,6 +247,19 @@ void qemu_anon_ram_free(void *ptr, size_t size); > > > > #endif > > > > +#if defined(__linux__) && \ > > + (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)) > > + /* Use 2 MiB alignment so transparent hugepages can be used by KVM. > > + Valgrind does not support alignments larger than 1 MiB, > > + therefore we need special code which handles running on Valgrind. */ > > +# define QEMU_VMALLOC_ALIGN (512 * 4096) > > +#elif defined(__linux__) && defined(__s390x__) > > + /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ > > +# define QEMU_VMALLOC_ALIGN (256 * 4096) > > +#else > > +# define QEMU_VMALLOC_ALIGN getpagesize() > > +#endif > > + > > int qemu_madvise(void *addr, size_t len, int advice); > > > > int qemu_open(const char *name, int flags, ...); > > diff --git a/util/oslib-posix.c b/util/oslib-posix.c > > index 6cc4b8f..4adde93 100644 > > --- a/util/oslib-posix.c > > +++ b/util/oslib-posix.c > > @@ -26,19 +26,6 @@ > > * THE SOFTWARE. > > */ > > > > -#if defined(__linux__) && \ > > - (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)) > > - /* Use 2 MiB alignment so transparent hugepages can be used by KVM. > > - Valgrind does not support alignments larger than 1 MiB, > > - therefore we need special code which handles running on Valgrind. */ > > -# define QEMU_VMALLOC_ALIGN (512 * 4096) > > -#elif defined(__linux__) && defined(__s390x__) > > - /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ > > -# define QEMU_VMALLOC_ALIGN (256 * 4096) > > -#else > > -# define QEMU_VMALLOC_ALIGN getpagesize() > > -#endif > > - > > #include "qemu/osdep.h" > > #include <termios.h> > > #include <termios.h> > > -- > > 2.6.6 > > > > >