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.
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)
>>> {
>>> /*
>>
>
>
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