Message ID | 20180405022002.17809-2-david@gibson.dropbear.id.au |
---|---|
State | New |
Headers | show |
Series | Helpers to obtain host page sizes for guest RAM | expand |
On Thu, 5 Apr 2018 12:20:01 +1000 David Gibson <david@gibson.dropbear.id.au> wrote: > qemu_mempath_getpagesize() gets the effective (host side) page size for > a block of memory backed by an mmap()ed file on the host. It requires > the mem_path parameter to be non-NULL. > > This ends up meaning all the callers need a different case for handling > anonymous memory (for memory-backend-ram or default memory with -mem-path > is not specified). > > We can make all those callers a little simpler by by "having" ? > qemu_mempath_getpagesize() accept NULL, and treat that as the anonymous > memory case. > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > --- Reviewed-by: Greg Kurz <groug@kaod.org> > exec.c | 21 ++++++--------------- > target/ppc/kvm.c | 8 ++------ > util/mmap-alloc.c | 26 ++++++++++++++------------ > 3 files changed, 22 insertions(+), 33 deletions(-) > > diff --git a/exec.c b/exec.c > index 02b1efebb7..b38b004563 100644 > --- a/exec.c > +++ b/exec.c > @@ -1488,19 +1488,14 @@ void ram_block_dump(Monitor *mon) > */ > static int find_max_supported_pagesize(Object *obj, void *opaque) > { > - char *mem_path; > long *hpsize_min = opaque; > > if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) { > - mem_path = object_property_get_str(obj, "mem-path", NULL); > - if (mem_path) { > - long hpsize = qemu_mempath_getpagesize(mem_path); > - g_free(mem_path); > - if (hpsize < *hpsize_min) { > - *hpsize_min = hpsize; > - } > - } else { > - *hpsize_min = getpagesize(); > + char *mem_path = object_property_get_str(obj, "mem-path", NULL); > + long hpsize = qemu_mempath_getpagesize(mem_path); > + g_free(mem_path); > + if (hpsize < *hpsize_min) { > + *hpsize_min = hpsize; > } > } > > @@ -1513,11 +1508,7 @@ long qemu_getrampagesize(void) > long mainrampagesize; > Object *memdev_root; > > - if (mem_path) { > - mainrampagesize = qemu_mempath_getpagesize(mem_path); > - } else { > - mainrampagesize = getpagesize(); > - } > + mainrampagesize = qemu_mempath_getpagesize(mem_path); > > /* it's possible we have memory-backend objects with > * hugepage-backed RAM. these may get mapped into system > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > index 1bd38c6a90..f393eae127 100644 > --- a/target/ppc/kvm.c > +++ b/target/ppc/kvm.c > @@ -496,12 +496,8 @@ bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path) > char *mempath = object_property_get_str(mem_obj, "mem-path", NULL); > long pagesize; > > - if (mempath) { > - pagesize = qemu_mempath_getpagesize(mempath); > - g_free(mempath); > - } else { > - pagesize = getpagesize(); > - } > + pagesize = qemu_mempath_getpagesize(mempath); > + g_free(mempath); > > return pagesize >= max_cpu_page_size; > } > diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c > index 2fd8cbcc6f..fd329eccd8 100644 > --- a/util/mmap-alloc.c > +++ b/util/mmap-alloc.c > @@ -50,19 +50,21 @@ size_t qemu_mempath_getpagesize(const char *mem_path) > struct statfs fs; > int ret; > > - do { > - ret = statfs(mem_path, &fs); > - } while (ret != 0 && errno == EINTR); > - > - if (ret != 0) { > - fprintf(stderr, "Couldn't statfs() memory path: %s\n", > - strerror(errno)); > - exit(1); > - } > + if (mem_path) { > + do { > + ret = statfs(mem_path, &fs); > + } while (ret != 0 && errno == EINTR); > > - if (fs.f_type == HUGETLBFS_MAGIC) { > - /* It's hugepage, return the huge page size */ > - return fs.f_bsize; > + if (ret != 0) { > + fprintf(stderr, "Couldn't statfs() memory path: %s\n", > + strerror(errno)); > + exit(1); > + } > + > + if (fs.f_type == HUGETLBFS_MAGIC) { > + /* It's hugepage, return the huge page size */ > + return fs.f_bsize; > + } > } > #ifdef __sparc__ > /* SPARC Linux needs greater alignment than the pagesize */
On Thu, Apr 05, 2018 at 03:56:36PM +0200, Greg Kurz wrote: > On Thu, 5 Apr 2018 12:20:01 +1000 > David Gibson <david@gibson.dropbear.id.au> wrote: > > > qemu_mempath_getpagesize() gets the effective (host side) page size for > > a block of memory backed by an mmap()ed file on the host. It requires > > the mem_path parameter to be non-NULL. > > > > This ends up meaning all the callers need a different case for handling > > anonymous memory (for memory-backend-ram or default memory with -mem-path > > is not specified). > > > > We can make all those callers a little simpler by > > by "having" ? Yes, oops. > > qemu_mempath_getpagesize() accept NULL, and treat that as the anonymous > > memory case. > > > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > > --- > > Reviewed-by: Greg Kurz <groug@kaod.org> > > > exec.c | 21 ++++++--------------- > > target/ppc/kvm.c | 8 ++------ > > util/mmap-alloc.c | 26 ++++++++++++++------------ > > 3 files changed, 22 insertions(+), 33 deletions(-) > > > > diff --git a/exec.c b/exec.c > > index 02b1efebb7..b38b004563 100644 > > --- a/exec.c > > +++ b/exec.c > > @@ -1488,19 +1488,14 @@ void ram_block_dump(Monitor *mon) > > */ > > static int find_max_supported_pagesize(Object *obj, void *opaque) > > { > > - char *mem_path; > > long *hpsize_min = opaque; > > > > if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) { > > - mem_path = object_property_get_str(obj, "mem-path", NULL); > > - if (mem_path) { > > - long hpsize = qemu_mempath_getpagesize(mem_path); > > - g_free(mem_path); > > - if (hpsize < *hpsize_min) { > > - *hpsize_min = hpsize; > > - } > > - } else { > > - *hpsize_min = getpagesize(); > > + char *mem_path = object_property_get_str(obj, "mem-path", NULL); > > + long hpsize = qemu_mempath_getpagesize(mem_path); > > + g_free(mem_path); > > + if (hpsize < *hpsize_min) { > > + *hpsize_min = hpsize; > > } > > } > > > > @@ -1513,11 +1508,7 @@ long qemu_getrampagesize(void) > > long mainrampagesize; > > Object *memdev_root; > > > > - if (mem_path) { > > - mainrampagesize = qemu_mempath_getpagesize(mem_path); > > - } else { > > - mainrampagesize = getpagesize(); > > - } > > + mainrampagesize = qemu_mempath_getpagesize(mem_path); > > > > /* it's possible we have memory-backend objects with > > * hugepage-backed RAM. these may get mapped into system > > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > > index 1bd38c6a90..f393eae127 100644 > > --- a/target/ppc/kvm.c > > +++ b/target/ppc/kvm.c > > @@ -496,12 +496,8 @@ bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path) > > char *mempath = object_property_get_str(mem_obj, "mem-path", NULL); > > long pagesize; > > > > - if (mempath) { > > - pagesize = qemu_mempath_getpagesize(mempath); > > - g_free(mempath); > > - } else { > > - pagesize = getpagesize(); > > - } > > + pagesize = qemu_mempath_getpagesize(mempath); > > + g_free(mempath); > > > > return pagesize >= max_cpu_page_size; > > } > > diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c > > index 2fd8cbcc6f..fd329eccd8 100644 > > --- a/util/mmap-alloc.c > > +++ b/util/mmap-alloc.c > > @@ -50,19 +50,21 @@ size_t qemu_mempath_getpagesize(const char *mem_path) > > struct statfs fs; > > int ret; > > > > - do { > > - ret = statfs(mem_path, &fs); > > - } while (ret != 0 && errno == EINTR); > > - > > - if (ret != 0) { > > - fprintf(stderr, "Couldn't statfs() memory path: %s\n", > > - strerror(errno)); > > - exit(1); > > - } > > + if (mem_path) { > > + do { > > + ret = statfs(mem_path, &fs); > > + } while (ret != 0 && errno == EINTR); > > > > - if (fs.f_type == HUGETLBFS_MAGIC) { > > - /* It's hugepage, return the huge page size */ > > - return fs.f_bsize; > > + if (ret != 0) { > > + fprintf(stderr, "Couldn't statfs() memory path: %s\n", > > + strerror(errno)); > > + exit(1); > > + } > > + > > + if (fs.f_type == HUGETLBFS_MAGIC) { > > + /* It's hugepage, return the huge page size */ > > + return fs.f_bsize; > > + } > > } > > #ifdef __sparc__ > > /* SPARC Linux needs greater alignment than the pagesize */ >
diff --git a/exec.c b/exec.c index 02b1efebb7..b38b004563 100644 --- a/exec.c +++ b/exec.c @@ -1488,19 +1488,14 @@ void ram_block_dump(Monitor *mon) */ static int find_max_supported_pagesize(Object *obj, void *opaque) { - char *mem_path; long *hpsize_min = opaque; if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) { - mem_path = object_property_get_str(obj, "mem-path", NULL); - if (mem_path) { - long hpsize = qemu_mempath_getpagesize(mem_path); - g_free(mem_path); - if (hpsize < *hpsize_min) { - *hpsize_min = hpsize; - } - } else { - *hpsize_min = getpagesize(); + char *mem_path = object_property_get_str(obj, "mem-path", NULL); + long hpsize = qemu_mempath_getpagesize(mem_path); + g_free(mem_path); + if (hpsize < *hpsize_min) { + *hpsize_min = hpsize; } } @@ -1513,11 +1508,7 @@ long qemu_getrampagesize(void) long mainrampagesize; Object *memdev_root; - if (mem_path) { - mainrampagesize = qemu_mempath_getpagesize(mem_path); - } else { - mainrampagesize = getpagesize(); - } + mainrampagesize = qemu_mempath_getpagesize(mem_path); /* it's possible we have memory-backend objects with * hugepage-backed RAM. these may get mapped into system diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index 1bd38c6a90..f393eae127 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -496,12 +496,8 @@ bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path) char *mempath = object_property_get_str(mem_obj, "mem-path", NULL); long pagesize; - if (mempath) { - pagesize = qemu_mempath_getpagesize(mempath); - g_free(mempath); - } else { - pagesize = getpagesize(); - } + pagesize = qemu_mempath_getpagesize(mempath); + g_free(mempath); return pagesize >= max_cpu_page_size; } diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 2fd8cbcc6f..fd329eccd8 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -50,19 +50,21 @@ size_t qemu_mempath_getpagesize(const char *mem_path) struct statfs fs; int ret; - do { - ret = statfs(mem_path, &fs); - } while (ret != 0 && errno == EINTR); - - if (ret != 0) { - fprintf(stderr, "Couldn't statfs() memory path: %s\n", - strerror(errno)); - exit(1); - } + if (mem_path) { + do { + ret = statfs(mem_path, &fs); + } while (ret != 0 && errno == EINTR); - if (fs.f_type == HUGETLBFS_MAGIC) { - /* It's hugepage, return the huge page size */ - return fs.f_bsize; + if (ret != 0) { + fprintf(stderr, "Couldn't statfs() memory path: %s\n", + strerror(errno)); + exit(1); + } + + if (fs.f_type == HUGETLBFS_MAGIC) { + /* It's hugepage, return the huge page size */ + return fs.f_bsize; + } } #ifdef __sparc__ /* SPARC Linux needs greater alignment than the pagesize */
qemu_mempath_getpagesize() gets the effective (host side) page size for a block of memory backed by an mmap()ed file on the host. It requires the mem_path parameter to be non-NULL. This ends up meaning all the callers need a different case for handling anonymous memory (for memory-backend-ram or default memory with -mem-path is not specified). We can make all those callers a little simpler by qemu_mempath_getpagesize() accept NULL, and treat that as the anonymous memory case. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> --- exec.c | 21 ++++++--------------- target/ppc/kvm.c | 8 ++------ util/mmap-alloc.c | 26 ++++++++++++++------------ 3 files changed, 22 insertions(+), 33 deletions(-)