From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: Peter Xu <peterx@redhat.com>
Cc: qemu-devel@nongnu.org,
Leonardo Bras Soares Passos <lsoaresp@redhat.com>,
James Houghton <jthoughton@google.com>,
Juan Quintela <quintela@redhat.com>
Subject: Re: [PATCH RFC 09/21] ramblock: Add RAM_READONLY
Date: Mon, 23 Jan 2023 19:42:30 +0000 [thread overview]
Message-ID: <Y87jJtu529cI4OZ0@work-vm> (raw)
In-Reply-To: <20230117220914.2062125-10-peterx@redhat.com>
* Peter Xu (peterx@redhat.com) wrote:
> This allows us to have RAM_READONLY to be set in ram_flags to show that
> this ramblock can only be read not write.
>
> We used to pass in readonly boolean along the way for allocating the
> ramblock, now let it be together with the rest ramblock flags.
>
> The main purpose of this patch is not for clean up though, it's for caching
> mapping information of each ramblock so when we want to mmap() it again for
> whatever reason we can have all the information on hand.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
> backends/hostmem-file.c | 3 ++-
> include/exec/memory.h | 4 ++--
> include/exec/ram_addr.h | 5 ++---
> softmmu/memory.c | 8 +++-----
> softmmu/physmem.c | 16 +++++++---------
> 5 files changed, 16 insertions(+), 20 deletions(-)
>
> diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
> index 25141283c4..1daf00d2da 100644
> --- a/backends/hostmem-file.c
> +++ b/backends/hostmem-file.c
> @@ -56,9 +56,10 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
> ram_flags = backend->share ? RAM_SHARED : 0;
> ram_flags |= backend->reserve ? 0 : RAM_NORESERVE;
> ram_flags |= fb->is_pmem ? RAM_PMEM : 0;
> + ram_flags |= fb->readonly ? RAM_READONLY : 0;
> memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name,
> backend->size, fb->align, ram_flags,
> - fb->mem_path, fb->readonly, errp);
> + fb->mem_path, errp);
> g_free(name);
> #endif
> }
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index c37ffdbcd1..006ba77ede 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -188,6 +188,8 @@ typedef struct IOMMUTLBEvent {
> /* RAM is a persistent kind memory */
> #define RAM_PMEM (1 << 5)
>
> +/* RAM is read-only */
> +#define RAM_READONLY (1 << 6)
>
> /*
> * UFFDIO_WRITEPROTECT is used on this RAMBlock to
> @@ -1292,7 +1294,6 @@ void memory_region_init_resizeable_ram(MemoryRegion *mr,
> * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
> * RAM_NORESERVE,
> * @path: the path in which to allocate the RAM.
> - * @readonly: true to open @path for reading, false for read/write.
> * @errp: pointer to Error*, to store an error if it happens.
> *
> * Note that this function does not do anything to cause the data in the
> @@ -1305,7 +1306,6 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
> uint64_t align,
> uint32_t ram_flags,
> const char *path,
> - bool readonly,
> Error **errp);
>
> /**
> diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
> index f4fb6a2111..0bf9cfc659 100644
> --- a/include/exec/ram_addr.h
> +++ b/include/exec/ram_addr.h
> @@ -110,7 +110,6 @@ long qemu_maxrampagesize(void);
> * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
> * RAM_NORESERVE.
> * @mem_path or @fd: specify the backing file or device
> - * @readonly: true to open @path for reading, false for read/write.
> * @errp: pointer to Error*, to store an error if it happens
> *
> * Return:
> @@ -119,10 +118,10 @@ long qemu_maxrampagesize(void);
> */
> RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
> uint32_t ram_flags, const char *mem_path,
> - bool readonly, Error **errp);
> + Error **errp);
> RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
> uint32_t ram_flags, int fd, off_t offset,
> - bool readonly, Error **errp);
> + Error **errp);
>
> RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
> MemoryRegion *mr, Error **errp);
> diff --git a/softmmu/memory.c b/softmmu/memory.c
> index e05332d07f..2137028773 100644
> --- a/softmmu/memory.c
> +++ b/softmmu/memory.c
> @@ -1601,18 +1601,16 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
> uint64_t align,
> uint32_t ram_flags,
> const char *path,
> - bool readonly,
> Error **errp)
> {
> Error *err = NULL;
> memory_region_init(mr, owner, name, size);
> mr->ram = true;
> - mr->readonly = readonly;
> + mr->readonly = ram_flags & RAM_READONLY;
> mr->terminates = true;
> mr->destructor = memory_region_destructor_ram;
> mr->align = align;
> - mr->ram_block = qemu_ram_alloc_from_file(size, mr, ram_flags, path,
> - readonly, &err);
> + mr->ram_block = qemu_ram_alloc_from_file(size, mr, ram_flags, path, &err);
> if (err) {
> mr->size = int128_zero();
> object_unparent(OBJECT(mr));
> @@ -1635,7 +1633,7 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
> mr->terminates = true;
> mr->destructor = memory_region_destructor_ram;
> mr->ram_block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, offset,
> - false, &err);
> + &err);
> if (err) {
> mr->size = int128_zero();
> object_unparent(OBJECT(mr));
> diff --git a/softmmu/physmem.c b/softmmu/physmem.c
> index b5be02f1cb..6096eac286 100644
> --- a/softmmu/physmem.c
> +++ b/softmmu/physmem.c
> @@ -1534,7 +1534,6 @@ static int file_ram_open(const char *path,
>
> static void *file_ram_alloc(RAMBlock *block,
> int fd,
> - bool readonly,
> bool truncate,
> off_t offset,
> Error **errp)
> @@ -1589,7 +1588,7 @@ static void *file_ram_alloc(RAMBlock *block,
> perror("ftruncate");
> }
>
> - qemu_map_flags = readonly ? QEMU_MAP_READONLY : 0;
> + qemu_map_flags = (block->flags & RAM_READONLY) ? QEMU_MAP_READONLY : 0;
> qemu_map_flags |= (block->flags & RAM_SHARED) ? QEMU_MAP_SHARED : 0;
> qemu_map_flags |= (block->flags & RAM_PMEM) ? QEMU_MAP_SYNC : 0;
> qemu_map_flags |= (block->flags & RAM_NORESERVE) ? QEMU_MAP_NORESERVE : 0;
> @@ -2057,7 +2056,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
> #ifdef CONFIG_POSIX
> RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
> uint32_t ram_flags, int fd, off_t offset,
> - bool readonly, Error **errp)
> + Error **errp)
> {
> RAMBlock *new_block;
> Error *local_err = NULL;
> @@ -2065,7 +2064,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
>
> /* Just support these ram flags by now. */
> assert((ram_flags & ~(RAM_SHARED | RAM_PMEM | RAM_NORESERVE |
> - RAM_PROTECTED)) == 0);
> + RAM_PROTECTED | RAM_READONLY)) == 0);
>
> if (xen_enabled()) {
> error_setg(errp, "-mem-path not supported with Xen");
> @@ -2100,8 +2099,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
> new_block->used_length = size;
> new_block->max_length = size;
> new_block->flags = ram_flags;
> - new_block->host = file_ram_alloc(new_block, fd, readonly,
> - !file_size, offset, errp);
> + new_block->host = file_ram_alloc(new_block, fd, !file_size, offset, errp);
> if (!new_block->host) {
> g_free(new_block);
> return NULL;
> @@ -2120,11 +2118,11 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
>
> RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
> uint32_t ram_flags, const char *mem_path,
> - bool readonly, Error **errp)
> + Error **errp)
> {
> int fd;
> - bool created;
> RAMBlock *block;
> + bool created, readonly = ram_flags & RAM_READONLY;
>
> fd = file_ram_open(mem_path, memory_region_name(mr), readonly, &created,
> errp);
> @@ -2132,7 +2130,7 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
> return NULL;
> }
>
> - block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, 0, readonly, errp);
> + block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, 0, errp);
> if (!block) {
> if (created) {
> unlink(mem_path);
> --
> 2.37.3
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
next prev parent reply other threads:[~2023-01-23 19:43 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-17 22:08 [PATCH RFC 00/21] migration: Support hugetlb doublemaps Peter Xu
2023-01-17 22:08 ` [PATCH RFC 01/21] update linux headers Peter Xu
2023-01-17 22:08 ` [PATCH RFC 02/21] util: Include osdep.h first in util/mmap-alloc.c Peter Xu
2023-01-18 12:00 ` Dr. David Alan Gilbert
2023-01-25 0:19 ` Philippe Mathieu-Daudé
2023-01-30 4:57 ` Juan Quintela
2023-01-17 22:08 ` [PATCH RFC 03/21] physmem: Add qemu_ram_is_hugetlb() Peter Xu
2023-01-18 12:02 ` Dr. David Alan Gilbert
2023-01-30 5:00 ` Juan Quintela
2023-01-17 22:08 ` [PATCH RFC 04/21] madvise: Include linux/mman.h under linux-headers/ Peter Xu
2023-01-18 12:08 ` Dr. David Alan Gilbert
2023-01-30 5:01 ` Juan Quintela
2023-01-17 22:08 ` [PATCH RFC 05/21] madvise: Add QEMU_MADV_SPLIT Peter Xu
2023-01-30 5:01 ` Juan Quintela
2023-01-17 22:08 ` [PATCH RFC 06/21] madvise: Add QEMU_MADV_COLLAPSE Peter Xu
2023-01-18 18:51 ` Dr. David Alan Gilbert
2023-01-18 20:21 ` Peter Xu
2023-01-30 5:02 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 07/21] ramblock: Cache file offset for file-backed ramblocks Peter Xu
2023-01-30 5:02 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 08/21] ramblock: Cache the length to do file mmap() on ramblocks Peter Xu
2023-01-23 18:51 ` Dr. David Alan Gilbert
2023-01-24 20:28 ` Peter Xu
2023-01-30 5:05 ` Juan Quintela
2023-01-30 22:07 ` Peter Xu
2023-01-17 22:09 ` [PATCH RFC 09/21] ramblock: Add RAM_READONLY Peter Xu
2023-01-23 19:42 ` Dr. David Alan Gilbert [this message]
2023-01-30 5:06 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 10/21] ramblock: Add ramblock_file_map() Peter Xu
2023-01-24 10:06 ` Dr. David Alan Gilbert
2023-01-24 20:47 ` Peter Xu
2023-01-25 9:24 ` Dr. David Alan Gilbert
2023-01-25 14:46 ` Peter Xu
2023-01-30 5:09 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 11/21] migration: Add hugetlb-doublemap cap Peter Xu
2023-01-24 12:45 ` Dr. David Alan Gilbert
2023-01-24 21:15 ` Peter Xu
2023-01-30 5:13 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 12/21] migration: Introduce page size for-migration-only Peter Xu
2023-01-24 13:20 ` Dr. David Alan Gilbert
2023-01-24 21:36 ` Peter Xu
2023-01-24 22:03 ` Peter Xu
2023-01-30 5:17 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 13/21] migration: Add migration_ram_pagesize_largest() Peter Xu
2023-01-24 17:34 ` Dr. David Alan Gilbert
2023-01-30 5:19 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 14/21] migration: Map hugetlbfs ramblocks twice, and pre-allocate Peter Xu
2023-01-25 14:25 ` Dr. David Alan Gilbert
2023-01-30 5:24 ` Juan Quintela
2023-01-30 22:35 ` Peter Xu
2023-02-01 18:53 ` Juan Quintela
2023-02-06 21:40 ` Peter Xu
2023-01-17 22:09 ` [PATCH RFC 15/21] migration: Teach qemu about minor faults and doublemap Peter Xu
2023-01-30 5:45 ` Juan Quintela
2023-01-30 22:50 ` Peter Xu
2023-02-01 18:55 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 16/21] migration: Enable doublemap with MADV_SPLIT Peter Xu
2023-02-01 18:59 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 17/21] migration: Rework ram discard logic for hugetlb double-map Peter Xu
2023-02-01 19:03 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 18/21] migration: Allow postcopy_register_shared_ufd() to fail Peter Xu
2023-02-01 19:09 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 19/21] migration: Add postcopy_mark_received() Peter Xu
2023-02-01 19:10 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 20/21] migration: Handle page faults using UFFDIO_CONTINUE Peter Xu
2023-02-01 19:24 ` Juan Quintela
2023-02-01 19:52 ` Juan Quintela
2023-01-17 22:09 ` [PATCH RFC 21/21] migration: Collapse huge pages again after postcopy finished Peter Xu
2023-02-01 19:49 ` Juan Quintela
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