From: Stefan Hajnoczi <stefanha@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>, qemu-devel@nongnu.org
Cc: "Fam Zheng" <fam@euphon.net>,
"John G Johnson" <john.g.johnson@oracle.com>,
thuth@redhat.com, "Jagannathan Raman" <jag.raman@oracle.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
qemu-block@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>,
"Denis V. Lunev" <den@openvz.org>,
"Philippe Mathieu-Daudé" <philmd@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Daniel P. Berrangé" <berrange@redhat.com>,
"Wainer dos Santos Moschetta" <wainersm@redhat.com>,
"Elena Ufimtseva" <elena.ufimtseva@oracle.com>,
"Igor Mammedov" <imammedo@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Alex Bennée" <alex.bennee@linaro.org>
Subject: [PULL v4 09/27] memory: alloc RAM from file at offset
Date: Wed, 10 Feb 2021 09:26:10 +0000 [thread overview]
Message-ID: <20210210092628.193785-10-stefanha@redhat.com> (raw)
In-Reply-To: <20210210092628.193785-1-stefanha@redhat.com>
From: Jagannathan Raman <jag.raman@oracle.com>
Allow RAM MemoryRegion to be created from an offset in a file, instead
of allocating at offset of 0 by default. This is needed to synchronize
RAM between QEMU & remote process.
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 609996697ad8617e3b01df38accc5c208c24d74e.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/exec/memory.h | 2 ++
include/exec/ram_addr.h | 4 ++--
include/qemu/mmap-alloc.h | 4 +++-
backends/hostmem-memfd.c | 2 +-
hw/misc/ivshmem.c | 3 ++-
softmmu/memory.c | 3 ++-
softmmu/physmem.c | 12 +++++++-----
util/mmap-alloc.c | 8 +++++---
util/oslib-posix.c | 2 +-
9 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/include/exec/memory.h b/include/exec/memory.h
index ed292767cd..c6fb714e49 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -998,6 +998,7 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
* @size: size of the region.
* @share: %true if memory must be mmaped with the MAP_SHARED flag
* @fd: the fd to mmap.
+ * @offset: offset within the file referenced by fd
* @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
@@ -1009,6 +1010,7 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
uint64_t size,
bool share,
int fd,
+ ram_addr_t offset,
Error **errp);
#endif
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 40b16609ab..3cb9791df3 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -121,8 +121,8 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
uint32_t ram_flags, const char *mem_path,
bool readonly, Error **errp);
RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
- uint32_t ram_flags, int fd, bool readonly,
- Error **errp);
+ uint32_t ram_flags, int fd, off_t offset,
+ bool readonly, Error **errp);
RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
MemoryRegion *mr, Error **errp);
diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h
index 8b7a5c70f3..456ff87df1 100644
--- a/include/qemu/mmap-alloc.h
+++ b/include/qemu/mmap-alloc.h
@@ -17,6 +17,7 @@ size_t qemu_mempath_getpagesize(const char *mem_path);
* @readonly: true for a read-only mapping, false for read/write.
* @shared: map has RAM_SHARED flag.
* @is_pmem: map has RAM_PMEM flag.
+ * @map_offset: map starts at offset of map_offset from the start of fd
*
* Return:
* On success, return a pointer to the mapped area.
@@ -27,7 +28,8 @@ void *qemu_ram_mmap(int fd,
size_t align,
bool readonly,
bool shared,
- bool is_pmem);
+ bool is_pmem,
+ off_t map_offset);
void qemu_ram_munmap(int fd, void *ptr, size_t size);
diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c
index e5626d4330..69b0ae30bb 100644
--- a/backends/hostmem-memfd.c
+++ b/backends/hostmem-memfd.c
@@ -55,7 +55,7 @@ memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
name = host_memory_backend_get_name(backend);
memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
name, backend->size,
- backend->share, fd, errp);
+ backend->share, fd, 0, errp);
g_free(name);
}
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index 0505b52c98..603e992a7f 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -495,7 +495,8 @@ static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
/* mmap the region and map into the BAR2 */
memory_region_init_ram_from_fd(&s->server_bar2, OBJECT(s),
- "ivshmem.bar2", size, true, fd, &local_err);
+ "ivshmem.bar2", size, true, fd, 0,
+ &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 23e8e33001..874a8fccde 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -1612,6 +1612,7 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
uint64_t size,
bool share,
int fd,
+ ram_addr_t offset,
Error **errp)
{
Error *err = NULL;
@@ -1621,7 +1622,7 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
mr->destructor = memory_region_destructor_ram;
mr->ram_block = qemu_ram_alloc_from_fd(size, mr,
share ? RAM_SHARED : 0,
- fd, false, &err);
+ fd, offset, false, &err);
if (err) {
mr->size = int128_zero();
object_unparent(OBJECT(mr));
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 96efaef97a..19e0aa9836 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -1543,6 +1543,7 @@ static void *file_ram_alloc(RAMBlock *block,
int fd,
bool readonly,
bool truncate,
+ off_t offset,
Error **errp)
{
void *area;
@@ -1593,7 +1594,8 @@ static void *file_ram_alloc(RAMBlock *block,
}
area = qemu_ram_mmap(fd, memory, block->mr->align, readonly,
- block->flags & RAM_SHARED, block->flags & RAM_PMEM);
+ block->flags & RAM_SHARED, block->flags & RAM_PMEM,
+ offset);
if (area == MAP_FAILED) {
error_setg_errno(errp, errno,
"unable to map backing store for guest RAM");
@@ -2024,8 +2026,8 @@ static void ram_block_add(RAMBlock *new_block, Error **errp, bool shared)
#ifdef CONFIG_POSIX
RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
- uint32_t ram_flags, int fd, bool readonly,
- Error **errp)
+ uint32_t ram_flags, int fd, off_t offset,
+ bool readonly, Error **errp)
{
RAMBlock *new_block;
Error *local_err = NULL;
@@ -2079,7 +2081,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
new_block->max_length = size;
new_block->flags = ram_flags;
new_block->host = file_ram_alloc(new_block, size, fd, readonly,
- !file_size, errp);
+ !file_size, offset, errp);
if (!new_block->host) {
g_free(new_block);
return NULL;
@@ -2110,7 +2112,7 @@ 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, readonly, errp);
+ block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, 0, readonly, errp);
if (!block) {
if (created) {
unlink(mem_path);
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index 890fda6a35..e6fa8b598b 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -87,7 +87,8 @@ void *qemu_ram_mmap(int fd,
size_t align,
bool readonly,
bool shared,
- bool is_pmem)
+ bool is_pmem,
+ off_t map_offset)
{
int prot;
int flags;
@@ -150,7 +151,8 @@ void *qemu_ram_mmap(int fd,
prot = PROT_READ | (readonly ? 0 : PROT_WRITE);
- ptr = mmap(guardptr + offset, size, prot, flags | map_sync_flags, fd, 0);
+ ptr = mmap(guardptr + offset, size, prot,
+ flags | map_sync_flags, fd, map_offset);
if (ptr == MAP_FAILED && map_sync_flags) {
if (errno == ENOTSUP) {
@@ -174,7 +176,7 @@ void *qemu_ram_mmap(int fd,
* if map failed with MAP_SHARED_VALIDATE | MAP_SYNC,
* we will remove these flags to handle compatibility.
*/
- ptr = mmap(guardptr + offset, size, prot, flags, fd, 0);
+ ptr = mmap(guardptr + offset, size, prot, flags, fd, map_offset);
}
if (ptr == MAP_FAILED) {
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index bf57d3b030..36820fec16 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -230,7 +230,7 @@ void *qemu_memalign(size_t alignment, size_t size)
void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared)
{
size_t align = QEMU_VMALLOC_ALIGN;
- void *ptr = qemu_ram_mmap(-1, size, align, false, shared, false);
+ void *ptr = qemu_ram_mmap(-1, size, align, false, shared, false, 0);
if (ptr == MAP_FAILED) {
return NULL;
--
2.29.2
next prev parent reply other threads:[~2021-02-10 9:34 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-10 9:26 [PULL v4 00/27] Block patches Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 01/27] .github: point Repo Lockdown bot to GitLab repo Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 02/27] gitmodules: use GitLab repos instead of qemu.org Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 03/27] gitlab-ci: remove redundant GitLab repo URL command Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 04/27] docs: update README to use GitLab repo URLs Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 05/27] pc-bios: update mirror URLs to GitLab Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 06/27] get_maintainer: update repo URL " Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 07/27] multi-process: add the concept description to docs/devel/qemu-multiprocess Stefan Hajnoczi
2023-06-06 14:21 ` Philippe Mathieu-Daudé
2021-02-10 9:26 ` [PULL v4 08/27] multi-process: add configure and usage information Stefan Hajnoczi
2021-02-10 9:26 ` Stefan Hajnoczi [this message]
2021-02-10 9:26 ` [PULL v4 10/27] multi-process: Add config option for multi-process QEMU Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 11/27] multi-process: setup PCI host bridge for remote device Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 12/27] multi-process: setup a machine object for remote device process Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 13/27] io: add qio_channel_writev_full_all helper Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 14/27] io: add qio_channel_readv_full_all_eof & qio_channel_readv_full_all helpers Stefan Hajnoczi
2021-02-11 15:34 ` Max Reitz
2021-02-11 15:46 ` Daniel P. Berrangé
2021-02-11 15:48 ` Jag Raman
2021-02-10 9:26 ` [PULL v4 15/27] multi-process: define MPQemuMsg format and transmission functions Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 16/27] multi-process: Initialize message handler in remote device Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 17/27] multi-process: Associate fd of a PCIDevice with its object Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 18/27] multi-process: setup memory manager for remote device Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 19/27] multi-process: introduce proxy object Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 20/27] multi-process: add proxy communication functions Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 21/27] multi-process: Forward PCI config space acceses to the remote process Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 22/27] multi-process: PCI BAR read/write handling for proxy & remote endpoints Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 23/27] multi-process: Synchronize remote memory Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 24/27] multi-process: create IOHUB object to handle irq Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 25/27] multi-process: Retrieve PCI info from remote process Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 26/27] multi-process: perform device reset in the " Stefan Hajnoczi
2021-02-10 9:26 ` [PULL v4 27/27] docs: fix Parallels Image "dirty bitmap" section Stefan Hajnoczi
2021-02-10 17:33 ` [PULL v4 00/27] Block patches Peter Maydell
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