On 10/02/17 11:41, David Gibson wrote: > 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.
I cannot find it in any public tree, where did it go?
>
>
>>
>> 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)
>>>>> {
>>>>> /*
>>>>
>>>
>>>
>>
>
>
>
>
--
Alexey
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