On 09/12/11 18:39, Sasha Levin wrote:
> On Fri, 2011-12-09 at 17:55 +1100, Matt Evans wrote:
>> Add a --hugetlbfs commandline option to give a path to hugetlbfs-map guest
>> memory (down in kvm__arch_init()). For x86, guest memory is a normal
>> ANON mmap() if this option is not provided, otherwise a hugetlbfs mmap.
>>
>> Signed-off-by: Matt Evans <matt@xxxxxxxxxx>
>> ---
>> tools/kvm/builtin-run.c | 4 ++-
>> tools/kvm/include/kvm/kvm.h | 4 +-
>> tools/kvm/include/kvm/util.h | 4 +++
>> tools/kvm/kvm.c | 4 +-
>> tools/kvm/util.c | 45 ++++++++++++++++++++++++++++++++++++++++++
>> tools/kvm/x86/kvm.c | 20 +++++++++++++++--
>> 6 files changed, 73 insertions(+), 8 deletions(-)
>>
>> diff --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c
>> index 7969901..0acfe81 100644
>> --- a/tools/kvm/builtin-run.c
>> +++ b/tools/kvm/builtin-run.c
>> @@ -82,6 +82,7 @@ static const char *guest_mac;
>> static const char *host_mac;
>> static const char *script;
>> static const char *guest_name;
>> +static const char *hugetlbfs_path;
>> static struct virtio_net_params *net_params;
>> static bool single_step;
>> static bool readonly_image[MAX_DISK_IMAGES];
>> @@ -422,6 +423,7 @@ static const struct option options[] = {
>> OPT_CALLBACK('\0', "tty", NULL, "tty id",
>> "Remap guest TTY into a pty on the host",
>> tty_parser),
>> + OPT_STRING('\0', "hugetlbfs", &hugetlbfs_path, "path", "Hugetlbfs path"),
>>
>> OPT_GROUP("Kernel options:"),
>> OPT_STRING('k', "kernel", &kernel_filename, "kernel",
>> @@ -807,7 +809,7 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
>> guest_name = default_name;
>> }
>>
>> - kvm = kvm__init(dev, ram_size, guest_name);
>> + kvm = kvm__init(dev, hugetlbfs_path, ram_size, guest_name);
>>
>> kvm->single_step = single_step;
>>
>> diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
>> index 5fe6e75..7159952 100644
>> --- a/tools/kvm/include/kvm/kvm.h
>> +++ b/tools/kvm/include/kvm/kvm.h
>> @@ -30,7 +30,7 @@ struct kvm_ext {
>> void kvm__set_dir(const char *fmt, ...);
>> const char *kvm__get_dir(void);
>>
>> -struct kvm *kvm__init(const char *kvm_dev, u64 ram_size, const char *name);
>> +struct kvm *kvm__init(const char *kvm_dev, const char *hugetlbfs_path, u64 ram_size, const char *name);
>> int kvm__recommended_cpus(struct kvm *kvm);
>> int kvm__max_cpus(struct kvm *kvm);
>> void kvm__init_ram(struct kvm *kvm);
>> @@ -54,7 +54,7 @@ int kvm__enumerate_instances(int (*callback)(const char *name, int pid));
>> void kvm__remove_socket(const char *name);
>>
>> void kvm__arch_set_cmdline(char *cmdline, bool video);
>> -void kvm__arch_init(struct kvm *kvm, const char *kvm_dev, u64 ram_size, const char *name);
>> +void kvm__arch_init(struct kvm *kvm, const char *kvm_dev, const char *hugetlbfs_path, u64 ram_size, const char *name);
>> void kvm__arch_setup_firmware(struct kvm *kvm);
>> bool kvm__arch_cpu_supports_vm(void);
>> void kvm__arch_periodic_poll(struct kvm *kvm);
>> diff --git a/tools/kvm/include/kvm/util.h b/tools/kvm/include/kvm/util.h
>> index dc2e0b9..1f6fbbd 100644
>> --- a/tools/kvm/include/kvm/util.h
>> +++ b/tools/kvm/include/kvm/util.h
>> @@ -20,6 +20,7 @@
>> #include <limits.h>
>> #include <sys/param.h>
>> #include <sys/types.h>
>> +#include <linux/types.h>
>>
>> #ifdef __GNUC__
>> #define NORETURN __attribute__((__noreturn__))
>> @@ -75,4 +76,7 @@ static inline void msleep(unsigned int msecs)
>> {
>> usleep(MSECS_TO_USECS(msecs));
>> }
>> +
>> +void *mmap_hugetlbfs(const char *htlbfs_path, u64 size);
>> +
>> #endif /* KVM__UTIL_H */
>> diff --git a/tools/kvm/kvm.c b/tools/kvm/kvm.c
>> index c54f886..35ca2c5 100644
>> --- a/tools/kvm/kvm.c
>> +++ b/tools/kvm/kvm.c
>> @@ -306,7 +306,7 @@ int kvm__max_cpus(struct kvm *kvm)
>> return ret;
>> }
>>
>> -struct kvm *kvm__init(const char *kvm_dev, u64 ram_size, const char *name)
>> +struct kvm *kvm__init(const char *kvm_dev, const char *hugetlbfs_path, u64 ram_size, const char *name)
>> {
>> struct kvm *kvm;
>> int ret;
>> @@ -339,7 +339,7 @@ struct kvm *kvm__init(const char *kvm_dev, u64 ram_size, const char *name)
>> if (kvm__check_extensions(kvm))
>> die("A required KVM extention is not supported by OS");
>>
>> - kvm__arch_init(kvm, kvm_dev, ram_size, name);
>> + kvm__arch_init(kvm, kvm_dev, hugetlbfs_path, ram_size, name);
>>
>> kvm->name = name;
>>
>> diff --git a/tools/kvm/util.c b/tools/kvm/util.c
>> index 4efbce9..90b6a3b 100644
>> --- a/tools/kvm/util.c
>> +++ b/tools/kvm/util.c
>> @@ -4,6 +4,11 @@
>>
>> #include "kvm/util.h"
>>
>> +#include <linux/magic.h> /* For HUGETLBFS_MAGIC */
>> +#include <sys/mman.h>
>> +#include <sys/stat.h>
>> +#include <sys/statfs.h>
>> +
>> static void report(const char *prefix, const char *err, va_list params)
>> {
>> char msg[1024];
>> @@ -99,3 +104,43 @@ size_t strlcat(char *dest, const char *src, size_t count)
>>
>> return res;
>> }
>> +
>> +void *mmap_hugetlbfs(const char *htlbfs_path, u64 size)
>> +{
>> + char mpath[PATH_MAX];
>> + int fd;
>> + int r;
>> + struct statfs sfs;
>> + void *addr;
>> +
>> + do {
>> + /*
>> + * QEMU seems to work around this returning EINTR... Let's do
>> + * that too.
>> + */
>> + r = statfs(htlbfs_path, &sfs);
>> + } while (r && errno == EINTR);
>> +
>> + if (r)
>> + die("Can't stat %s\n", htlbfs_path);
>> +
>> + if (sfs.f_type != HUGETLBFS_MAGIC) {
>> + die("%s is not hugetlbfs!\n", htlbfs_path);
>> + }
>> +
>> + if (sfs.f_bsize == 0 || (unsigned long)sfs.f_bsize > size) {
>> + die("Can't use hugetlbfs pagesize %ld for mem size %lld\n",
>> + sfs.f_bsize, size);
>> + }
>> +
>> + snprintf(mpath, PATH_MAX, "%s/kvmtoolXXXXXX", htlbfs_path);
>> + fd = mkstemp(mpath);
>> + if (fd < 0)
>> + die("Can't open %s for hugetlbfs map\n", mpath);
>> + unlink(mpath);
>> + ftruncate(fd, size);
>
> Getting this thing here:
>
> cc1: warnings being treated as errors
> util.c: In function 'mmap_hugetlbfs':
> util.c:141:11: error: ignoring return value of 'ftruncate', declared with attribute warn_unused_result
> make: *** [util.o] Error 1
>
Ooookay, I swear I'm not seeing that here, GCC 4.6.2 & no extra -W flags added.
I've added a check of ftruncate()'s return value, anyway.
Thanks,
Matt
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