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-rw-r--r--accel/kvm/kvm-all.c28
-rw-r--r--accel/stubs/kvm-stub.c5
-rw-r--r--include/exec/memory.h20
-rw-r--r--include/exec/ram_addr.h2
-rw-r--r--include/exec/ramblock.h1
-rw-r--r--include/sysemu/kvm.h2
-rw-r--r--system/memory.c5
-rw-r--r--system/physmem.c34
8 files changed, 90 insertions, 7 deletions
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index db0b1a16ed..1b7bbd838c 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -92,6 +92,7 @@ static bool kvm_has_guest_debug;
static int kvm_sstep_flags;
static bool kvm_immediate_exit;
static uint64_t kvm_supported_memory_attributes;
+static bool kvm_guest_memfd_supported;
static hwaddr kvm_max_slot_size = ~0;
static const KVMCapabilityInfo kvm_required_capabilites[] = {
@@ -2419,6 +2420,11 @@ static int kvm_init(MachineState *ms)
}
kvm_supported_memory_attributes = kvm_check_extension(s, KVM_CAP_MEMORY_ATTRIBUTES);
+ kvm_guest_memfd_supported =
+ kvm_check_extension(s, KVM_CAP_GUEST_MEMFD) &&
+ kvm_check_extension(s, KVM_CAP_USER_MEMORY2) &&
+ (kvm_supported_memory_attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE);
+
kvm_immediate_exit = kvm_check_extension(s, KVM_CAP_IMMEDIATE_EXIT);
s->nr_slots = kvm_check_extension(s, KVM_CAP_NR_MEMSLOTS);
@@ -4138,3 +4144,25 @@ void kvm_mark_guest_state_protected(void)
{
kvm_state->guest_state_protected = true;
}
+
+int kvm_create_guest_memfd(uint64_t size, uint64_t flags, Error **errp)
+{
+ int fd;
+ struct kvm_create_guest_memfd guest_memfd = {
+ .size = size,
+ .flags = flags,
+ };
+
+ if (!kvm_guest_memfd_supported) {
+ error_setg(errp, "KVM does not support guest_memfd");
+ return -1;
+ }
+
+ fd = kvm_vm_ioctl(kvm_state, KVM_CREATE_GUEST_MEMFD, &guest_memfd);
+ if (fd < 0) {
+ error_setg_errno(errp, errno, "Error creating KVM guest_memfd");
+ return -1;
+ }
+
+ return fd;
+}
diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c
index ca38172884..8e0eb22e61 100644
--- a/accel/stubs/kvm-stub.c
+++ b/accel/stubs/kvm-stub.c
@@ -129,3 +129,8 @@ bool kvm_hwpoisoned_mem(void)
{
return false;
}
+
+int kvm_create_guest_memfd(uint64_t size, uint64_t flags, Error **errp)
+{
+ return -ENOSYS;
+}
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 8626a355b3..679a847685 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -243,6 +243,9 @@ typedef struct IOMMUTLBEvent {
/* RAM FD is opened read-only */
#define RAM_READONLY_FD (1 << 11)
+/* RAM can be private that has kvm guest memfd backend */
+#define RAM_GUEST_MEMFD (1 << 12)
+
static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
IOMMUNotifierFlag flags,
hwaddr start, hwaddr end,
@@ -1307,7 +1310,8 @@ bool memory_region_init_ram_nomigrate(MemoryRegion *mr,
* @name: Region name, becomes part of RAMBlock name used in migration stream
* must be unique within any device
* @size: size of the region.
- * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_NORESERVE.
+ * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_NORESERVE,
+ * RAM_GUEST_MEMFD.
* @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
@@ -1369,7 +1373,7 @@ bool memory_region_init_resizeable_ram(MemoryRegion *mr,
* (getpagesize()) will be used.
* @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
* RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
- * RAM_READONLY_FD
+ * RAM_READONLY_FD, RAM_GUEST_MEMFD
* @path: the path in which to allocate the RAM.
* @offset: offset within the file referenced by path
* @errp: pointer to Error*, to store an error if it happens.
@@ -1399,7 +1403,7 @@ bool memory_region_init_ram_from_file(MemoryRegion *mr,
* @size: size of the region.
* @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
* RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
- * RAM_READONLY_FD
+ * RAM_READONLY_FD, RAM_GUEST_MEMFD
* @fd: the fd to mmap.
* @offset: offset within the file referenced by fd
* @errp: pointer to Error*, to store an error if it happens.
@@ -1723,6 +1727,16 @@ static inline bool memory_region_is_romd(MemoryRegion *mr)
bool memory_region_is_protected(MemoryRegion *mr);
/**
+ * memory_region_has_guest_memfd: check whether a memory region has guest_memfd
+ * associated
+ *
+ * Returns %true if a memory region's ram_block has valid guest_memfd assigned.
+ *
+ * @mr: the memory region being queried
+ */
+bool memory_region_has_guest_memfd(MemoryRegion *mr);
+
+/**
* memory_region_get_iommu: check whether a memory region is an iommu
*
* Returns pointer to IOMMUMemoryRegion if a memory region is an iommu,
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index de45ba7bc9..07c8f86375 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -110,7 +110,7 @@ long qemu_maxrampagesize(void);
* @mr: the memory region where the ram block is
* @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
* RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
- * RAM_READONLY_FD
+ * RAM_READONLY_FD, RAM_GUEST_MEMFD
* @mem_path or @fd: specify the backing file or device
* @offset: Offset into target file
* @errp: pointer to Error*, to store an error if it happens
diff --git a/include/exec/ramblock.h b/include/exec/ramblock.h
index 848915ea5b..459c8917de 100644
--- a/include/exec/ramblock.h
+++ b/include/exec/ramblock.h
@@ -41,6 +41,7 @@ struct RAMBlock {
QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
int fd;
uint64_t fd_offset;
+ int guest_memfd;
size_t page_size;
/* dirty bitmap used during migration */
unsigned long *bmap;
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 594ae9b460..217f3fe17b 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -537,6 +537,8 @@ void kvm_mark_guest_state_protected(void);
*/
bool kvm_hwpoisoned_mem(void);
+int kvm_create_guest_memfd(uint64_t size, uint64_t flags, Error **errp);
+
int kvm_set_memory_attributes_private(hwaddr start, uint64_t size);
int kvm_set_memory_attributes_shared(hwaddr start, uint64_t size);
diff --git a/system/memory.c b/system/memory.c
index a229a79988..c756950c0c 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -1850,6 +1850,11 @@ bool memory_region_is_protected(MemoryRegion *mr)
return mr->ram && (mr->ram_block->flags & RAM_PROTECTED);
}
+bool memory_region_has_guest_memfd(MemoryRegion *mr)
+{
+ return mr->ram_block && mr->ram_block->guest_memfd >= 0;
+}
+
uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
{
uint8_t mask = mr->dirty_log_mask;
diff --git a/system/physmem.c b/system/physmem.c
index a4fe3d2bf8..f5dfa20e57 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1808,6 +1808,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
const bool shared = qemu_ram_is_shared(new_block);
RAMBlock *block;
RAMBlock *last_block = NULL;
+ bool free_on_error = false;
ram_addr_t old_ram_size, new_ram_size;
Error *err = NULL;
@@ -1837,6 +1838,19 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
return;
}
memory_try_enable_merging(new_block->host, new_block->max_length);
+ free_on_error = true;
+ }
+ }
+
+ if (new_block->flags & RAM_GUEST_MEMFD) {
+ assert(kvm_enabled());
+ assert(new_block->guest_memfd < 0);
+
+ new_block->guest_memfd = kvm_create_guest_memfd(new_block->max_length,
+ 0, errp);
+ if (new_block->guest_memfd < 0) {
+ qemu_mutex_unlock_ramlist();
+ goto out_free;
}
}
@@ -1888,6 +1902,13 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
ram_block_notify_add(new_block->host, new_block->used_length,
new_block->max_length);
}
+ return;
+
+out_free:
+ if (free_on_error) {
+ qemu_anon_ram_free(new_block->host, new_block->max_length);
+ new_block->host = NULL;
+ }
}
#ifdef CONFIG_POSIX
@@ -1902,7 +1923,7 @@ 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 | RAM_NAMED_FILE | RAM_READONLY |
- RAM_READONLY_FD)) == 0);
+ RAM_READONLY_FD | RAM_GUEST_MEMFD)) == 0);
if (xen_enabled()) {
error_setg(errp, "-mem-path not supported with Xen");
@@ -1939,6 +1960,7 @@ 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->guest_memfd = -1;
new_block->host = file_ram_alloc(new_block, size, fd, !file_size, offset,
errp);
if (!new_block->host) {
@@ -2018,7 +2040,7 @@ RAMBlock *qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
int align;
assert((ram_flags & ~(RAM_SHARED | RAM_RESIZEABLE | RAM_PREALLOC |
- RAM_NORESERVE)) == 0);
+ RAM_NORESERVE | RAM_GUEST_MEMFD)) == 0);
assert(!host ^ (ram_flags & RAM_PREALLOC));
align = qemu_real_host_page_size();
@@ -2033,6 +2055,7 @@ RAMBlock *qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
new_block->max_length = max_size;
assert(max_size >= size);
new_block->fd = -1;
+ new_block->guest_memfd = -1;
new_block->page_size = qemu_real_host_page_size();
new_block->host = host;
new_block->flags = ram_flags;
@@ -2055,7 +2078,7 @@ RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags,
MemoryRegion *mr, Error **errp)
{
- assert((ram_flags & ~(RAM_SHARED | RAM_NORESERVE)) == 0);
+ assert((ram_flags & ~(RAM_SHARED | RAM_NORESERVE | RAM_GUEST_MEMFD)) == 0);
return qemu_ram_alloc_internal(size, size, NULL, NULL, ram_flags, mr, errp);
}
@@ -2083,6 +2106,11 @@ static void reclaim_ramblock(RAMBlock *block)
} else {
qemu_anon_ram_free(block->host, block->max_length);
}
+
+ if (block->guest_memfd >= 0) {
+ close(block->guest_memfd);
+ }
+
g_free(block);
}
generated by cgit v1.2.3 (git 2.26.2) at 2025-01-15 09:56:09 +0000