[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH] backends/hostmem: Fix support of memory-backend-memfd in qem
From: |
David Hildenbrand |
Subject: |
Re: [PATCH] backends/hostmem: Fix support of memory-backend-memfd in qemu_maxrampagesize() |
Date: |
Wed, 10 Aug 2022 09:32:23 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 |
On 10.08.22 08:32, Thomas Huth wrote:
> It is currently not possible yet to use "memory-backend-memfd" on s390x
> with hugepages enabled. This problem is caused by qemu_maxrampagesize()
> not taking memory-backend-memfd objects into account yet, so the code
> in s390_memory_init() fails to enable the huge page support there via
> s390_set_max_pagesize(). Fix it by looking at the memory-backend-memfd
> in the host_memory_backend_pagesize() function, too.
>
> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2116496
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
> include/sysemu/hostmem.h | 8 +++++++-
> backends/hostmem-memfd.c | 2 --
> backends/hostmem.c | 27 +++++++++++++++++----------
> 3 files changed, 24 insertions(+), 13 deletions(-)
>
> diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h
> index 9ff5c16963..d983ae6c01 100644
> --- a/include/sysemu/hostmem.h
> +++ b/include/sysemu/hostmem.h
> @@ -34,10 +34,16 @@ OBJECT_DECLARE_TYPE(HostMemoryBackend,
> HostMemoryBackendClass,
> /* hostmem-file.c */
> /**
> * @TYPE_MEMORY_BACKEND_FILE:
> - * name of backend that uses mmap on a file descriptor
> + * name of backend that uses mmap on a file
> */
> #define TYPE_MEMORY_BACKEND_FILE "memory-backend-file"
>
> +/* hostmem-memfd.c */
> +/**
> + * @TYPE_MEMORY_BACKEND_MEMFD:
> + * name of backend that uses mmap on a memfd file descriptor
> + */
> +#define TYPE_MEMORY_BACKEND_MEMFD "memory-backend-memfd"
>
> /**
> * HostMemoryBackendClass:
> diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c
> index 3fc85c3db8..1ab2085e49 100644
> --- a/backends/hostmem-memfd.c
> +++ b/backends/hostmem-memfd.c
> @@ -18,8 +18,6 @@
> #include "qapi/error.h"
> #include "qom/object.h"
>
> -#define TYPE_MEMORY_BACKEND_MEMFD "memory-backend-memfd"
> -
> OBJECT_DECLARE_SIMPLE_TYPE(HostMemoryBackendMemfd, MEMORY_BACKEND_MEMFD)
>
>
> diff --git a/backends/hostmem.c b/backends/hostmem.c
> index 624bb7ecd3..ebce887105 100644
> --- a/backends/hostmem.c
> +++ b/backends/hostmem.c
> @@ -306,22 +306,29 @@ bool host_memory_backend_is_mapped(HostMemoryBackend
> *backend)
> return backend->is_mapped;
> }
>
> -#ifdef __linux__
> size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
> {
> + size_t pagesize = 0;
> +
> +#ifdef __linux__
> Object *obj = OBJECT(memdev);
> - char *path = object_property_get_str(obj, "mem-path", NULL);
> - size_t pagesize = qemu_mempath_getpagesize(path);
>
> - g_free(path);
> + if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND_FILE)) {
> + char *path = object_property_get_str(obj, "mem-path", NULL);
> + pagesize = qemu_mempath_getpagesize(path);
> + g_free(path);
> + } else if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND_MEMFD) &&
> + object_property_get_bool(obj, "hugetlb", &error_abort)) {
> + pagesize = object_property_get_int(obj, "hugetlbsize", &error_abort);
> + }
> +#endif
Why can't we simply rely on
qemu_ram_pagesize(memdev->mr.ram_block);
?
--
Thanks,
David / dhildenb