On Thu, Feb 09, 2017 at 12:48:19PM +0100, Paolo Bonzini wrote: > > > On 09/02/2017 06:43, Alexey Kardashevskiy wrote: > > On 03/01/17 10:34, David Gibson wrote: > >> On Thu, Dec 22, 2016 at 04:22:11PM +1100, Alexey Kardashevskiy wrote: > >>> getrampagesize() returns the largest supported page size and mainly > >>> used to know if huge pages are enabled. > >>> > >>> However is implemented in target-ppc/kvm.c and not available > >>> in TCG or other architectures. > >>> > >>> This renames and moves gethugepagesize() to mmap-alloc.c where > >>> fd-based analog of it is already implemented. This renames and moves > >>> getrampagesize() to exec.c as it seems to be the common place for > >>> helpers like this. > >>> > >>> This first user for it is going to be a spapr-pci-host-bridge which > >>> needs to know the largest RAM page size so the guest could try > >>> using bigger IOMMU pages to save memory. > >>> > >>> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > >> > >> Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> > >> > >> Seems sensible to me, but I'm not comfortable merging this via my tree > >> since it touches such core code. Probably should go via Paolo. > > > > Paolo, ping? > > It's just code movement, go ahead.
Ok, I've merged this in my tree.
>
> Paolo
>
> >
> >
> >>
> >>> ---
> >>> include/exec/ram_addr.h | 1 +
> >>> include/qemu/mmap-alloc.h | 2 +
> >>> exec.c | 82 ++++++++++++++++++++++++++++++++++++
> >>> target-ppc/kvm.c | 105
> >>> ++--------------------------------------------
> >>> util/mmap-alloc.c | 25 +++++++++++
> >>> 5 files changed, 113 insertions(+), 102 deletions(-)
> >>>
> >>> diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
> >>> index 54d7108a9e..3935cbcfcd 100644
> >>> --- a/include/exec/ram_addr.h
> >>> +++ b/include/exec/ram_addr.h
> >>> @@ -91,6 +91,7 @@ typedef struct RAMList {
> >>> } RAMList;
> >>> extern RAMList ram_list;
> >>>
> >>> +long qemu_getrampagesize(void);
> >>> ram_addr_t last_ram_offset(void);
> >>> void qemu_mutex_lock_ramlist(void);
> >>> void qemu_mutex_unlock_ramlist(void);
> >>> diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h
> >>> index 933c024ac5..50385e3f81 100644
> >>> --- a/include/qemu/mmap-alloc.h
> >>> +++ b/include/qemu/mmap-alloc.h
> >>> @@ -5,6 +5,8 @@
> >>>
> >>> size_t qemu_fd_getpagesize(int fd);
> >>>
> >>> +size_t qemu_mempath_getpagesize(const char *mem_path);
> >>> +
> >>> void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared);
> >>>
> >>> void qemu_ram_munmap(void *ptr, size_t size);
> >>> diff --git a/exec.c b/exec.c
> >>> index 08c558eecf..d73b477a70 100644
> >>> --- a/exec.c
> >>> +++ b/exec.c
> >>> @@ -32,6 +32,7 @@
> >>> #endif
> >>> #include "sysemu/kvm.h"
> >>> #include "sysemu/sysemu.h"
> >>> +#include "sysemu/numa.h"
> >>> #include "qemu/timer.h"
> >>> #include "qemu/config-file.h"
> >>> #include "qemu/error-report.h"
> >>> @@ -1218,6 +1219,87 @@ void qemu_mutex_unlock_ramlist(void)
> >>> }
> >>>
> >>> #ifdef __linux__
> >>> +/*
> >>> + * FIXME TOCTTOU: this iterates over memory backends' mem-path, which
> >>> + * may or may not name the same files / on the same filesystem now as
> >>> + * when we actually open and map them. Iterate over the file
> >>> + * descriptors instead, and use qemu_fd_getpagesize().
> >>> + */
> >>> +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);
> >>> + if (hpsize < *hpsize_min) {
> >>> + *hpsize_min = hpsize;
> >>> + }
> >>> + } else {
> >>> + *hpsize_min = getpagesize();
> >>> + }
> >>> + }
> >>> +
> >>> + return 0;
> >>> +}
> >>> +
> >>> +long qemu_getrampagesize(void)
> >>> +{
> >>> + long hpsize = LONG_MAX;
> >>> + long mainrampagesize;
> >>> + Object *memdev_root;
> >>> +
> >>> + if (mem_path) {
> >>> + mainrampagesize = qemu_mempath_getpagesize(mem_path);
> >>> + } else {
> >>> + mainrampagesize = getpagesize();
> >>> + }
> >>> +
> >>> + /* it's possible we have memory-backend objects with
> >>> + * hugepage-backed RAM. these may get mapped into system
> >>> + * address space via -numa parameters or memory hotplug
> >>> + * hooks. we want to take these into account, but we
> >>> + * also want to make sure these supported hugepage
> >>> + * sizes are applicable across the entire range of memory
> >>> + * we may boot from, so we take the min across all
> >>> + * backends, and assume normal pages in cases where a
> >>> + * backend isn't backed by hugepages.
> >>> + */
> >>> + memdev_root = object_resolve_path("/objects", NULL);
> >>> + if (memdev_root) {
> >>> + object_child_foreach(memdev_root, find_max_supported_pagesize,
> >>> &hpsize);
> >>> + }
> >>> + if (hpsize == LONG_MAX) {
> >>> + /* No additional memory regions found ==> Report main RAM page
> >>> size */
> >>> + return mainrampagesize;
> >>> + }
> >>> +
> >>> + /* If NUMA is disabled or the NUMA nodes are not backed with a
> >>> + * memory-backend, then there is at least one node using "normal"
> >>> RAM,
> >>> + * so if its page size is smaller we have got to report that size
> >>> instead.
> >>> + */
> >>> + if (hpsize > mainrampagesize &&
> >>> + (nb_numa_nodes == 0 || numa_info[0].node_memdev == NULL)) {
> >>> + static bool warned;
> >>> + if (!warned) {
> >>> + error_report("Huge page support disabled (n/a for main
> >>> memory).");
> >>> + warned = true;
> >>> + }
> >>> + return mainrampagesize;
> >>> + }
> >>> +
> >>> + return hpsize;
> >>> +}
> >>> +#else
> >>> +long qemu_getrampagesize(void)
> >>> +{
> >>> + return getpagesize();
> >>> +}
> >>> +#endif
> >>> +
> >>> +#ifdef __linux__
> >>> static int64_t get_file_size(int fd)
> >>> {
> >>> int64_t size = lseek(fd, 0, SEEK_END);
> >>> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> >>> index 6e91a4d8bb..e0abffa8ad 100644
> >>> --- a/target-ppc/kvm.c
> >>> +++ b/target-ppc/kvm.c
> >>> @@ -42,6 +42,7 @@
> >>> #include "trace.h"
> >>> #include "exec/gdbstub.h"
> >>> #include "exec/memattrs.h"
> >>> +#include "exec/ram_addr.h"
> >>> #include "sysemu/hostmem.h"
> >>> #include "qemu/cutils.h"
> >>> #if defined(TARGET_PPC64)
> >>> @@ -325,106 +326,6 @@ static void kvm_get_smmu_info(PowerPCCPU *cpu,
> >>> struct kvm_ppc_smmu_info *info)
> >>> kvm_get_fallback_smmu_info(cpu, info);
> >>> }
> >>>
> >>> -static long gethugepagesize(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);
> >>> - }
> >>> -
> >>> -#define HUGETLBFS_MAGIC 0x958458f6
> >>> -
> >>> - if (fs.f_type != HUGETLBFS_MAGIC) {
> >>> - /* Explicit mempath, but it's ordinary pages */
> >>> - return getpagesize();
> >>> - }
> >>> -
> >>> - /* It's hugepage, return the huge page size */
> >>> - return fs.f_bsize;
> >>> -}
> >>> -
> >>> -/*
> >>> - * FIXME TOCTTOU: this iterates over memory backends' mem-path, which
> >>> - * may or may not name the same files / on the same filesystem now as
> >>> - * when we actually open and map them. Iterate over the file
> >>> - * descriptors instead, and use qemu_fd_getpagesize().
> >>> - */
> >>> -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 = gethugepagesize(mem_path);
> >>> - if (hpsize < *hpsize_min) {
> >>> - *hpsize_min = hpsize;
> >>> - }
> >>> - } else {
> >>> - *hpsize_min = getpagesize();
> >>> - }
> >>> - }
> >>> -
> >>> - return 0;
> >>> -}
> >>> -
> >>> -static long getrampagesize(void)
> >>> -{
> >>> - long hpsize = LONG_MAX;
> >>> - long mainrampagesize;
> >>> - Object *memdev_root;
> >>> -
> >>> - if (mem_path) {
> >>> - mainrampagesize = gethugepagesize(mem_path);
> >>> - } else {
> >>> - mainrampagesize = getpagesize();
> >>> - }
> >>> -
> >>> - /* it's possible we have memory-backend objects with
> >>> - * hugepage-backed RAM. these may get mapped into system
> >>> - * address space via -numa parameters or memory hotplug
> >>> - * hooks. we want to take these into account, but we
> >>> - * also want to make sure these supported hugepage
> >>> - * sizes are applicable across the entire range of memory
> >>> - * we may boot from, so we take the min across all
> >>> - * backends, and assume normal pages in cases where a
> >>> - * backend isn't backed by hugepages.
> >>> - */
> >>> - memdev_root = object_resolve_path("/objects", NULL);
> >>> - if (memdev_root) {
> >>> - object_child_foreach(memdev_root, find_max_supported_pagesize,
> >>> &hpsize);
> >>> - }
> >>> - if (hpsize == LONG_MAX) {
> >>> - /* No additional memory regions found ==> Report main RAM page
> >>> size */
> >>> - return mainrampagesize;
> >>> - }
> >>> -
> >>> - /* If NUMA is disabled or the NUMA nodes are not backed with a
> >>> - * memory-backend, then there is at least one node using "normal"
> >>> RAM,
> >>> - * so if its page size is smaller we have got to report that size
> >>> instead.
> >>> - */
> >>> - if (hpsize > mainrampagesize &&
> >>> - (nb_numa_nodes == 0 || numa_info[0].node_memdev == NULL)) {
> >>> - static bool warned;
> >>> - if (!warned) {
> >>> - error_report("Huge page support disabled (n/a for main
> >>> memory).");
> >>> - warned = true;
> >>> - }
> >>> - return mainrampagesize;
> >>> - }
> >>> -
> >>> - return hpsize;
> >>> -}
> >>> -
> >>> static bool kvm_valid_page_size(uint32_t flags, long rampgsize, uint32_t
> >>> shift)
> >>> {
> >>> if (!(flags & KVM_PPC_PAGE_SIZES_REAL)) {
> >>> @@ -454,7 +355,7 @@ static void kvm_fixup_page_sizes(PowerPCCPU *cpu)
> >>> has_smmu_info = true;
> >>> }
> >>>
> >>> - rampagesize = getrampagesize();
> >>> + rampagesize = qemu_getrampagesize();
> >>>
> >>> /* Convert to QEMU form */
> >>> memset(&env->sps, 0, sizeof(env->sps));
> >>> @@ -2177,7 +2078,7 @@ uint64_t kvmppc_rma_size(uint64_t current_size,
> >>> unsigned int hash_shift)
> >>> /* Find the largest hardware supported page size that's less than
> >>> * or equal to the (logical) backing page size of guest RAM */
> >>> kvm_get_smmu_info(POWERPC_CPU(first_cpu), &info);
> >>> - rampagesize = getrampagesize();
> >>> + rampagesize = qemu_getrampagesize();
> >>> best_page_shift = 0;
> >>>
> >>> for (i = 0; i < KVM_PPC_PAGE_SIZES_MAX_SZ; i++) {
> >>> diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
> >>> index 5a85aa3c89..564c79109c 100644
> >>> --- a/util/mmap-alloc.c
> >>> +++ b/util/mmap-alloc.c
> >>> @@ -39,6 +39,31 @@ size_t qemu_fd_getpagesize(int fd)
> >>> return getpagesize();
> >>> }
> >>>
> >>> +size_t qemu_mempath_getpagesize(const char *mem_path)
> >>> +{
> >>> +#ifdef CONFIG_LINUX
> >>> + 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 (fs.f_type == HUGETLBFS_MAGIC) {
> >>> + /* It's hugepage, return the huge page size */
> >>> + return fs.f_bsize;
> >>> + }
> >>> +#endif
> >>> +
> >>> + return getpagesize();
> >>> +}
> >>> +
> >>> void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
> >>> {
> >>> /*
> >>
> >
> >
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
signature.asc
Description: PGP signature
